US3866160A - Signaling the location of underwater wells - Google Patents

Abstract

Method and apparatus for use in locating the position of underwater wells involves a signal emitter adapted to be propelled through a flow line to a selected point proximate a wellhead where it signals the location of the well for such purposes as establishing the vertical re-entry point of the well for workover rigs.

Description

United States Patent 91 Brasier [451 Feb. 11,1975

1 1 SIGNALING THE LOCATION OF UNDERWATER WELLS [76] Inventor: Charles A. Brasier, 4508 Wade Dr.,

Metairie, La. 70003 [22] Filed: May 29, 1969 2 1 Appl. No.: 828,925

[52] US. Cl. 340/5 R, 166/65 R, 166/153, 166/156, 166/253, 18l/0.5 R, 18l/0.5 A

[51] Int. Cl. H041) 13/02, E2lb 47/12 [58] Field of Search 166/65 R, 253, 66, 77, 166/153, 156; l81/0.5 A, 0.5 P, 0.5 R; 340/5 [56] References Cited UNITED STATES PATENTS 4/1959 En Dean et a1, 340/18 NC 1/1964 McStravick 4/1967 Yetman WORK-OVER VESSEL 3,401,749 9/1968 Daniel 166/46 3,407,384 9/1968 Wiley 3,554,284 1/1971 Nystrom 166/250 OTHER PUBLICATIONS C. A. Brasier et al., Pump-Down Completion and Workover Techniques for Satellite Underwater Wells, ASME Publication 67-PET-40, July 13, 1967.

Primary Examiner-Maynard R. Wilbur Assistant Examiner-11. A. Birmiel Attorney, Agent, or Firm-John S; Schneider [57] ABSTRACT Method and apparatus for use in locating the position of underwater wells involves a signal emitter adapted to be propelled through a flow line to a selected point proximate a wellhead where it signals the location of the well for such purposes as establishing the vertical re-entry point of the well for workover rigs.

4 Claims, 8 Drawing Figures PATENTEU H975 3,866,160

SHEET 10F 2 WORK-OVER VESSEL 1:1

INVEN'IOR.

CHARLES A. BRASIER,

kqgf Mm ATTORNEY;

PMEHTEUFEBI 1 I915 3.866.160

SHEEIZOFZ lh I; l: A 1

IHI

m m v i l INVENTOR.

CHARLES A. BRASIER, BY K ATTORNEY.

SIGNALING THE LOCATION OF UNDERWATER WELLS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the problem of locating underwater wells. More particularly, the invention is directed to locating an underwater well having a flow line extending into the well from an accessible but remote point. More specifically, the invention is concerned with method and apparatus for employing through flow line techniques to run tools, and the like, in wells, and is particularly adapted to the use of such techniques in underwater wells.

2. Description of the Prior Art Devices (such as acoustical beacons) are known and used to mark and signal the location of underwater wells, so that, for example, vertical re-entry can be made through the wellhead into a well for workover operations. These signal devices, typically attached by divers at or near the well or wellhead, are continuously subjected to the rigors of the underwater environment, which accelerates the end of the useful life of their energy sources, usually batteries. This necessitates periodic replacement or maintenance of the signal device or its power source, a difficult operation that takes highly expensive manpower and seagoing equipment. As exploration for oil moves into deeper and deeper waters, to the extent that divers are still able to do these jobs, the costs will get even dearer, and known methods of locating the underwater wellhead to protect the investment it represents will be inadequate.

SUMMARY OF THE INVENTION This invention overcomes the limitations and problems associated with the deployment, protection and recovery of known underwater signal devices by making use of equipment usually already on site with techniques now in the hands of producers of oil from subsea locations. It has as its purposes and objects the provision of apparatus and method that not only is useful for locating the position of an underwater well, but further, permits installation, retrieval and change of underwater signal devices without the use of divers or remote manipulators. In addition, it provides an underwater signaling device which is not subjected to the ocean environment. A special feature of the invention is that it enables one signal source to be used to serve several wells, thereby reducing the number of sources needed for that purpose.

