| CLAIMS The clamed invention is: 1. A method for diverting a flow of oil from a pipe of an oil well, comprising extending a tube having first and second openings through a wall of the pipe so that the tube is positioned between first and second portions of the pipe to divert flow of the fluid, from a portion of the flow region along the first portion of the pipe, into the first tube opening and through a portion of the tube and out the second tube opening. 2. The method of claim 1 wherein positioning of the tube diverts a majority of the oil flowing through the first portion of the pipe into the tube instead of into the second portion of the pipe. 3. The method of claim 1 wherein the step of extending the tube through the wall of the pipe includes cutting through the wall to remove a portion of the wall and then extending the tube through an opening which results from removal of the portion of the wall. 4. The method of claim 3 wherein extending the tube includes cutting completely through two opposing portions of the pipe wall and then extending the tube through two openings in the wall to extend the tube completely through the wall. 5. The method of claim 3 wherein cutting results in removal of a disk shaped portion of the wall. 6. The method of claim 3 wherein the tube includes first and second opposing end portions and a central axis extending between the end portions, the method including configuring the tube with a circular saw positioned about the first end portion and about the central axis of the tube, wherein the step of cutting through the wall is performed by rotating the circular saw. 7. The method of claim 6 further including applying a force which presses blades of the saw against the wall of the pipe and moves the tube through the wall of the pipe as a first hole is cut through the wall. 8. A cutting assembly for diverting a flow which would otherwise pass through a segment of a pipe or out of the pipe, comprising: a tool, configured to cut through a wall of the pipe, the tool having a body portion, an aperture interior to the body portion and first and second opposing end portions positioned along a central axis, the first end portion including an opening to the aperture through which diverted flow may pass and a set of cutting blades about the opening suitable for cutting through the wall, the second end portion including a coupling arrangement for connection to effect movement of the tool, the body portion including a port positioned between the first and second end portions to provide a flow path from outside the body, through the port, along the aperture and out the first end portion. 9. The assembly of claim 8 further including a drive system connected to the second end of the tool, the drive system configured to effect both rotation of the cutting teeth about the tool axis and displacement of the body portion along the tool axis whereby a combination of the rotation and displacement of the body portion facilitate penetrating the pipe wall with the cutting blades. 10. The assembly of claim 9 wherein the drive system enables displacement of the tool a sufficient distance into the pipe to position the port over a portion of the pipe to receive the flow for passage through the aperture and out the opening of the first end portion. 11. The apparatus of claim 10 wherein, with the pipe extending in a first direction, the apparatus is configured for attachment to the pipe wall with the drive system positioned to displace the body portion in a direction perpendicular to the first direction. 12. A method for diverting a flow which would otherwise pass through a first segment of a pipe and into a second segment of the pipe or out of the pipe, comprising: cutting through a portion of a wall of the pipe; providing a tubular body having an aperture therein which extends along an axis and between first and second opposing ends of the tubular body, the tubular body including a port; and positioning the port of the tubular body to receive the flow from the first segment of the pipe and divert the flow into the aperture. 13. The method of claim 12 further including passing the diverted flow through the first end. 14. The method of claim 12 wherein the step of cutting is performed by rotating a blade. 15. The method of claim 12 wherein the tubular body includes a cutting blade positioned about the axis and cutting is performed by rotating the blade about the axis while applying a force with a linear actuator to move the blade in a direction along the axis and apply a force which pushes the blade against the pipe. 16. The method of claim 14 wherein a combination of rotating and displacing the blade facilitates penetrating the pipe wall with the blade and displacing the port within the flow emanating from the first pipe segment. 17. The method of claim 16 wherein cutting and rotating are effected by coupling a drive system to the tube wherein the drive system is configured to effect both rotation of the cutting teeth about the tool axis and displacement of the body portion along the axis whereby a combination of the rotation and displacement of the body portion facilitate penetrating the pipe wall with the blade and extending the tool a sufficient distance into the pipe to position the port over a portion of the pipe to receive the flow for passage through the aperture and out the opening of the first end portion. 18. A cylindrically shaped tool having first and second end portions along a central axis, the tool including: a set of cutting blades about the first end portion; and a shaft positioned about the second end and extending away from the first end portion by which rotation of the cutting blades is effected with rotation of the shaft, the tool is attached to a shaft tool to effect rotation about the axis. |
OF OIL FROM A WELL HEAD
Priority Based on Related Application
[001] This application claims priority from U.S. Provisional Application No.
61/354,888 filed June 15, 2010.
Field of the Invention
[002] The present invention relates to systems and methods for mitigating uncontrolled flow of oil through walls, including walls of pipes and, more
specifically, to provision of an alternate path by which an uncontrolled or undesired flow of oil can be mitigated or diverted. In one series of embodiments the inventive concepts are applicable to mitigation of uncontrolled flow of oil or gas from an underwater well bore, particularly in relation to underwater well heads.
Background
[003] It is imperative to prevent and mitigate oil well blowouts because they present great risk to human life and damage the environment. These and other types of spills pose large environmental clean-up costs and socio-economic upheaval. The problems are particularly acute when uncontrolled flow results from off-shore oil wells. It has been generally established in the petroleum industry that a series of large valve systems, termed a blowout preventer, should be positioned in-line with the wellhead to provide primary and secondary systems to stop the flow of oil under blowout conditions. Blowout preventers may be regarded as failsafe designs in a limited sense. That is, when one valve system fails to actuate as intended, one or more secondary valve systems or prevention mechanisms are available as back-ups to reduce the risk that uncontrolled flow will continue unabated. This, of course, presumes that standard inspections and established procedures are followed and that the valves are properly maintained.
[004] With occurrence of human fatalities and economic and environmental disasters due to uncontrolled spills, additional solutions should be made available which quickly seal well bores and other flow paths in the event a blowout preventer malfunctions or when a spill occurs due to other causes. With respect to well bores, a number of conventional approaches are available to close the well when a pipeline rupture occurs or the blowout preventer malfunctions, these including use of a containment dome, connection of a riser insertion tube, or injection of dense material into the blowout preventer followed by sealing the well with cement. As one example, it has at times been effective to counter the pressure at the well head to perform what is referred to as a top kill. In this procedure dense material is pumped down the drill string or through a secondary line which bypasses the blowout preventer. The resulting downward pressure can prevent upward movement of oil and gas. The foregoing solutions have, at times, been effective in particular contexts, but none of these have provided a universal solution to rapidly abate the toxic flow of petroleum products into bodies of water.
