US3032104A - Completion and working over of wells - Google Patents

Description

May I, 1962 w. M. OREILLY COMPLETION AND WORKING OVER 0F WELLS 3 Sheets-5heet 1 Filed Oct. '7, 1959 11:! V EN TOR.

WALLACE M. O'REILLY,

y 1, 1962 w. M. O'REILLY 3,032,104

COMPLETION AND WORKING OVER 0F WELLS Filed Oct. 7, 1959 5 Sheets-Sheet 2.

FIG. 5.

I I VV ENTOR. WALLACE M. O'REILLY,

ATR

May 1, 1962 w. M. OREILLY COMPLETION AND WORKING OVER 0F WELLS 5 Sheets-Sheet 3.

Filed Oct. 7, 1959 F IG. 8.

INVENTOR.

WALLACE M. O'REILLY,

ATTORNE Y.

3,032,104 COMPLETION AND WORKING OVER OF WELLS Wallace M. OReilly, Midland, Tex., assignor, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla., a corporation of Delaware Filed Oct. 7, 1959, Ser. No. 845,005 7 Claims. (Cl. 166-35) The present invention is directed to a method for cornpleting and working over a well. More specifically, the invention is concerned with the completion and working over of wells penetrating a plurality of hydrocarbon productive zones. In its more specific aspects, the invention is directed to completing and working over of wells for simultaneous and separate production from a plurality of hydrocarbon productive zones.

The present invention may be briefly described as a method for completing and working over a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone. The well has an eccentric second pipe string which is fluidly connected at its lower end to the first pipe string at a point between the two zones. The two zones are separately perforated and the perforated zones are isolated from each other above the point of fluid interconnection for separate production of hydrocarbons from each of the zones. The lower zone may be perforated first and then the two zones are isolated from each other and the upper zone is then perforated last. The production from the upper zone proceeds upwardly through the first pipe string and production from the lower zone proceeds upwardly through the second pipe string.

One of the zones is isolated from the other of the zones when it is desired to work over the one zone and a workover fluid such as a cementitious material, stimulating agents such as hydrochloric acid, surface active agents, and plastics, consolidating agents, and the like are flowed down the first pipe string to the first zone and any excess is removed up the second pipe string with fluid in the well being displaced up the second pipe string.

It is contemplated in the practice of the present invention that the upper zone may be isolated from the first pipe string and a workover fluid flowed down the first pipe string and up the second pipe string for Working over the lower zone. It is also contemplated that the zones may be isolated below the point of fluid interconnection and a workover fluid flowed down the first pipe string and up the second pipe string to work over the upper zone. It is further contemplated that when necessary, the two zones may be isolated above the point of fluid interconnection and the two zones separately pumped to produce hydrocarbons to exhaustion of the two zones.

In the practice of the present invention, the first pipe string is of such diameter that all tools may be lowered downwardly therethrough while the second pipe string is of such diameter sufiicient to conduct fluids to the wellhead. It is further contemplated in the practice of the present invention that the first pipe string will be reduced in diameter from a point just above the point of fluid interconnection to its greatest depth in the well.

The diiference in diameters of the upper and lower portions of the first pipe string will permit easy passage in the upper portion for tools having sealing elements (packers) or holding elements such as slips or dogs which may require a closer fit in the lower portion where they will be employed. The same end result may be accomplished by using a single sized string equipped with seating and/or sealing nipples having fixed diameters which are positioned to become increasingly smaller toward the bottom of the hole.

States ateht ice The present invention will be further illustrated by reference to the drawing in which:

FIGS. 1 to 6, inclusive, are a stepwise illustration in partial section of apparatus for practicing a preferred mode of the present invention;

FIGS. 7a and 7b are elevational views partly in section of a pump tool suitable for use in the present invention; and

FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7a.

Referring now to the drawing and particularly to FIGS. 1 to 6 in which identical numerals will be employed to designate identical parts, numeral 11 designates a borehole drilled from the earths surface, not shown, to penetrate a plurality of hydrocarbon productive zones 12 and 13 which are vertically spaced apart. Arranged in the well bore 11 is a first pipe string 14 which extends from the wellhead, not shown, at least into the hydrocarbon productive zone 13. Connected into pipe string 14 at a point between the hydrocarbon productive zones 12 and 13 is a second pipe string 15 which is of smaller diameter than the pipe string 14. It is to be noted that the lower section 16 of the pipe string 14 is of lesser diameter than the upper section 17.