Briefly, these and other objects of the invention are accomplished by a signal emitter adapted to be propelled to and from a selected point in a conduit forming a passageway extending from an accessible remote place into an underwater well having a wellhead. The selected point in the conduit is proximate the wellhead. In one aspect, the conduit is curved, and either fluid pressure or mechanical force originating externally of the conduit is exerted against the signal emitter to propel it through the conduit. When the signal emitter is adapted for fluid pressure propulsion, at least a portion of the signal emitter is shaped to close the annulus between it and the inner wall of the conduit sufflciently to permit it to be pumped through the conduit to the selected point in the conduit. By inserting a signal emitter adapted to be propelled through a conduit forming a passageway extending into an underwater well from an accessible remote place, and then by moving it through the conduit to a predetermined point in the conduit proximate the wellhead of that underwater well, one is enabled to signal the precise location of that well.

BRIEF DESCRIPTION OF THE DRAWINGS Forms in which the invention may be embodied are shown in the drawings accompanying and forming part of the present specification. Referring to the drawings:

FIG. 1 is a schematic view of a well completed off water bottom showing curved conduit extending into a wellhead;

FIG. 2 is a side elevational view of a portion of conduit remote from an underwater wellhead, with a portion of the conduit broken away to reveal a signal emitter in passage;

FIG. 3 is a side elevational view of a portion of a Christmas tree at an underwater wellhead, with a portion ofa conduit extending into the wellhead being broken away to show a signal emitter which has been run into place;

FIG. 4 is a schematic view of a well completed on water bottom in which curved conduit extends into a wellhead;

FIG. 5 is a view in vertical longitudinal section of a portion of conduit carrying a mechanically propelled signal emitter in transit;

FIG. 6 is the same view as FIG. 5, but showing a signal emitter being moved by fluid pressure;

FIG. 7 is a side elevational view of a signal emitter of this invention; and

FIG. 8 is a schematic top plan view of a conduit system in which the present invention may be employed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The forms shown in the drawings will now be described in detail for the purpose of illustrating how the general principles of the invention may be carried out.

Referring now to the drawings, in which identical numerals identify like parts in the various embodiments, and in particular to FIGS. 1 and 4, reference numeral 10 indicates the surface of a body of water 11 in which an underwater well generally indicated by reference numeral 12 is completed. In FIG. 1, underwater well 12 is completed at a wellhead 13 on a submerged platform 14 off water bottom 15. In FIG. 4., underwater well 12 is completed on water bottom 15 A well casing 16 is arranged in the underwater well and cemented into place by the usual techniques. Attached to well casing 16 by flange members or connectors 17 is a wellhead Christmas tree 18 which is closed at its open end by flanged member or connector 19. It will be noted that the well 12 is completed substantially below water surface 10.

Connected to the Christmas tree 18 are a plurality of curved flow lines conduits 20 and 21, whose passage into the Christmas tree is regulated by wing valves 22 and 23. Flow lines 20 and 21, which are interconnected above wing valves 22 and 23 by a bypass valve 24, connect respectively to tubing or pipe strings 25, 26 which extend into the well to one or more hydrocarbon productive strata (not shown) from which oil and/or gas may be obtained or into which fluids may be injected. The tubing strings 25, 26 may suitably be interconnected at one or more points intermediate their end for workover operations and the like. Flow lines 20 and 21 extend into well 12 from an accessible remote station, such as the support platform 27 which may be grounded on bottom by suitable structure as illustrated in FIG. 4, or an onshore site 28 as illustrated in FIG. 1.

In FIG. 1, flow lines and 21 are terminally closed with suitable removable covers 29. A line 30 provided with suitable valves connects a pump 31 into flow lines 20 and 21. Pump 31 is connected to a source of fluid 32 by means of a line 33. That fluid may suitably be oil produced from strata underlying water bottom 15. Similarly, in FIG. 4, lines 20 and 21 are adapted to be connected by valve controlled line 30 to a pump (not shown). Fluid can pass from a source 32 into lines 20 and 21 under control of valved lines 34. Lines 20 and 21 have valves on both sides of the inlet from line 30. In addition, platform 27 is provided with a pipe reel 35 onto which is wound a continuous length of substantially inflexible tubing 36 (tubing which will support its own weight). Tubing 36 feeds off pipe reel 35 across straightening rollers 37 (such as described by McStravick in US. Pat. No. 3,116,793 issued Jan. 7, 1964) through an adapter 38 into flow line 21.

