WO2011160160A1

WO2011160160A1 - A shut-in tool

Info

Publication number: WO2011160160A1
Application number: PCT/AU2011/000068
Authority: WO
Inventors: Craig Thorne
Original assignee: Dst Australia Pty Ltd
Priority date: 2010-06-21
Filing date: 2011-01-21
Publication date: 2011-12-29
Also published as: AU2011269712A1

Abstract

A rotational shut-in tool 100 has a fluid end 112 including a housing sub 130. The housing sub 130 has circulation ports 1303 through which fluid is purged from the shut-in tool 100. A flow opening in the housing sub 130 receives well fluid from a zone of interest. The fluid end 112 includes a production mandrel 136 which is displaceable in the housing sub 130. The production mandrel 136 has a production flow passage 1363 and a production port 1362 open to the passage 1363. The production mandrel 136 is displaced between: a flow position wherein the production port 1362 is in fluid communication with the flow opening of the housing sub 130 to receive well fluid in the production flow passage 1363; a shut-in position wherein the production port 1362 is closed off from the flow opening of the housing sub 130; and a purge position wherein the production port 1362 is in fluid communication with the circulation ports 1303 of the housing sub 130 to purge fluid from the shut-in tool 100.

Description

A SHUT-IN TOOL

FIELD OF THE INVENTION

The invention relates to a shut-in tool for use in drill stem testing including formation fall-off, leak-off, defit and injection testing. In particular, although not exclusively, the invention relates to the fluid end of a rotating shut-in tool.

BACKGROUND TO THE INVENTION

Drill stem testing is used to measure one or more of productive capacity, formation pressure, drainage, permeability and transmissibility of a hydrocarbon reservoir or formation. The general procedure for a drill stem test is to lower a test string into a wellbore on drill pipe. The test string has flow ports through which well fluid can enter the test string. The test string may include a hydraulic tool having a main tester valve which remains closed to prevent entry of well fluid into the test string via the flow ports during its trip into the wellbore. Once the test string reaches a predetermined depth, with the flow port in a zone of interest, a packer (or spaced packers if it is a straddle test) is set to isolate the zone of interest. The main tester valve is then opened, allowing well fluid in the zone of interest to flow into the test string. Suitable gauges in the test string record the well fluid properties and pressures.

A more complete profile of the hydrocarbon reservoir can be obtained by measuring the pressure build-up in the zone of interest under flow and shut-in conditions. Data of formation pressures, drainage permeability, and transmissibility can be collected under these flow and shut-in conditions. To obtain the shut-in conditions the test string may include a shut-in tool having a fluid end (also referred to as a mechanical valve) which may be opened or closed to selectively allow the flow of fluid into and out of the shut-in tool. The fluid end is selectively closed and opened for respective shut-in and flow periods. Closing the fluid end stops flow of well fluid into the test string and allows pressure to build up in the zone of interest. The pressure build-up during shut-in is recorded for analysis.

Conventional rotating shut-in tools allow for sequential opening and closing of their fluid ends. A typical shut-in test will start with a pre-flow period wherein the fluid end is open. The fluid end is then closed by right hand rotation of a rotating head sub of the shut-in tool for an initial shut-in period. After the initial shut-in period the fluid end is opened by right hand rotation of the rotating head sub for a main-flow period. The fluid end is subsequently closed again by right hand rotation of the rotating head sub for a final-shut in period. The rotating head sub is rotated by drill pipe from above hole.

DISCLOSURE OF THE INVENTION

In one form, although it need not be the only or indeed the broadest form, the invention resides in the fluid end of a shut-in tool, the fluid end including:

a housing sub having an operatively upper end and an operatively lower end, the housing sub including:

at least one circulation port in a wall of the housing sub, wherein fluid can be selectively purged from the shut-in tool through the circulation port, and

a flow opening at the operatively lower end of the housing sub to receive well fluid from a zone of interest; and

wherein a production mandrel of the shut-in tool is displaceable in the housing sub, the production mandrel having:

a production flow passage in which well fluid is receivable, and

a production port which is open to the production flow passage, wherein the production mandrel is selectively displaceable between:

a flow position wherein the production port is in fluid communication with the flow opening of the housing sub to receive well fluid in the production flow passage;

a shut-in position wherein the production port is closed off from the flow opening of the housing sub; and

a purge position wherein the production port is in fluid communication with the circulation port of the housing sub to purge fluid from the production flow passage through the circulation port. The fluid end may include the production mandrel.

The fluid end is preferably configured for the production mandrel to be displaceable to an injection position wherein the production port is in fluid communication with the flow opening of the housing sub to inject fluid from the production flow passage to the zone of interest.

The fluid end preferably includes a production sleeve within the housing sub, the production mandrel displaceably received in the production sleeve, the production sleeve including two or more longitudinally spaced sleeve ports in a wall of the production sleeve, wherein the production port of the production mandrel is in fluid communication with one of the sleeve ports when opposite the one of the sleeve ports and the production port is closed off by the wall of the production sleeve when the production port is opposite the wall of the production sleeve.

The production sleeve and the housing sub are preferably dimensioned and configured so that a chamber is defined between the wall of the production sleeve and the wall of the housing sub, and wherein the chamber is in fluid communication with the flow opening of the housing sub.

A first of the two or more longitudinally spaced sleeve ports is preferably in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the first of the two or more longitudinally spaced sleeve ports when the production mandrel is in the flow position.

A second of the two or more longitudinally spaced sleeve ports is preferably in fluid communication with the circulation port of the housing sub, and the production port of the production mandrel is located opposite the second of the two or more longitudinally spaced sleeve ports when the production mandrel is in the purge position.

A third of the two or more longitudinally spaced sleeve ports is preferably in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the third of the two or more longitudinally spaced sleeve ports when the production mandrel is in the injection position.

The fluid end preferably includes a ported hub located in the chamber between the wall of the production sleeve and the wall of the housing sub, the ported hub dividing the chamber into an upper chamber and a lower chamber, the ported hub including:

one or more radial flow passages fluidly connecting the circulation port of the housing sub with one of the two or more longitudinally spaced sleeve ports, and

one or more transverse flow passages fluidly connecting the upper chamber and the lower chamber.