Summary of the invention
[005] In the past, it has been proposed to close underwater oil spills by covering or filling the bore hole with dirt or small particles. The process is based on recognition that forces from the well head can, at least in part, be offset with the weight of material sent down an overlying pipeline under pressure. The effectiveness of such a process is seen to be limited. For example, particles used to cover a well head may easily be flushed away by the continued movement of petroleum through the well head with the resulting drag forces on the injected material. According to
embodiments of the invention, a more effective procedure utilizes a mechanism to divert flow of the oil away from a ruptured region instead of plugging the bore hole. Accordingly, a solution is provided to close underwater oil spills or leaks based on diversion of the flow of oil. In one example, an alternate path for the flow is created. In one system for doing so a segment of a pipeline structure is modified to incorporate tools and an alternate flow path to mitigate the uncontrolled flow of the oil.
[006] According to one series of embodiments of the invention, a method is provided for diverting a flow of oil from a pipe of an oil well. A tube having first and second openings is extended through a wall of the pipe so that the tube is positioned between first and second portions of the pipe to divert flow of the fluid. The flow from a portion of the flow region along the first portion of the pipe is diverted into the first tube opening and through a portion of the tube and out the second tube opening.
[007] According to another series of embodiments a method is provided for diverting a flow which would otherwise pass through a first segment of a pipe and into a second segment of the pipe or out of the pipe. The method includes cutting through a portion of a wall of the pipe, providing a tubular body having an aperture in the pipe. The body extends along an axis and between first and second opposing ends of the tubular body. The tubular body includes a port which is positioned to receive the flow from the first segment of the pipe and divert the flow into the aperture.
[008] There is also provided a cylindrically shaped tool having first and second end portions along a central axis. The tool includes a set of cutting blades about the first end portion and a shaft positioned about the second end, extending away from the first end portion, by which rotation of the cutting blades is effected with rotation of the shaft.
[009] In still another series of embodiments, a cutting assembly is provided for diverting a flow which would otherwise pass through a segment of a pipe or out of the pipe. The assembly includes a tool, configured to cut through a wall of the pipe, the tool having a body portion, an aperture interior to the body portion and first and second opposing end portions positioned along a central axis. The first end portion includes an opening to the aperture through which diverted flow may pass and a set of cutting blades about the opening suitable for cutting through the wall. The second end portion includes a coupling arrangement for connection to effect movement of the tool. The body portion includes a port positioned between the first and second end portions to provide a flow path from outside the body, through the port, along the aperture and out the first end portion. Brief Description of the Figures
[0010] Figure 1 A is a perspective view of a diverter tube according to the invention taken along a major axis thereof;
[0011] Figure IB is a view in cross section of the diverter tube shown in Figure 1A;
[0012] Figure 1C is a view of a first end of the diverter tube shown in Figure 1A;
[0013] Figure ID is a perspective view of a housing for a rotational motor drive unit incorporated in an assembly according to the invention;
[0014] Figure 2 A is an exploded view of an apparatus according to the invention incorporating the diverter tube of Figures 1 for positioning about an underwater pipe structure 70;
[0015] Figure 2B is a view in cross section which further illustrates components of the apparatus shown in Figure 2A;
[0016] Figure 2C is a partial cut-away view of the apparatus of Figure 2B having coupled ends of sections clasped about the pipe structure shown in Figure 2A;
[0017] Figure 2D is a perspective view illustrating coupled ends of sections of the apparatus shown in Figure 2C;
[0018] Figure 2E is a side view of the coupled ends shown in Figure 2D in an unclasped configuration;
[0019] Figure 2F illustrates an arrangement of cables attaching the apparatus to the structure of Figure 2A during installation of the apparatus;
[0020] Figure 3A illustrates holes formed in opposing positions along a wall of the underwater pipe structure shown in Figure 2A after passage of a saw through the structure;
[0021] Figure 3B is a view, from below the holes shown in Figure 3 A, of the pipeline structure illustrating positioning of an inlet port of the diverter tube 10 shown in Figures 1 and 2 relative to the pipeline walls;
[0022] Figure 4 is a perspective view illustrating a chamber in an open configuration, showing an end of a frame assembly fitting against a pipeline structure;
[0023] Figure 5 is a perspective view of the chamber shown in Figure 4 in a closed configuration about the pipeline structure; [0024] Figure 6A illustrates a system, including the chamber shown in Figure 5 and a frame assembly for cutting through the pipeline structure and diverting flow of oil according to an alternate embodiment of the invention;
[0025] Figure 6B is a view taken along line B - B of Figure 6 A illustrating attachment of an end of the frame assembly to the pipeline structure;
[0026] Figure 6C is a view in cross section taken along line C - C of Figure 6A illustrating details of a coupling attached to a rail;
[0027] Figures 7A and 7B each provide a perspective view of a diverter tube having a circular saw at one end and a flat bar extending across the portions of the body at an opposing end with a shaft coupler attached to the flat bar for alignment between the shaft and the saw;
[0028] Figure 8A provides an end view of the coupler shown in Figures 7;
[0029] Figure 8B provides a side view of the coupler shown in Figure 8A attached to both a diverter tube and a motor shaft;
[0030] Figure 9 illustrates an alternate arrangement wherein a portion of frame assembly shown in Figure 6A which extends away from the chamber includes bypass relief valves and a flanged end for coupling the assembly to a new riser pipe to direct diverted oil to the water surface for recovery; and
[0031] Figure 10 illustrates another embodiment of a method and apparatus according to the invention.
[0032] In accord with common practice, the various described features may not be drawn to scale, but are drawn to emphasize specific features relevant to the invention. Like reference characters denote like elements throughout the figures and text.
Detailed Description of the Invention
[0033] The following description is exemplary and not limiting of the inventive concepts disclosed. The term bore as used herein refers to the hollow part of a tube or pipe without regard to how the hollow part is formed. It is also noted that various movements and activities described herein can be performed with well known robotic systems which may be remotely controlled. [0034] Embodiments of the invention include systems and methods for diverting or mitigating an undesirable flow which can cause environmental or economic damage. The following examples are provided in the context of an uncontrolled flow of oil from an underwater well to mitigate a flow into a body of water. The flow may result from breakage in the wall of a pipeline or failure of a blowout preventer. A feature according to embodiments of the invention is an ability to divert most or all of the flow passing through the bore of the pipeline (i.e., the region interior to the pipeline wall) before the flow reaches a ruptured portion of the pipeline and thereby limit or completely prevent flow of the oil into the body of water.
[0035] A method of intervention which so diverts the flow includes placement of a bypass channel adjacent or through the pipeline. Generally, the bypass tube has an inlet port for receiving flow into an interior hollow section of the tube, referred to herein as an aperture, and an outlet port through which the flow exits the aperture. The inlet port, the aperture and the outlet port are in fluid communication with one another, thereby forming the bypass channel.