A signal emitter 40 adapted to be propelled through a flow line conduit, in accordance with this invention, is illustrated in FIG. 2. A housing 41 encloses a sonic pinger or radioactive source or an electrical high frequency transmitter. Housing 41 is fitted with a piston 42 closing the annulus between the inner wall of flow line conduit and the housing sufficiently to permit the signal emitter to be pumped through the flow line by fluid pressure exerted against the piston. Another way in which signal emitter 40 is adapted to be pumped through a flow line is shown in FIG. 6. The signal emitter 40 may be carried by a tool or locomotive assembly 43 constructed for movement in a flow line. In the form illustrated, the signal emitter housing 41 is secured to a locomotive assembly 43 comprised of a series assembly of two-way pump cups 44 and 45 closing the interior of flow line 20 sufficiently to permit locomotive assembly 43 to be pumped therethrough. The pistons employed on signal emitter 40 and locomotive assembly 43 may suitably be structured with ball valve passages as known to the art. The housing 41 of the signal emitter 40 may have nonclosure runners or slides 46 to decrease wobbling or prevent jamming of the emitter housing during passage. The piston 42 of the signal emitter 40 in FIG. 2 may incorporate the whole length of the housing to provide this protection. The fluid pressure exerted against signal emitter 40 or locomotive assembly 43 to pump the signal emitter through flow line 20 is supplied by the action of pump 31.

In addition to the pumpdown methods of delivering a signal emitter through a conduit to a predetermined site, mechanical force originating externally of the conduit may be exerted on the signal emitter to accomplish the same result. As shown in FIGS. 4 and 5, a signal emitter 40 is adapted to be propelled through flow line 20 by the feed of the continuous length of tubing 36 from pipe reel 35 across straightening rollers 44.

Loops presently formed in two-inch flow lines have a typical diameter of about 5 feet, and the length of any cylindrical segment moved through such flow lines is limited to about 8 to l0 inches. Various levels of power may be needed to drive the circuitry of different signal emitters transmitting radio frequencies, yet space limitations may limit the size of the power source that can be contained in the same housing with the circuitry. However, as illustrated in FIG. 7, the signal emitter may be made up of a segment 47, containing the signal generating circuitry, electrically linked by a flexible coupling 48 to another segment 49, containing one or more power sources. Segment 49 may be connected by a flexible coupling to another segment carrying a power source, and in this way, any desired level of power to drive the signal generating circuitry may be obtained.

The preselected point in the conduit to which the signal emitter is propelled is proximate the wellhead of well 12. Most advantageously, where the wellhead is fitted with a Christmas tree, as illustrated in FIGS. 1 and 4, the wing valves 22 and 23 may be closed, the bypass valve 24 opened, and the signal emitter of FIG. 3 or locomotive assembly and signal emitter of FIG. 4 pumped down to lodge at the site of the wing valve 22 in the flow line 20. Generally, the task of locating the re-entry point of the well, which is the wellhead, is less advantageously served by placing the signal emitter below the wellhead. However, in some instances, such as when the wellhead is a substantial distance above water bottom (FIG. 1), it may be desired to locate the signal source in the flowline at some distance intermediate the level of wellhead 13 and water bottom 15, or in some instances, even adjacent water bottom 15. This may be accomplished by propelling the signal emitter to the wellhead and then pumping the volume of fluid through the flow line which would displace a column of fluid whose height equals the distance down the flow line from the wellhead which it is desired to place the emitter. Alternatively, the tubing 36 driven by pipe reel 35 may be employed to propel the signal emitter down the flow line to a preselected site adjacent the wellhead or between it and the water bottom by measuring the length of tubing rolled off the reel into the flow line.

In the practice of the present invention, referring to the FIGS. 1-7 inclusive, the position of an underwater well 12, and particularly wellhead 13, is made ascertainable by inserting a signal emitter 40 adapted to be propelled through a flow line into such flow line, closing the flow lines with covers 29, and propelling the signal emitter through the flow line to a selected point in the flow line conduit proximate the wellhead 13, where it operates to signal the position of the well.

As illustrated in FIGS. 1 and 3, signal emitter 40 has been pumped to Christmas tree 18 with wing valves 22 and 23 closed and the bypass valve 24 open. A sonic pinger, a radioactive source, or a high frequency transmitter in signal emitter 37 sends out signal which are picked up by an acoustical, radioactive or high frequency signal detector carried by a workover rig or the like riding on water surface 10.

To retrieve the pumped down locomotive assembly and sonic emitter, the wing valves 22 and 23 are maintained closed and bypas valve 24 is kept open. Fluid is pumped down through the flow line 21 to reverse circulate flow between flow lines 21 and 20 and thereby pump signal emitter 40 through flow line 20 from the Christmas tree 18 on the wellhead 13 to support platform 27 or onshore site 28, where the signal emitter may be removed from line 20.

