HANDLING PIPE

The present invention relates to an elevator for lifting pipe and a method for handling pipe. The elevator is particularly but not exclusively, for lifting singles and stands of drill pipe to facilitate the construction of boreholes. The elevator is also particularly but not exclusively useful in handling pipes to facilitate connection of the pipe to a string of pipe in a wellbore, wherein make-up or break-out is conducted in Continuous

Circulation System or Continuous Circulation whilst

Drilling System.

In the construction of an oil or gas well, a borehole is drilled. A drill bit is arranged on the end of a drill string and is rotated to bore the borehole. A drilling fluid known as "drilling mud" is pumped through the drill string to the drill bit to lubricate the drill bit. The drilling mud is also used to carry the cuttings produced by the drill bit and other solids to the surface through an annulus formed between the drill string and the borehole and/or casing lining the borehole.

In one prior art method of drilling a borehole with a drilling rig is to use a kelly bar having a square or other multisided cross-section, connected to a top joint of the drill string, which is used to rotate the drill string. A rotary table at the derrick floor level rotates the kelly bar while simultaneously the kelly bar can move vertically through a drive bushing within the rotary table at the rig floor. In another prior art method, a top drive drilling unit is suspended in a derrick grips and rotates the drill string and a kelly bar is not used.

It is important to be able to control pressure in the borehole in relation to the pressure in the

formation. In certain circumstances the driller may deem that under-balanced drilling is required, wherein the pressure exerted on a formation exposed in a wellbore is below the internal fluid pressure of that formation. Thus, if sufficient porosity and permeability exist, formation fluids enter the wellbore. The drilling rate typically increases as an under-balanced condition is approached. However, the driller may deem that overbalanced drilling is required, wherein the amount of pressure in the wellbore exceeds the pressure of fluids in the formation. This excess pressure is required inter alia to prevent reservoir fluids (oil, gas or water) from entering the wellbore. However, excessive overbalance can dramatically slow the drilling process by effectively strengthening the near-wellbore rock and limiting removal of drilled cuttings under the bit. In addition, high overbalance pressures coupled with poor drilling mud properties can cause differential sticking problems. Because reservoir pressures vary from one formation to another, while the drilling mud is relatively constant density, overbalance varies from one zone to another. The driller is able to vary the drilling condition from under-balanced to over-balanced by altering the density of the drilling mud by using weighting agents to increase or decrease the density of the drilling mud.

If the pressure in the well is not controlled properly, the speed of drilling is not maximised. In a worst case scenario, the well may collapse due to lack of pressure in the borehole. This is more likely to happen when drilling through particular types of formation.

In the past, circulation of drilling fluid is stopped during make-up or break-out of a single joint or stand of drill pipe. A fill valve or mud saver valve is

used to contain pressure in the drill string during the make-up or break-out procedure. However, the valve has to be connected and disconnected each time. Thus there is discontinuous circulation, although pressure is substantially maintained in the well, a pulse of pressure change is noted.

It is often preferable to maintain drilled cuttings in suspension in the drilling fluid to facilitate moving them away from the drill bit and to prevent them from falling back down in a wellbore. Cessation of drilling mud circulation can cause the drilled cuttings to sink. To counter this in many prior art systems additional fluid weighting is attempted, often increasing the viscosity of the fluid. This results in the need for more pumping power at the surface to move the thicker fluid; but such an increase in pump force can result in over pressuring the wellbore which can cause formation damage or loss of fluids.

A continuous circulation system has been developed and is disclosed in PCT Publication No. WO 98/16716, which allows circulation of drilling mud to be carried out throughout the making-up and breaking-out of pipe to and from a pipe string. WO 98/16716 discloses, inter alia the use of an upper set of pipe rams to apply and seal about a single or stand of pipe to be connected to the string, a lower set of pipe rams to apply and seal about the pipe at the top of the string in the well to create a chamber therebetween and a blind ram to seal off the chamber between the end pin of the pipe to be connected and the box of the pipe at the top of the string to form upper and lower chambers. A drilling mud inlet is arranged in the lower chamber between the set of blind rams and the lower set of pipe rams. A drilling mud

supply is also connected to the top end of the pipe to be connected, thus to make a connection, the lower pipe rams are activated and seal about the top end of the string of pipe in the wellbore and the blind rams are activated to form a lower chamber about the top of the drill string. Drilling mud is allowed to flow into the lower chamber and circulate into the top of the drill string. The drilling mud passes through the drill string to the drill bit and returns through an annulus formed by the drill string and the borehole. The drilling mud is processed by shale shakers, centrifuges and the like to remove cuttings therefrom, additives added if needed and then circulated to the lower chamber. Meanwhile, a single or stand of pipe is lowered into the top of the continuous circulation system. The upper pipe rams are activated to seal about the pipe. The upper end of the single or stand of pipe is attached to the supply of drilling mud and drilling mud flows into the upper chamber by activation of a valve. The pressures in the upper and lower chambers are now substantially equal. The blind ram is opened and the pin end of the single or stand of pipe is stabbed into the box in the top end of the string of pipe and spun and torqued to make the connection. The drilling mud in the chamber may be drained and the upper and lower pipe rams opened to allow the pipe string with the added single or stand of pipe to be lowered into the well. Thus a circulation is continuous through the pipe string and annulus whilst the connection is made and broken.

Various improvements to the continuous circulation system have been made, including conducting continuous circulation whilst drilling. Thus allowing continuous rotation of the drill string to allow drilling to continue whilst the single or stand of pipe is connected

or disconnected from the string. This is useful for drilling with drill pipe or when drilling with casing.

Elevators are used in these operations to selectively support pipe and to facilitate moving singles and stands of pipe and any tool connectable to the pipe string from one location to another about the drilling rig.

United States Published Patent Application Publication No. 2003-0221519 published December 4, 2003 (USSN 382080, filed: March 5, 2003) discloses an apparatus that permits sections of tubulars to be connected to or disconnected from a string of pipe during a drilling operation. The apparatus further permits the sections of drill pipe to be rotated and to be axially translated during the connection or disconnection process. The apparatus further allows for the continuous circulation of fluid to and through the tubular string during the makeup or breakout process. The apparatus defines a rig assembly comprising a top drive mechanism, a rotary drive mechanism, and a fluid circulating device. Rotation and axial movement of the tubular string is alternately provided by the top drive and the rotary drive. Additionally, continuous fluid flow into the tubular string is provided through the circulation device and alternately through the tubular section once a connection is made between an upper tubular connected to the top drive mechanism and the tubular string. This application also discloses a method for connecting an upper tubular to a top tubular of a tubular string while continuously drilling, the method including steps of: operating a rotary drive to provide rotational and axial movement of the tubular string in the wellbore; positioning the upper tubular above the top tubular of

the tubular string, the upper tubular configured to have a bottom threaded end that connects to a top threaded end of the top tubular; changing a relative speed between the upper tubular and the top tubular to threadedly mate the bottom threaded end of the upper tubular and the top threaded end of the top tubular such that the upper tubular becomes a part of the tubular string; releasing the tubular string from engagement with the rotary drive; and operating a top drive to provide rotational and axial movement of the tubular string in the wellbore.

