US3603386A

US3603386A - Subsea guideline anchoring method and apparatus

Info

Publication number: US3603386A
Application number: US858661A
Authority: US
Inventors: William A Talley Jr
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1969-09-17
Filing date: 1969-09-17
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

A method and an apparatus for locating and anchoring bottom-tosurface guidelines of a subsea guidance and alignment system to be utilized in conjunction with servicing or drilling subaqueous wells by lowering a pair of self-anchoring ends of unanchored guidelines on a spacer frame which is guided to the subaqueous bottom on a pair of previously anchored guidelines. The free guidelines are anchored upon contact of the self-anchoring ends with predetermined anchorage locations on the subaqueous bottom. The operation may be repeated to anchor other guidelines at other anchorage locations on the subaqueous bottom by utilizing the initially free and subsequently anchored guidelines as guides for lowering the space frame carrying the self-anchoring ends of other free guidelines.

Description

United States Patent 3,302,709 2/1967 Postlewaite 3,503,442 3/1970 Doddetal.

ABSTRACT: A method and an apparatus for locating and anchoring bottom-to-surface guidelines of a subsea guidance and alignment system to be utilized in conjunction with servicing or drilling subaqueous wells by lowering a pair of self anchoring ends of unanchored guidelines on a spacer frame which is guided to the subaqueous bottom on a pair of previously anchored guidelines. The free guidelines are anchored upon contact of the self-anchoring ends with predetermined anchorage locations on the subaqueous bottom. The operation may be repeated to anchor other guidelines at other anchorage locations on the subaqueous bottom by utilizing the initially free and subsequently anchored guidelines as guides for lowering the space frame carrying the self-anchoring ends of other free guidelines.

PATENTED SEP 7 I97! SHEET 1 OF 4 PATENIEDSEP new 3.603386 SHEET 2 BF 4 SUBSEA GUIDELINE ANCHORING METHOD AND APPARATUS BACKGROUND OF THE INVENTION This invention relates to subaqueous fluid mineral producing wells.

In drilling or servicing subaqueous wells, it is necessary to provide means for locating drilling equipment and wellhead servicing equipment at precise locations on the subaqueous bottom. Conventionally, this equipment is guided to the precise locations by guidelines forming part of a guidance and alignment system (G&A system) extending from the surface to the subaqueous bottom. The anchoring of the guidelines at the precise locations has been achieved in various ways.

One way has involved the lowering of a base of operations which carries the guidelines to the subaqueous bottom before any drilling is conducted. In instances where a plurality of wells have been drilled on a single subaqueous site, a base of operations carrying the guidelines has been lowered for each well. After the well has been drilled, a wellhead is established at each well and the guidelines are withdrawn. While the above-described way of anchoring guidelines is somewhat satisfactory for the drilling of subaqueous wells, there are problems in servicing these wells after the guidelines have been withdrawn.

The problems arise out of the necessity to rely upon divers or personnel operating manipulators from a submersible unit in order to reanchor the guidelines. For example, divers cannot be utilized to reanchor the guidelines at subaqueous well locations of considerable depth or in water having a low temperature. Thus, divers may not be utilized at various deep water, offshore well locations where the temperature of the water may be as low as 35 F. nor can divers be utilized in more shallow areas where the water is cold because of the prevailing weather conditions. Furthermore, there are various temporary conditions which may preclude the use of divers such as turbidity, current and surface conditions of the water. Although these temporary conditions will pass, rather long and extremely costly delays will be encountered awaiting more favorable conditions which will allow the divers to enter the water. Even when the divers finally do enter the water, their very slow operational capability which bectiirneseven slower with increased depth of the water will resultr in further costly delays. In some cases, the cost of the delays arising both out of the inability of the divers to enter the water and the slow speed at which the divers are capable of working once entering the water may render the cost of servicing the wells prohibitive when the combined costs of the divers on an hourly basis and the surface rig on an hourly basis are considered.

Although a submersible unit may be utilized in spite of deep water and low temperature conditions which would preclude the use of a diver, they too have their limitations with respect to their manipulator capabilities and their ability to operate under certain temporary turbidity, current, and surface conditions. As with divers, these temporary conditions will cause delay in anchoring the guidelines on the subaqueous bottom and thus a high cost in waiting time or down time for the surface rig. Furthennore, a submersible unit is at least as expensive as divers on a per-hour basis of operation and the cost of transporting these submersible units to the well site is very high.

