US3554281A

US3554281A - Retrievable circulating valve insertable in a string of well tubing

Info

Publication number: US3554281A
Application number: US850893A
Authority: US
Inventors: John H Ecuer
Original assignee: Pan American Petroleum Corp
Current assignee: Pan American Petroleum Corp
Priority date: 1969-08-18
Filing date: 1969-08-18
Publication date: 1971-01-12
Anticipated expiration: 1988-01-12

Abstract

A system for use particularly in multiple completion wells to facilitate the use of '''' (pumpdown tools). Two production strings are connected downhole by a crossover port. During normal producing operations the port is closed. When it is desired to use PDT, or pumpdown tools, the crossover port is opened, thereby establishing a circulating path down one string and up the other. The port is opened by merely applying pressure in one of the strings.

Description

United States Patent John H. Ecuer Lafayette, La.

Aug; 18, 1969 Jan. 12, 1971 Pan American Petroleum Corporation Tulsa, Okla.

a corporation of Delaware Inventor Appl. No. Filed, Patented Assignee RETRIEVABLE CIRCULATING VALVE INSERTABLE IN A STRING or WELL TUBING 5 Claims, 3 Drawing Figs.

US. Cl. 166/155, 7 166/224 Int. Cl E2lb 33/16, E2lb 33/00 Field of Search [56] References Cited UNITED STATES PATENTS 3,053,322 9/1962 Kline 166/224 3,130,782 4/1964 Rike 166/313 3,294,174 12/1966 Vincent 166/224 3,361,206 l/l968 Raulins..... 166/315 3,376,935 4/1968 Baker 166/224 3,381,753 5/1968 Fredd 166/189 Primary Examiner-James A. Leppink Attorneys-Paul F. Hawley and John D. Gassett ABSTRACT: A system for use particularly in multiple completion wells to facilitate the use of PDT (pumpdown tools). Two production strings are connected downhole by a crossover port. During normal producing operations the port is closed. When it is desired to use PDT, or pumpdown tools, the crossover port is opened, thereby establishing a circulating path down one string and up the other. The port is opened by merely applying pressure in one of the strings.

I PAIENTEB JAN12I97I SHEET 2 BF 2 JOHN H. ECUER FIG.

ATTORNEY RETRIEVABLE CIRCULATING VALVE INSERTABLE IN A STRING OF WELL TUBING.

BACKGROUND OFTI-IE mvahriou Field of the Invention Setting of the Invention ing offshore wells'in which a stationary platform is erectedwhich is supported by the ocean bottom and extends to above the surface of the waterLIf the platform system is used, the completion procedure can be quite similar to those used on dry land but a may 'also use PDT technique with crossover. However, when the well head assembly is placed on the ocean floor, a new set of problems is raised with respect to carrying out workover operations, maintenance or otheroperations in a' completed well. In order to carry out some of the more simple workover operations, such as perforating a well casing or removing paraffin, it has become necessary to develop an entirely new line of welltools which can be, pumped through a production line from some remote location which may be a mile ormore away. These tools enter the well by passing down the tubing string to be subsequently selectively positioned to carry out the selected operations. After'completing the operation, the tool in the tubing string within the wall is ordinarily removed by a reverse circulation operation. These tools and techniques are commonly called through-the-flow-line-type operations or PDT equipment because they are pumped down through the production flow line string. There has been considerable literature on this type operation. Further, commercially available tools can 'readily be obtained, for example, from Otis Engineering-Corporation, Dallas, Texas.

Although there has been-considerable effort expended to date developing hydraulic PDT equipment, there are still certain areas where improvementis needed. One such area is in the adaptation of the system to multiple completion well, i.e., the wells are separately produced from more than one productive zone. The need exists for an improvedsystem for providing a crossover between two production strings and means for opening and closing the crossover. This invention provides such improved means sothat the two strings can be usedfor separate production with'the port closed, or with the'port opened it can be used to circulate PDT equipment.

BRIEF DESCRIPTION OF THE INVENTION This is a devicefor use in PDT systems. In accordance with this invention atleast two production strings are suspended in the well. Near the lower end a port means or passage connects the two strings. A standing valve recess is provided in at least one of the strings immediately below the crossover port. A

special standing valve is provided. In ordinary operations the In a preferred embodiment a standing valve housing having a port in it is positioned adjacent the crossover port. A standing valve cage or. carrier is mounted inside thehousing and is held in an upper position by a shear pin. When in this position the standing valve cage seals the crossover port. By applying pressure to the string in which the standing valve is located. the shear pin is sheared and ports in the upper part of the standing valve cage are aligned with the ports in the crossover and in the standing valve housing. Thus, communication is obtained between the two strings. The standing valve and its housing can be pumped in or retrieved with latch-on or PDT equipment.