The ported hub may be integrally formed with the production sleeve.

In another form, the invention resides in a shut-in tool having a fluid end as defined and described hereinabove, the shut-in tool including a screw mechanism to selectively displaceable the production mandrel between the flow position, shut-in position and purge position.

The shut-in tool preferably comprises:

a fluid end including:

at least one circulation port in a wall of the housing sub through which fluid can be selectively purged from the shut-in tool, and

a flow opening at the operatively lower end of the housing sub to receive well fluid from a zone of interest; and a production mandrel displaceable in the housing sub, the production mandrel having:

a production flow passage in which fluid is receivable, and a production port which is open to the production flow passage, wherein the production mandrel is selectively displaceable between:

a purge position wherein the production port is in fluid communication with the circulation port of the housing sub to purge fluid from the production flow passage through the circulation port.

In yet another form, the invention resides in a method of drill stem testing using a shut-in tool, the method including:

displacing a production mandrel of the shut-in tool to a flow position wherein a production port of the production mandrel is in fluid communication with a flow opening in a housing sub of the shut-in tool, thereby to allow well fluid to flow into a production flow passage of the production mandrel;

displacing the production mandrel to a shut-in position wherein the production port is closed off from the flow opening of the housing sub; and displacing the production mandrel to a purge position wherein the production port is in fluid communication with a circulation port of the housing sub to purge fluid in production flow passage from the shut-in tool through the circulation port.

The method preferably includes displacing the production mandrel to an injection position wherein the production port is in fluid communication with the flow opening of the housing sub to inject fluid from the production flow passage via the flow opening of the housing sub.

The method preferably includes displacing the production mandrel by rotation of drill pipe to which the shut-in tool is connected

Reference to the fluid end of the shut-in tool must be interpreted to include reference to a mechanical valve of a shut-in tool as is known in the art of drill stem testing. Further features of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, wherein:

FIG 1 shows a longitudinally sectioned view of a rotational shut-in- tool including a fluid end in accordance with one embodiment of the invention;

FIG 2 shows a longitudinally sectioned view of the fluid end of the shut-in-tool of FIG 1 ;

FIG's 3 to 7 show the fluid end of FIG 2 in successive phases of the shut-in tool during an example drill stem testing program;

FIG 3 shows a longitudinally sectioned view of the fluid end during a pre-flow phase of the shut-in tool;

FIG 4 shows a longitudinally sectioned view of the fluid end during an initial shut-in phase of the shut-in tool;

FIG 5 shows a longitudinally sectioned view of the fluid end during a purge phase of the shut-in tool;

FIG 6 shows a longitudinally sectioned view of the fluid end in an injection phase of the shut-in tool;

FIG 7 shows a longitudinally sectioned view of the shut-in tool in a final shut-in phase of the shut-in tool;

FIG 8 shows a longitudinally sectioned view of the shut-in tool of

FIG 1 with a production mandrel of the fluid end in a closed position; FIG 9 shows a longitudinally sectioned view of another embodiment of a rotational shut-in tool in accordance with the invention;

FIG 10 shows a side view of an upper jack mandrel of the shut-in tool of FIG 9;

FIG 11 shows a longitudinally sectioned view of the upper jack mandrel of FIG 10, sectioned along section line A-A of FIG 10;

FIG 12 shows a side view of a lower jack mandrel of the shut-in tool of FIG 9;

FIG 13 shows an end view of the lower jack mandrel of FIG 12; FIG 14 shows a longitudinally sectioned view of the lower jack mandrel of FIG 12, sectioned along section line A-A of FIG 12;

FIG 15 shows a side view of a jack mandrel housing of the shut-in tool of FIG 9;

FIG 16 shows a longitudinally sectioned view of the jack mandrel housing of FIG 15, sectioned along section line A-A of FIG 15;

FIG 17 shows a side view of a production mandrel of the shut-in tool of FIG 9;

FIG 18 shows a longitudinally sectioned view of the production mandrel of FIG 17, sectioned along section line A-A of FIG 17;

FIG 19 shows a side view of a housing sub of the shut-in tool of

FIG 9;

FIG 20 shows a longitudinally sectioned view of the housing sub of FIG 19, sectioned along section line A-A of FIG 19;

FIG 21 shows a side view of a production sleeve of the shut-in tool of FIG 9;

FIG 22 shows a longitudinally sectioned view of the production sleeve of FIG 21 , sectioned along section line A-A of FIG 21 ;

FIG 23 shows another longitudinally sectioned view of the production sleeve FIG 21 , sectioned along section line A-A of FIG 21 ;

FIG 24 shows a fluid end of the shut-in tool of FIG 9 in more detail;

FIG 25 shows the fluid end of FIG 24 during a pre-flow phase of the shut-in tool of FIG 9; FIG 26 shows the fluid end of FIG 24 during an initial shut-in phase of the shut-in tool of FIG 9;

FIG 27 shows the fluid end of FIG 24 during a purge phase of the shut-in tool of FIG 9;

FIG 28 shows the fluid end of FIG 24 during an injection phase of the shut-in tool of FIG 9;

FIG 29 shows the fluid end of FIG 24 during a final shut-in phase of the shut-in tool; and

FIG 30 is a diagrammatic flow diagram of the method of drill stem testing using the shut-in tool of FIG 1 or FIG 9.

DETAILED DESCRIPTION OF THE INVENTION FIG 1 shows a rotational shut-in tool 10 in accordance with one embodiment of the invention. The shut-in tool 10 has an upper end 6 and a lower end 8. The shut-in tool 10 has a fluid end 12 (also referred to as mechanical valve) at a lower end region of the shut-in tool 10. The shut-in tool 10 has a rotatable head sub 14 connectable to drill pipe. The drill pipe imparts right handed turns on the head sub 14 when the drill pipe is rotated. A driller selectively rotates the drill pipe via a drive of the drill rig.