Besides the expense associated with the use of divers and/or submersible units for anchoring guidelines to a plurality of bases of operation for servicing purposes alone, there is also considerable expense involved in relocating a surface rig so that each of the plurality of bases of operations may be lowered to its own separate location initially before drilling commences. Furthermore, there are great difficulties in lowering these bases of operations in the proper spatial relationship, one to the other, so that a production satellite may be utilized in conjunction with a plurality of the subaqueous wells.

SUMMARY OF THE INVENTION It is an object of this invention to provide a means and method for anchoring subsea guidelines which may be utilized under substantially all conditions.

It is also an object of this invention to provide a means and method for anchoring the subsea guidelines which minimizes the use of divers and submersible units. 7

It is a further object of this invention to provide a means and method for anchoring subsea guidelines adjacent a plurality of subaqueous wells having predetermined spatial relationships therebetween.

It is a still further object of this invention to provide a means and method for anchoring subsea guidelines which will minimize the waiting or downtime of surface rigs.

These and other objects may be accomplished by lowering at least one free guideline from the surface to the subaqueous bottom on a spacer means which is guided by a plurality of previously anchored guidelines from the surface to the subaqueous bottom and anchoring the free guidelines without utilizing submerged personnel.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the invention in use in an offshore drilling operation;

FIG. 2 is a top plan view of the invention in use in servicing two particular subaqueous well locations of FIG. 1;

FIG. 3 is a front elevational view of FIG. 2;

lFIG. 4 is a cross-sectional view taken along section lines 4--4 of FIG. 2;

FIG. 5 is a partial cutaway view of anchoring and anchorage means; and

FIGS. 6a-6d are side elevational views of the guideline anchoring, testing and withdrawal operations.

DESCRIPTION OF THE PREFERRED EMBODIMENT By referring first to FIG. 1, there will be seen an offshore drilling or servicing unit in the form of a drilling vessel 10, similar to that shown in US. Pat. No. Re.26,290, floating on the surface of the water 12 above a subaqueous base of operations 14 at the subaqueous bottom 16. The base of operations 14 may be of the guide base or template type for establishing a plurality of series-arranged subaqueous well locations. For illustrative purposes, four such well locations A-D have been shown.

Each of the well locations includes a wellhole 18 which, for purposes of clarification, have been designated as well holes ISA-18D. If the unit on the surface of the water 12 is a drilling vessel, the well holes 18 will be position guides for receiving a drill string as shown. If the unit floating on the water 12 is a servicing unit, the well holes 18 will be capped with submerged wellheads, not shown.

In addition to the well holes 18, each of the well locations A-D has a group of anchorage means associated therewith in the base of operations 14. The groups include a plurality of guideline anchorage means 20 which are associated with a single well location and a plurality of guideline anchorage means 22 which are located between each two well locations. Again, for purposes of clarity, guideline anchorage means 20 have been designated with one of the letters A-D indicating the adjacent well location and the plurality of guideline anchorage means 22 have been designated with two of the letters A-D indicating the nearest well locations.

More particularly, it will be seen that the group of guideline anchorage means associated with the: well location A include a pair of guideline anchorage means 20A and the group of anchorage meansat the next well location B includes another pair of anchorage means 208. Anchorage means 22AB and 228A are located between the well locations A and B. The pattern of anchorage means 20 and 22 is then repeated at well locations C and I).

By utilizing a spacer means in the form of a spacer frame 24 and a previously anchored (either [lowered with the base of operations or anchored by submerged personnel) plurality of guidelines in the form of a pair of guidelines 26 having anchoring means anchored at the anchorage means 20A, a plurality of guidelines 28 having anchoring means at the free ends thereof may be anchored at anchorage means 22A and 223. This may be accomplished by lowering the spacer frame 24 and the free ends of the guidelines 28 along the guidelines 26 as shown with the spacer frame 24 and the guidelines 26 serving to properly index the guidelines 28 with respect to the anchorage means 22AB and 228A.

