US3741517A

US3741517A - Subterranean clamping mechanism for submarine wells

Info

Publication number: US3741517A
Application number: US00113842A
Authority: US
Inventors: I Pogonowski
Original assignee: Texaco Inc
Current assignee: Texaco Inc
Priority date: 1971-02-09
Filing date: 1971-02-09
Publication date: 1973-06-26
Anticipated expiration: 1990-06-26

Abstract

The invention relates to a marine apparatus which includes a clamping device that is submergible beneath the water''s surface to be aligned with, and to squeezably deform the upstanding well casing of an uncontrollably flowing well. The apparatus includes a clamping yoke having spaced apart arms which define an opening or slip for registering about the upstanding well casing. A pair of displaceable cross members extend from the termini of the arms to interlock with each other and to engage the well casing. A hydraulic cylinder carried on the yoke is adapted to urge the clamping device into contact with the casing whereby to deform and crush the latter against the interlocked cross members.

Description

United States Patent 191 Pogonowski SUBTERRANEAN CLAMPING MECHANISM FOR SUBMARINE WELLS Int. Cl. Fl6k 7/07, E2lb 33/06 Field of Search 166/55, 55.1; 251/4-10, 1; 269/129, 156; 138/99; 294/64 BC, 83 R [5 6] References Cited UNITED STATES PATENTS 6/1941 Goode 294/83 R 3/1968 Hunger.. 294/88 [451 June 26, 1973 Primary Examiner-Martin P. Schwadron Assistant Examiner-Richard Gerard Attarney--Thomas H. Whaley and Carl G. Ries 57 ABSTRACT The invention relates to a marine apparatus which includes a clamping device that is submergible beneath the waters surface to be aligned with, and to squeezably deform the upstanding well casing of an uncontrollably flowing well. The apparatus includes a clamping yoke having spaced apart arms which define an opening or slip for registering about the upstanding well casing. A pair of displaceable cross members extend from the termini of the arms to interlock with each other and to engage the well casing. A hydraulic cylinder carried on the yoke is adapted to urge the clamping device into contact with the casing whereby to deform and crush the latter against the interlocked cross members.

1 Claim, 6 Drawing Figures SUBTERRANEAN CLAMPING MECHANISM FOR SUBMARINE WELLS BACKGROUND OF THE INVENTION upstanding outer shell. The conductor for crude oil or gas comprises a smaller flow line from about 6 to 10 inches in diameter. Normally, said conductor is positioned within the casing and extends downwardly to a gas pressure source of the crude product.

Under normal operating conditions, upon completion of such a submerged offshore well, the fluid carrying flow line is provided with a Christmas tree arrangement to permit control of the fluids, both liquid and gas, which are drawn from the subterranean reservoir under pressure. This Christmas tree or valve arrangement connected to the flow line is adjustable to regulate flow from the reservoir and can be remotely or manually actuated. Where however, unusual circumstances arise such that the well pressure exceeds a controllable level, or due to an equipment failure, the fluid, both liquid and gas, will gush in an uncontrolled stream from the reservoir.

This uncontrolled escape is not only an economic disaster, but carries the morepertinent stigma of being a potential mass pollutant of both the surrounding water and the atmosphere. Further, ejection of raw well gases into the atmosphere constitutes a tire hazard that can result in both material damage and loss of life when such a well erupts and the gasesaccidentally ignite.

There presently exists a number of means whereby to stem this uncontrolled fluid flow from a submerged well. Preferably, the well is capped or plugged in such manner to either cut off the escaping fluids, or to permit the latter to be controllably regulated. The patent danger to such an operation is however the inability to bring personnel such as divers or submarine equipment to the immediate vicinity of the submerged Well head whereby to work on the latter.

Toward overcoming a situation as stated above, where a well is uncontrollably emitting quantities of petroleum fluids, the present apparatus permits the submerged wellto be closed or choked off by a remote operation. Further, the operation is effectual, and minimizesthe danger to operating personnel. The device includes a controllably submerged body or yoke having movable parts which are actuated from the waters surface, which device is lowered to the floor in of the well head to be closed.

The body includes at least two forwardly depending arms which define a slip therebetween for engaging or registering about a protruding well head casing. With the casing positioned between the respective arms, cross members, normally aligned with the arms, are pivotally displaced into the slip area whereby to interlock and complete the encirclement of the casing. Thereafter, a remotely actuated clamping head exerts the vicinity external pressure against the casing wall and internal flow line respectively to deform and crush both of said members and thereby stem the uncontrolled fluid flow.

DESCRIPTION OF THE DRAWINGS FIG. 1 represents a vertical elevation view of a subterranean offshore well head which extends from the ocean floor and terminates at a point above the waters surface.

FIG. 2 is a top view taken along line 2-2 of FIG. 1,

shown with the clamping yoke fixedly engaged to the I well casing.