The shut-in tool 10 further includes a jack mandrel housing 16 in which is housed a cross head 18 and a jack shaft 20. A thrust bearing 26 between the jack mandrel housing 16 and the head sub 14 allows for rotation of the head sub 14 without rotating the remainder of the shut-in tool 10. The thrust bearing 26 is held by a bearing clamp 28. The head sub 14 is connected to the jack shaft 20 so that rotation of the head sub 14 rotates the jack shaft 20. The jack shaft 20 has an external screw thread 22 along part thereof. The cross head 18 is screw-threadingly received by the screw thread 22 of the jack shaft 20. The cross head 18 rides in a splined passage 24 in the jack mandrel housing 16. The passage 24 allows longitudinal translation of the cross head 18 up and down in the passage 24 as the head sub 14 is rotated. A production mandrel 36 of the shut-in-tool 10 is connected to the cross head 18 so that the production mandrel 36 is displaced as the head sub 14 is rotated.

FIG 2 shows the fluid end 12 of the shut-in tool 10 in more detail. The fluid end 12 comprises a housing sub 30, a production sleeve 32, and a ported hub 34 between the housing sub 30 and the production sleeve 32. The production mandrel 36 of the shut-in-tool 10 is displaceably located in the production sleeve 32.

The housing sub 30 is cylindrical having an outer diameter (OD) of 5 inches or 3.5 inches depending on the size of wellbore being tested. The housing sub 30 has an internal Acme service joint thread 40 at its upper end and an external API tool joint thread 42 at its lower end. A ring of four circulation ports 44 are formed in the wall 46 of the housing sub 30. The circulation ports 44 are circumferentially spaced in the wall 46. The circulation ports 44 are open to an annulus between the outside of the housing sub 30 and the wellbore wall (not shown). A mouth 48 at the lower end of the housing sub 30 is a flow opening through which well fluid from the zone of interest flows. The test string may include a hydraulic tool having a main tester valve which is opened to allow flow of well fluid from the zone of interest to the mouth 48.

The production sleeve 32 is cylindrical having an OD which is smaller than the inner diameter (ID) of the housing sub 30. A fluid chamber 50 is thus defined between the housing sub 30 and the production sleeve 32. The production sleeve 32 includes three rings of longitudinally spaced sleeve ports, namely a first ring of lower sleeve ports 52, a second ring of intermediate sleeve ports 54 and a third ring of upper sleeve ports 56. The production sleeve 32 has an open lower end 58 and an external thread at its upper end 59. The respective rings of sleeve ports 52, 54, 56 are longitudinally spaced along the length of the production sleeve 32 from the lower end 58 to the upper end 59.

The ported hub 34 is located in the chamber 50 between the housing sub 30 and the production sleeve 32. The ported hub 34 divides the chamber 50 into an upper chamber 68 and a lower chamber 69. The ported hub 34 is ring-shaped. The ported hub 34 has radial flow passages 60 and transverse passages 62. The radial flow passages 60 extend between the inside and the outside of the ported hub 34. The transverse passages 62 extend between the upper side and the lower side of the ported hub 34. The transverse passages 62 fluidly connect the upper chamber 68 and the lower chamber 69. The radial flow passages 60 and the transverse passages 62 are not interconnected. The ported hub 34 is located at a position relative to the housing sub 30 so that the radial flow passages 60 are in register with the circulation ports 44 of the housing sub 30 and in register with the intermediate sleeve ports 54 of the production sleeve 32. The ported hub 34 fluidly connects the circulation ports 44 and the intermediate sleeve ports 54, thereby to provide a flow passage 64 between the annulus and the intermediate sleeve ports 54. The ported hub 34 has inner and outer O-rings 66 to seal the flow passage 64.

The production mandrel 36 is longitudinally displaceable in the production sleeve 32. The production mandrel 36 is generally cylindrical. The production mandrel 36 has a wall 70 defining a production flow passage 72. A production port 74 is defined in the wall 70 of the production mandrel 36. The production port 74 is open to the production flow passage 72. The wall 70 is grooved above and below the production port 74 to locate O-rings 76 on the production mandrel 36. The O-rings 76 isolate a section 78 of the mandrel 36 in which the production port 74 is defined. The section 78 is narrowed having a smaller outer diameter where the production port 74 is located.

Having described the shut-in tool 10, and particularly the fluid end 12, the operation of the fluid end 12 will now be described with reference to FIG's 3 to 7. FIG's 3 to 7 show the sequential phases of drill stem testing and the associated positions of the production mandrel 36 in the fluid end 12. The production mandrel 36 is in a different position for each phase of the drill stem test as will be described. FIG's 3 to 7 all show the fluid end 12 in a condition wherein the main tester valve of the hydraulic tool (if used in the test string) is open to allow well fluid to flow into the chamber 50 between the housing sub 30 and the production sleeve 32 via the mouth 48 of the housing sub 30.

FIG 3 shows the fluid end 12 during a pre-flow phase of the shut-in tool 10. The production mandrel 36 is located in a pre-flow position wherein the production port 74 is opposite the lower sleeve ports 52 of the production sleeve 32. During the pre-flow phase pressure from the formation in the zone of interest is released. Well fluid in the zone of interest flows up the test string via the fluid end 12 for a predetermined flow period or up to surface. Well fluid enters the chamber 50 and fills the chamber 50. The well fluid flows into the production flow passage 72 and up the test string to a predetermined level or to the surface of the well. The fluid in the chamber 50 passes through the lower sleeve ports 52 in the production sleeve 32 and then through the production port 74 in the production mandrel 36 and up the production flow passage 72. The chamber 50 is closed off at the upper end of the housing sub 30, where the jack mandrel housing 16 screws into the fluid end 12. Areas in the fluid end 12 which are filled with well fluid during the pre-flow phase are shaded and the flow of the well fluid is indicated by arrows.