The lowering of the spacer frame 24 may be accomplished by utilizing a running means in the form of a drill string 30 or, in the alternative, a cable which is attached to the spacer frame 24 at the center of gravity thereof. By utilizing the center of gravity as the point of attachment for the running means, the spacer frame 24 may be maintained substantially parallel to the base of operations 14 to achieve proper anchoring of the guidelines 28 at the anchorage means 22AB and 223A. In addition to the predetermined spatial relationships among the group of anchorage means 20A, 22AB, and 2213A which correspond with the guideline-receiving means 32 on the spacer frame 24 and assure the proper indexing and anchorage of the guidelines 28, the anchorage means 20A and 22AB also have a predetermined spatial relationship with respect to the wellhole 18A to permit use as a part of a conventional G&A system such as that shown in U.S. Pat. No. 3,293,867 assigned to the assignee of this invention. Preferably, the anchorage means 20A and 22AB are equidistant from the wellhole 18A at the apices of an equilateral triangle for this purpose to permit a drill bit or servicing mechanism to be lowered on the anchored guidelines 26 and one guideline 28 with the utmost stability. 7

Since it is desirable that the drill string 30 be attached to the spacer frame 24 at the center of gravity thereof but not necessarily equidistantly spaced from any three of the guidelinereceiving means 32, nonalignment may be provided between the wellhole 18A and the point of attachment 34 at the center of gravity of the spacer frame 24. The rest of the spacer frame 24 may also be of a configuration so as to achieve nonalignment with the wellhole 18A to avoid interference with any wellhead extending therefrom. Accordingly, the spacer frame 24 may comprise a yoke configuration having ends 36 with guideline-receiving means 32 for the guidelines 26 and a center portion 38 including the point of attachment 34 and guideline-receiving means 32 for the guidelines 28.

Once the drilling or servicing of the well at the well location A is completed by utilizing the anchored

guidelines

26 and 28 which are anchored at the anchorage means 20A and 22AB, a subsequent plurality of guidelines may be anchored at the next well location in the series, well location B. This may be accomplished by merely reorienting the spacer frame 24, either by flipping (turning the spacer frame over) or rotating the

spacer frame

24, 180 after the spacer frame 24 has been raised to the surface and the

guidelines

26 and 28 removed from the receiving means 32 so that the guideline-receiving means 32 of the spacer frame ends 36 overlie and are aligned with the anchorage means 208. The spacer frame 24 may then be lowered to the base of operations 14 to properly anchor guidelines at the anchorage means 208. After achieving the proper anchorage, spacer frame 24 will be raised by raising the drill string 30 and servicing or drilling may commence with use of guidelines for guiding the needed equipment to the well.

Before the guidelines, which permit drilling and servicing at the subsequent well location C in the series, may be anchored, it is necessary to bridge the gap between the well location B and the well location C by anchoring guidelines at the anchorage means 228C and 22CB located between well locations B and C. This too is accomplished by flipping or rotating the spacer frame 24 so that the spacer frame 24 is lowered along the guidelines anchored at the anchorage means 208 carrying unanchored guidelines at guideline-receiving means 32 in the center 38 of the spacer frame 24. These subsequently anchored guidelines may in turn be utilized to anchor guidelines at the anchorage means 20C of the well location C. Note that there will be no drilling or servicing by utilizing the guidelines anchored at anchorage means 228C and 22CB since there is no adjacent well location.

These steps may be repeated until all of the well locations of the series have been drilled or serviced by utilizing the G&A system including certain of the guidelines anchored by this method. It will be appreciated that only four well locations have been shown in the base of operations 14 and that it will oftentimes be desirable to have many more. For example, it might be desirable to utilize an annular base of operations so that the wells will be annularly arranged in a series to permit the use of a production satellite of the carrousel type as disclosed in U.S. Pat. application Ser. No. 740,578, filed June 27, [968 and assigned to the assignee of this invention.

Referring now to FIGS. 2 and 3, the shape of the spacer frame 24 is more clearly shown as comprising legs 40 of the yoke ends 36 and leg 42 at the yoke center 38. In the environment of FIGS. 2 and 3, the spacer frame 24 is utilized to anchor guidelines for a servicing G&A system with the need to avoid interference with an established wellhead 44 and a production pipe 46. As mentioned previously, this is accomplished in part by providing a point of attachment 34 which is located at the center of gravity of the spacer frame 24 but in nonalignment with the wellhead 44. The point of attachment 34 is located at the intersection of truss members 48. The avoidance of interference is also achieved in part by having the legs 40 of the yoke configuration spaced outwardly from the wellhead 44. In order to strengthen the legs 40 in their spread position, truss members 50 are provided.