[0036] In the following examples, a bypass tube is inserted through the wall of a pipeline. The tube may, for example, have a wall which is cylindrical in shape and first and second ends positioned along a central axis. The cylindrical wall defines the aperture and the inlet port is formed through the cylindrical wall. The first end of the tube is open and the corresponding opening at the first end of the tube serves as the outlet port. The flow of oil may be diverted by positioning the inlet port in line with the bore of the pipeline to cut off flow to the ruptured region and send the flow through the bypass channel.
[0037] With reference to Figure 1A there is shown a diverter tube 10 suitable for practicing several embodiments of the invention. According to these embodiments, the tube 10 is multi-functional, serving as a tool to cut through a wall in a pipe structure and providing a bypass channel to divert flow of fluid otherwise passing through a damaged portion of the pipe structure. The tube 10 is illustrated as a body having a cylindrically shaped wall 14 defining an aperture 16 within the wall 14. An axis 18 central to the wall 14 extends between first and second opposing end regions 20, 22. The wall 14 includes an inlet port 28 which provides an entry opening to the aperture 16. An outlet port 30 is positioned in the end region 20 of the tube 10, e.g., an open end of the tube 10. Fluid flowing into the inlet port 28 to the aperture 16 exits the aperture 16 through the outlet port 30. In this regard, the second end region is sealed to prevent fluid flowing through the aperture from exiting through the second end region 22. A series of cutting blades 34, arranged as a circular saw 36, are positioned about the first end region 20. In this example the blades 34 are positioned on an edge 38 of the wall 14 which defines the outlet port 30. The blades 34 are oriented to cut in a direction parallel with the axis 18.
[0038] Figure IB is a view in cross section of the diverter tube 10 taken along a plane passing through the axis 18. The aperture 16 is closed in the end region 22 with a sealing plate 42 welded to the side of the wall 14 within the tube. Placing the sealing plate in the end region prevents fluid passing through the aperture 16 from exiting the tube 10 through the end region 22. A shaft 44, positioned on the axis 18, is mounted to the sealing plate 42 to couple the tube 10 to a drive system which imparts linear displacements in directions along the axis 18 and rotational motion about the axis 18. Movement of the diverter tube provides a force to press the blades 34 against a wall of a pipeline while the blades 34 are rotated to provide a sawing action which cuts a hole through the pipeline wall. With the drive system configured to effect both rotation of the cutting blades 34 about the tube axis 18 and displacement of the body portion along the tube axis 18, the combination of rotation and displacement of the body portion facilitates penetrating the pipe wall with the circular saw 36 and then extending the tube 10 a further distance into or through the pipeline. This allows positioning of the inlet port 28 over a portion of the pipeline, in line with the bore of the pipeline, to send a flow of oil through the bypass channel.
[0039] In addition to having the inlet port 28 formed through the wall 14, the tube 10 includes a series of pressure relief holes 50 formed in the wall 14 between the inlet port 28 and the cutting blades 34 which enable flow of oil across the axis 18 of the tube 10 to continue flow of oil through the bore of the pipeline as the tube 10 is used to cut into the walls of the pipeline. The relief holes can reduce the force associated with the pressure of flowing oil exerted against surfaces of the tube, which forces could counter the forces applied to displace the tube into and through the pipeline bore. [0040] Figure 1C is a view of the end region 20 of the diverter tube 10 taken along the axis 18 to illustrate a grate 54, also shown in Figure IB, positioned in the aperture 16 between the circular saw 36 and the inlet port 28. The grate 54 comprises slots or other shaped apertures 58 such as the illustrated squares formed with metal bars 62, which prevent relatively large debris, resulting from cutting with the blades 34, from flowing through the aperture 16 and out the inlet port 28 before the port 28 is placed in line with the pipeline bore to divert the flow of oil.
[0041] With reference to the exploded view of Figure 2A and the view in cross section of Figure 2B an apparatus 60 incorporates the diverter tube 10. Figure 2 A illustrates an underwater pipe structure 70 having experienced a rupture in a region 72 from which there is an uncontrolled outpouring of oil 74 into surrounding water. For simplicity of illustrating the invention, the rupture is shown as a complete break where a segment (not shown) of the pipe structure 70 has been completely severed. However, the rupture may be any of a wide variety of types which can result from damage to, or malfunction experienced at, any position near or above a well head, or at, above or below a blowout preventer. The rupture may result from partial detachment of a portion of the pipeline structure or a loss in the integrity of a wall portion or a joint in the structure. The illustrated pipe structure 70 may comprise two concentrically positioned pipes, e.g., a cylindrical outer pipe wall 70a which functions as a casing positioned about a cylindrical inner pipe wall 70b which may normally carry a flow of oil 74. The outer pipe wall 70a may have an inside diameter on the order of 20 inches (51cm) and the inner pipe wall 70b may have an inside diameter on the order of 9 inches (23 cm). When a rupture occurs along the inner pipe wall 70b it is possible for the oil 74 to flow along the outer pipe wall 70a, thereby requiring containment of flow passing along both pipe walls 70a and 70b. Although not illustrated, it is also noted the drill bit used to open the well may remain in the inner pipe 70b, rendering it relatively difficult to close a rupture in the inner pipe 70b by bending or crimping the pipe wall 70b.
[0042] The apparatus 60 is exemplary of numerous designs which enable cutting into or through a pipe structure to divert a flow of oil. In this embodiment oil 74 passing from a first segment 76 of the pipe structure 70 is diverted through the tube 10 to prevent the oil 74 from passing into a damaged segment 78 of the pipe structure and out from the ruptured region 72. A two part frame assembly comprising tube-shaped sections 80, 82 having flanged ends 86, 88 houses several working components of the apparatus 60. The flanged ends are joined together to couple the sections 80, 82 into one unit. The section 80 houses a linear actuator 90 having a piston 92 extendable into the section 82. A cylindrically shaped wall 94 of the section 82 is of a diameter, D, which is sufficient to house the diverter tube 10 for movement along the interior of the wall 94 based on movement of the piston 92. In this arrangement of working components, the axis 18 of the diverter tube 10 is substantially co-aligned with a central axis of the cylindrically shaped wall 94 of the section 82. With the sections 80 and 82 co-aligned with one another and the diverter tube, as shown in the figures, reference to the axis 18 in Figures 2 also denotes an axis central to the sections 80 and 82 which passes through and beyond the pipe structure 70. The view in cross section of the apparatus 60 shown in Figure 2B is taken through the axis 18. The pipe structure 70 is illustrated as vertical in orientation with the axis 18 perpendicular to the pipe structure 70. The sections 80 and 82 are perpendicular to the vertical orientation of the pipe structure 70.