In some prior art systems in which a top drive is used for drilling, a stand of drill pipe (e.g. a 90 feet stand comprising three interconnected pieces of drill pipe) is threadedly connected to and below a saver sub. The saver sub is connected to part of a top drive drilling unit and, once drilling has proceeded down to the extent of the length of a stand, the saver sub has entered into and is located within a chamber of a continuous fluid circulation system. In order to add a new stand with this type of prior art system, a connection is broken within a fluid circulating system, the top drive drilling unit is raised and, along with it, the saver sub is raised and exits from the top of the continuous circulation system. In order, then, to connect a new stand of drill pipe, a portion of a top drive drilling unit (e.g. an elevator) is, in some prior art methods, moved away from the wellbore. Typically an elevator is associated with the top drive drilling unit, but this elevator often cannot be used to receive and support the new stand because a saver sub interferes with the operation.

In many cases, as a top drive drilling unit is raised, it is desirable to backream to circulate fluid

and rotate the string coming out of the hole (the wellbore) as the top drive drilling unit is raised, e.g. to smooth out the hole and prevent the formation of keyseats. Another problem with such drilling systems is that it is desirable to drill down as far as possible with each new stand of drill pipe; but items and apparatuses

(e.g. elevators) suspended below a top drive drilling unit prevent further downward progress of the top drive drilling unit unless they are moved out of the way away from the wellbore centreline so that the top drive drilling unit can continue to rotate the drill string as the top drive drilling unit's saver sub enters the continuous circulation system (and the top drive approaches the continuous circulation system) . Typically, the elevator is moved in one direction away from the wellbore centerline (and prior art elevators that only open to one side are used) .

The prior art discloses a wide variety of elevators used in wellbore operations, including, but not limited to, those in U.S. Patents 6,626,238; 6,073,699; 5,848,647; 5,755,289; 4,834,441; 4,354,706; 4,126,348; 3,403,791; 3,330,354; 3,287,776; 3,193,116; 3,140,523; 1,844,379; 1,842,638; 1,448,100; 1,371,835; 1,113,659; and 1,021,984.

In accordance with the present invention, there is provided An elevator for use in wellbore operations, the elevator comprising a first body member having front and back ends and a second body member having front and back ends, which together form a throat for receiving a pipe, a front release apparatus for releasably connecting together the front ends, and a back release apparatus for releasably connecting together the back ends

characterised in that, the elevator further comprises actuation apparatus for selectively operating a chosen one of the front release apparatus or the back release apparatus. Pipe is herein intended to include inter alia singles of drill pipe, stands of drill pipe, casing, liner, premium tubular, tools for insertion into a wellbore.

Preferably, the front release apparatus comprises a first latch apparatus for selectively latching together the first front end and the second front end. Advantageously, the latch apparatus also provides a pin about which the body members can pivot to open a throat for insertion of a pipe. Preferably, the back release apparatus comprises second latch apparatus for selectively latching together the first back end and the second back end.

Advantageously, the activation apparatus comprises handle apparatus connected at least one of the body members and manipulable to activate at least one of the front and back release apparatus. Preferably, the activation apparatus comprises a first handle movable with respect to the first body member, the first handle movable to selectively operate the front release apparatus, and a second handle movable with respect to the first body member, the second handle movable to selectively operate the back release apparatus. Advantageously, at least one of the first handle and second handle are movable about a pin to operate their respective front and back release apparatus. Preferably, the elevator further comprises a rod extending through the first body member, the rod connected at the front of the elevator to the second handle at one end and the back

release apparatus at the back of the elevator.

Advantageously, the elevator further comprises a locking apparatus for selectively locking the elevator closed, preventing the activation apparatus from operating. Preferably, the locking apparatus comprises a removable pin to selectively allow the movement of said handle.

Preferably, the elevator further comprises a first activation apparatus, advantageously, within the second body member. Preferably, the first activation apparatus is fixed at one end with respect to the second body member and the other end movable with respect to the second body member and fixed to the front release apparatus for moving a latch upon actuation by said first actuation apparatus. Preferably, the first activation apparatus is fixed at one end with respect to the second body member and the other end movable with respect to the second body member and fixed to the front release apparatus for moving the body members apart upon actuation by said second actuation apparatus. The latch in the front release apparatus is not activated, thus retracting the first activation apparatus will cause the elevator to open the back of the elevator pivoting about the front release apparatus which remains closed. Advantageously, the elevator further comprises a second activation apparatus fixed at one end with respect to the second body member and the other end movable with respect to the second body member and fixed to the back release apparatus for moving a latch upon actuation by said second actuation apparatus. Preferably, the elevator further comprises a second activation apparatus fixed at one end with respect to the second body member and the other end movable with respect to the second body member

and fixed to the back release apparatus for moving the body members apart upon actuation by said first actuation apparatus. The latch in the back release apparatus is not activated, thus retracting the second activation apparatus will cause the elevator to open the front of the elevator pivoting about the back release apparatus which remains closed.

Preferably, the activation apparatus comprises a piston and cylinder. Preferably, the piston and cylinders are activated with either hydraulic or pneumatic fluid and are preferably a double acting piston and cylinder having fluid inlet ports both in front of and behind the piston to activate the piston rod both extending and retracting using positive pressure. Preferably, the at least one piston and cylinder has a full stroke length, and retention apparatus for selectively restraining the piston and cylinder to inhibit the piston and cylinder from extending to their full stroke lengths so that the release apparatuses are positionable to properly connect ends of the body members together.

Advantageously, the elevator further comprises at least one insert on an interior of the first and second body members. Preferably, the insert comprises low friction material to allow the body of the pipe to slide through the throat of the elevator so that an upstand or box of greater dimension that the body of the pipe can abut the top of the elevator. Alternatively, the insert may comprise high friction material to positively grip the pipe and inhibit the pipe from sliding through the throat of the elevator.

Preferably, the elevator further comprises a first main pin extending through the first front end of the first body member, the second front end of the second

body member and the front release apparatus, the first body member and the second side body member pivotable about the first main pin, a second main pin extending through the first back end of the first body member, the second back end of the second body member, and the back release apparatus, the first body member and the second body member pivotable about the second main pin.

The present invention also provides an apparatus for elevating pipe comprising the elevator of the invention which uses a piston and cylinder, the apparatus further comprising a source of fluid under pressure in communication with a fluid channel network and a flow control apparatus for continuously applying fluid under pressure from the source to the piston and cylinder devices to continuously bias the piston and cylinder devices in an elevator-opening configuration.