In order to avoid interference between the pipe 46 and the end legs 40 of the yoke configuration, the anchorage means 20A as well as the anchorage means 22AB and 228A, not shown in FIG. 3, comprise pedestals 52 extending up above the pipe 46 which passes along the upper surface of the base of operations 14. Thus, even when the spacer frame 24 is resting upon the pedestals 52 and the anchoring means 54 of the guidelines 26 are latched within the pedestals 52, interference between the spacer frame 24 and the pipe 46 is avoided. The avoidance of interference is also achieved at well location B where the position of the spacer frame 24 is shown in phantom and the pedestals 52 are shown in full.

The anchoring of the

guidelines

26 and 28 at the base of operations 14 may be understood by reference to FIG. 4 wherein the anchoring means 54 of the guidelines 28 is shown as latched within the pedestals S2. The anchoring means 54 comprises a guide pin 55 connected to the cable 28 by a suitable coupling means 56 and is adapted to be received by the guideline-receiving means 32 in the spacer frame 24 and the anchorage means 228A in the form of the pedestals 52 having a receptacle 60. i

In order to accomplish a self or automatic latching of the anchoring means 54 with the anchorage means 22BA, sheara ble and spring-loaded anchoring latching elements 64 are located on the lower portion of the pin 55. As the pin enters the receptacle 60, the latching element 64 will be retracted compressing the springs until the latching elements 64 reach an annular recess 66 in the wall of the receptacle 60. Upon reaching the annular recess 66, the latching elements will snap outwardly into the recess 66 to provide anchoring of the guideline 28.

In order to prevent the spacer frame 24 from slippingdown over the pin as the guidelines 28 in the spacer frame 24 are lowered to the subaqueous bottom 16, a flange 68 extends outwardly from the pin and a lower surface 70 of the spacer frame 24 bears thereupon. The flange 68 also serves as astop for the pin thereby avoiding premature shearing of the.

latching elements 64 which might occur if the latching elements 64 were jammed beyond the recess 66. Spacer frame latching elements 72 are provided in combination with an'an- Y nular recess 74 in the spacer frame 24 to prevent the spacer frame 24 from coming out of the aperture 58. Without the latching elements 72 and the annular recess 74 holding the pin 55 in the aperture 58, the pointed end 76 of the pin 55 would not be maintained in the proper attitude to be able to locate the receptacle 60. However, by utilizing latching elements 72 which have rounded faces, the spacer frame 24 may be pulled free from the anchoring means 54 and raised to the surface to permit the drilling or servicing by the G&A system.

The outer surfaces of the anchoring latching elements 64 which are both shearable and spring-loaded, as mentioned previously, are shown in somewhat fuller detail in FIG. 5. In order to permit the latching elements 64 to enter the receptacle 60 the outer surface 78 is arcuately tapered inwardly from the upper portion to the lower portion and a complementary recess 80 is provided in the pin which tapers inwardly from the lower portion to the upper portion. Tapered surface 78 will rub along the wall of the receptacle 60 as the pin is inserted into the pedestals 52 so as to force the latching elements 64 into the complementary recess 80 while simultaneously compressing a spring 82 which is located between the latching elements 64 and a tapered wall 84 of the recess 80. Once the latching elements 64 reach the annular recess 66, the latching elements 64 snap outwardly such that latching surfaces 86 at the upper portion of the latching elements 64 pass beneath a latching surface 88 of the recess 66. The latching elements 64 are held in place byretainer plates 90 secured to the pin 55 by screws 92 which bear upon tabs 94 and the lower portion of the tapered surfaces 78 of the latching elements 64.

