Present invention relates to an arrangement for re¬ moving drill cuttings and the like from the upper end of a control pipe projecting upwards from a sea bottom in con¬ nection with well drilling in the sea bottom, where the drill cuttings are adapted to be lifted upwardly through the control pipe as it is drilled downwardly through the sea bottom.

In offshore well drilling it is usual in the intro¬ ductory drilling phase to control the drill stem with associated drill crown through a control pipe projecting upwardly from the sea bottom. It is customary to empty drill cuttings from the upper end of the control pipe directly out over the sea bottom as one drills down in the bottom formation. It is usual that drill cuttings are built up into a conically amassed mound around the control pipe as the well drilling operation progresses. After a certain period of drilling separate removal of the mound of drill cuttings or portions of the latter is thereafter effected by means of suitable mechanical transport equipment, including the conveying of drill cuttings to a remotely disposed delivery location.

With the present invention the aim is to avoid the afore-mentioned interim emptying of drill cuttings on the sea bottom and instead to undertake a continuous removal of the drill cuttings from the control pipe directly to a remotely disposed delivery location as the drill cuttings are lifted up towards the upper portion of the control pipe. In order to be able to achieve such a solution cer¬ tain changes must be effected in the upper end of the con¬ trol pipe. According to the invention the arrangement is char¬ acterised in that the control pipe, preferably by means of an extension of the latter , - is provided with an upper end stopper member and an outlet laterally directed below the end stopper member, which is adapted to be connected to a separate discharge conduit via an intermediate pressure water-driven suction arrangement, for delivery of drill cuttings and the like directly to a remotely disposed deposit location.

By means of forcibly controlling the flow of drill cuttings from the upper end of the control pipe or an extension of the latter there is hereby the possibility according to the invention to empty the drill cuttings directly into a discharge conduit to a remotely disposed deposit location. By means of a suction arrangement in the form of an ejector arrangement one can ensure that the drill cuttings are carried along into the flow of pressure water from the ejector to the discharge conduit and are led further by means of pressure water to the deposit location. If necessary the control pipe can be adapted for direct coupling of the suction arrangement with associated equipment to same, but in practice a simpler solution is achieved by employing a cooperating, separate extension member in addition to the control pipe. According to the invention it is preferred that an extension of the control pipe designed as a housing member forms a part of a mounting unit, which is separately con-

trollable along control lines to and from a specific posi¬ tion on a base frame secured on the sea bottom, the mount¬ ing unit including guide means, which cooperate with the control lines and with equivalent control means on the base frame, for controlling the housing member into an accurately aligned position relative to the control pipe for axial coupling together of these, and that the housing member is provided uppermost with an internally arranged end stopper member and in connection with an annular cham- ber in the housing member disposed below is connected to an externally arranged suction arrangement (ejector) with associated connection to the discharge conduit.

Further features of the present invention will be evident from the following description having regard to the accompanying drawings, in which:

Fig. 1 shows in perspective a submersible mounting unit which is to be mounted on a cover-base frame on the sea bottom.

Fig. 2 shows in a corresponding perspective the mounting unit mounted in place on the cover-base frame according to Fig. 1.

Fig. 3 shows a side view of the mounting unit, illu¬ strated partly cut through.

Fig. 4 shows a plan view of the mounting unit. Fig. 5 shows a side view of the mounting unit with associated cable for hydraulic drive medium.

Fig. 6 shows a perspective view of the mounting unit.

Fig. 7 shows a side view of the mounting unit with cooperating support and control means drawn in broken lines.

Fig. 8 shows schematically a hydraulic flow diagram in connection with the mounting unit as shown in Fig. 1-7. Fig. 9 shows in part a vertical section of the mounting unit according to a first embodiment.

Fig. 10 shows in part a vertical section of the mounting unit according to a second embodiment.

Fig. 11 shows in vertical section a part of the mounting unit according to a third embodiment, equipped with a throttle valve which is shown in the open position. Fig. 12 shows the same as in Fig. 11 with the throttle valve in the closed position.