FIG 4 shows the fluid end 12 during an initial shut-in phase of the shut-in tool 10. The shut-in tool 10 changes from the pre-flow phase to the initial shut-in phase by displacing the production mandrel 36 a distance upwardly relative to the production sleeve 32. The production mandrel 36 is displaced upwardly by right hand rotation of the head sub 14 of the shut-in tool 10. During the initial shut-in phase, the zone of interest is closed in for testing static reservoir pressure build up or various other tests. In the initial shut-in phase of the shut-in tool 10 there is no fluid communication between the fluid in the chamber 50 and the production flow passage 72. The production mandrel 36 is located in an initial shut-in position with the production port 74 located between the intermediate sleeve ports 54 and the lower sleeve ports 52. The production port 74 is opposite the wall of the production sleeve 32. O- rings 76 on the mandrel 36 at either side of the production port 74 isolate the production port 74 from any fluid communication with the chamber 50. Areas in the fluid end 12 which are filled with well fluid during the intial shut-in phase are shaded. There is no flow of well fluid during the initial shut-in phase.

FIG 5 shows the fluid end 12 during a purge phase of the shut-in tool 10. The shut-in tool 10 changes from the initial shut-in phase to the purge phase by displacing the production mandrel 36 a distance upwardly relative to the production sleeve 32. The production mandrel 36 is displaced upwardly by right hand rotation of the rotating head sub 14 of the shut-in tool 10. The production mandrel 36 is displaced to a purge position wherein the production port 74 is opposite the intermediate sleeve ports 54 of the production sleeve 32. During the purge phase, the well fluid in the test string (referred to as pre-flow fluid) is purged into the annulus via the circulation ports 44 in the housing sub 30. Purge fluid, such as fresh water, KCL water, drilling mud etc. is pumped from the surface down the test string and displaces the pre-flow fluid in the production flow passage 72 by purging the pre-flow fluid into the annulus. The pre-flow fluid is pumped down the production flow passage 72, out of the production port 74, through the intermediate sleeve ports 54 and out of the circulation ports 44 via the radial flow ports 60 in the ported hub 34. Areas in the fluid end 12 which are filled with pre-flow fluid being purged are shaded and the flow of the pre-flow fluid is indicated by arrows.

FIG 6 shows the fluid end 12 in an injection phase of the shut-in tool 10. The shut-in tool 10 changes from the purge phase to the injection phase by displacing the production mandrel 36 a distance upwardly relative to the production sleeve 32. The production mandrel 36 is displaced upwardly by right hand rotation of the rotating head sub 14 of the shut-in tool 10. The production mandrel 36 is displaced to an injection position wherein the production port 74 is opposite the upper sleeve ports 56 of the production sleeve 32. During the injection phase, injection fluid is pumped into the zone of interest via the fluid end 12. A variety of injection fluid may be pumped into the zone of interest, depending on types of tests required. The injection fluid is pumped down the production flow passage 72, out of the production port 74, through the upper sleeve ports 56 and into the upper chamber 68. From the upper chamber 68 it flows through the transverse passages 62 in the ported hub 34 to the lower chamber 69. From the lower chamber 69 the injection fluid is pumped down the test string and into the zone of interest isolated by the packer. Areas in the fluid end 12 which are filled with injection fluid being pumped to the zone of interest are shaded and the flow of the injection fluid is indicated by arrows.

The shut-in tool 10 may also be operated in a main flow phase when the shut-in tool 12 is as configured shown in FIG. 6. If the shut-in tool 10 is operated in a main-flow phase, well fluid flows from the zone of interest into the fluid end 12 of the shut-in-tool instead of injection fluid being injected from the fluid end 12.

FIG 7 shows the shut-in tool 10 in a final shut-in phase of the shut- in tool 10. The shut-in tool 10 changes from the injection phase to the final shut-in phase by displacing the production mandrel 36 a distance upwardly relative to the production sleeve 32. The production mandrel 36 is displaced upwardly by right hand rotation of the head sub 14 of the shut-in tool 10. During the final shut-in phase, the zone of interest is isolated by the packer for testing pressure build up. In the final shut-in phase of the shut-in tool 10 there is no fluid communication between the fluid in the chamber 50 and the production flow passage 72. The production mandrel 36 is in a final shut-in position wherein the production port 74 of the production mandrel 36 is located above the upper sleeve ports 56 and opposite the wall of the production sleeve 32. O-rings on the mandrel 36 below the production port 74 isolate the production port 74 from any fluid communication with the chamber 50. Areas in the fluid end 12 which are filled with well fluid during the final shut-in phase are shaded.

The production mandrel 36 is displaced sequentially between the various positions as shown from FIG's 3 to 7 by right hand rotation of the rotating head sub 14 of the shut-in tool 10. The production mandrel 36 may be in the pre-flow position when the shut-in tool 10 is run in-hole and a hydraulic tool with main tester valve is included in the test string. Ten right hand turns of the head sub 14 displaces the production mandrel from the pre-flow position to the initial shut-in position. Another ten right hand turns of the head sub 14 displaces the production mandrel to the purge position. Twenty right hand turns of the head sub 14 displaces the production mandrel to the injection position. A last ten right hand turns of the head sub 14 displaces the production mandrel to the final shut-in phase. Left hand rotation of the rotating head sub 14 via the drill pipe is not allowable in-hole as there is a risk of the drill pipe unscrewing.

Alternatively, the production mandrel 36 may be in a closed position when the shut-in tool 10 is run in-hole without a hydraulic tool in the test string. The closed-position of the production mandrel 36 in a closed condition of the shut-in tool 10 is shown in FIG 8. In the closed condition of the shut-in tool 10 there is no fluid communication between the fluid in the chamber 50 and the production flow passage 72. The production mandrel 36 is located in the closed position with the production port 74 below the lower sleeve ports 52. The production port 74 is opposite the wall of the production sleeve 32. O-rings 76 on the mandrel 36 at either side of the production port 74 isolate the production port 74 from any fluid communication with the chamber 50. There is no flow of well fluid up the shut-in tool 10 when the production mandrel 36 is in the closed position. The fluid end 12 thus functions as a main tester valve and a separate hydraulic tool with main tester valve is not required. Once the test sting is run in hole and the packers set, well fluid is allowed to flow into the test string by displacing the production mandrel 36 upwardly from the closed position to the pre-flow position as depicted in FIG 3. The production mandrel 36 is displaced upwardly by right hand rotation of the head sub 14 of the shut-in tool 10.

