Method for creating a landing nipple

Abstract

The present invention relates to a method for creating a landing nipple having an annular edge in a well tubular metal structure on which a projection unit of an intervention downhole tool may land, comprising lowering a downhole tool section comprising a tubular metal element having a first outer diameter in a first condition into an existing well to a predetermined position, expanding the tubular metal element from the first condition to a second condition having a second outer diameter in which the tubular metal element abuts an inner face of the well tubular metal structure, creating the annular edge in the well, landing the projection unit on the annular edge, and performing an operation by an operational tool at a predetermined distance from the annular edge.

Description

[0001] METHOD FOR CREATING A LANDING NIPPLE

[0002] The present invention relates to a method for creating a landing nipple having an annular edge in a well tubular metal structure on which a projection unit of an intervention downhole tool may land.

[0003] When a well is to be completed, the well tubular metal structure, e.g. a completion or production string, is assembled so that a landing nipple is mounted as part of the well tubular metal structure at a predetermined distance from e.g. a sliding sleeve, which needs to be adjusted later on by intervening the well to open or close the sliding sleeve. The position of the landing nipple is thus decided upon when planning the well design. Later on when the well is to be intervened, e.g. for drilling a hole in the well tubular metal structure or for drilling or milling out a restriction such as a nipple or a stuck valve, no landing nipple is located at a position near such operation, and if the operation for some reason fails, and the intervention tool needs to be pulled out and redressed, or a drill or cutting bit needs to be replaced before re-entering the well to continue the operation, the position at which the first part of the operation was performed can be difficult to relocate.

[0004] It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved solution for providing a higher degree of success when an intervention operation is performed downhole.

[0005] The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a method for creating a landing nipple having an annular edge in a well tubular metal structure on which a projection unit of an intervention downhole tool may land, comprising:

[0006] - lowering a downhole tool section comprising a tubular metal element having a first outer diameter in a first condition into an existing well to a predetermined position,

[0007] P2975PC00- expanding the tubular metal element from the first condition to a second condition having a second outer diameter in which the tubular metal element abuts an inner face of the well tubular metal structure, creating the annular edge in the well, - landing the projection unit on the annular edge, and

[0008] - performing an operation by an operational tool in a predetermined distance from the annular edge.

[0009] By expanding the tubular metal element, a landing nipple can be created at any position in the well needed for the operation to be performed, even though a tool must be pulled out of the well before finalising the operation. Thus, the success of the operation is substantially increased because if the operational tool for some reason is failing e.g. to cut through the well tubular metal structure, such as a casing, the position of the cut can always be found, continued and thus finalised so that the operation becomes successful. By expanding the tubular metal element, a simple landing nipple is created without decreasing the inner diameter of the well.

[0010] Moreover, the annular edge may be a projection edge extending along the entire inner face of the well tubular metal structure. The annular edge may be formed by at least the wall thickness of the tubular metal element. The annular edge may be inclined, forming a decreasing inner diameter of the well, and in that way the annular edge is formed by both the thickness of the tubular metal element and a distance from the outer face of the tubular metal element to the inner face of the well tubular metal structure.

[0011] Also, the method may further comprise retracting the downhole tool, changing a condition of the operational tool and reintroducing the downhole tool until the projection unit lands on the annular edge, continuing the operation. Thus, a tool can easily be redressed if the cutting edge is worn and the operation is slowed down or even stopped, as the operation can be optimised by retracting the tool and replacing the worn parts, after which the operation can be continued by landing on the annular edge again. Changing a condition of the downhole tool may also be to replace the bit with another kind of bit, such as changing from a drilling bit to a milling bit, or to replace the tool with another kind of tool.

[0012] In addition, the method may further comprise activating the projection unit to move from a retracted position to a projected position before landing the projection

[0013] P2975PC00unit on the annular edge. By having a projectable projection unit, restrictions higher up in the well can be passed while it is still possible to land on a much smaller annular edge. Furthermore, the annular edge can be made much smaller than known landing nipples as the projection unit is able to move to the projected position and catch and land on the annular edge.

[0014] Furthermore, the method may also comprise releasing the downhole tool section from the tubular metal element after expansion of the tubular metal element.

[0015] Moreover, the method may further comprise moving the projection unit to land on the annular edge after expansion of the tubular metal element.

[0016] Also, the downhole tool section may comprise an expansion tool.

[0017] Further, the projection unit may comprise at least one projectable arm.

[0018] In addition, the expansion tool may have an expansion packer or a mandrel for expanding the tubular metal element from the first outer diameter to the second outer diameter.

[0019] Furthermore, the packer may be inflatable.

[0020] Moreover, the mandrel may be expandable.

[0021] Also, the tubular metal element may have a first wall thickness of 0.5-50 mm, preferably 10-30 mm, in the first condition.

[0022] Further, the tubular metal element may have a second wall thickness of 0.5-50 mm in the second condition that is smaller than the first wall thickness.

[0023] In addition, the predetermined distance may be 100-5000 mm, preferably 200-2000 mm.

[0024] Furthermore, the method may also comprise retracting the downhole tool section from the well tubular metal structure.

[0025] P2975PC00Also, the method may further comprise introducing the intervention downhole tool after expansion of the tubular metal element.