Fig. 13 and 14 show a plan view' of the throttle valve in a closed and an open position respectively.

Fig. 15 shows control means of the throttle valve and associated hydraulic coupling layout. In Fig. 1 there is illustrated a sea bottom 20 which supports a cover-base frame 21 via four end supports 22 which are anchored in a manner not shown further directly in the sea bottom 20. The base frame 21 is shown with several mutually isolated cells 23, of which two cells 23a and 23b carry their respective control arrangement 24 for controlling their respective mounting unit 25 which is to be mounted on the base frame 21. The control arrangement 24 on the base frame 21 is provided with four vertical guide means 26 which shall cooperate with four correspond- ing control means 27 on the mounting unit 25.

In Fig. 1 the mounting unit is shown during sub¬ mersion in the sea towards the base frame 21 on the sea bottom 20. Two parallel guide lines 28a, 28b are drawn from bore rig 28 (see Fig. 5) or from a bore vessel via an associated control means 27 in the mounting unit 25 to the top 26a of two diametrically opposed guide means 26. On leading the mounting unit 25 down all four control means 27 can be controlled into accurate engagement on equiva¬ lent support portions of the upper end of the associated four guide means 26.

In Fig. 2 the mounting unit 25 is shown fastened in place on the control arrangement 24 on the base frame 21.

The mounting unit 25 comprises a square frame 29 (see Fig. 3-7) which at each of the four corners carries the afore-mentioned control means 27. From the square frame 29 there extends radially inwards a series of carrier arms 29a which are rigidly connected to a hori-

zontal carrier ring 30. The carrier ring 30 is welded fast to a vertically extending, middle, pipeshaped housing mem¬ ber 31 and braced relative to the housing member 31 via a series of separated, vertical triangular plates 31' ' ' . The housing member 31 with associated carrier frame 29 and equipment, which are mounted on the latter, is adapted to be lifted and lowered as a unit via a carrier head 32 (see Fig. 3) , which is axially slidable on a drill stem 34 and which during lifting and lowering of the mounting unit is carried via a carrier ring 33 on the drill stem 34. The carrier head 32 forms in addition an upper end stopper member or sealing member in the housing member 31. In Fig. 3 the housing member 31 is shown as an extension member of a control pipe 35 projecting upwards from the sea bottom 20, the housing member 31 being threaded into place inter¬ nally in the control pipe 35, controlled via the mounting unit 25 by the control arrangement 24 on the base frame 21.

In Fig. 6 there are shown four of in all six locking means 36, which shall lock fast the carrier head 32 to the housing member 31 during lifting and lowering of the mounting unit via the drill stem 34. At the same time the locking means 36 ensure that the carrier head 32 forms an end stopper member which seals off the upper end of the housing member 31. The locking means 36 are placed with a uniform angular intermediate spacing around the upper end of the housing member 31 just below a conical upwardly directed guide flange portion 37 which forms an upper termination on the housing member 31. The locking means 36 can be operated via remotely controlled hydraulic control mechanisms. In Fig. 6 the mounting unit 25 is shown landed directly on the control pipe 35 in a support position against its upper conical end portion 35a.

In Fig. 1, 2, 5 and 6 there is shown a flexible pipe cable 38 which extends from the rig (or the vessel) down to the mounting unit 25 and which is controlled by means of control rings 39 vertically along the one guide line

28a and which is put out parallel to the putting out of the mounting unit 25. The pipe cable 38 is shown in Fig. 5 wound up on a drum 40 on a rig deck 42. The pipe cable 38 is shown passing over a guide roller arrangement 43 which is fastened to the under side of a rig deck 44 arranged above the rig deck 42. The guide lines 28a, 28b are led from their respective guide discs 45 which are suspended on the under side of the rig deck 44. The pipe cable 38 feeds pressure medium to a pressure medium distributor 38a and from this with branch conduits (see Fig. 8) to the various hydraulic units which are employed in connection with the mounting unit 25.