FIG 9 shows a longitudinally sectioned view of another embodiment of a rotational shut-in tool 100 in accordance with the invention. The shut-in tool 100 is similar to the shut-in tool 10 and operates in the same sequential phases as described for shut-in tool 10. Features of the shut-in tool 100 which are the same or similar to features of the shut-in tool 10 are similarly referenced for the shut-in tool 100 as they are for the shut-in tool 100.

The shut-in tool 100 has an upper end 106 and a lower end 108. A longitudinal axis 109 of the shut-in tool 100 extends from the upper end 106 to the lower end 108. The shut-in tool 100 has a fluid end 112 (or mechanical valve) at a lower end region of the shut-in tool 0.

Recited from the upper end 106 to the lower end 108, the shut-in tool comprises: a rotatable head sub 114; a thrust bearing 126; a bearing clamp 128; a packing nut 127; a packing box 129; jack mandrel housing 116; housing sub 130 of the fluid end 112; and a bottom sub 110.

The shut-in tool 100 includes an upper jack mandrel 102 and a lower jack mandrel 104. The upper jack mandrel 102 is rotatably captured relative to the jack mandrel housing 116. The lower jack mandrel 104 is non-rotatably held in the jack mandrel housing 116 and is displaceable along the longitudinal axis 109 by rotation of the upper jack mandrel 102. The lower jack mandrel 104 is screw-threadingly engaged to the upper jack mandrel 102 so that rotation of the upper jack mandrel 102 displaces the lower jack mandrel 104 along the longitudinal axis 109 in the jack mandrel housing 116.

The shut-in-tool 100 includes a production mandrel 136. The production mandrel 136 extends into the jack mandrel housing 116 and into the housing sub 130. The production mandrel 136 is fixed to the lower jack mandrel 104 so that the production mandrel 136 is displaced as the lower jack mandrel 104 is displaced by rotation of the head sub 1 4.

The shut-in tool 100 further includes a production sleeve 132 having a bore. The production sleeve 132 is located in the housing sub 130. Part of the production mandrel 136 is received within the bore of the production sleeve 132 and is displaceable along the bore.

FIG 10 is a side view of the upper jack mandrel 102. FIG 11 is a longitudinally sectioned view of the upper jack mandrel 102, sectioned along section line A-A of FIG 10. The upper jack mandrel 102 has an external upper joint thread 1021 and an external jack screw thread 1022. An external collar 1023 is located between the upper joint thread 1021 and the jack screw thread 1022. The upper jack mandrel 102 is fixed to the head sub 114 by screwing the upper joint thread 1021 into the head sub 114. Rotation of the head sub 114 rotates the upper jack mandrel 102. Referring to FIG 9, the collar 1023 is captured between the packing box 129 and the jack mandrel housing 116 in an assembled condition of the shut-in tool 100 to prevent displacement of the upper jack mandrel 102 along the longitudinal axis 109. The upper jack mandrel 102 has a fluid flow passage 1024 along which fluid in the test string can flow to the head sub 114 and from the head sub 114 and also to a from the production mandrel 136. Part of the fluid flow passage 1024 has a bore 1025 in which a stem part of the production mandrel 136 is received. The production mandrel 136 is displaced along the bore 1025 as the head sub 114 is rotated.

FIG 12 is a side view of the lower jack mandrel 104, and FIG 13 is an end view of the lower jack mandrel 104. FIG 14 is a longitudinally sectioned view of the lower jack mandrel 102, sectioned along section line A-A of FIG 12. Referring to FIG's 12 to 14, the lower jack mandrel 104 has an internal jackscrew thread 1041 and an internal lower screw thread 1042. Two spline formations in the form of keys 1043 of the lower jack mandrel 104 protrude outwardly. The internal jackscrew thread 1041 of the lower jack mandrel 104 engages the external jack screw thread 1022 of the upper jack mandrel 102 so as to be displaceable relative to the upper jack mandrel 102 as the upper jack mandrel 102 is rotated. The internal lower screw thread 1042 screws onto the production mandrel 136, thereby to fix the production mandrel 136 to the lower jack mandrel 104.

FIG 15 is a side view of the jack mandrel housing 116. FIG 16 is a longitudinally sectioned view of the jack mandrel housing 116, sectioned along section line A-A of FIG 15. The jack mandrel housing 116 has an internal upper screw thread 1161 , an external lower joint thread 1162 and an internal lower joint thread 1163. Two opposite longitudinal grooves 1164 (only one groove 1164 shown in FIG 16) are formed internally in a wall of the jack mandrel housing 116. The internal upper screw thread 1161 screws onto the packing box 129, thereby to fix the jack mandrel housing to the packing box 129. The housing sub 130 screws onto the external lower joint thread 1162 and the production sleeve 132 screws into the internal lower joint thread 1163. The keys 1043 of the lower jack mandrel 04 ride in the grooves 1164 of the jack mandrel housing 116 to prevent rotation of the lower jack mandrel 104 in the jack mandrel housing 116.

FIG 17 is a side view of the production mandrel 136. FIG 18 is a longitudinally sectioned view of the production mandrel 136, sectioned along section line A-A of FIG 17. The production mandrel 136 has an upper end 1366 and a lower end 1367. The production mandrel 136 has a wall 1361 defining a production flow passage 1363. The production flow passage 1363 extends to the upper end 1366 of the production mandrel 136. A production port 1362 is defined in the wall 1361 of the production mandrel 136. The production flow passage 1363 terminates below the production port 1362. The lower end 1367 region of the production mandrel 136 is solid. The production port 362 of the production mandrel 136 corresponds with the production port 74 of the production mandrel 36 of shut-in tool 10.