[0043] A partial cut-away view of the apparatus 60 coupled to the pipe structure 70 is shown in Figure 2C. A hydraulic motor 96 is affixed to the wall 94 for sliding engagement along the axis 18. The motor 96 drives the shaft 44 which is
mechanically coupled to the sealing plate 42 of the diverter tube 10 to effect rotation of the circular saw 36. The motor 96 is mounted in a housing 98, shown in Figure ID, having a pair of guides 100 (e.g., in the form of rectangular-shaped flanges) positioned along opposing sides of the housing 98. A pair of tracks 102 are positioned along opposite sides of the wall 94 in the interior of the tube-shaped section 82. Each track 102 is positioned to receive one of the guides 100 of the motor housing 98. The piston 92 of the actuator 90 is attached to a side 104 of the motor 96 opposite the side to which the shaft 44 is connected to the motor 96. Hydraulic lines (not shown) are configured to effect movement of the piston 92 and rotation of the motor 96 and shaft 44.
[0044] An end 108 of the tube-shaped section 82, opposite the flanged end 86 is attachable to the pipe structure 70. The apparatus 60 further includes a tube-shaped section 106 having opposing ends 112 and 114. The end 112 is attachable to the pipe structure 70. The section 106 has a cylindrically shaped wall 116 having an inside diameter, comparable to or larger than the diameter, D, of the wall 94 of the section 80 in order to receive the diverter tube 10 when the diverter tube 10 is displaced through the pipe structure and into the section 106 based on movement of the piston 92. The central axis of the cylindrically shaped wall 116 of the section 106 is substantially co-aligned with the axis 18 so that the tube-shaped section 106 is positioned to receive the diverter tube 10 and a flow of oil 74 as provided by the diverter tube 10 for delivery through the end 114 for collection.
[0045] As shown in Figures 2B and 2C, the apparatus 60 is attached to the pipe structure 70 by coupling the ends 108 and 112 of the sections 82 and 106 around the pipe structure 70 and fastening the ends 108 and 112 together. In the illustrated embodiment, the ends 108 and 112 are bodies having portions 118 and 120, approximately semi-cylindrical in shape, which may be clasped about the structure 70. The end 108 includes an opening 122 and the end 112 includes an opening 126. The openings 122 and 126 are each of a diameter, D, or larger. When the ends 108 and 112 are clasped about the structure 70 the openings 122, 126 are each centered about the axis 18 in order to receive the diverter tube 10 therethrough. See, also, Figure 2D.
[0046] The end 108 has a pair of flanged side edges 130, 132 which each extends along a major axis of the semi cylindrical body portion 118. The end 112 has a pair of flanged side edges 140, 142 which each extends along a major axis of the semi cylindrical body portion 120. The flanged side edges 130, 140 are in a hinge plate configuration having interdigitated members 130a and 140a in a mating arrangement. Each of the edge members 130a, 140a includes an aperture for receiving a hinge pin. With the edge members brought together in an interdigitated manner, the apertures are aligned and a pin 144 extends through the apertures of all of the members thereby hinging the ends 108 and 112 to one another in a clam shell arrangement.
[0047] The flanged side edges 132, 142 each have a set of bolt holes 148. When the semi cylindrical body portions 120 are rotated around the hinge pin 144 to enclose a portion of the pipe structure 70, the holes 148 in different edges become aligned with one another in order to pass fasteners (e.g., bolts 150) through pairs of the holes 148 and tightly secure the ends together (e.g., with nuts 154). See, again, Figure 2C. In other embodiments the flanged side edges 132, 142 may also be in a hinge plate configuration having interdigitated members 130a and 140a in a mating arrangement coupled together with another pin 144.
[0048] With the flanged side edges 132, 142 secured to one another with bolts 150 and nuts 154, a compressible seal material 160 (e.g., a polymer) is applied or otherwise positioned over the concave inner surfaces 162 of the ends which would otherwise come into direct contact with the pipe structure 70. See the side view of the Figure 2E. The use of fasteners such as bolts and nuts may be preferred in order to compress the material 160 and form a tight seal at the interface between each of the ends 108, 112 and the pipe structure to prevent oil 74 from escaping through the interfaces once the circular saw 36 penetrates walls of the structure 70. A gate valve 166 is positioned to control flow of diverted oil passing through the end 114 of the tube section 106.
[0049] The apparatus 60 can be positioned about the pipe structure 70 with remotely operated robotic equipment after the pre-assembled apparatus is lowered to the vicinity of the structure. Figure 2F illustrates an arrangement of chain segments 170 which can attach the apparatus to the structure 70. In this example, collars 172 are two piece ring-type clamps which are placed above and below the intended location of the apparatus. Each collar 172 includes a pair of eyelets or clamps 176 to which one end of a chain segment 170 is affixed. The other end of each chain is affixed to a similar eyelet or clamp 178 mounted on one of the sections 108, 112.
[0050] According to one method for diverting a flow of oil from a riser pipe of an oil well, the apparatus 60 is lowered as a pre-assembled body with, for example, cables attached to the illustrated chain segments. Each of the four chain segments 170 may be attached to a different cable to provide sufficient ability to both control and lower the apparatus 60 to a desired location and to then orient the apparatus 60 in a desired position for connection to the pipeline structure. The apparatus may be lowered with the ends 108, 112 of the segments 82 and 106 arranged in a closed position, i.e., with the flanged side edges 132, 142 coupled to one another with bolts 150 and with the flanged side edges 130, 140 either hinged together or coupled together with bolts 150. Lowering the apparatus in this configuration may reduce stresses on hinged members and provide greater control over movement of the apparatus as it is lowered. [0051] Once the apparatus is positioned near the desired location about the pipeline structure 70, one of the collars 172 is installed about the first segment 76 of the pipeline structure 70 and the other collar 172 is installed about the second segment 76 of the pipeline structure 70. The positions of the collars can be adjusted and the chain segments can be tensioned to stabilize the apparatus 60 about the pipeline structure 70 in a manner which permits closing of the ends 108, 112 around the pipeline structure as shown in Figures 2C and 2F. Next, the ends 108, 112 are tightly clamped about the structure 70 with the aid of the bolts 150 such that the wall 116 of the section 106 is aligned along the axis 118 with the wall 94 of the section 82. At this point of installation of the apparatus 60, or after the diverter tube is extended through the walls of the pipeline structure 70, a riser line (not shown in the figures) can be attached to the gate valve 166 to capture and send diverted oil to the water surface for collection in, for example, a tanker. Next, with the gate valve 166 in a closed position, the linear actuator 90 and the motor 96 are hydraulically powered to displace the end region 20 of the diverter tube 10 toward and against the pipeline structure and turn the circular saw 36 to initiate a cut through the pipeline walls 70a and 70b. As shown in a cross sectional view taken along the axis 18 and through the structure 70, Figure 3 A illustrates holes 120 and 122 formed in opposing positions along the pipeline wall 70a after passage of the circular saw 36 therethrough. Dashed lines 124, 126 indicate disk or circular shaped portions of the wall 70a which have been removed. With the diameter of the circular saw 36 exceeding the outside diameter of the wall 70b, a complete section 128 of the wall 70b is removed as indicated by dashed lines. Once the wall portions 124, 126 and 128 are cut they can be flushed through the section 82 and out the valve 166 before a riser line (not shown in the figures) is attached to the gate valve 166 for collection of the diverted oil 74.