The present invention also provides a method for handling pipe in wellbore operations using the elevator as claimed in any preceding claim, the method comprising the step of actuating the actuation apparatus for selectively operating a chosen one of the first release apparatus or the second release apparatus to form an open throat, placing a portion of a tubular member within the elevator, and closing the elevator to support the tubular member with the elevator.

The present invention also provides a method for handling pipe, the method comprising the steps of opening the front of an elevator, closing the elevator about the pipe, lifting the pipe to above well centre, connecting the pipe to a string of pipe in a wellbore, opening the back of the elevator an swinging the elevator away from the well centre. Preferably, a continuous circulation apparatus is located at well centre, the pipe lifted

thereabove and inserted therein. Advantageously, the pipe is guided into the continuous circulation apparatus with a pipe guide attached to the continuous circulation apparatus on extendible arms. Another problem with such drilling systems is that it is desirable to drill down as far as possible with each new stand of drill pipe; but items and apparatuses

(e.g. elevators) suspended below a top drive drilling unit prevent further downward progress of the top drive drilling unit unless they are moved out of the way away from the wellbore centreline so that the top drive drilling unit can continue to rotate the drill string as the top drive drilling unit's saver sub enters the continuous circulation system (and the top drive approaches the continuous circulation system) . Typically, the elevator etc. are moved in one direction away from the wellbore centreline (and prior art elevators that only open to one side are used) .

The present invention, in at least certain embodiments, teaches a new top drive drilling system with a top drive drilling unit and joint breaking system and an elevator suspended beneath it.

In certain aspects, the elevator has dual opposed members which have dual interactive connection apparatuses so that either side of the elevator can be opened. Thus, the elevator can be opened on one side to permit the elevator unit to be moved away from the wellbore center line so that the top drive drilling unit can drill the drill string down as far as possible before adding a new piece or stand of drill pipe; and then the elevator can be opened from the other side for receiving a new piece or stand of drill pipe (and in a backreaming operation in accordance with the present invention the

reverse is true) .

In certain aspects, such an elevator has dual opposed selectively releasable latch mechanisms and dual opposed handling projections. Such apparatus and methods with an elevator suspended below a top drive drilling unit, the elevator having dual opposed structures so that either side thereof can be opened, one side being opened permitting movement away from a wellbore centre for further drill down of a drill string and the other side being opened for receiving a new stand of drill pipe to be added to the drill string (or to accomplish the reverse in a backreaming operation) .

For a better understanding of the present invention, reference will now be made, by way of example, to the accompanying drawings, in which:

Figure IA is a front elevation of part of a prior art drilling rig incorporating a top drive over a well centre;

Figure IB is a side elevation taken from line IB-IB shown in Figure IA but showing the top drive swung to a position over a mouse-hole to pick up a stand of pipe; Figure 1C shows a fragmentary front elevation of part of the drilling rig shown in Figure IA showing the top drive swung to a retracted position permitting the top drive to be raised and lowered to trip a stand of pipe into the well or to pull the string out of the well; Figure 2 is a perspective view of part of a drilling rig comprising a top drive and a continuous circulation apparatus;

Figure 3 is a perspective view of an elevator in accordance with the present invention; Figure 4 is a perspective view of a top drive apparatus incorporating a connection tool;

Figures 5A, 5B, 5C and 6 are perspective views of a pipe connection apparatus;

Figure 6A is a top view of a pipe connection apparatus depending from links of a top drive, the pipe connection apparatus and a stand of drill pipe located away from well centre, the pipe connection apparatus comprising an elevator in accordance with the present invention open and supported by arms in a position out of line with a rotor of the top drive;

Figure 6B is a side view of the pipe connection apparatus and the top of the stand of drill pipe shown in Figure 6A;

Figure 6C is a top view of the pipe connection apparatus shown in Figure 6A with the elevator closed about the top of a stand of pipe;

Figure 6D is a side view of the pipe connection apparatus shown in Figure 6A with the elevator closed about the top of the stand of pipe;

Figure 6E is a side view of the pipe connection apparatus shown in Figure 6A with the elevator closed about the top of the stand of pipe and a position in line with the rotor of the top drive;

Figures 7A, 7B and 7C show a side view of a continuous circulation apparatus located over well centre and a pipe guide apparatus for guiding the lower end of the stand of pipe into the continuous circulation apparatus, showing steps in a method of moving the stand of pipe held in the pipe connection apparatus as shown in Figure 6D toward and in line with the continuous circulation apparatus and well centre;

Figures 8 and 9 show a side view of the pipe connection apparatus shown in Figure 6D depending from links of a top drive, with a saver sub depending from a rotor of the top drive and the top of the stand of pipe to be connected to a pipe string, showing steps in a method of connecting the stand of pipe to the saver sub of the top drive using the pipe connection apparatus;

Figures 1OA, HA, 12A, and 13A show a top view of the pipe connection apparatus and the stand of pipe shown in Figure 6A showing steps in a method of connecting the stand of pipe to a pipe string; Figures 1OB, HB, 12B and 13B are side views of the pipe connection apparatus, links, lower part of the top drive and the stand of pipe shown in Figure 6A showing the steps shown in Figures 1OA, HA, 12A, and 13A;

Figure 14 shows a side view of part of a drilling rig comprising a top drive slideably mounted on a derrick, a pipe connection apparatus depending from the top drive on links and a continuous circulation apparatus arranged over well centre showing a step in a method of lowering the connected stand of pipe into the well on the pipe string, with the pipe connection apparatus swung to one side about the continuous circulation apparatus;

Figure 15A shows a top view of the pipe connection apparatus and the stand of pipe shown in Figure 6A showing a step in a method of disconnecting the stand of pipe from a pipe string;

Figure 15B is a side view of the pipe connection apparatus, links, lower part of the top drive and the stand of pipe shown in Figure 6A showing the step shown in Figures 15A;

Figure 16 of the pipe connection apparatus, links, lower part of the top drive and the stand of pipe shown in Figure 6A showing a step in a method of disconnecting the stand of pipe from a pipe string;

Figures 17 and 18 show a side view of the pipe connection apparatus shown in Figure 6D depending from links of a top drive, with a saver sub depending from a rotor of the top drive and the top of the stand of pipe to be connected to a pipe string, showing steps in a method of disconnecting the stand of pipe to the saver sub of the top drive using the pipe connection apparatus;

Figure 19 shows a side view of the continuous circulation apparatus located over well centre and the pipe guide apparatus for guiding the lower end of the stand of pipe away from the continuous circulation apparatus, showing steps in a method of moving the stand of pipe held in the pipe connection apparatus as shown in

Figure 6D away from the continuous circulation apparatus and well centre;

Figures 2OA, 2IA, and 22A show a top view of the pipe connection apparatus and the stand of pipe shown in Figure 6A showing steps in a method of moving the stand of pipe away from the pipe string;

Figures 20B, 2IB and 22B are side views of the pipe connection apparatus, links, lower part of the top drive and the stand of pipe shown in Figure 6A showing the steps shown in Figures 1OA, HA, 12A, and 13A;