Various objects and a better understanding of the invention can be had from the following description taken in conjunction with the drawings.

DRAWINGS FIG. 1 illustrates a downhole arrangement of a crossover port between two production strings and the retrievable standing valve in a position closing ,the crossover port means.

FIG. 2 is similar to FIG. 1 except that the standing valve cage has been shifted to open the port means between the two strings of tubing.

FIG. 3 illustrates a pumpdown tool locomotive for use in retrieving the standing valve and its housing.

Attention is first directed to FIG. 1 which shows a first tubing string 10 which can be called the short string and a second tubing string 12 which, for convenience, can be called the long string. The short string is provided to produce fluid from an upper formation 14 and the long string is provided to produce from a lower prodtlcing interval l6. A packer l8 prevents communication in the casing 20 between production from the two zones. 7

Near the lower end of the short string 10 is a crossover-port 22 which, when open, establishes fluid communication between the short string 10 and the long string 12. A standing valve recess 24 having-upwardly facing shoulder 26 is provided in the long string just below the crossover port 22. A short distance above crossover port 22 there is provided a latching groove 28 in long string 12. A retrievable tool for holding the standing valve is shown in the long string 12. This includes outer housing 30 resting on seat 26 of recess 24. The housing contains ports 32 which are on the same horizontal level as crossover port 22. These ports 232 are spaced around the housing and radial alignment is not necessary. Sealing means such as cups 34' and 36 are, respectively, placed below and above port 32 so as to prevent fluid communication from crossover port 22 up between the'retrievabletool 29 and the wall of long string 12. Piston cups 35 are provided at the upper end of housing 30 to keep sand out of latching groove 28.- The piston cups 35 also make it possible to pump the housing 30:

and its associated parts back down the string 12.

Mounted within housing 30 is a standing valve cage 38: This valve cage means 38 serves a double function. Besides the ordinary function as a valve cage, it serves as a sleevetvalverfor closing and opening port 22. This cage valve means 38 is held. in its upper position by shear pin 40; When in this position thew lower part of the cage 38 acts as a sleeve valve and .sealsnhe" crossover port 22 and port 32 of the housingso that fluid com-2 munication between the two strings is not permitted. Seals-44 and 46, above and below, respectively, port 32', are provided.

Cage 38 has ports 39 in the upper end and when in'the. position of FIG. 1, ports 39 are above seals 46. The lower-end of; standing valve cage 38 is provided with a valve seat :48and fa ball valve 50. "T his permits production to flowupwardlythrough long string 12.

Housing 30 is held in place against seat '26 by latching-dogs 52. These latching dogs 52 are mounted in the-upper wall. of

housing 30 about pivots 60 and are biased outwardlyluNotoh means 28 are provided in the wall of housing 30so-that th'e" latching dogs 52 can pivot about point 60. LatchingdogsS-Z also include tripping shoulders 64. It is noted that latching dogs 52 are below piston cups 35 and serve to keep the sand away from the latching dogs.

FIG. 1 showed the position of the standing valve-cageduring.

normal production operations. When it is desired totreat the two strings as a circulating string for the pumpdown tool, it is necessary to open the port 22 between the two. Before the port is opened, both completions (through strings l and 12) are shut in. If wells are of equal pressure, merely shut wells in and shear pin in long string. If one well has more pressure than the other, enough back pressure would have to be maintained on system to prevent this well from flowing. Opening of port 22 is accomplished simply by applying sufficient pressure in long string 12 to shear pin 40. When this pin is sheared the standing valve cage is driven to the position shown in FIG. 2. At this time it will be seen that the port means 39 in the upper end of standing valve cage 38 is aligned with the port 32 of housing 30 and also with the crossover port means 22.

When the standing valve cage is in the position shown in FIG. 2, the system is then available or in a condition to be operated as the conventional PDT system; that is, fluid can be pumped down one string and up the other. If will be recalled that it is this completion of the hydraulic circuit which makes the system operable. A device sometimes called a locomotive and at other times called an operating tool is moved along one string of the circulating path. This operating tool or locomotive carries with it any of a number of tools for performing downhole operations, such as perforating guns, paraffin scrappers, etc. The locomotive and its associated tool are pumped down through whichever string it is desired to perform the operation. If the operation is to be performed in the long string 12 in which a retrievable tool is, it is normally desired to remove the retrievable tool before attempting the workover operation in that string. This is conveniently accomplished by pumping locomotive with its latch-on tool down the long string 12. To provide this, the locomotive is provided with a collet which is used for pulling the retrievable tool. Attention is directed to FIG. 3 which generally illustrates a locomotive for retrieving the housing 30 and its associated parts. This includes a locomotive section 70 and a lower latching portion 72. Lower latching portion 72 includes latching dogs 74. These latching dogs 74 are designed to latch into latching grooves 76 in the inner wall of the upper end of housing 30. There are locomotives" commercially available and the one shown here is merely for purpose of illustrating the overall operations. Thus, as locomotives such as illustrated by numeral 70 and latching means 72 are well known, no more detail will be given. When it is desired to remove the retrievable housing 30 and associated parts, the locomotive of FIG. 3 is pumped down long string" 12 in a known manner. When the locomotive reaches the housing 30, latching dog 74 latches into latching grooves 76. Just before this occurs though, the lower end of the plug 72 strikes unlatching shoulder 64 thus unlatching locking dogs 52. As soon as the 'tool is locked in, fluid is then circulated down short string and back up string 12. This forces the locomotive to the surface and it brings with it the retrievable housing 30 and its associated parts. Once the retrievable tool 29 is removed, the locomotive and its operating tool are lowered down through long string 12 so that the desired operation can be performed.