[0052] Figure 3B is a view of the pipeline structure from below the holes 120, 122, 124 and 126, illustrating positioning of the inlet port 28 of the diverter tube 10 in approximate alignment with the pipeline walls 70a and 70b.
[0053] Once the diverter tube 10 is finally positioned as shown in Figure 3B, and with a riser line (not shown) connected to the gate valve 166, with gate valve in an open position, the flow of oil 74 is diverted through the gate valve for collection.
Positioning of the tube 10 diverts a majority of the oil 24 flowing through the first segment 76 of the pipeline structure out of the second opening of the diverter tube 10 instead of into the damaged segment 78 of the pipe structure and out from the ruptured region 72.
[0054] Figures 4 - 9 illustrate an alternate embodiment of the invention. With initial reference to Figures 4 and 5, there is shown a two piece chamber 200 designed to close about the underwater pipe structure 70, also referred to herein as a well pipe or a marine riser pipe. The chamber 200, which is filled with a relatively impervious material such as concrete, is simply shown as a box structure which may formed of welded steel, being nominally two meters on each side, but the chamber could be cylindrical or otherwise shaped. The chamber comprises two like sections 202 and 204 that are hinged together. Hinges 210 are positioned to connect the sections together along an edge 214 of the section 202 and along an edge 216 of the section 204 so that the two sections can close about the pipe structure 70. In the closed configuration an edge 220 of the section 202 is brought together with an edge 222 of the section 204 and, for example, fork and blade closing latches 230 through which pins 232 are inserted, secure the chamber in the closed configuration.
[0055] Each of the sections 202, 204 has, formed in both an upper side 240 and a bottom side 242 thereof, a semi-circular hole 246 positioned such that when the chamber is closed a first hole 248 is provided about the center of the upper side 240 and a second hole 248 is provided about the center of the bottom side 242 having a diameter approximately the same as that of the pipe wall 70a. Accordingly, the hinged sections 202 and 204 can be closed about the pipe structure 70 as shown in Figure 2. Referring also to the schematic illustration of Figure 6A, the chamber 200 also includes an inlet port 236 for receiving the relatively impervious material, e.g., cement, and an outlet port 238 from which water or other fluid may exit the chamber as, for example, cement flows into the chamber 200 prior to curing into concrete.
[0056] One section 204 of the chamber 200 has welded to it a frame assembly 250 in the form of a cylindrically shaped housing having first and second ends 251, 252. An edge 253 at the end 251 of the housing has a contour which fits against the cylindrical wall 70a. That is, the contour of the edge 253 is patterned to mate with the cylindrical shape of the wall 70a so that the end 251 can fit snugly against the exterior surface of the wall 70a. See Figure 6B. The end 251 extends through a wall 254 of the chamber 200 a predetermined distance such that the edge 253 contacts or nearly contacts the wall 70a. A seal material 255 is placed about the interface between the edge 253 and the wall 70a of the pipe structure 70 to prevent intrusion of cement into the interior of the frame assembly.
[0057] With the pipe structure 70 having a vertical orientation with respect to the sea floor, the frame assembly 250 has a horizontal orientation with respect to the pipe structure 70 when attached to the chamber 200. That is, with the frame assembly 250 extending through the wall 254, a portion of the cylindrically shaped housing adjacent the wall 254 is welded to the wall 254 to secure the position and orientation of the frame assembly 250. To effect greater stability under loads, supports, e.g., gussets, may be welded between the wall 254 and the assembly 250.
[0058] With further reference to Figure 6A, the chamber 200 and the frame assembly 250 are part of a larger system 255 which comprises cutting equipment to bore through the pipe structure 70. The system 255 comprises a hydraulic actuator 256 fixedly mounted on a rail 257. The rail is welded with gussets to the same wall 254 of the chamber 200 to which the frame assembly 250 is welded. The rail 257 is also of a horizontal orientation with respect to the pipe structure 70, extending to the chamber wall 254 and parallel with the frame assembly 250. The rail 257 is in the shape of a "T", providing a track surface 258 along which the hydraulic actuator 256 displaces a hydraulic motor 259 toward or away from the pipe structure 70. The view of Figure 6C illustrates a coupling unit 260 securely positioned about flanges 257F of the rail 257, attaching the motor 259 to the "T" rail for sliding engagement along the surface 258.
[0059] With reference also to Figure 7 A, a diverter tube 270 serves as a tool to cut through a wall in the pipe structure 70 and also provides a bypass channel to divert flow of oil otherwise passing through a damaged portion of the pipe structure. The tube 270, as further illustrated in Figure 7B, includes a body portion 272 having a cylindrically shaped wall 274 defining an aperture 276 within the wall 274. An axis central to the wall 274, corresponding to the axis used with reference to the tube 10 and the apparatus 60, is also referred to as axis 18. The axis 18 extends between first and second opposing end regions 277, 278 of the tube 270. The wall 274 includes an inlet port 280 which serves as an entry opening to the aperture 276. An outlet port 282 is positioned in the second end region 278 of the tube 270, e.g., one of two open ends of the tube 270 positioned along the axis 18. Another port 286 is positioned in the first end region 270 of the tube 260, also along the axis 18. Fluid flowing into the inlet port 280 to the aperture 276 exits the aperture through the outlet port 282. As a point of distinction with respect to the diverter tube 10, the first end region 277 is not sealed and also provides a passageway 280 into the tube 270, through the aperture 276 and to the outlet port 282. A series of cutting blades 34, arranged as a circular saw 36, are positioned about the first end region 277 on an edge 288 of the wall 274. The blades 34 are oriented to cut into the pipeline structure 70 as the diverter tube 260 moves toward and through the pipeline structure in a direction parallel with the axis 18. The actuator 256 and the motor 258 are mounted on the beam 257 for hydraulic movement of the motor. The motor 258 is coupled to the diverter tube 270 through a shaft 290.