FIG. 3 is a front elevation view of the present apparatus.

FIG. 4 is similar to FIG. 2 showing the clamping device in a partially actuated condition.

FIG. 5 illustrates in cross section a casing and flow line subsequently to being deformed and FIG. 6 is a section view taken on line 6-6 of FIG. 4.

Referring to FIG. 1, an offshore well of the type presently contemplated is shown generally as consisting of an upstanding casing 10 formed of a series of end connected steel tubular members, 30 to 48 inches in diameter. The elongated casing extends from a position near to, or adjacent the waters surface, downwardly to a desired depth in the substratum depending upon the consistenc-y and composition of the latter. The elongated casing is fixed in place by a cement collar 14 or other suitable means as to be rigidly held in its imbedded position. Following normal construction of such a device, casing 10 surrounds a centrally positioned flow line 11 which extends downwardly, past the casing lower end, and terminates in a liquid or oil reservoir.

Flow line 11 normally comprises threadably connected lengths of drill pipe varying from 6 to 10 inches in diameter. The pipe sections are sequentially connected as the depth of the well increases, and function to carry petroleum fluids either gas or crude oil, from the pressurized reservoir to the waters surface.

Flow line 1 1 is connected at its upper end to a Christmas tree arrangement 12 presently illustrated by a plurality of valves extending from the flow line upper end whereby to control and direct liquid and gases passing upwardly from the reservoir. Raw fluids leaving the well are either separated, or passed directly by pipeline to a storage or refinery facility.

It is appreciated that the instant arrangement of casing '10 and flow line 11, together with the above surface Christmas tree 12, is illustrative of a number of variations that could beapplied to an offshore well. For example, in many instances the entire unit, including flow line and Christmas tree, are completely submerged and remain at the floor of the body of water whereby to minimize the possibility of said equipment constituting a navigational hazard. In such an instance the wellhead is remotely operated to control fluid flow by use of any of several known systemsJThe latter include pneumatic or electrical systems which connect to submerged actuators for the various valves. Further, such submerged well heads are communicated with a storage area for the produced fluids by underwater flow lines which extend from the well head to a suitable gathering point either onshore or otherwise located.

Referring to FIG. 1, the casing clamping device 13 is illustrated in a submerged condition at the floor of a body of water whereby to engage, and be positioned about casing 10 at a point adjacent the ocean floor. It should be noted that the clamping apparatus is normally disposed in a generally horizontal disposition to most readily be aligned with upstanding well casing 10. Further, the disposition of the clamping device can be regulated not only by carriage means in sliding contact with the ocean floor, but also by a suitable buoyancy system. In the instance of the latter, and while not presently shown, the clamping device 13 can be controllably submerged to a desired distance from the waters surface by use of a float arrangement adapted to suspend the same.

Clamping device 13 comprises in essence a bifurcated body or yoke 16 having a central portion 21 from which a pair of diametrally opposed

arms

17 and 18 depend in a horizontal direction. Spaced apart

arms

17 and 18 define a slip area 19 therebetween of sufficient width, and adapted to register about the outside of well casing 10. Each arm comprises a structural member having a substantial cross section, particularly at the juncture with the body central section 21.

As shown in FIG. 2, the terminal end of each arm, 17 for example, is slotted along the inner side to receive a displaceable cross member operably connected thereto at vertically positioned hinge pin 22. Displaceable cross member 23 is pivotally connected at one end by way of said pin 22 whereby to move in a horizontal plane. As shown in FIG. 2, a forwardly extending protrusion 24 depending from the arm 17 outer end, affords a lateral guide means whereby to align the respective arms with casing as the clamping device is drawn to and about the casing.

Arms

17 and 18 as noted, are provided with displaceable, coacting

cross members

23 and 26 respectively. Said cross members are adapted to be controllably moved toward each other in a plane horizontal to, or within the common plane of the respective arms. Each cross member, such as 23, includes an elongated shank which extends from the hinge 22 and terminates at a remote contact face 27. The latter is provided with a hardened, anvil-like surface for engaging the casing 10 outer wall at such time as the cross members are engaged.

As shown in FIGS. 2 and 4, when the cross members are withdrawn they lie substantially within the corresponding arm. Thus, open area 19 is free of obstructions to register about casing 10. However, with said cross members in the extended or actuated position they are disposed outwardly from the respective arms and are engaged approximately centrally of said open area 19.

To best withstand the axial force urged against the locked cross arms, the included angle therebetween is such as to distribute the resulting stress. Thus the casing deforming force will be transferred through the respective cross members and pivot pins, and thence into the

arms

17 and 18.