The production mandrel 136 is externally grooved above and below the production port 1362 to locate O-rings on the production mandrel 136. The O-rings isolate a section 364 of the mandrel 136 in which the production port 1362 is defined.

FIG 19 is a side view of the housing sub 130. FIG 20 is a longitudinally sectioned view of the housing sub 130, sectioned along section line A-A of FIG 19. The housing sub 130 is generally cylindrical having a cylindrical wall 1306. Te housing sub 130 has an operatively upper end 1307 and an operatively lower end 1308. The housing sub 30 has an internal service joint thread 1301 at its upper end 1307 and an external tool joint thread 1302 at its lower end 1308. A ring of four circulation ports 1303 are formed in the wall 1306 of the housing sub 30. The circulation ports 1303 are intermediate the upper end 1307 and the lower end 1308. The circulation ports 1303 of the housing sub 130 correspond with the circulation ports 44 of the housing sub 30 of the shut- in tool 10. The circulation ports 1303 are open to an annulus between the outside of the housing sub 130 and the wellbore wall (not shown), in use. A mouth 1304 at the lower end of the housing sub 30 is a flow opening through which well fluid from the zone of interest flows. The test string may include a hydraulic tool having a main tester valve which is opened to allow flow of well fluid from the zone of interest to the mouth 1304 via the bottom sub 110.

FIG 21 is a side view of the production sleeve 132. FIG's 22 and 23 are longitudinally sectioned views of the production sleeve 132, sectioned along section line A-A of FIG 21. The production sleeve 132 is generally cylindrical having a wall 1328. The production sleeve 132 includes an integrally formed ported hub 134. The production sleeve 132 has an outer joint thread 1321 at its upper end for screwing into the jack mandrel housing 116 to fix the production sleeve 132 relative to the jack mandrel housing 116.

The production sleeve 132 includes three sets of sleeve ports defined in the wall 1328, namely a first ring of lower sleeve ports 1322, a second set of two intermediate sleeve ports 1323 which extend through the ported hub 134, and a third ring of upper sleeve ports 1324. The respective sets of sleeve ports 1322, 1323, 1324 are longitudinally spaced along the length of the production sleeve 32 from a lower end 1326 to and upper end 1327 of the production sleeve 132.

The ported hub 134 is collar-like having a generally annular shape. The ported hub 134 has a number of transverse passages 1341 and two radial flow passages in the form of the intermediate sleeve ports 1323. The transverse passages 1341 extend longitudinally between an upper end and a lower end of the ported hub 134. The intermediate sleeve ports 1323 extend from the inside of the production sleeve 132 to the outside of the ported hub 134. The intermediate sleeve ports 1323 and the transverse passages 1341 are not interconnected and thus not in flow communication. The ported hub 134 has external grooves 1342 for receiving O-rings.

FIG 24 shows the fluid end 112 of the shut-in tool 100 in more detail. The production sleeve 132 is located in the housing sub 130 with the intermediate sleeve ports 1323 opposite the circulation ports 1303 of the housing sub 130. A flow passage 164 is thus provided between the annulus and the intermediate sleeve ports 1323. The flow passage 164 of the fluid end 112 corresponds to the flow passage 64 of the fluid end 12.

A fluid chamber 150 is defined between the housing sub 130 and the production sleeve 132. The fluid chamber 150 is divided into an upper chamber 168 and a lower chamber 169 by the ported hub 134. The transverse passages 1341 of the ported hub 134 fluidly connect the upper chamber 168 and the lower chamber 169. The ported hub 134 divides the fluid chamber 150 in the same manner as the ported hub 34 divides the fluid chamber 50 of the shut-in tool 10. The chamber 150 is closed off at the upper end of the housing sub 130, where the jack mandrel housing 116 screws into the fluid end 112.

The production mandrel 136 is located in the bore of the production sleeve 132. The production mandrel 136 is longitudinally displaceable in the production sleeve 132 by the lower jack mandrel 104 as is described with reference to FIG's 24-29 below.

The shut-in tool 100 is in the closed condition shown in FIG 24 when the shut-in tool 100 is run in-hole. In the closed condition of the shut- in tool 100, the production mandrel 136 is in a closed position relative to the production sleeve 132. With the production mandrel 136 in the closed position, there is no fluid communication between fluid in the chamber 150 and the production flow passage 1363. The fluid in the chamber 150 is well fluid which enters the chamber 150 as the shut-in tool is run in-hole or an hydraulic tool of the test string is opened to allow well fluid from the zone of interest to flow into the chamber 150. The production mandrel 136 is located in the closed position with the production port 362 below the lower sleeve ports 1322. The production port 1362 is opposite the wall 1328 of the production sleeve 132. O-rings 176 on the production mandrel 136 at either side of the production port 1362 isolate the production port 1362 from any fluid communication with the chamber 150. There can thus be no flow of well fluid to the production passage 1363 when the production mandrel 136 is in the closed position.

FIG 25 shows the fluid end 12 during a pre-flow phase of the shut- in tool 100. The production mandrel 136 is located in a pre-flow position wherein the production port 1362 is opposite the lower sleeve ports 1322 of the production sleeve 132. Well fluid enters the chamber 150 via the mouth 1034 of the housing sub 130 and fills the chamber 150. The well fluid flows into the production flow passage 1363 via the lower sleeve ports 1322 and up the test string to a predetermined level or to the surface of the well. The fluid in the chamber 150 passes through the lower sleeve ports 1322 in the production sleeve 132 and then through the production port 1362 in the production mandrel 136 and up the production flow passage 1363. The flow of the well fluid during the pre-flow stage is indicated by arrows.