[0060] With a piston 292 of the actuator 256 attached to the coupling unit 260, hydraulic movement of the piston 292 moves the motor 259 in a direction parallel with the horizontal orientation of the frame assembly 250. With the motor being coupled to the diverter tube 260 through the shaft 290, the diverter tube 260 is displaced within the frame assembly 250 and a force is provided for moving the diverter tube into and through the pipe structure 70. Hydraulic operation of the motor 259 turns the shaft 290 resulting in rotation of the circular saw 36 to cut through the pipe structure 70 as the diverter tube is forced against the structure 70 by the actuator 256. In the illustrated embodiment the shaft 264 is centered about the cylindrically shaped housing of the frame assembly 250 on the axis 18. The saw 36 is also symmetrically mounted within the frame assembly 250 on the axis 18. The cylindrically shaped wall 274 of the diverter tube body 272 has an outside diameter somewhat smaller than the inside diameter of the cylindrically shaped housing of the frame assembly. For example, with the pipeline structure 70 having an outside diameter of 22.5 inches (57cm), the frame assembly 250 may have an inside diameter about the same as the outside diameter of the cylindrical outer pipe wall 70a and the circular saw 36 may have a cutting diameter of 22.5 inches or slightly larger than the outside diameter of the wall 70a so that the circular saw 36 can completely sever the damaged segment 78 having the ruptured region 72 from the first segment 76 of the pipeline 70 at the interface of the pipeline 70 and the first end 251 of the frame assembly 250.
[0061] Both the diverter tube 10 and the diverter tube 260 may include multiple circular saw blades fixedly and concentrically mounted along and within the cylindrically shaped body. The outside diameter of the circular saw 36 may be smaller than the inside diameter of the cylindrically shaped wall 274. With this arrangement the saw 36 will cut a section of the pipe wall 70a which is smaller in dimension than the inside diameter of the cylindrically shaped wall 274.
[0062] The second end region 278 of the diverter tube 270 includes one or more cutouts 302 along the cylindrically shaped wall 274 which extend to an end 306 of the diverter tube 270. The two illustrated cut-outs 302 permit cut material and other debris resulting from operation of the circular saw to pass out of the aperture 276 of the body portion 272. After the cuts are complete, the actuator may retract the diverter tube 270 from the pipeline structure 70 so that the cut-outs 302 are outside of the frame assembly 250 and flow of oil can carry the cut material and other debris from the structure 70 out of the body portion 272 so as to not impede a flow of oil.
[0063] The system 255 includes a coupler 310 which allows a keyed end of the shaft 290 to be attached to or separated from the body portion 272 of the diverter tube 270. When attached to the body portion 272, the shaft 290 engages the body portion 272 for rotation of the body and the circular saw 36. With further reference to Figure 6, the coupler 310 is welded to the end 306 of the body portion 272. See, also, Figure 4 which provides a perspective view showing a flat bar 314 extending across the end 306 of the body portion. The coupler 310 centered on the axis 18 and there attached to the bar 314 for alignment with the shaft 290.
[0064] Figure 8 A provides a front or end view of the coupler 310 in a direction of the axis 18. The coupler is a cylindrically shaped body as illustrated in the side view of Figure 8B, which is taken along the axis 18, showing the coupler 310 attached to both the diverter tube 270 and the motor shaft 290. Dashed lines indicate features interior to the coupler. The coupler 310 is a cylindrically shaped body about four or more inches in diameter. A keyed end 322 of the motor shaft 290 is positioned in a keyway 326 within the cylindrically shaped body. The keyway within the cylindrically shaped coupler 310 is also of cylindrical shape as may be defined by the cylindrical outer wall 330 of the coupler 310. The keyway 326 may have a depth, D, of, for example, about six or more inches. Thus the keyway has a circular outer perimeter within which the keyed end 322 of the motor shaft 290 can rotate. The keyed shaft end 322 includes a pair of cogs 334 in diametrically opposing positions extending outward from the shaft 290 and which each are of a length as measured along the axial direction of the shaft (i.e., along a direction of the axis 18) somewhat less than the depth of the keyway so that the keyed end 322 may be fit within and be rotated within the keyway 326. The cogs 334 may extend outward from the shaft 290 to nearly the perimeter of the keyway 326. The coupler 310 includes a key opening 340 for receiving the cogs 334 into the keyway 326. The key opening 340 is formed in a cover plate 344 on the coupler 310 which constrains movement of the keyed end 322 of the shaft 290 when the end 322 is positioned within the keyway 326. The cover plate 344 is shown as formed of two separate sections although it could be one continuous plate welded against the cylindrically shaped body 48. The coupler 310 includes a pair of stops 350 mounted in diametrically opposite positions along the keyway perimeter. The stops 350 are shown to have a triangular shape with angled flat surfaces 352 for contact with flat surfaces of the cogs regardless as to whether the cogs rotate clockwise or counterclockwise to strike the stops 350. During operation of the motor 259 the cogs 334 transfer torque to the stops 350 via the shaft 290 to turn the circular saw 36.
[0065] With the actuator 256 coupled to move the hydraulic motor 259 along the beam 257, the beam may include any of a rail, track or one or more guides to assure displacement of the motor along the beam while assuring that the motor 259 does not move off of the beam 257. By way of example, an alternatives to the configuration shown in Figures 6, a pair of "T" or "L" shaped recesses may be formed along the beam257, with the motor mounted on a coupling 259 having mating rails inserted in the recesses to assure constrained motion as the motor moves toward or away from the pipeline structure. As the motor 259 provides a circular motion to the shaft 290, the circular saw 36 revolves or reciprocates to cut through the riser pipe. At the same time the actuator 256 applies a force through the shaft, in the direction of the axis 18, which force is transferred to the blades 34 and against the cutting surface (e.g., a wall of the structure 70) to assure movement of the saw 36 into and through the structure as a cut is made. The assembly 255 further includes a hydraulic gate valve 360 formed at an end 74 of the frame assembly 250. The gate valve is shown with the associated disk 78 in an open configuration while the shaft 290 extends from the motor 259 into the frame assembly 250. When the shaft 290 is disengaged from the coupler 310, leaving the diverter tube 270 within the chamber 2, the actuator 256 can retract the shaft 290, allowing the disk of the gate valve 360 to close and seal off the diverter tube 270.