Figure 23A is a top view of an elevator in accordance with the present invention for use in the method in accordance with the present invention;

Figure 23B is a perspective view of the elevator shown in Figure 23A;

Figure 23C is a view taken in cross-section of part of the elevator shown in Figure 23A;

Figures 23D is a top view of the elevator shown in Figure 23A shown in a first open position; Figures 23E is a top view of the elevator shown in Figure 23A shown in a second open position;

Figure 23F is a side view of the elevator shown in Figure 23A;

Figure 236 is a top cross-sectional view of the elevator shown in Figure 23A, taken along line Fig 236- 236 in Figure 23F;

Figure 23H is a top cross-sectional view of the elevator shown in Figure 23A, taken along line Fig 23H- 23H in Figure 23F; Figure 231 is top cross-sectional view taken along a third level of the elevator shown in Figure 23A;

Figure 23J is a side cross-sectional view of the elevator shown in Figure 23A;

Figure 23K is perspective exploded views of the elevator shown in Figure 23A, showing the top of the elevator;

Figure 23L is perspective exploded views of the elevator shown in Figure 23A, showing the underneath of the elevator;

Figures 24 and 24A are perspective views of part of the elevator shown in Figure 23A;

Figure 24B is an exploded view of the part shown in Figure 24A;

Figure 24C is a perspective view of another version of a part shown in Figure 24A;

Figure 24D is an exploded view of the part shown in Figure 24C; Figure 24E is a perspective view of a piece of the part shown in Figure 24D;

Figures 25, 25A, 26, 26A, 26B, 27, 27A, 28, 29, 29A, 30, 3OA, 31, 32 and 33 are perspective views of the elevator shown in Figure 23A showing steps in a method in accordance with the present invention;

Figure 34A is a top view of an elevator in accordance with the present invention; and

Figure 34B is a side view of the elevator of Figure 34A. Figures IA to 1C show a prior art rig and top drive system 10 as disclosed in U.S. 4,458,768 (incorporated fully herein for all purposes) .

The prior art drilling rig 10 illustrated in Figures IA to 1C has a derrick 11 arranged over a wellbore 12 being drilled by a drill bit (not shown) arranged on the end of a drill string 13 formed in conventional manner in a series of previously prepared stands of drill pipe connected together in end to end fashion in threaded

connections 14. The drill string 13 is rotated about its vertical axis 15 by a top drive drilling motor 16 connected to the upper end of the string. The drill string and top drive drilling motor 16 are supported and adapted to be moved up and down by a hoisting mechanism 17 including a crown block 18, travelling block 19, line 20, supporting travelling block 19 from block 18, and power driven draw works for reeling the line 20 in or out to raise or lower the travelling block 19. A hook 21 depends from the travelling block 19 from which the top drive drilling motor 16 is suspended, and which has a gate 121 adapted to be opened for connecting and disconnecting the top drive drilling motor 16. The top drive drilling motor 16 and hook 21 are guided during their upward and downward movement by two parallel elongate guide rails 22 and 23, which engage and guide a carriage 24 on which the top drive drilling motor 16 is arranged and a carriage 25 on which the travelling block is arranged. The two guide rails 22 and 23 are preferably of H section that continues from the upper extremity of each guide rail to its lower extremity. The guide rails 22 and 23 have upper sections which extend from the upper end of derrick 11 to a mid-derrick location and are attached rigidly to the derrick 11 for retention in positions of extension directly vertically and parallel to one another and to well axis 15. Beneath the mid- derrick location the two guide rails 22 and 23 have second portions or sections extending parallel to one another, continuing downwardly and to location 27, and mounted by two pivotal connections for swinging movement relative to upper sections and about a horizontal axis. An inclined mousehole 30 is used (Figure IB) . Single

drill pipe sections may be made up into stands of three sections in the mousehole.

The guide rails 22 and 23 have a third lowermost section which are carried by the second sections for swinging movement therewith between the vertical and inclined positions and which also are mounted by connections 31 and 32 for horizontal swinging movement about two axes 33 and 34 which are parallel to one another and to the longitudinal axes of the second sections.

The two pivotal connections 31 and 32 include two parallel mounting pipes or tubes 37 and 38 connected rigidly to the second sections. The two second guide rail sections are adapted to be power actuated between the vertical and inclined positions by a piston and cylinder mechanism 45 whose cylinder is connected to a horizontally extending stationary portion of the derrick, and whose piston rod acts against the tube 37 of pivotal connection 31. Carriage 25 to which travelling block 19 is connected includes two frames 56 and 57 extending partially about the rails 22 and 23 respectively and rotatably carrying rollers 58 which are received between and engage the front and rear flanges 59 of the various rail sections in a manner effectively locating carriage 25 against movement transversely of the longitudinal axis of the rail structure, and guiding the carriage for movement only longitudinally of the rails.

The top drive drilling motor 16 is arranged on a carriage structure 24, a power unit 61 for turning the string, and a conventional swivel 62 for delivering drilling fluid to the string.

The power unit 61 of the drilling assembly includes

a pipe section having a lower tapered external thread forming a pin and threadedly connectable to the upper end of drill string 13 to drive it. In most instances, a conventional crossover sub 72 and a short "pup joint" 73 are connected into the string directly beneath the power unit 61. At its upper end, pipe section 70 has a tapered internal thread connectable to the rotary stem 75 of swivel 62. This stem 75 turns with the drill string relative to the body 76 of the swivel 62, which body is supported in non rotating relation by a bail 77 engaging hook 21 of the travelling block 19. Drilling fluid is supplied to the swivel through a flexible inlet hose 78, whose second end is connected to the derrick at an elevated location 79 well above the level of the rig floor. For driving the tubular shaft 70, power unit 61 includes an electric motor.

Figure 2 shows a top drive drilling apparatus 100 which includes a top drive drilling unit 120 suspended in a derrick 112 (like the rig and derrick in Figure IA with the various parts etc. as shown in Figure IA) . A continuous circulation system (CCS) 130 rests on a rig floor 114.

The CCS 130 is any known continuous circulation system and is, in one aspect, a CCS system commercially available from Varco International, Inc. Alternatively, the CCS may be of the type shown in Figure 6A to 7.

An elevator 140 is suspended below the top drive drilling unit 120. Optionally, a connection tool apparatus 200 is suspended underneath the top drive 120. The connection tool apparatus 200 comprises a pipe gripping 150 and the elevator 140 is suspended from the pipe gripping 150. Any suitable known pipe gripping may be used for the pipe gripping 150 or, alternatively, a

pipe gripping may be used as disclosed in the co-pending PCT application no. PCT/GB05/ co-owned with the applicants for the present case and based on U.S. Patent Application entitled "Pipe Gripping And Top Drive Systems," U.S. Ser. No. 10/999,815 filed 30 ^th November 2004. The pipe gripping 150 is suspended from the top drive drilling unit 120 with links known as bails 118 and the elevator 40 is suspended from the pipe gripping 150 with movable arms 124. The pipe gripping apparatus may simply grip and inhibit the pipe for rotating or may be an active pipe gripping apparatus and may have a drive mechanism for gripping the pipe and rotating the pipe either as a spinner and/or have a high torque capacity to complete torquing of the screw joint between section of pipe to perfect the connection. A torque-turns monitoring apparatus which is well known in the art, such as the Franks system, may be provided to ensure the connection is completed properly and that binding in the threads has not occurred.