FIG 26 shows the fluid end 112 during an initial shut-in phase of the shut-in tool 100. The shut-in tool 100 changes from the pre-flow phase to the initial shut-in phase by displacing the production mandrel 136 a distance upwardly relative to the production sleeve 132. The production mandrel 136 is displaced upwardly by right hand rotation of the head sub 114 of the shut-in tool 100. During the initial shut-in phase of the shut-in tool 100 there is no fluid communication between the fluid in the chamber 150 and the production flow passage 1363. During the initial shut-in phase the production mandrel 136 is located in an initial shut-in position with the production port 1362 located between the intermediate sleeve ports 1323 and the lower sleeve ports 1322. The production port 1362 is thus opposite the wall of the production sleeve 132. O-rings 176 on the production mandrel 136 at either side of the production port 1362 isolate the production port 1362 from any fluid communication with the chamber 150. There is no flow of well fluid during the initial shut-in phase.

FIG 27 shows the fluid end 112 during a purge phase of the shut-in tool 100. The shut-in tool 100 changes from the initial shut-in phase to the purge phase by displacing the production mandrel 136 a distance upwardly relative to the production sleeve 132. The production mandrel 136 is displaced to a purge position wherein the production port 1362 is opposite the intermediate sleeve ports 1323 of the production sleeve 132. During the purge phase, the pre-flow fluid in the test string is purged into the annulus via the circulation ports 1303 in the housing sub 130. The pre-flow fluid is pumped from the production flow passage 1363 out of the production port 362, through the intermediate sleeve ports 1323 and out of the circulation ports 1303. The direction of flow of pre-flow fluid being purged during the purge phase is indicated by arrows.

FIG 28 shows the fluid end 112 in an injection phase of the shut-in tool 100. The shut-in tool 100 changes from the purge phase to the injection phase by displacing the production mandrel 136 a distance upwardly relative to the production sleeve 132. The production mandrel 136 is displaced to an injection position wherein the production port 1362 is opposite the upper sleeve ports 1324 of the production sleeve 132. Injection fluid is pumped down the production flow passage 1363, out of the production port 1362, through the upper sleeve ports 1324 and into the upper chamber 168. From the upper chamber 168 the injection fluid flows through the transverse passages 1341 in the ported hub 134 to the lower chamber 169. The transverse passages 1341 are indicated by broken lines in FIG 28. From the lower chamber 169 the injection fluid is pumped down the test string and into the zone of interest isolated by the packer(s). The lower sleeve ports 322 are closed off by the production mandrel 136. to prevent flow of injection fluid into the production sleeve 132. The flow of the injection fluid during the injection phase is indicated by arrows.

The shut-in tool 100 may also be operated in a main flow phase when the fluid end 112 is configured as shown in FIG. 28. If the shut-in tool 100 is operated in a main-flow phase, well fluid flows from the zone of interest into the fluid end 112 of the shut-in-tool 100 instead of injection fluid being injected from the fluid end 2.

FIG 29 shows the fluid end 112 in a final shut-in phase of the shut- in tool 100. The shut-in tool 100 changes from the injection phase to the final shut-in phase by displacing the production mandrel 136 a distance upwardly relative to the production sleeve 132. In the final shut-in phase of the shut-in tool 100 there is no fluid communication between the fluid in the chamber 150 and the production flow passage 1363. The production mandrel 136 is in a final shut-in position wherein the production port 1362 of the production mandrel 136 is located above the upper sleeve ports 1324 and opposite the wall 1328 of the production sleeve 132. O-rings 176 on the mandrel 136 below the production port 1362 isolate the production port 1362 from any fluid communication with the chamber 150. Areas in the fluid end 112 which are filled with well fluid during the final shut-in phase are shaded.

FIG 30 shows a diagrammatic flow diagram of the method 1000 of drill stem testing using the shut-in tool 10 or 100. The method is the same for both shut-in tools 10 or 00. The shut-in tool 10, 100 is run in-hole in the closed condition.

The production mandrel 36, 136 is then displaced to the flow position at step 1002 during a pre-flow phase of the shut-in tool 10, 100 as described with reference to FIG's 3 and 25, respectively. In the flow position of the production mandrel 36, 136 the production port 74, 1362 is in fluid communication with mouth 48, 1304, thereby to allow well fluid to flow into production flow passage 72, 1363.

The production mandrel 36, 136 is thereafter displaced to the shut- in position at step 1004 during an initial shut-in phase of the shut-in tool 10, 100 as described with reference to FIG's 4 and 26, respectively. In the shut-in position of the production mandrel 36, 136 the production port 74, 1362 is closed off from the mouth 48, 1304 of the housing sub 30, 130. The next step 1006 is for the production mandrel 36, 136 to be displaced to purge position during a purge phase of the shut-in tool 10, 100 as described with reference to FIG's 5 and 27, respectively. In the purge position of the production mandrel 36, 136 the production port 74, 1362 is in fluid communication with a circulation port 44, 1303 of housing sub 30, 130 to purge fluid in production flow passage 72, 1363 from the shut-in tool 10, 100.

At step 1008 production mandrel 36, 136 is displaced to an injection position during an injection phase of the shut-in tool 10, 100 as described with reference to FIG's 6 and 28, respectively. In the injection position of the production mandrel 36, 136 the production port 74, 1362 is in fluid communication with the mouth 48, 1304 of the housing sub 30, 130 to inject fluid from the production flow passage 72, 1363 to the zone of interest.

After the injection phase the production mandrel 36, 236 is displaced to a final shut-in position during the final shut-in phase of the shut-in tool 10, 100 as described with reference to FIG's 7 and 29, respectively.

The shut-in tool 10, 100 provides a platform for flexible drill stem testing programs. The shut-in tool 10, 100 can be operated in any of a number of sequences in opening and closing of the fluid end 12, 112 depending on requirements. Circulation ports 44, 1303 in the housing sub 30, 130 provide the fluid end 12, 112 with the added functionally that pre- flow can be purged from the test string and the annulus circulated. The fluid end 12, 112 can then be used to inject an injection fluid to the zone of interest. The Applicant envisages that further rings of sleeve ports may be added to the production sleeve 32, 132 to increase the number of phases through which the shut-in tool 10, 100 can cycle. A further ring of ports formed in the wall 46 of the housing sub 30, 130 is also envisaged for further functionality.