Since it frequently is necessary to pull up or withdraw guidelines anchored at one well location in a series to permit uninhibited work at subsequent well locations in the series, it is necessary to provide a means for releasing the anchoring means 54 from the anchorage means and 22. This may be accomplished by making the latching elements 64 shearable so that upon application of an axial force along the pin 55 and along the attached guidelines in an upward direction and of sufficient magnitude, the latching elements 64 will be sheared and the pin may be removed from the receptacle 60. Accordingly, the ear 96 defined by the upper portion of the tapered surface 78 and the latching surface 86 is made sufficiently strong to withstand the normal stresses of G&A system operations but sufficiently weak to permit shearing by a much greater force. A typical shear line 97 for the car 96 is shown to indicate the very small amount of the latching elements 64 which will remain within the receptacle 60. The sheared-off latching elements 64 may be replaced at the surface with new latching elements 64 by removing and reattaching the plates 90. It will be appreciated that such a small amount of material will not interfere with the anchoring of guidelines in the same receptacle 60 at a later point in time. In fact, the amount of material involved is so small as to permit the reuse of the receptacle 60 many times when subsequently servicing the wells.

Referring now to FIGS. 6a6d, there are disclosed a plurality of steps utilized in anchoring and releasing guidelines. In FIG. 6a, the anchoring means 54 attached to the guidelines 26 have been previously latched and anchored within the pedestals 52 of the anchorage means 20A. The previously anchored guidelines 26 are being utilized as a guide and index for locating and anchoring guidelines 28 at pedestals 52 of the anchorage means 22AB and 223A. In the position shown, a spacer frame is running along the guidelines 26 and guidelinereceiving means 32 in the from of guideline-running apertures 58 and the pins 55 of the anchoring means connected to the guidelines 28 are about to enter the receptacles 60 of the anchorage means 22AB and 22BA.

In FIG. 6b, the spacer frame 24 has been lowered to the top of the pedestals 52 and the pins of the guidelines 28 have been inserted into the pedestals 52 of the anchorage means 22AB and 223A. In this particular view, both the guidelines 26 and the guidelines 28 have been anchored.

Latching can only occur if the pins are inserted into the pedestals 52 up to the flanges 68. In order to test for the proper latching, the spacer frame 24 may be raised a few feet above the pedestals 52. If the guidelines 28 are placed under tension by pulling at the surface and the guidelines 28 remain under tension after the spacer frame 24 has been raised, this will indicate the proper latching and anchoring of the guidelines 28. If there is no longer any tension on the guidelines 28 after the spacer frame is raised, guidelines 28 may be raised to the spacer frame 24 until the lower surface 70 thereof rests on the flanges 68. The spacer frame may then be lowered again to the pedestals 52 in another effort to achieve appropriate latching of the anchoring means 54 associated with the guidelines 28. This testing and attempt to anchor the unanchored guidelines 28 may be repeated until proper anchoring is achieved.

In some instances, it may not be necessary to perform any operations with the G&A system at the particular well location. In these instances, it will be desirable to immediately withdraw the guidelines 26 as shown :in FIG. 6d as soon as the testing shown in FIG. 60 is completed. Of course, it is imperative that this testing be completed before the guidelines 26 are withdrawn by shearing the latching elements 64 off the pin as shown. The withdrawal of the guidelines 26 as shown in FIG. 6d without performing various operations with the G&A system would always be the case when the guideline being withdrawn is anchored at an anchorage means 22 not adjacent any well location such as anchorage means 228C and 22GB.

In the foregoing, a single spacer frame 24 has been described. However, it is appreciated that the particular spacer frame described is by no means the only spacer frame which may be utilized in the claimed method and apparatus. For example, the previously discussed spacer frame 24 has identical upper and lower surfaces to permit the spacer frame 24 to be flipped or inverted from one well location to another. However, this is not necessary since the spacer frame 24 may be rotated between well positions rather than flipped between well positions. With regard to the flipping of the spacer frame 24, it should be noted that the center leg 42 will be angularly disposed with respect to the end legs 40 rather than parallel as shown whenever an annular base of operations 14 is utilized and the spacer frame 24 is flipped from well location to well location. The angular disposition of the center leg 42 will permit the spacer frame to mark out a substantially annular path coinciding with the various well locations in the annular base of operations 14.

While a particular embodiment of the invention has been shown and described, it will be understood that various modifications may be made. The appended claims are intended to cover any such modifications within the spirit and scope of the invention.