At spaced apart points in the pipe string 14 are suitable supporting means 18, 19, 20, 21, and 22. Supporting means 18 and 19, which will suitably be landing nipples or other anchoring or suspending means, are designed to support various completion and servicing elements as will be described further. A suitable landing nipple is described in the Composite Catalog of Oil Field Equipment and Services, 1958-59 ed., vol. 3, p. 3971. Lowered into the pipe string 14 on a wire line 23 is a perforator 24 which suitably may be a bullet gun perforator, a shaped charge perforator, or a mechanical or chemical perforator. The perforator 24 is operated in zone 13 to form perforations 25 from the pipe string 14 into the zone 13, the perforations 25 penetrating cementitious material 26 such as Portland cement which cements the pipe strings 14 and 15 in the borehole 11.

After the perforations 25 have been made through the cement 26 and into the zone 13, the perforator 24 is withdrawn through the pipe string 14 and a suitable wireline plug or barrier member 27 may be placed on the landing nipple 20 and sealed therein by lowering the barrier member 27 on a wire line. A suitable barrier member is described in Serial No. 769,343, new Patent No. 2,966,946 filed October 24, 1958, entitled Apparatus for Use in a Well Bore. Thereafter a perforator such as 28 is lowered on wire line 23 and suitably oriented by orienting means 29 such that its operative surface is positioned in a direction away from the pipe string 15 and such that only the pipe string 14 will be penetrated. An orienting means suitable for practice of the present invention is described in Ser. No. 756,666, filed August 22, 1958, entitled Alignment Means for Perforating Multi-Pipe String Wells. After perforations have been made in zones 12 and 13, hydrocarbon production may be suitably had from the two zones as shown most clearly in FIG. 3, the production from the upper zone proceeding through perforations 30 into the pipe string 14 to the wellhead while production from the perforations 25 proceeds to the wellhead through pipe string 14 and then through pipe string 15 to the wellhead, the barrier 27 preventing comingling of flow from the two formations.

When it is desired to workover the two zones and particularly the lower zone 13, a first tubular conduit 31 is lowered through the pipe string 14 and sealingly suspended therein in landing nipples 19 and 20 such that the perforations 30 are completely blanked off and flow from the perforations 30 into the pipe string 14 is terminated, seals 19:: and 20a being provided on the exterior of tubular conduit 31 for effecting the seal. Sealingly suspended within the tubular member 31 is a second tubular member 32 having its upper end sealed by sealing means 33 in the lower end of the tubular member 31. This tubular member 32 is of suflicient length to extend below the fluid interconnection between the pipe strings 14 and 15 and to extend to within or adjacent to the lower zone 13. Workover fluids may now be flowed downwardly through the pipe string 14 and into the lower zone 13. For example, cementitious material, consolidation agents, stimulating agents, and the like may be flowed downwardly through the pipe string 14 and into zone 13 and any excess removed upwardly through the annulus 34 into the pipe string 15 to the well head. Any fluid in the pipe string 14 would be displaced likewise up the pipe string 15. Of course, it is realized that if the zone 13 is cemented to fill the perforations 25, it may be necessary to reperforate in the zone 13, or into either zone, or between the zone 12 and the zone 13, or in a zone lower than the zone 13 if the pipe string extends a sufficient distance below, as is contemplated in the present invention.

Thereafter the tubular conduits 31 and 32 may be removed and production resumed by placing a barrier member such as 27 on the landing nipple to isolate the two zones.

When it is desired to workover the upper zone 12, a barrier member or plug such as may be lowered on a wire line such as 23 and placed on the landing nipple 22 to close off flow from the zone 13 through the perforations 25. Thereafter, a workover fluid which may be a stimulating agent may be flowed down the pipe string 14 with any excess or displaced fluid proceeding upwardly to the wellhead through the pipe string 15. After the workover operation has been completed, the barrier or plug member 27 may be again placed on the landing nipple 20 and production resumed from the two zones, the barrier member 35 having been removed.

Under circumstances where the zones 12 and 13 lose their ability to flow through natural means, as shown in FIG. 6, a suitable pump tool 36 containing rod pumps may be located in the pipe string 14. The rod pumps are connected to, and reciprocated by, a sucker rod 38 extending to a suitable pumping unit at the earths surface, not shown. By reciprocation of the rod 38, production is again had simultaneously through the pipe strings 14 and 15 to the wellhead. The details of pump tool 36 are illustrated in FIGS. 7a and 7b.

Referring now to FIGS. 7a and 7b, there is shown a pump tool 36 comprising an elongated pump housing 40 provided with upper and lower pumping assemblies 41 and 42 interconnected by means of a rod 43. Housing 40 is provided with suitable seals 44, 45, and 46 to isolate production from the two zones 12 and 13. The lower end of housing 40 extends to within or adjacent the lower zone 13 and may suitably be latched in lower section 16 of tubing string 14 by means of a bottom hold-down latch 47 arranged in an annular recess 48.