Just above square frame 29 of the mounting unit 25 (see Fig. 8-10) the housing member 31 is equipped with a horizontal, annular chamber-forming ring pipe section 46 which over the whole longitudinal dimension communicates with the interior of the housing member 31 via an opening 46a directed radially inwards. The ring pipe section 46 is connected via an arcuate pipe stump 47 to the one side of a primary suction valve 48 (see Fig. 8) , while the oppo¬ site side of the suction valve (48) is connected via an additional arcuate pipe stump 49 to an ejector 50 or simi¬ lar suction arrangement. Between the suction valve 48 and the ejector 50 a short circuit valve 51 is connected up in the pipe stump. Sea water is supplied via a conduit stump 52 (see Fig. 8) with associated filter 53 to the inlet to a pump 54 and sea water under pressure is led via a con¬ duit 55 to the ejector 50. The pump 54 is driven by a hydraulic drive motor 56. Just after the ejector 50 there is arranged a back pressure valve 57. The valve 57 is followed by a discharge conduit 58, which leads to a re¬ motely disposed emptying location, for example in connec¬ tion with a separately arranged cuttings deposit (not shown further) formed for example as a container made of concrete.

In Fig. 8 there are illustrated hydraulic control conduits 59a, 59b from the distributor 38a to the drive motor 56, control conduits 60a, 60b to the valve 48, con¬ trol conduits 61a, 61b to the valves 57 and 51, a connec- tion conduit 62 between the valves 57 and 51 and a common connection conduit 63 between the connection conduit 62 and the one control conduit 60b to the valve 48. Corre¬ spondingly there is shown a branch conduit 64 from the control conduit 60b with additional branch conduits 64a, 64b, 64c to the illustrated hydraulic locking means 36, which shall lock fast the carrier head 32 to the housing member 31. In addition branch conduits 65a-65c extend from the locking means 36 to a common control conduit 66.

In Fig. 2 there is shown a separate control line 67 from the rig to an anchor 68 arranged at discharge end 58a of the discharge conduit 58.

Carrier head 32 of the housing member 31 is further illustrated in Fig. 9 and 10. An inner vertical sleeve portion 71 forms with its lower horizontal surface 71a a support against the carrier ring 33 on the drill stem 34, while an outer vertical sleeve portion 72 with an oblique surface 72a forms a supporting abutment against an equiva¬ lent oblique surface 37a in the upper guide surface 37 of the housing member 31. The cylindrical peripheral surface of the sleeve portion 72 is provided with a first, axially extending, slot-shaped control groove 73 for the reception of a spring-loaded control member 74 fastened on the housing member 31 so as to prevent mutual turning of the carrier head 32 and the housing member 31. The one of the afore-mentioned six locking means 36 is shown with asso¬ ciated locking bolt 36a in engagement with a lock member- forming cavity 75 in the sleeve portion 72. The sleeve portion 71 is provided with a thick-walled fastening flange 76 directed radially outwards, while the sleeve portion 72 is provided at its upper end with a more thin- walled fastening flange 77 directed radially inwards. The fastening flange 77 spans an annular gap between the

sleeve portions 71 and 72 and is fastened with fastening bolts 78 and associated fastening nuts 79 to overlapping fastening flange 76 of the sleeve portion. The thin-walled fastening flange 77 is supported with suitable inter- mediate spaces by means of vertically extending triangular plates 80 which project radially inwards from the inner surface of the sleeve portion 72. In Fig. 9 and 10 the ring pipe 46 is shown arranged radially just outside the carrier ring 33. The square frame 29 of the mounting unit 25 is, as shown in Fig. 9, welded fast to an upper section 31a of the housing member 31, resting against an annular flange 81 at the lower end of the section 31a. A lower section 31b of the housing member 31 carries an equivalent annular flange 82 which is fastened with bolts 83 to the flange

81. The annular flange 82 is braced by means of vertically extending triangular plates 84 which are shown resting against a conical lead flange 35a at the top of a surroun¬ ding upper portion of the control pipe 35 projecting up- wards from the sea bottom. It is possible in a ready manner to leave the housing member section 31b internally in the control pipe 35 while remaining portions of the mounting unit 25 are drawn upwardly again to the rig, so that the control pipe 35 is ready for installing of other drilling equipment in connection with a riser pipe and the like.