What is claimed is:

l. A method of locating and anchoring bottom-to-surface guidelines for use as part of a subsea guidance and alignment system in drilling or servicing a selected one of a plurality of subaqueous wells which comprises:

lowering at least one free guideline along a predetermined path in reference to previously anchored guidelines;

anchoring a free end of said at least one free guideline at a predetermined position at said :subaqueous bottom upon contact therewith;

disconnecting said previously anchored guidelines from the bottom after said at least one free guideline has been anchored; and

repeating the above steps for anchoring additional guidelines to the bottom in additional predetermined positions.

2. A method of locating and anchoring bottom-to-surface guidelines for use as a part of a subaqueous guidance and alignment system in successively drilling or servicing a plurality of subaqueous wells equally serially spaced along a subaqueous bottom by using a previously anchored plurality of guidelines at one well location in the series as guides in lowering a plurality of free guidelines from the surface to the bottom and as an index for anchoring said free guidelines between well locations.

3. The method of claim 2 wherein the previously anchored guidelines are removed from the subaqueous bottom and the anchored, previously free guidelines are utilized as guides in lowering a subsequent plurality of free guidelines from the surface to the bottom and as an index for anchoring said subsequent free guidelines at a subsequent subaqueous well location in the series.

4. A method of locating and anchoring bottom-to-surface guidelines of a subaqueous guidance and alignment system for offshore well production operations comprising the steps of:

establishing at least one group of anchorage means at a base of operations on the subaqueous bottom having predetermined spatial relationship among the individual anchorage means of said group;

anchoring at least one guideline to particular anchorage means of said group; attaching a free end of at least one other guideline to a spacer means; I

lowering said spacer means down along said at least one guideline such that said free end of said at least one other guideline and said at least one guideline has a spatial relationship thereamong substantially identical to the spatial relationships of said anchorage means of said group;

anchoring said at least one other guideline by securing said free end to another of said anchorage means of said raising said spacer means to the surface;

reorienting said spacer frame with respect to said at least one other guideline;

attaching a free end of at least one further guideline to said spacer means;

lowering said spacer means down along said at least one other guideline such that said free end of said at least one further guideline and said at least one other guideline have a spatial relationship thereamong identical to the spatial relationships between said another of said anchorage means and particular anchorage means of another group; and

anchoring said at least one further guideline by securing said free end to said particular anchorage means of said other group.

5. The method of claim 4 including the step of withdrawing said at least one guideline before anchoring said at least one further guideline.

6. The method of claim 4 including the step of withdrawing said at least one guideline before raising said spacer means to the surface.

7. The method of claim 4 including the steps of:

raising said spacer means off said subaqueous bottom; and

testing the anchorage of said at least one other guideline by applying tension thereto before withdrawing said at least one guideline.

8. A method of sequentially anchoring groups of guidelines at a plurality of serially arranged subaqueous well locations, one group being associated with each well by utilizing a plurality of anchored guidelines as guides for a spacer means while lowering a next plurality of guidelines thereon to the subaqueous bottom and anchoring the next plurality of guidelines at a predetermined location, utilizing the next plu rality of guidelines as guides for a spacer means while lowering a subsequent plurality of guidelines to the subaqueous bottom and anchoring the subsequent plurality of guidelines at a predetermined location, and continuing the sequential anchoring in the foregoing manner until all of the groups of guidelines have been anchored.

9. Apparatus for locating and anchoring bottom-to-surface guidelines of a subaqueous guidance and alignment system comprising:

a base adapted to be located at a subaqueous bottom includ' ing a well location means and anchorage means near said well location means and having predetermined spatial relationships thereamong, each of said anchorage means comprising receptacles having recesses therein; a plurality of guidelines havlng self-anchoring means adapted to automatically anchor at said anchorage means upon engagement therewith, each of said self-anchoring means comprising a pin having a spring-loaded anchorlatching element thereon which is shearable from said pin, said anchor-latching element being adapted to engage said recess on said anchorage means upon contact a spacer frame including a plurality of guideline-receiving means having said predetermined spatial relationships thereamong, more than one of said receiving means adapted to be guided along previously anchored guidelines when said spacer frame is lowered along said previously anchored guidelines carrying said selfanchoring means of at least one other of said plurality of guidelines at other of said guideline-receiving means; and

means for raising and lowering said spacer frame between the surface and said anchorage means.

10. The apparatus of claim 9 wherein said anchoring means includes a flange extending from said pin for support of said spacer frame.