The elevator 40 is preferably of the type having dual opposed doors which have dual interactive connection apparatuses so that either side of the elevator can be opened. Thus, the elevator can be opened on one side to permit drill pipe to enter the throat of the elevator and to exit the elevator from an opposing side. In certain aspects, such an elevator has dual opposed selectively releasable latch mechanisms and dual opposed handling projections. In one embodiment (see Figure 3) each link 80 has a lower portion 81 which passes through corresponding eyes 82 of the elevator 40 and has a top section 83 with dual spaced-apart tubular portions 84, 85 which receive

corresponding parts 86, 87 of the lower portion 81. Optionally, the links 80 have a top hollow tubular member 88, movable with respect to the pipe guide 50, to which the tubular portions 84, 85 are connected. The elevator 40 as shown in Figure 3 has two body members 89, each with an eye 82 which serve as lift points. An interior recess 83 of each body member 89 has a tapered portion 90 against which rests part of a tubular held by the elevator 40. Each body member 89 includes a selectively engageable latching mechanism 91 which cooperates with corresponding latch structure 92 on the other body member 89. Each latching mechanism 91 includes a projecting handle or arm 93. Optionally, each body member 89 includes a second handle or arm 94 to facilitate handling of the elevator 40 and/or operation of the latch mechanisms 91.

Figures 4 to 6 show a system 100 having a top drive drilling unit 102. Main links 104 connect the top drive 102 to eyes 121 of a support system 120. A pipe gripping system 110 is connected to and supported by the support system 120. A saver sub 160 is connected to a rotor (not shown) of the top drive drilling unit 102. The saver sub 160 is threadedly connected to a top drill pipe 106 of a drill string 108. The saver sub 160 is positioned for being gripped and rotated by the pipe gripping system 110. An elevator (not shown), which in one aspect is similar to the elevator 40 described above or to elevators in accordance with the present invention described below, is located below the pipe gripping system 110. The elevator is connected to the pipe gripping system 110 and, in one particular aspect, is connected as is the elevator 40 to the pipe gripping system 50, described above.

Each eye 121 has a movable lockable latch 122 which can be selectively opened for receiving a lower ring 104a. Each eye 121 has a body 123 with a shaft 125. Optionally, springs 126 encircle top portions of the shafts 125 and serve as rotational devices to rotationally moves a holding mechanism 150 around the links 104 to free the links 104. Studs 127 abut lower ends of the springs 126 and hold them in position on the shafts 125. As shown in Figure 5A, the holding mechanism 150 has a housing 151 comprising upper and lower plates 151a and 151b to which are pivotally connected two plate members 152. The housing 151 is fixed to a pair of shafts 125 extending upwardly from a pipe gripping apparatus 110. Each plate member 152 has an open throat 155 within which is releasably positioned part of main link 104. The open throat is defined by two fingers 157a and 157b and the remaining plate member which are all integrally formed from one sheet plate of metal, although any other suitable material may be used. Each plate member 152 pivots on top of a shaft 125. To selectively prevent such pivoting, a pin 156b is inserted through each plate members 152. A yoke plate 156 is arranged centrally on the end of a rod of a piston/cylinder apparatus 156a, which cylinder is fixed to the housing 151 and the rod of which passes through the upper and lower plates 151a and 151b. The yoke plate 156 has two ends, each connected to top of the pins 156b. Upoon retraction of the rod into the piston/cylinder 156a, the pins 156b pass through holes in each plate member 152 to lock the plate member 152 in position. The plate member has at least one hole to lock the links and the pipe gripping apparatus in relation to one another when depending vertically and in

line with the well centre. Thus upon rotation of a stand of pipe, the reactive torque is taken by through the links 104. Figure 5A to 5C show the pipe gripping apparatus in a lowered position in-line with well centre or at least in line with a stand of pipe to be connected to a drill string. The main links 104 are held within the throats 155 which are sufficiently deep so that the main links 104 as shown in Figure 5A cannot move out of the throats 155 when in position as in Figure 5A. With the bolts 156c removed when the cylinder 156a raises the plate 156, the members 152 are free to pivot and, thus, the main links 104 are freed to move away from the throats 155, as shown in Figure 6, wherein the pipe gripping apparatus 110 and the housing 151 through the support system 120 inter alia may act as a back-up tong to transfer reactive torque from an active pipe gripping apparatus which may rotate the saver sub 160 and/or the stand or single of pipe 106.

The support system 120 has piston/cylinders 128 for moving the gripping system 110 up and down. Upper ends of piston rods 128d are secured to the bodies 123 of the eyes 121 and lower ends of the housings 132 are secured to a main body 129 of the pipe gripping apparatus 110. Optional protective railings 131 connected to the main body 129 encompass part of the perimeter of the pipe gripping system 110 to inter alia protect various parts of the pipe gripping apparatus. Mounting posts 128c, move in corresponding tubes 128a. The mounting posts are of heavy construction to withstand reactive torque from the pipe gripping apparatus 110.

Figure 5B shows the entire saver sub 160, which is not connected to the rotor of the top drive (not shown) . Figure 6 shows the plate members 152 pivoted with respect

to the links 104 and the pipe gripping apparatus 110 moved away from and hanging substantially parallel to a vertical axis of the saver sub 160 and drill pipe 106. Optional skid pieces 131a are apparatus 110 past apparatus with which it may come in contact as it is lowered (e.g. a CCS system).

Figures 6A - 22B illustrate steps in certain methods in accordance with the present invention with certain embodiments of apparatuses in accordance with the present invention. Figures 6A - 14 illustrate one method in accordance with the present invention for running pipe into a wellbore; and Figures 15A - 22B illustrate one method in accordance with the present invention for pulling pipe out of a hole. As shown in Figures 6A and 6B a top drive system 10a (like the apparatus shown in Figures 4 to 6) having a top drive 20a from which links 104a are suspended. A connection tool apparatus 200 comprising a support apparatus 202 and a pipe gripping apparatus 210 (like the pipe gripping apparatus 110) . An elevator 230 which may be like the elevator 140 disclosed above, depends from the pipe gripping apparatus 110. The elevator 230 has opposed elevator halves 231, 232. The elevator 230 is shown in an open position for receiving, encompassing, and supporting a piece or stand of drill pipe 206. In one embodiment, to initiate the sequence of steps shown in Figures 15A - 22B, a driller at a driller's console (see Figure 2, console DC) presses a selected button and the sequence is begun. As shown in Figures 6C and 6D, the drill pipe 206 has been offered up (manually by a derrickman or by a pipe handling machine) into the elevator 230 and the elevator 230 has been closed shut around the drill pipe

206 (e.g. a derrickman uses an hydraulic system to close the elevator halves 231, 232 about the drill pipe body) .