[0066] With regard to the diverter tubes 10 and 270, the ports 28, 280 have been disclosed as circular holes 33 but these may be of varied shape or may be slots. In one series of embodiments, the ports extend less than, for example, 180 degrees about the cylindrically shaped body of the diverter tube in order to provide effective diversion of flow. For example, when the port is oriented directly at the flow from an underlying pipeline structure, the port opening may extend less than 180 degrees, so that the flow from the first segment 76 of the pipe structure 70 is blocked by the diverter tube to prevent the flow from passing into the damaged segment 78 of the pipe structure. Other considerations include the effective cross section of the port 28, 280 in order to provide a satisfactory flow rate.
[0067] An exemplary method of using the described system 255 begins with formation of the two part chamber 200 and positioning the chamber to enclose a portion of the pipeline structure 70 along the sea bed floor. That is, the chamber 200 is lowered to the seabed floor and then closed about the riser pipe using the
aforedescribed fasteners. With the chamber in the closed configuration, the frame assembly 250 is positioned against a segment of the pipeline structure 70, e.g., against a portion of the first segment 76, as described in Figures 6.
[0068] The diverter tube 270 is initially positioned in the frame assembly 250 with connection via the shaft 290 to the hydraulic motor 259 and to the actuator 256. With reference to Figures 8, the keyed shaft end 322 is secured in the coupler 310.
Next, cement is pumped into the inlet port 236 of the chamber 200 to fill the chamber. Once the concrete is cured the system 255 is operated to cut through the pipeline segment. Initially the piston 292 of the actuator 256 extends outward toward the chamber 200 to move the diverter tube 270 along the beam 257 and press the saw 36 against the pipeline structure 70. [0069] The motor 259 turns the saw 36 to cut through the walls of the structure 70, e.g., the outer and inner walls 70a and 70b, in a sequence of cuts. A first hole is first cut through one side of the wall 70a, followed by a cut through the entire inner wall 70b which has a diameter smaller than the diameter of the saw 36, followed by a cut through a second side of the wall 70a.
[0070] See, also Figures 3 which apply to the system 255 as well as the apparatus 60, with holes 120 and 122 formed in opposing positions along the pipeline wall 70a after passage of the circular saw 36 therethrough. Dashed lines 124, 126 indicate disk or circular shaped portions of the wall 70a which have been removed. With the diameter of the circular saw 36 exceeding the outside diameter of the wall 70b, a complete section 128 of the wall 70b is removed as indicated by dashed lines. Once the wall portions 124, 126 and 128 are cut they can be flushed through the cut-outs 302 which permit cut material and other debris resulting from operation of the circular saw to pass out of the aperture 276 of the body portion 272 and out the valve 360 before a riser line (not shown in Figure 6 A) is attached to the valve 360 for collection of the diverted oil 24.
[0071] The holes 120 and 122 are in alignment with the axis 18. If the saw 36 includes multiple rows of blades, the cut may consume a thickness of, perhaps, 1.5 inches while resulting in relatively small sized debris that can easily pass through the cut-outs 302. In one embodiment of the method, the holes are formed with complete revolutions of the saw 36, but the saw or other blade arrangements can be cut with reciprocating motions.
[0072] The cuts may result in circular plates of cut metal having diameters smaller than the inside diameter of the cylindrically shaped body of the diverter tube 270. Once the blade cuts a first hole and extends completely through one side of the wall 70a, the actuator piston 292 can be retracted to pull the shaft 290 and the diverter tube 270 away from the chamber 200 such that the cut-outs 302 become positioned outside of the frame assembly 250. At this time, with a hole, e.g., hole 122, formed in the pipeline structure 70, part of the oil flow is diverted into the assembly 250 and such flow can carry the circular plate or disk 126 and smaller debris out of the assembly 250 (through the cut-outs) and into the water. [0073] Next, the actuator 256 is controlled to extend the diverter tube 270 back into the pipeline structure and position the saw 36 against the inner pipe wall 70b for cutting therethrough with operation of the actuator 256 and the motor 259. Then the actuator piston 292 can again be retracted to pull the shaft 290 and the diverter tube 270 away from the chamber 200 such that the complete section 128 of the wall 70b which has been cut away can be removed by again positioning the cut-outs 302 outside of the frame assembly 250.
[0074] In one embodiment of the method, the second hole 120 in the pipeline wall 70a may be formed with reciprocating movement of the saw over an angle of less than 180 degrees and with the port 280 of the diverter tube 270 always facing in a downward direction. That is, with limited reciprocating motion of the blades 34 and with the port 280 always positioned to receive oil flow from the first segment 76 of the pipe structure 70, for passage through the diverter tube 270, the second hole 120 is cut through the second wall portion while flow of oil is without significant interruption or significant build-up of back pressure. As the saw 36 creates the second hole 120, flow through the damaged segment 78 is reduced or cut off while flow through the diverter tube increases to approximately the same flow rate that went through the damaged segment 78. With the actuator 256 continuing to move the saw 36 in the same direction, the cut extends into the concrete beyond the second hole and places the cutting blade several inches into the concrete where it remains in place.
[0075] When there is concern that significant build-up of back pressure may occur when cutting through the inner pipe wall 70b to cut out the complete section 128 of the wall 70b, the section 128 can also be cut with reciprocating movement of the saw over an angle of less than 180 degrees and with the port 280 of the diverter tube 270 always facing in a downward direction. That is, with the port 280 always positioned to receive oil flow from the first segment 76 of the pipe structure 70 for passage through the diverter tube 270, the section 128 of the wall 70b is cut through while flow of oil is without significant interruption or significant build-up of back pressure.
[0076] Once all of the cuts made with the saw 36 are completed, the keyed end 332 of the shaft 290 is removed from the coupler 310 by rotating the cogs 334 into alignment with the key opening 340 followed by retraction of the shaft 290 by the actuator piston 292 so that the keyed end 322 is positioned outside of the frame assembly 250 in order for the hydraulic valve 360 to be closed. Once the valve is closed the well is capped off.
[0077] In lieu of completely shutting the well down with the valve 360, an
arrangement may be had as shown in the partial view of Figure 9 where the portion of the diverter pipe extending away from the chamber 200 includes, in addition to the valve 360, one or more bypass relief valves 370 between the valve 360 and the chamber 200, and a flanged end 374 for coupling the frame assembly 250 to a flanged end 384 of an elbow section 386 of a new riser pipe through which flow can be directed to the water surface.
[0078] Recognizing that flow from the diverter tube 270 may continue to send some oil past the frame assembly and into the damaged segment 78 of the structure 70, a second pouring of cement can be formed over the chamber 200 with the pour extending into the severed segment 78 and in a form positioned over the chamber 200.