1 l. The apparatus of claim 10 wherein each said anchoring means includes a spacer frame latching element extending from said pin above said flange, and said guideline-receiving means comprises an aperture extending through said frame having a latching recess for receiving said spacer frame latching element 12. The apparatus of claim 9 wherein said spacer frame comprises a yoke and said guideline-receiving means comprise apertures located at the ends and center of said yoke.

13. The apparatus of claim 12 wherein two of said apertures are located at said center of said yoke and one of said apertures is located at each of said ends of said yoke.

Claims

1. A method of locating and anchoring bottom-to-surface guidelines for use as part of a subsea guidance and alignment system in drilling or servicing a selected one of a plurality of subaqueous wells which comprises: lowering at least one free guideline along a predetermined path in reference to previously anchored guidelines; anchoring a free end of said at least one free guideline at a predetermined position at said subaqueous bottom upon contact therewith; disconnecting said previously anchored guidelines from the bottom after said at least one free guideline has been anchored; and repeating the above steps for anchoring additional guidelines to the bottom in additional predetermined positions.

4. A method of locating and anchoring bottom-to-surface guidelines of a subaqueous guidance and alignment system for offshore well production operations comprising the steps of: establishing at least one group of anchorage means at a base of operations on the subaqueous bottom having predetermined spatial relationship among the individual anchorage means of said group; anchoring at least one guideline to particular anchorage means of said group; attaching a free end of at least one other guideline to a spacer means; lowering said spacer means down along said at least one guideline such that said free end of said at least one other guideline and said at least one guideline has a spatial relationship thereamong substantially identical to the spatial relationships of said anchorage means of said group; anchoring said at least one other guideline by securing said free end to another of said anchorage means of said group; raising said spacer means to the surface; reorienting said spacer frame with respect to said at least one other guideline; attaching a free end of at least one further guideline to said spacer means; lowering said spacer means down along said at least one other guideline such that said free end of said at least one further guideline and said at least one other guideline have a spatial relationship thereamong identical to the spatial relationships between said another of said anchorage means and particular anchorage means of another group; and anchoring said at least one further guideline by securing said free end to said particular anchorage means of said other group.

7. The method of claim 4 including the steps of: raising said spacer means off said subaqueous bottom; and testing the anchorage of said at least one other guideline by applying tension thereto before withdrawing said at least one guideline.

8. A method of sequentially anchoring groups of guidelines at a plurality of serially arranged subaqueous well locations, one group being associated with each well by utilizing a plurality of anchored guidelines as guides for a spacer means while lowering a next plurality of guidelines thereon to the subaqueous bottom and anchoring the next plurality of guidelines at a predetermined location, utilizing the next plurality of guidelines as guides for a spacer means while lowering a subsequent plurality of guidelines to the subaqueous bottom and anchoring the subsequent plurality of guidelines at a predetermined location, and continuing the sequential anchoring in the foregoing manner until all of the groups of guidelines have been anchored.

9. Apparatus for locating and anchoring bottom-to-surface guidelines of a subaqueous guidance and alignment system comprising: a base adapted to be located at a subaqueous bottom including a well location means and anchorage means near said well location means and having predetermined spatial relationships thereamong, each of said anchorage means comprising receptacles having recesses therein; a plurality of guidelines having self-anchoring means adapted to automatically anchor at said anchorage means upon engagement therewith, each of said self-anchoring means comprising a pin having a spring-loaded anchor-latching element thereon which is shearable from said pin, said anchor-latching element being adapted to engage said recess on said anchorage means upon contact a spacer frame including a plurality of guideline-receiving means having said predetermined spatial relationships thereamong, more than one of said receiving means adapted to be guided along previously anchored guidelines when said spacer frame is lowered along said previously anchored guidelines carrying said self-anchoring means of at least one other of said plurality of guidelines at other of said guideline-receiving means; and means for raising and lowering said spacer frame between the surface and said anchorage means.

11. The apparatus of claim 10 wherein each said anchoring means includes a spacer frame latching element extending from said pin above said flange, and said guideline-receiving means comprises an aperture extending through said frame having a latching recess for receiving said spacer frame latching element.

12. The apparatus of claim 9 wherein said spacer frame comprises a yoke and said guideline-receiving means comprise apertures located at the ends and center of said yoke.