The emitter delivered to site by tubing 36 is retrieved by withdrawing the tubing to which the emitter is attached. Alternatively, if the tubing has already been withdrawn, a grabber" tool may be run down the flow line and attached to the emitter by pump or mechanical action and retrieved by pumping or by retrieval of tub- As illustrated in FIG. 8, the signal emitter of the present invention may be utilized to locate the positions of a selected one of a plurality of horizontally spaced un' derwater wells 50, 51, 52 and 53. Each ofthe underwater wells has conventional wellheads (not shown) mounting therein at least two pipe strings (e.g., 50a and 50b in well 50). These two pipe strings are interconnected at some point along their length, such as adjacent their lower ends. Each of the wells 50, 51, 52 and 53 is connected into a single flow line circuit that is normally underwater except at an accessible remote platform 54, where the flow line circuit starts and ends.

The flow line circuit is made up of fluidly communicating conduits 55, 56, 57, 58, 59, 60, 61, 62 and 63, which form fluid passageways. In the flow line circuit, flow line conduits 55 and 56 each extend from the remote platform 54, where they are accessible, to connect, respectively, with an interconnecting pipe string in underwater wells 50 and 53, e.g., pipe strings 50a and 53a. The other interconnecting pipe strings of wells 50, 53 and the interconnecting pipe strings of wells 51, 52 are successively fluidly interconnected by underwater flow lines 57, 58 and 59. Flow line 57 interconnects pipe string 50b (interconnected with pipe string 50a) with pipe string 51a; flow line 59 interconnects pipe string 51b (interconnected with pipe string 51a) with pipe string 52a; and flow line 58 interconnects pipe string 52b (interconnected with pipe string 52a) with pipe string 53b, interconnected with pipe string 53a. One or both of the pipe strings connected into the flow line circuit may be controlled by means of valves, in the manner disclosed in Ser. No. 604,670, filed Nov. 21, 1967 for Thomas W. Childers and Edmond R. Genois and having a common assignee with the present application.

Bypass flow line conduits 60, 61, 62 and 63, respectively proximate each of the wells 50, 51, 52 and 53, interconnect, respectively, flow line conduits 55 and 57, 57 and 59, 59 and 58, and 58 and 56. Admission of fluid into any of bypass conduits 60, 61, 62 and 63 or into the pipe strings of wells 50, 51, 52 and 53 is controlled by a flow path diverter switch, constructed, for example, after the teachings of US. Pat. Nos. 398,836; 904,414; 3,206,140; and 3,410,501. The flow path diverter switch is placed proximate either or both entrances of the bypass conduit at all wells, for example, at one of the connection unions between a bypass conduit and one of the flow path conduits, as illustrated in FIG. 8, in which the flow path diverter switches are enumerated 64, 65, 66 and 67. Placement of the diverter switch at the left entrance to the bypass conduit, as illustrated in FIG. 8, permits clockwise flow through the flow line circuit. Conversibly, placement of the diverter switch at the right entrance to the bypass conduit allows counter-clockwise flow. Diverter switch installation at both entrances of the bypass conduit enables the operator to use both clockwise and counter-clockwise flow. Each of the bypass flow lines 60, 61, 62 and 63 is provided with a suitable foraminous stop 68, 69, 70 and 71, respectively, mounted therein to control (permit or prevent) passage of through flow line tools through the bypass flow line while permitting fluid passage, therethrough. Compare, for example, the foraminous vane of US. Pat. No. 3,261,048.

To establish a flow path to a position proximate a se lected well, all the flow path diverter switches between the remote accessible platform 54 and the flow path diverter switch of the well immediately past the selected well are actuated to establish a mandatory flow path into the bypass conduits from the platform 54 up to and inclusive of the bypass conduit of the selected well. All the bypass conduit stops between the diverter valve of the selected well and the remote platform 54 are opened and the stop for the bypass conduit of the selected well is closed. For example, in FIG. 8, flow path diverter switches 64, 65 and 66 are operated to divert flow into bypass conduits 60, 611 and 62, and bypass conduit stops 68 and 69 are opened while stop 70 is closed. Thus, a tool attaching or incorporating a signal emitter may be inserted into remotely accessible conduit 55 and propelled by fluid pressure exerted on it, successively through conduits 55, 60, 57, 61 and 59 into conduit 62, where it is lodged. By this manner, the position of a selected underwater well among a plurality of underwater wells may be ascertained. Retrieval of the signal emitter may be effected by opening stop 70, switching diverter valve 67 into bypass conduit 63, and opening bypass conduit stop 71 to open a circuit for the emitter back to platform 54.