Figure 6E illustrates the drill pipe 206 being lifted into position off a rig floor to a location above a continuous circulation system 240 (see Figure 7A) which may be any continuous circulation system referred to herein. As shown in Figure 6E as compared to Figure 6B, the elevator 230 has moved below the gripping system 210 and the drill pipe 206 is lined up generally with a longitudinal axis of a saver sub 260 (like the saver sub 160 or any saver sub referred to herein) . Such alignment is facilitated by an over center connection of ends 208a of piston/cylinder devices 208 (see also Figure 8) to links 214. The devices 208 urge the elevator 230 toward the position shown in Figure 6B. Other ends 208b of the piston/cylinder devices 208 are connected to the gripping system 210. The elevator 230 is lowered into the position shown in Figure 6E by its own weight and by the weight of the drill pipe. The links 214 abut stops 208f which prevent the links 214 from moving past the position shown in Figure 6E and the over center connection of the ends 208a facilitates maintaining the elevator 230 and the drill pipe in the position shown in Figure 6E.

As the driller lifts the drill pipe 206 as shown in Figure 4 in the elevator 140, a pipe holder 244 of a pipe guide 242 is offered up to the drill pipe 206, using the arrangement of piston and cylinders, as shown in Figure 7A to move the pipe holder 244 closer to the pipe 206. Optionally a roughneck facilitates moving the drill pipe 206 into the pipe holder 244. The pipe guide 242 is mounted on top of the continuous circulation system (CCS) 240 as shown in Figure 7A. The CCS 240 is positioned on the rig floor in the same position as the CCS 30 is shown

in Figure 2 .

The pipe guide shown in Figures 7A to 7C may be of the type disclosed in co-pending PCT application no. co-owned with the applicants for the present case and based on U.S. Patent Application entitled "Method and apparatus for wellbore operations" and assigned U.S. Provisional application No. 60/631,954 filed 30 ^th November 2004 and U.S. Ser. No. 11/176,976 filed 7 ^th July 2005, which discloses inter alia an apparatus for guiding pipe, the apparatus comprising a base, a first extendible member extending from said base and a second extendible member pivotally secured to the first extendible member and a pipe holder attached to the first extendible member. A lower set of pipe rams 269, as shown in Figure 6C, are in a closed position sealing about the top of the string of pipe 209 in the wellbore. A blind set of rams 268 seals off above the top of the string of pipe to form a lower chamber (not shown) . The chamber (not shown) is provided with a drilling mud line (not shown) supplying clean drilling mud from shale shakers, centrifuges and the like, which was obtained from solids laden drilling mud returned from the annulus of the wellbore formed between the wellbore and the pipe running therethrough. Thus drilling mud is circulated through the lower chamber into the top of the string of drill pipe.

Figure 7B illustrates the driller lowering the top drive and hence the elevator 140 and pipe 206 to stab the drill pipe 206 into the CCS 240 after the pipe has been correctly aligned with the CCS 240 using the pipe guide 242. A snubber 246 of the CCS 240 selectively grips the pipe. As shown in Figure 6C optionally, jaws (not shown) in the snubber 246 close on and grip the drill pipe 206

whose bottom end 206a is not yet connected to a drill string 209 whose upper end is held within the system 240. An upper set of pipe rams 270 close and seal about the pipe 206. The bottom end 206a of the drill pipe 206 rests on top of a set of closed blind ram blocks (shown by a horizontal dotted line 241) , or is held slightly thereabove of a middle pressure chamber of the system 240.

Figures 8 and 9 illustrate steps in connecting the lower end of the saver sub 260 to an upper end 206b of the drill pipe 206. As shown in Figure 8 the saver 260 is positioned for lowering down to the drill pipe 206. The top drive 20a and the connection tool apparatus 200 are lowered to stab a lower end 260a of the saver sub 260 into the top end 206b of the drill pipe 206. In the position shown in Figure 9 the jaws of the gripping system 210 are not gripping this splined portion 260c.

The top drive 20a rotates the saver sub 260 while the snubber 246 holds the drill pipe 206 thereby making- up the connection between the saver sub 260 and the drill pipe 206.

Drilling mud returned is then switched to flow through the swivel (not shown, but like swivel 62 in Figure 1C) , through the saver sub 260 and into the pipe 206 and into an upper chamber (not shown) between the upper pipe rams 270 and the blind rams 268.

The blind rams 268 are opened, there being equal mud pressure in the upper and lower chambers. The pipe 206 is lowered on the top drive 120 and the top drive 120 rotates the pipe 206 to spin the connection and to torque the connection. Alternatively, a tong is provided on top of the CCS 240 above the upper pipe ram 270 or the gripper unit 150 is used to spin and/or torque the

connection. The upper and lower chambers may be drained of surplus drilling mud and the upper and lower pipe rams 270, 269 are opened and drilling is recommenced. If the pipe 206 consists of a stand of three pipes, drilling can continue for approximately 10m before the procedure is repeated by first activating the lower pipe rams 269 to seal about the top end of the string in the well.

As shown in Figures 1OA and 1OB elevator doors 231 and 232 are opened and the elevator 230 is swung on movable arms 24 away and out of disengagement with the pipe 206 and thus away from the wellbore centreline by activating the piston and cylinder arrangements 141. The elevator doors 231 and 232 may be opened remotely or a roughneck may open the elevator doors 231 and 232 manually. The elevator doors 231 and 232 may then be closed or opened and then closed about a tugger line 250 which passes over a block in the top of the derrick and on to a winch (not shown) . The connection apparatus 200 depending from the bails 118 is swung out on the wellbore centreline by winching the tugger line 250, whereupon the elevator 140 seats itself on a seat 254 attached to the end of the tugger line 250 and pulls connection tool apparatus 200 out of line with the wellbore centreline, as shown in Figure 14, allowing the pipe to be lowered into the continuous circulation system 240 to locate the top of the drill string above the lower pipe rams but below the blind rams. Rotation of the drill string occurs during this phase, drilling down the wellbore. The saver sub 260 is now disconnected from the drill string by activating the top drive.

The continuous circulation system 240 maintains fluid circulation in the wellbore during connection makeup (e.g. connection of saver sub to drill pipe) . A

curved or slanted portion 239a of a body 239 to which the links 214 are connected facilitates contact of the body 239 by the continuous circulation system 240and movement of the body 239 past the continuous circulation system 240 in the event of such contact. The lower end of the tugger cable 250 is connected to an anchor 252 with a lower part 254 that is located beneath the elevator 230 and which has a portion larger in diameter than the elevator 230 so that the tugger cable 250 is secured to and held in position with respect to the elevator 230. Optionally, a power system 104b (shown schematically, Figure 14) moves the continuous circulation system 240 out of the way and the tugger cable is not used.