Referring to FIG. 6, to afford the

respective cross members

23 and 26 mutual strength when in the locked or engaged position, as shown in FIG. 4, said cross members are provided with a slidably engaging lock joint at the remote face thereof. Said joint comprises in its simplest form a tang 28 depending from cross member 23, which slidably registers within a corresponding groove 29 on cross member 26. Thus, and as shown in FIG. 4, when the respective cross members are withdrawn outwardly from their normal position within their arms, they in effect, complete the closure about casing 10. With the cross members so positioned, actuation of the clamping head 36 in a forward direction will serve to center casing 10 with respect to the clamping surfaces.

Cross members

23 and 26 can be actuated to their engaged position as shown in FIGS. 4 and 6 by a number of mechanical means adapted to the purpose. In the instant arrangement said means includes one or more hydraulically powered

cylinders

31 and 32 which are pivotally positioned at one end to the upper and lower surfaces of arm 23. They are further connected at the other end to cross member post 33. To bring the cross members into their withdrawn position,

cylinders

31 and 32 are actuated whereby to position the member within the corresponding arm.

With the casing 10 held within the clamping device, partial actuation of hydraulic cylinder 34 will center casing 10. Thus, the casing, as shown in FIG. 4, will be engaged by head 36. Further, advancing said head will thereafter bring the mating faces of locked

cross members

23 and 26 into contact with the casing outer wall.

Head 36 can be adjustable, or more preferably replaceable to properly conform to the size of a particular well casing being deformed. As shown, head 36 is provided with a curved contacting face to properly engage a relatively extensive portion of the casing periphery whereby to achieve the desired crushing effect of both casing 10 and the inner positioned flow line 11.

After being properly aligned, as casing 10 is subjected to increased external pressure from opposed sides due to the progressive movement of hydraulic head 36, the casing will assume the general disposition shown in FIG. 5. With further actuation of cylinder 34, outer casing 10 will be deformed to the point that it crushes and substantially or completely closes the inner positioned flow line 11. Thus, passage of both liquid and gas from the reservoir through the flow line 11, will be precluded. In such condition, the closed well can be readily worked on or further closed by application of a cap or other device to further preclude uncontrolled fluid flow.

With the casing 10 closed off, the clamping device 13 is removed by withdrawing clamping head 36 back into the hydraulic cylinder 34. Thereafter, the

respective cross members

23 and 26 are withdrawn by actuation of the

respective cylinders

31 and 32 such that the cross members fold into and adjacent to the

arms

17 and 18. The entire clamping device can then be withdrawn from the casing and returned to the Waters surface.

To facilitate movement along the ocean floor, and as shown in FIG. 1, clamping unit 13 is carried on a carriage 37 or similar propellable unit. The latter in one form, comprises a skid device from which the clamping unit is supported. A plurality of intermediate connecting

members

38 and 39 are fixed, or telescopically adjustable to raise the clamping device a sufficient height beyond the ocean floor to permit the skid to be towed along said floor in a manner as to readily engage casing 10.

Toward facilitating positioning of the clamping device about casing 10, each

arm

17 and 18 is provided with a curved rubbing surface, on protrusion 24, and with means to connect to a towing cable. The towing cables, as a matter of convenience can be connected to the skid or carriage 37. In either instance, the inner surface of the clamping device is so arranged with respect to the cables that when the latter are towed by a floating vessel at the waters surface, the clamping device will tend to position itself about the casing.

Obviously many modifications and variations of the invention, as hereinafter set forth, may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A marine apparatus for deforming a subterranean flow line communicated with a pressurized fluid source and carrying an uncontrolled flow of said fluid therefrom, which apparatus comprises;

a. a yoke having a pair of spaced apart parallel arms depending therefrom, and defining a slip area therebetween,

b. said arms forming an opening at the remote ends thereof to receive said flow line,

0. means for controllably positioning said yoke at an under water location and in engagement with said subterranean flow line, whereby to dispose the latter within said slip area,

d. an elongated beam removably extending from said respective arms and traversing said slip area, said beam comprising discrete cross members pivotally connected at one end to the respective arms, and being pivotally displaceable between a withdrawn position adjacent to said respective arms, and an extended position within said slip area whereby to engage the other of said cross members, and locking means on said respective cross members at the remote end from said pivot point whereby to releasably engage a corresponding cross member end.

Claims

1. A marine apparatus for deforming a subterranean flow line communicated with a pressurized fluid source and carrying an uncontrolled flow of said fluid therefrom, which apparatus comprises; a. a yoke having a pair of spaced apart parallel arms depending therefrom, and defining a slip area therebetween, b. said arms forming an opening at the remote ends thereof to receive said flow line, c. means for controllably positioning said yoke at an under water location and in engagement with said subterranean flow line, whereby to dispose the latter within said slip area, d. an elongated beam removably extending from said respective arms and traversing said slip area, said beam comprising discrete cross members pivotally connected at one end to the respective arms, and being pivotally displaceable between a withdrawn position adjacent to said respective arms, and an extended position within said slip area whereby to engage the other of said cross members, and locking means on sAid respective cross members at the remote end from said pivot point whereby to releasably engage a corresponding cross member end.