Upper pump assembly 41 includes a pump plunger 49 slidably arranged in a chamber 50 in housing 40. Pump plunger 49 is provided on its upper and lower ends with ball check valves 51 and 52, respectively, to permit passage of fluid into and out of plunger 49 as it reciprocates in chamber 50. Arranged below plunger 49 is an annular wall member 53 having formed therein a plurality of passageways 54 each provided with a ball check valve 55. Wall member 53 is also provided with a bore 56 through which connecting rod 43 may extend. A second annular wall member 57 positioned below wall member 53 forms a chamber 58 within housing 40. Chamber 58 is provided with ports 59 for fluid communication with production zone 12. Wall member 57 has formed therein a bore 60 provided with seals 61 to sealingly engage rod 43 which extends therethrough.

Lower pump assembly 42 includes a pump plunger 62 slidably arranged in a chamber 63 in pump housing 40.

Pump plunger 62 is provided on its upper and lower ends with ball check valves 64 and 65, respectively, to permit passage of fluid into and out of plunger 62 as it reciprocates in chamber 63. As can be seen in the drawing, housing 40 is provided with a lower pump standing valve 66 which may be a ball check valve to permit fluid flow into chamber 63.

In operation as the sucker rod 38 is reciprocated fluid from lower zone 13 is pumped through check valve 66, plunger 62, port 67, and port 68 upwardly through pipe string 15. Production from upper zone 12 is pumped through check valve 55, plunger 49, port 69, and port 70 upwardly through pipe string 14 with the seals 45 and 61 isolating production from the zones 12 and 13.

It is to be noted that the pump tool 36 is placed in a common housing to facilitate installation and removal from the well.

The present invention is of considerable importance and utility in that it is possible to produce simultaneously and separately from two zones and yet workover the two zones by lowering tools only through one pipe string while providing a plurality of pipe strings for conducting of fluids from the one pipe string through which completion and working-over is performed. A minimum of equipment is required and all operations are conducted by wireline.

The nature and objects of the present invention having been completely described and illustrated, what I wish to claim as new and useful and secure by Letters Patent is:

1. In a well having a first pipe string arranged therein extending at least to a lower hydrocarbon productive Zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises sepa rately perforating the upper and lower zones from within the first pipe string, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, production from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating one of said zones from the pipe string through which said one zone is produced, and flowing fluid down the first pipe string to the other of said zones and removing any excess fluid up the second pipe string.

2. In a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises separately perforating the upper and lower zones from within the first pipe string, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, production from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating said upper zone from said first pipe string and flowing fluid down the first pipe string to the lower zone, and removing any excess fluid up the second pipe string.

3. In a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises separately perforating the upper and lower zones from within the first pipe string, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, production from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating said lower zone from said second pipe string, and flowing fluid down the first pipe string to the upper zone, and removing any excess fluid up the second pipe string.

4. In a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises separately perforating the upper and lower zones from within the first pipe string, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, pro duction from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating said upper zone from said first pipe string, flowing a workover fluid down the first pipe string to the lower zone and removing any excess workover fluid up the second pipe string, re-establishing communication between said upper zone and said first pipe string, isolating said lower zone from said second pipe string, and then flowing a workover fluid down the first pipe string to the upper zone and removing any excess workover fluid up the second pipe string.

5. In a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises separately perforating the upper and lower zones from within the first pipe string, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, production from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating said upper zone from said first pipe string and flowing a workover fluid down the first pipe string to the lower zone and removing any excess workover fluid up the second pipe string, re-establishing communication between said upper zone and said first pipe string, isolating said lower zone from said second pipe string, and flowing a workover fluid down the first pipe string to the upper zone and removing any excess workover fluid up the second pipe string, re-establishing communication between said lower zone and said second pipe string, then again isolating said zones from each other above said point and below the upper productive zone and separately pumping hydrocarbons from said zones.

6. In a well having a first pipe string arranged therein extending to a lower hydrocarbon productive zone spaced below an upper hydrocarbon productive zone and having an eccentric second pipe string fluidly connected at its lower end to the first pipe string at a point between said two zones, the method which comprises separately perforating the upper and lower zones, isolating said zones from each other above said point and below the upper productive zone and separately obtaining production from each of said zones, production from the upper zone proceeding upwardly through the first pipe string and production from the lower zone proceeding upwardly through the second pipe string, isolating one of said zones from one of said pipe strings and flowing a work over fluid down the first pipe string to the other of said zones and removing any excess workover fluid up the second pipe string, said zones being separately perforated by lowering a perforator through the first pipe string and operating it first in the lower zone and then in the upper zone.

7. A method in accordance with claim 6 in which said zones are isolated above said point and below the upper productive zone after the lower zone is perforated.

References Cited in the file of this patent UNITED STATES PATENTS 2,642,803 Morris et a1 June 23, 1953 2,760,578 Tausch Aug. 28, 1956 2,911,048 Dublin et a1. Nov. 3, 1959 2,935,131 McCune May 3, 1960

Images