[0079] There has been described a system and method for stopping and diverting flow of oil from a pipeline structure, e.g., a riser pipe, positioned over an underwater well. The system may be installed as a precautionary measure about a well for immediate deployment of the saw 36 when a problem occurs with a blowout preventer or a problem occurs with a segment of pipeline above the blow-out preventer.
[0080] According to another embodiment Figure 10 provides is a simplified schematic illustration of an apparatus 60' which, except as now described, is in all respects similar in form and function to the apparatus 60 shown in Figures 2B and 2C. In lieu of having two separate tube shaped sections 82 and 106 which are connected to one another at respective ends 112, 144 with a hinge arrangement or flanges fastened together with bolts and the like, the system 60' is formed of a unitary body 400 coupled in line with the pipe structure 70. The body 400 is exemplary, being in the form of a four port coupling in the configuration of a cross, with each port 402, 404, 406, 408 having a flange 402f, 404f, 406f, 408f for connection of an adjoining tube section of the body 400 with another component. In this example, the body 400 is connected between a lower well outer casing 414 and a blowout preventer 418. The well casing 414 is connected to a well head (not shown) at or beneath a sea bed. The casing 414 would normally rise upward from the well head for connection with the blowout preventer 418. However, the apparatus 60' is positioned in line between these components with the flange 402f of the port 402 connected to a flange 414f of the well casing 414 and the flange 404f of the port 404 connected to a flange 420f of an inlet section 420 leading oil flow to the interior of the blowout preventer. Oil flowing from the casing 414 passes into the port 402 by passing through the flange 402f and into an adjoining tube section 402t in the interior of the body 400. The flow continues upward through the body and out the port 404 by passing through a tube section 404t of the body 400 leading to the flange 404f, and then passing through the flange 420 into the inlet section 420 of the blowout preventer 418. Each of the tube sections has a cylindrically shaped wall. Thus the inlet section 420 of the blowout preventer receives a flow of oil from the well casing 414 for flow through the blowout preventer as it should under normal operating conditions. The apparatus 60' is installed in place while allowing normal operating conditions, but includes components of the system 60 to divert the flow of oil when there is a rupture or a failure in normal operation of the oil well components such as a portion of the pipeline structure above the blowout preventer, as might be the case for the example shown in Figures 2, or such as a failure in operation of the blowout preventer.
[0081] The body 400 includes a tube section 406t which corresponds functionally to the section 82 shown in Figures 2B and 2C, housing the diverter tube 10 similar in form and function to the embodiment of the diverter tube 10 shown in Figures 1 and 2. The diverter tube 10 is not shown in Figure 10 in order to better present other features of designs according to the apparatus 60'.
[0082] The tube section 406t also contains the motor 96 and mechanical connections therebetween with a shaft 44 and is coupled to the section 80 (see again Figures 2B and 2C) which houses the linear actuator 90. The piston 92 is connected to motor housing 98 and the motor 96 and is extendable from the section 80 into the tube section 406t for direct connection with the motor housing. As described for the system 60, the tube section 406t includes tracks 102 which receive guides 100 of the motor housing to effect movement of the motor along a central axis of the tube section. The port 406 of tube section 406t is connected via the flange 406f to the flanged end 86 of the section 80. The tube section 406t and the diverter tube 430 positioned therein are cylindrical in shape, both symmetrically aligned along a common axis with the section 80. The common axis corresponds to the axis 18 as described for other embodiments and is so designated in Figure 10.
[0083] The body 400 further includes a tube section 408t functionally equivalent to the section 106 shown in Figures 2B and 2C. The flange 408f at the port 408 is connected to a valve 166 for recovery of the oil diverted through the assembly 60'. Another distinction between the assembly 60' and other embodiments is that the well casing 414, which corresponds to the outer pipe wall 70a, terminates at the flange 414f while the inner pipe wall 70b which carries a flow of oil 74 from the well head continues through the body 400 and into the blowout preventer 418. The wall 70b is shown in phantom lines as having been severed according to the same principles of the invention described with respect to the embodiment of Figures 1 and 2 such that the section 128 of the wall 70b has been removed, leaving a lower section 428 below the axis 18 and an upper section 432 above the axis 18. Further, it is noted that for this and other embodiments there may be a drill 440 inside the pipe wall 70b. As shown in Figure 10, after the circular saw of the diverter tube 10 has removed the section 128 of the wall 70b, the drill 440 is also severed, leaving two segments 440a and 440b of the drill.
[0084] Although the diverter tube 10 is not shown in Figure 10, it is to be understood that one segment 44a of the drill is positioned above the diverter tube 10 (and above the axis 18) and the other section 440b is below the diverter tube 10 (and below the axis 18), and the port 28 of the diverter tube is positioned directly above the lower section 428 (below the axis 18) to receive the flow of oil from the well head. In this regard, the diverter tube 10 is sized to provide a seal to mitigate the flow of oil into the blowout preventer. When a recovery pipe is connected to the valve 166 and the valve 166 is opened, the flow of oil is diverted through the aperture 16 and through the valve. However, to avoid possible problems caused by a drill 440 getting jammed into the port 28 of the diverter tube 10, the port may comprise a plurality of smaller apertures (e.g., two cm or less in diameter) to prevent a cut end of the drill from passing into the aperture 16 of the tube 10.
[0085] To have the apparatus 60' positioned in line with the well pipe casing 414 while the well is properly flowing oil into the blowout preventer, the sections 406t and 408t may be sealed off . With the diverter tube 10 positioned entirely within the section 406t, a seal plate 448 is placed in front of the saw 36 to block flow of oil into the section 406t. A second seal plate 452 may be placed in the tube section 408t to assure there is no flow out of the section during normal well operations. Noting that each of the tube sections 402t, 404t, 406t and 408t has a cylindrically shaped wall, the plates 448 and 452 may be welded in place, each in alignment with a wall 456 of the adjoining section 402t and in alignment with a wall 458 of the adjoining section 404t. According to an alternate embodiment of the invention, the seal plates are installed prior to placing the body 400 in line with the well casing and blowout preventer. In the event of a failure of the blowout preventer (e.g., in order to bypass the blowout preventer) or a rupture in the portion of the pipeline structure positioned above the body 400, the seals are cut with the circular saw of the diverter tube 10 with debris removed as aforedescribed so that flow of oil can be diverted through the section 408t for recovery.
[0086] While various embodiments of the present invention have been described, such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. By way of example, the principles disclosed can be readily applied to mitigate flows of liquids and gases other than hydrocarbons through a variety of ruptured systems. The invention is only to be limited only by the spirit and scope of the appended claims.
Next Patent: COMPOSITION AND METHOD FOR TREATING OVERACTIVE BLADDER