In Fig. 10 an alternative solution is shown of the solution according to Fig. 9 in connection with ready dis¬ mounting of the mounting unit 25 (with exception of the lower section 31b') from the control pipe 35 projecting upwards from the sea bottom. According to Fig. 10 the lower section 31b' is made with a thick-walled con¬ struction and rests with a collar portion 86 against an annular-cavity 35b at the upper end of the control pipe 35. In an equivalent annular cavity 87 internally in the collar portion 86 there is fixed, in a separately releasable manner, not shown further, a thin-walled guide

pipe 88 having an upper funnel-shaped guide flange 88a which is arranged just below the ring pipe 46. The guide pipe 88 is fastened by means of an annular flange 89 which forms a supporting abutment against upper surface 86a of the collar portion 86 to the annular flange 81 of the upper housing member section 31a with bolts 83 for releasing the guide pipe 88 and the thick-walled lower section 31b' from the mounting unit 25.

In an embodiment as shown in Fig. 11-15 the carrier head 32 as illustrated in the embodiments in Fig. 1-10 is replaced by a throttle valve 90. The throttle valve 90 can have the same carrier function and the same end stopper function as the carrier head 32 according to Fig. 1-10. In the locked position the throttle valve 90 can form a sup- porting abutment against the carrier ring 33 on the drill stem 34. Two throttle valve plates 90a and 90b are shown which are moveable towards and away from each other rela¬ tive to the inner hollow space of the housing member 31 by means of a pair of hydraulic pressure cylinders 91a, 91b. The throttle valve plates 90a, 90b pass through a guide gap 92 which is defined between an upper section 31' and a lower section 31'' of the housing member 31 across the latter. The sections 31' and 31'' are combined with each other into a coherent unit by means of transition portions 93a and 93b, as shown in Fig. 13 and 14 and which are extended with flange portions 94a, 94b fastened to their respective sections 31', 31''. The plates 90a, 90b are fastened at the one end to their respective cross stays 95a, 95b by means of hydraulically operated locking means 96, while at opposite ends they are provided with a pair of control pins 97a, 97b which in the closed position of the throttle valve plates engage with equivalent guide- forming cavities in the opposite cross stay 95a and 95b respectively. Between the control pins 97a, 97b the plates extend with a V-shaped cavity 90c and in the closed posi¬ tion of the plates V-shaped cavities of the plates define a substantially circular opening 90c for reception of the

drill stem 34. In the open position of the plates the whole pipe cross-section is exposed as shown by the guide surface 37 for unhindered carrying through of drill stem with drill crown and remaining equipment. The cross stays 95a, 95b are separately fastened with opposite brackets 98 to a cross bar 99 which is connected to cylinder member 91a' , 91b' of the pressure cylinders 91a, 91b and to pis¬ ton member 91a", 91b" of the pressure cylinders respect¬ ively. In Fig. 15 two control conduits 100a and 100b are shown for controlling the respective opening and closing of the throttle valve plates. In the control conduit 100a which controls the opening of the throttle valve plates there is inserted a back pressure valve 101 within the control conduit branching off into branch conduits 102a, 102b to the one end of their respective cylinder member 91a ⁷ , 91b'. The control conduit 100b branches off into branch conduits 103a, 103b to the other end of their re¬ spective cylinder 91a, 91b. A pair of branch conduits 104a, 104b are shown from the conduit 100a to the one locking means 96a and a branch conduit 104c from the con¬ duit 100a to the other locking means 96b. The locking means 96a, 96b are held in the locking position by their respective compression spring 105 in an associated chamber 106 which is in connection with a common drainage conduit 107.