After the various operations have been performed with the PDT equipment, it is then desired to rerun the retrievable tool 29. However, before this is done, the standing valve cage 38 is placed on the position shown in FIG. 1 and a new shear pin 40 installed. The retrievable tool is then placed in the long string 12 and driven by hydraulic pressure to the position shown in FIG. 1. It will be noted that the shear pin 40 is of sufficient S strength to permit the tool to be driven to the well bore. However, the shear pin is of such low strength that it can be sheared by the application of pressure as described above. When the tool is repositioned as shown in FIG. 1, normal production operations can again be resumed.

While the above preferred embodiment has been described with a great deal of detail, other modifications can be made thereto without departing from the spirit or scope of the invention.

lclaim:

1. An apparatus to facilitate the use of through-the-flow-line tools in multiple completed wells which comprises:

a long string of tubing suspended in a well bore; a short string of tubing suspended in a well bore;

a passage downhole between said long string and said short string, said passage having a first port opening into a said long string and a second port opening into said short string;

first seat means in said long string below said first port means;

a retrievable tool set on said first seat, said retrievable tool permitting unidirectional flow of fluid upwardly therethrough; and

said retrievable tool including valve means having a first position and a second position, said valve means when in said first position closing said first port to prevent the communication of fluid between said long string and said short string, and when in said position opening said first port.

2. An apparatus as defined in claim 1 in which said retrieva- 35 ble tool includes:

a hollow housing member having a port therein opposite said first port of said passage when said body member is seated on said seat means of said long string;

and said valve means including:

a standing valve in said housing member, said standing valve having a cage and a ball therein, said cage having ports near its upper end; and

shearable means holding said standing valve cage in a first position so as to seal said first port, said standing valve cage when in a second position having its port aligned with said first port.

3. An apparatus as defined in claim 2 including latching dog means between said housing member and the inner wall of said long string of tubing.

4. An apparatus as defined in claim 3 including a latching groove in the inner wall of said housing member near its upper end.

S. An apparatus as defined in claim 3 including piston cup means mounted on the upper end of said housing member so 55 that said housing member can be pumped down said long string.

Patent No.

Inventor(s) It is certified that error appears and that said Letters Patent are hereby Column Column Column Column Column 3,

Column 3,

Column Column UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,55% Dated January 12, 1971 John H. Ecuer in the above-identified patent corrected as shown below:

line 36, "well" should read --well--.

line 20, after "into" delete "a".

line 32, after first "said' insert second--.

Signed and sealed this 20th day of April 1971.

(SEAL) Attest:

ETHARD M FIE-TC HER JR Attesting Officer WILLIAM E. SCHUYLER, JR. Commissioner of Patents

Claims

1. An apparatus to facilitate the use of through-the-flow-line tools in multiple completed wells which comprises: a long string of tubing suspended in a well bore; a short string of tubing suspended in a well bore; a passage downhole between said long string and said short string, said passage having a first port opening into a said long string and a second port opening into said short string; first seat means in said long string below said first port means; a retrievable tool set on said first seat, said retrievable tool permitting unidirectional flow of fluid upwardly therethrough; and said retrievable tool including valve means having a first position and a second position, said valve means when in said first position closing said first port to prevent the communication of fluid between said long string and said short string, and when in said position opening said first port.

2. An apparatus as defined in claim 1 in which said retrievable tool includes: a hollow housing member having a port therein opposite said first port of said passage when said body member is seated on said seat means of said long string; and said valve means including: a standing valve in said housing member, said standing valve having a cage and a ball therein, said cage having ports near its upper end; and shearable means holding said standing valve cage in a first position so as to seal said first port, said standing valve cage when in a second position having its port aligned with said first port.

5. An apparatus as defined in claim 3 including piston cup means mounted on the upper end of said housing member so that said housing member can be pumped down said long string.