Throughout the specification the aim has been to describe the invention without limiting the invention to any one embodiment or specific collection of features. Persons skilled in the relevant art may realize variations from the specific embodiments that will nonetheless fall within the scope of the invention. For example, normally the shut-in tool 10, 100 is run in the open-hole environment. However, the shut-in tool 10, 100 is well suited for drill stem testing in cased-hole.

It will be appreciated that various other changes and modifications may be made to the embodiment described without departing from the spirit and scope of the invention.

Claims

1. A fluid end of a shut-in tool, the fluid end including:

2. The fluid end of claim 1 , wherein the fluid end includes the production mandrel.

3. The fluid end of claim 1 or claim 2, wherein the fluid end is configured for the production mandrel to be displaceable to an injection position wherein the production port is in fluid communication with the flow opening of the housing sub to inject fluid from the production flow passage to the zone of interest.

4. The fluid end of any one of the preceding claims, wherein the fluid end includes a production sleeve within the housing sub, the production mandrel displaceably received in the production sleeve, the production sleeve including two or more longitudinally spaced sleeve ports in a wall of the production sleeve, wherein the production port of the production mandrel is in fluid communication with one of the sleeve ports when opposite the one of the sleeve ports and the production port is closed off by the wall of the production sleeve when the production port is not opposite the sleeve ports.

5. The fluid end of claim 4, wherein the production sleeve and the housing sub are dimensioned and configured so that a chamber is defined between the wall of the production sleeve and the wall of the housing sub, and wherein the chamber is in fluid communication with the flow opening of the housing sub.

6. The fluid end of claim 4 or claim 5, wherein a first of the two or more longitudinally spaced sleeve ports is in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the first of the two or more longitudinally spaced sleeve ports when the production mandrel is in the flow position.

7. The fluid end of claim 6, wherein a second of the two or more longitudinally spaced sleeve ports is in fluid communication with the circulation port of the housing sub, and the production port of the production mandrel is located opposite the second of the two or more longitudinally spaced sleeve ports when the production mandrel is in the purge position.

8. The fluid end of claim 6 or claim 7, wherein a third of the two or more longitudinally spaced sleeve ports is in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the third of the two or more longitudinally spaced sleeve ports when the production mandrel is in the injection position.

9. The fluid end of any one of claims 5 to 8, wherein the fluid end includes a ported hub located in the chamber between the wall of the production sleeve and the wall of the housing sub, the ported hub dividing the chamber into an upper chamber and a lower chamber, the ported hub including:

10. The fluid end of claim 9, wherein the ported hub is located at a position wherein the radial flow passages of the ported hub fluidly connects the circulation port of the housing sub with the second of the two or more longitudinally spaced sleeve ports.

11. The fluid end of claim 9 or claim 10, wherein the ported hub is integrally formed with the production sleeve.

12. A shut-in tool having:

a fluid end including:

a production mandrel displaceable in the housing sub, the production mandrel having:

13. The shut-in tool of claim 12, wherein the shut-in tool is configured for the production mandrel to be displaceable to an injection position wherein the production port is in fluid communication with the flow opening of the housing sub to inject fluid from the production flow passage to the zone of interest.

14. The shut-in tool of claim 12 or claim 13, wherein the shut in tool includes a production sleeve within the housing sub, the production mandrel displaceably received in the production sleeve, the production sleeve including two or more longitudinally spaced sleeve ports in a wall of the production sleeve, wherein the production port of the production mandrel is in fluid communication with one of the sleeve ports when opposite the one of the sleeve ports and the production port is closed off by the wall of the production sleeve when the production port is not opposite one of the sleeve ports.

15. The shut-in tool of claim 14, wherein the production sleeve and the housing sub are dimensioned and configured so that a chamber is defined between the wall of the production sleeve and the wall of the housing sub, and wherein the chamber is in fluid communication with the flow opening of the housing sub.

16. The shut-in tool of claim 14 or claim 15, wherein a first of the two or more longitudinally spaced sleeve ports is in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the first of the two or more longitudinally spaced sleeve ports when the production mandrel is in the flow position.

17. The shut-in tool of claim 16, wherein a second of the two or more longitudinally spaced sleeve ports is in fluid communication with the circulation port of the housing sub, and the production port of the production mandrel is located opposite the second of the two or more longitudinally spaced sleeve ports when the production mandrel is in the purge position.

18. The shut-in tool of claim 16 or claim 17, wherein a third of the two or more longitudinally spaced sleeve ports is in fluid communication with the flow opening of the housing sub and the production port of the production mandrel is located opposite the third of the two or more longitudinally spaced sleeve ports when the production mandrel is in the injection position.

19. The shut-in tool of any one of claims 15 to 18, wherein the fluid end includes a ported hub located in the chamber between the wall of the production sleeve and the wall of the housing sub, the ported hub dividing the chamber into an upper chamber and a lower chamber, the ported hub including:

radial flow passages fluidly connecting the circulation port of the housing sub with one of the longitudinally spaced sleeve ports, and

transverse flow passages fluidly connecting the upper chamber and the lower chamber.

20. The shut-in tool of claim 19, wherein the ported hub is located at a position wherein the radial flow passages of the ported hub fluidly connects the circulation port of the housing sub with the second of the two or more longitudinally spaced sleeve ports.

21. The shut-in tool of claim 20 or claim 21 , wherein the ported hub is integrally formed with the production sleeve.

22. The shut-in tool of any one of claims 12 to 21 , wherein the shut-in tool includes a screw mechanism to selectively displaceable the production mandrel between the flow position, shut-in position and purge position.

23. A method of drill stem testing using a shut-in tool, the method including:

24. The method of drill stem testing of claim 23, wherein the method further includes displacing the production mandrel to an injection position wherein the production port is in fluid communication with the flow opening of the housing sub to inject fluid from the production flow passage via the flow opening of the housing sub.

25. The method of drill stem testing of claim 23 or claim 24, wherein the method includes displacing the production mandrel by rotation of drill pipe to which the shut-in tool is connected.