Figures 15A, 15B, and 16 illustrate the beginning of a method in accordance with the present invention for pulling drill pipe out of a wellbore. In order to latch the elevator 230 onto the drill pipe 206 (top piece in a stand) the back side 235 of the elevator 230 is opened, the elevator is lowered against the force of the devices 208, (Figures 15A, 15B) and the elevator is then moved onto the drill pipe 206 (e.g. by a derrickman and/or by venting the devices 208) .

As shown in Figure 17, jaws 211, 212 of the gripping system 210 have closed around and are not gripping the splined portion 260c of the saver sub 260 while the snubber 246 of the continuous circulation system 240 holds the drill pipe 206. After the step shown in Figure 17, the pipe gripping apparatus 210 is lowered so that its jaws grip the drill pipe 206 and then its jaws break the saver-sub/drill-pipe connection. Hydraulic cylinder devices 200c move the pipe gripping apparatus 210 down. Preferably, the snubber 246 comprises a torquing tong (not shown) . The jaws 211, 212 are then moved to be

aligned with splines on the saver sub 260. The pipe gripping apparatus 210 may be active and rotate the saver sub 260, or may be passive and simply hold the saver sub 260 rotationally fixed, and allow torque from the tong apparatus in the snubber 246 to rotate the drill pipe. The pipe gripping apparatus 210 will transfer reactive torque to maintin the saver sub 260 rotationally stationary through the support system 202 to the links 104. Once the connection is broken, the top drive 20a rotates (spins) the saver sub 260 to totally disconnect the saver sub 260 from the drill pipe 206. As shown in Figure 18, the drill pipe 206 has been released from the snubber 246, the top drive 20a and the connection tool system 200 is raised away from the drill pipe 206 with the drill pipe 206 still within the elevator 230 and with the bottom end 206a in a position as shown in Figure 7C. The driller then picks up the stand of drill pipe with the top drive system, deploys the pipe guide 242 over the center of the system 240, and grasps the drill pipe with the holder 244 of the pipe guide 242, then, as shown in Figure 19, the stand of drill pipe is moved away from the system 240 using the pipe guide 242.

As shown in Figures 20A, 20B the drill pipe single or stand is then lifted on the links 214 out of alignment with well centre and then lowered with the top drive so its bottom end rests on a rig floor 14a.

As shown in Figures 21A, 21B, the front 233 of the elevator 230 is opened by the derrickman who pulls the drill pipe 206 out of the elevator 230 for racking back in a fingerboard of the derrick. As shown in Figures 22A, 22B, the elevator 230 is closed.

Figures 23A - 23L illustrate a dual sided elevator 330 in accordance with the present invention (like the

elevator 230) which has two side bodies 331, 332 which selectively are openable and closable using latch mechanisms 341, 342 (either one of which is optional in certain aspects). Arms 351, 352 extend from the side bodies 331, 332 respectively. As shown in Figure 23D a front 333 of the elevator 330 is open and as shown in Figure 23E a back 335 of the elevator 330 is open.

Figure 23C shows parts of the latch mechanisms 341, 342 in more detail. To release the latch mechanism 341, a pin 379 is removed and a front release handle 362 is pulled about pin 362a so that its end 363 releases a projection 364 of a member 365 thereby releasing a hinge/latch assembly 392 of the latch 341 and permitting the opening of the front end 333 by allowing the two side bodies 331, 332 to pivot about a pin 367 which holds them together. The handle 362 pivots about a pin 362a which secures the handle 362 to the side body 331. The elevator 330 is opened by the action of a piston system (like that of the piston 420 described below) located at the back of the elevator.

A hinge/latch hook assembly 370 which includes a bar 371 pivotably mounted with a pin 372 to the side body 332 has an end 373 forced outwardly by a spring 374 which is partially within a recess 374a in the side body 332 and which also has an exterior end that abuts the end 373 of the bar 371. A pin 375 pins a roller 375a to the bar 371. A spring 369 with a first end in a recess 369a in the side body 331 has a second end that abuts the end 363 and pushes the bar 371 outwardly. With the pin 379 in place, the back end 335 of the elevator 330 can be opened by removing a pin 361 and pulling on a rear release handle 381 which also pivots about the pin 368. Pulling on the handle 381 results in

the pulling of a release rod 382 which extends through a channel 383 through the side body 331 and has an end 384 pivotably attached with a pin 385 to a release member 386. A spring 387 in a recess 387a in the side body 331 resists pulling of the release rod 382 and urges release rod 382 towards back end 335. Movement of the release member 386 resulting from pulling of the release rod 382 moves a projection 388 of a member 389 releasing a hinge/latch assembly 390 of the latch 342 and allowing the two side bodies 331, 332 to pivot about a pin 391 which holds them together to open the back end 335 of the elevator 330 (assisted by the hydraulic system with the piston 420, described below) . In one aspect the rear release handle is optional and the rear latch is optional.

Optionally, inserts 393 are positioned in corresponding recesses 393a in the side bodies 331, 332 for contacting and facilitating the holding of a tubular (e.g. casing, tubing, pipe, drill pipe, drill collar, etc.) within the elevator 330. These may be pads to facilitate sliding of a body of a pipe, such that an upstand or box of the elevator can slide along the body of the pipe until the oversized box or upstand hits and seats the top of the elevator 330. A hinge/latch hook assembly 401 which includes a bar 402 pivotably mounted with a pin 403 to the side body 332 has an end 404 forced outwardly by a spring 405 partially in a recess 405a in the side body 332 and which has an exterior end that abuts the end 404 of the bar 402. A pin 406 holds a roller 406a (like the roller 375a) to an end 407 of the bar 402 to the side body 332.

Figures 24A and 24B show the hinge/latch assembly 392 which has an upper hinge latch body 411; a piston rod

pivot pin 412 through holes 356, 357 to which an end of a piston rod 420a is connected; a lower hinge latch body 413; a front hinge latch body 414; a projection 415 which is used in closing the elevator as the piston 420 is pushing on the assembly 392, but the projection 415 co- acts with the roller 375a to prevent the latch from fully engaging until a member 364 abuts part of the side 331. It is within the scope of the present invention to delete either piston 420 or piston 420a and its associated devices, lines, and mechanisms. A shaft 365c of a member 365 projects through a hole 416b in the assembly body 411. The member 365 has a body 365a with a top end 365d which projects beyond the plate 411. A projection 365b projects from the body 365a. The projection member 364 is receivable in a recess 363a of the end 363 of the handle 362 (see Figure 23K) . A groove 365f in a lower part 365e of the body 365a receives a nub 353 of a latch body 414 (see Figure 24E) . A shaft portion 365g of the body 365a is received in a corresponding hole 413b of a lower plate 413. Bolts 354 through holes 355 extending into holes 356a (in part 356) and 357a (in part 357) secure the body 414 to the plates 411, 413. The rear latch 390 has parts like that of the front latch 392 and the parts of the rear latch 390 as labelled in Figures 24C and 24D are like the corresponding parts in Figures 24A, 24B, and 24E with like numerals indicating like parts (e.g. part 414s in Figures 24C and 24D is like part 414 in Figures 24A and 24B and, e.g. part 411s is like part 411. The piston 420 is within the side 332 of the elevator 330 and selectively moves the assembly 392 to latch the elevator shut. Hydraulic power fluid is applied through channels in the arm 352 and the side body

332 (channels 337, 338, 339) and ports 1, 2 for a piston 420a. A similar piston device 420d latches the back side 335 of the elevator shut.