The nature and objects of the present invention, having been fully described and illustrated, what id claimed is:

I claim:

1. A method of locating the position of a selected underwater well among a plurality of horizontally spacedapart wells, each having an underwater wellhead and at least two interconnected pipe strings, each of said wellheads being interconnected successively to another of said wellheads by underwater conduits forming fluid passageways providing fluid communication from one well to another, at least two of said wells having a remotely accessible conduit fluidly communicating with a remotely accessible location, said remotely accessible conduits forming with said underwater conduits a flow line circuit beginning and ending at said remote accessible place, said method comprising:

a. inserting a signal emitter into one of said remotely accessible conduits; and

b. propelling said signal emitter through said flow line circuit to a selected position in said flow line circuit proximate said selected underwater well.

2. An apparatus for signaling the location of a selected underwater well among a. plurality of horizontally spaced-apart underwater wells, each having an underwater wellhead and at least two interconnected pipe strings, each of said wellheads being interconnected successively to another of said wellheads by underwater conduits forming fluid passageways providing fluid communication from one well to another, said apparatus comprising:

for each of at least two of said wells, a remotely accessible conduit extending :into the wellhead of such well from a remotely accessible place, said conduits of said wells forming with said underwater conduits a flow line circuit beginning and ending in said remote accessible place, and

a signal emitter in at least one of said remotely accessible conduits adapted to be propelled therecircuit proximate a second underwater well in said circuit for location of said second well.

4. The method of claim 1 wherein said signal emitter is recovered from a second of said remotely accessible conduits after traveling through said flow line circuit.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,866,160 DATED 1 February 11, 1975 INVENTOR(S) Charles A. Brasier it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the bibliographical data:

Exxon Production Research Add [73] Assignee:

Company, Houston, Tex.-

Signed and sealed this 24th day of June 1975.

(SEAL) Attest: C. MARSHALL DANN RUTH C. I'IASON Commissioner of Patents Attesting Officer and Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3 6 1 DATED February 11, 1975 iNVENTOR(S) 3 Charles A. Brasier it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the bibliographical data:

Add --[73] Assignee: Exxon Production Research Company, Houston, Tex.--

Signed and sealed this 24th day of June 1975.

SEAL) At t e S t 1 C MARSHALL DANN C. MASON Commissioner of Patents Attesting, Officer and Trademarks

Claims (4)

1. A method of locating the posItion of a selected underwater well among a plurality of horizontally spaced-apart wells, each having an underwater wellhead and at least two interconnected pipe strings, each of said wellheads being interconnected successively to another of said wellheads by underwater conduits forming fluid passageways providing fluid communication from one well to another, at least two of said wells having a remotely accessible conduit fluidly communicating with a remotely accessible location, said remotely accessible conduits forming with said underwater conduits a flow line circuit beginning and ending at said remote accessible place, said method comprising: a. inserting a signal emitter into one of said remotely accessible conduits; and b. propelling said signal emitter through said flow line circuit to a selected position in said flow line circuit proximate said selected underwater well.

2. An apparatus for signaling the location of a selected underwater well among a plurality of horizontally spaced-apart underwater wells, each having an underwater wellhead and at least two interconnected pipe strings, each of said wellheads being interconnected successively to another of said wellheads by underwater conduits forming fluid passageways providing fluid communication from one well to another, said apparatus comprising: for each of at least two of said wells, a remotely accessible conduit extending into the wellhead of such well from a remotely accessible place, said conduits of said wells forming with said underwater conduits a flow line circuit beginning and ending in said remote accessible place, and a signal emitter in at least one of said remotely accessible conduits adapted to be propelled therethrough to a selected position in said flow line circuit proximate a selected underwater well.

3. The method of claim 1 wherein said signal emitter is propelled first to a position in said flow line circuit proximate a first underwater well in said circuit for location of said first well, and then to a position in said circuit proximate a second underwater well in said circuit for location of said second well.

4. The method of claim 1 wherein said signal emitter is recovered from a second of said remotely accessible conduits after traveling through said flow line circuit.

Images