Figures 25 to 33 illustrate various steps in certain methods in accordance with the present invention for opening and closing the elevator 330.

Pins 361, 379 extend through holes in a top plate 421 and a bottom plate 422 of the side body 331.

As shown in Figure 25 the elevator 330 is closed, latched, and locked at both ends. As shown in Figures 26A and 27A, opening of the front end 333 is initiated.

As shown in Figure 27, the front end 333 of the elevator 330 is open. The front release handle 362 has been returned to its initial position by the force of the spring 369 pushing out against the end 363. The rear hinge/latch assembly 390 has fully rotated and acts as a hinge for the pivoting of the side bodies 331, 332.

Figure 28 illustrates the initiation of closing of the elevator 330 when its front end 333 is open. Figure 29 illustrates the elevator continuing to close. The elevator 330 continues to close as shown in Figures 30 and 31. As shown in Figure 32 and Figure 33, the side body 331 is closed and the elevator is latched.

As shown in Figure 25 the elevator 330 is closed, latched, and locked. The pin 379 is in place and prevents movement of the handle 362. Pressure from a pressure system PS with a valve, line to tank, and Fluid

Under Pressure inlet line, is being applied to both pistons 420 and 420a which are attempting to retract and they would, therefore, if permitted to, open the elevator

330 (i.e. the elevator is biased open in this configuration) . Fluid under pressure is applied via Port

2 and Port 4 to the pistons 420 and 420a; but, as in

Figure 25, the pistons 420 and 420a are restrained and cannot (until released) open the elevator.

As shown in Figure 25A, the pin 379 has been removed releasing the handle 362. Pulling on the handle 362 moves the handle 362 toward and against the spring 369 and brings the handle 362's end 363 into contact with the projection 364 of the member 365 of the hinge/latch assembly 392 of the latch mechanism 342. The resulting movement of the member 365 results in releasing the projection 365b from a groove 331a in the body 331. Thus the assembly 392 is released and allowed to rotate about the pin 391 to initiate opening of the elevator 330 (see Figure 26) .

Figure 26B illustrates opening of the elevator as the assembly 392 continues to rotate about the pin 391. The piston 420 is retracting rotating the assembly 392. As this occurs, the member 365 continues to rotate and its part 365e contacts the roller 375a of the assembly 370. The handle 362 has been moved back to its resting position.

As shown in Figure 26A, with the hinge/latch assembly 390 of the rear latch mechanism 341 locked and latched, when the piston 420a is retracted, the elevator 330 is opened as the side bodies 331, 332 pivot about the pin 367. The side bodies move relative to each other as the elevator is opening. Fluid under pressure applied to Port 4 retracts the piston 420a.

As shown in Figures 27 and 27A, the elevator 330 is open and the piston 420a is fully retracted. As shown, e.g., in Figure 25A, an end 420e of the piston 420 has a slot 420s within which the pin 412 can move (or, put another way, the slot 420s can move about the pin 412) . The latch assembly 392 rotates and the pin

412 has a fixed location on the latch assembly 392. When the latch assembly 392 rotates, the location of a centre line of the pin 412 does not stay in line with a centre line of the piston 420. The slot 420s allows the pin 412 to move in a desired arc to accommodate motion of the piston 420. Alternatively, the piston could be mounted, e.g., linked to the side body, so it moves for such accommodation.

Figure 29 illustrates initiation of closing of the elevator 330. As Shown in Figure 29A, the piston 420 extends, rotating the assembly 392 until the projection 415 of the front hinge latch body 414 lockingly engages the roller 375a of the assembly 370, thereby preventing the assembly 392 from rotating all the way to latching and closing. Thus, as desired, the motion of the assembly 392 is limited until a later point when the part 365b is again in position to enter the groove 331a to lock the elevator. Fluid under pressure is being applied through Ports 1 and 3 to the piston 420a from the pressure system PS with a valve VA closed. Extension of the piston 420a closes the elevator 330.

Figures 30 and 3OA show the elevator 330 nearly closed as the member 365 contacts the side body 331. Part 365e of the member 365 contacts the roller 375a of the assembly 370 overcoming the spring 374 and moves the assembly 370 out of engagement with the projection 415. This allows the cylinder 420 to extend and to push the assembly 392 to rotate the assembly 392 into place. In one aspect closing is initiated by an operator pushing a button on a control console to activate a valve to apply fluid under pressure to Ports 1 and 3, or to Ports 1 - 4. Figure 31 illustrates rotation of the assembly 392 driven by the piston 420 as the elevator is closing.

Figure 32 illustrates rotation of the assembly 392 prior to latching. Figure 33 depicts latching of the elevator 330. For latching the member 365 rotates so that the projection 364 enters the recess 363a of the end 363 of the handle 362 and the gripping force of the spring 369 then pushes the projection 365b into the groove 331a. In this position, the assembly 392 is prevented from rotating out and the elevator 330 is latched. To lock the elevator 330 the pin 379 is reinstalled preventing movement of the handle 362. As shown in Figure 27 when the assembly 392 is fully retracted the top end 365d of the body 365a contacts the side body 332. This orients the member 365 in a position ready for subsequent closing. The assembly 370 is making contact with the part 365e. In proceeding to a closing step, e.g. in Figure 29, the top end 365d is no longer touching the side body 332 and the member 365 is free to rotate. A nub 353 on the latch body 414 is positioned within a groove 365f. The groove 365f is sized and located, with the nub 353 within it, so that the member 365 is prevented from over-rotating and ending up in the wrong location.

Figures 34A and 34B illustrate how abutment of shackles 230a on each side of the elevator 330 against rods 23Or - 23Ou provide for maintaining the elevator 330 in a desired orientation, e.g. as in Figures 6B (as shown in Figure 34B) and in Figure 1OB (as shown in dotted line in Figure 34B) . As shown in Figure 34B, with the shackle 230a abutting the rod 230s the elevator is maintained in the position of Figure 6B. As shown in dotted line in Figure 34B once the elevator has shifted it can go no further than the position shown in Figure 1OB due to the abutment of the shackle 230a by the rod 23Ou.