[0026] Further, the operational tool may be a milling bit, a drilling bit, a manipulation tool, a tubing punching tool, a stroking tool, a perforation tool, a tubing cutting tool or a similar tool.

[0027] In addition, the tubular metal element may have a first section with a first inner diameter and a second section with a second inner diameter, the first inner diameter being smaller than the second inner diameter, at least in the second condition.

[0028] Moreover, the first section may be expanded less than the second section.

[0029] Also, the first section may have a first section wall thickness that is larger than a second section wall thickness of the second section.

[0030] In addition, the tubular metal element may comprise at least one sealing part arranged on an outer face of the tubular metal element.

[0031] Furthermore, at least one groove may be is arranged in the outer face of the tubular metal element, and the sealing part may be arranged in the groove.

[0032] Finally, a back-up element may be arranged in the groove adjacent to the sealing part to back up the sealing part during expansion.

[0033] The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:

[0034] Fig. 1A shows a partly cross-sectional view of a downhole tool section comprising a tubular metal element before expansion of the tubular metal element,

[0035] Fig. IB shows a partly cross-sectional view of an intervention downhole tool landed on the landing nipple in the form of the expanded tubular metal element and performing an operation,

[0036] P2975PC00Fig. 1C shows a cross-sectional view of the expanded tubular metal element forming a landing nipple and a reference point for re-entering the operational tool to the same position for continuing the operation,

[0037] Fig. ID shows a partly cross-sectional view of the intervention downhole tool having re-entered the well and continuing the operation,

[0038] Fig. 2A shows a partly cross-sectional view of a downhole tool section comprising another tubular metal element before expansion of the tubular metal element,

[0039] Fig. 2B shows a cross-sectional view of the tubular metal element of Fig. 2A in its expanded second condition forming a landing nipple and a reference point for reentering the operational tool to the same position for continuing the operation,

[0040] Fig. 3A shows a partly cross-sectional view of a downhole tool section comprising yet another tubular metal element before expansion of the tubular metal element, and

[0041] Fig. 3B shows a cross-sectional view of the tubular metal element of Fig. 3A in its expanded second condition forming a landing nipple and a reference point for reentering the operational tool to the same position for continuing the operation.

[0042] All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.

[0043] The present invention relates to a method for creating a landing nipple having an annular edge 1 in a well tubular metal structure 2 on which a projection unit 3 of an intervention downhole tool 4 may land for performing an operation downhole, as shown in Fig. 1C. The operation may be any operation for intervening the well by pulling a sleeve, drilling or punching a hole, cutting the well tubular metal structure 2, as shown in Fig. IB, or e.g. milling or drilling out a restriction in the well. The method for creating a landing nipple as a reference point comprises lowering a downhole tool section 4a comprising a tubular metal element 5 having a first outer diameter OD1 in a first condition into an existing well to a predetermined position, as shown in Fig. 1C, then expanding the tubular metal element 5 from the first condition to a second condition having a second outer

[0044] P2975PC00diameter OD2 in which the tubular metal element 5 abuts an inner face 6 of the well tubular metal structure 2, creating the annular edge 1 in the well, before landing the projection unit 3 on the annular edge 1 and performing an operation by an operational tool 7 at a predetermined distance DI from the annular edge 1, as shown in Fig. IB.

[0045] The annular edge 1 is a projection edge 12 extending along the entire inner face 6 of the well tubular metal structure 2 so that a tool can dock and land on the edge 1 at a predetermined distance from the position at which the operation is to be performed. The annular edge 1 is formed by at least the wall thickness of the tubular metal element 5.

[0046] When a well is to be completed a well, the well tubular metal structure 2, e.g. a completion or production string, is assembled so that a landing nipple is mounted as part of the well tubular metal structure 2 at a predetermined distance from e.g. a sliding sleeve, which needs to be adjusted later on by intervening the well to open or close the sliding sleeve. The position of the landing nipple is thus decided upon when planning the well design. Later on when the well is to be intervened, e.g. for drilling a hole in the well tubular metal structure 2 or for drilling or milling out a restriction such as a nipple or stuck valve, no landing nipple is positioned near such operation, and if the operation for some reason fails, and the intervention tool needs to be pulled out and redressed, or a drill or cutting bit needs to be replaced before re-entering the well to continue the operation, the position at which the first part of the operation was performed can be difficult to relocate.

[0047] By expanding the tubular metal element 5, a landing nipple can be created at any position in the well needed for the operation to be performed, even though a tool has to be pulled out of the well before finalising the operation. By expanding the tubular metal element 5, a simple landing nipple is created without decreasing the inner diameter of the well.

[0048] Thus, the method may further comprise retracting the downhole tool, as seen in Fig. 1C, changing a condition of the operational tool and reintroducing the downhole tool until the projection unit 3 lands on the annular edge 1, as shown in Fig. ID, continuing the operation at the same position, e.g. continuing cutting in a same cut 17 as just previously made and thereby finishing the cut. Thus, the method of providing a landing nipple in an existing well before performing an

[0049] P2975PC00operation increases the success rate of the operation. Furthermore, a new landing nipple is created without substantially decreasing the inner diameter of the well tubular metal structure 2.

[0050] The downhole tool section 4a may also be part of the intervention downhole tool 4 so that the downhole tool section 4a first expands the tubular metal element 5, then releases from the expanded tubular metal element 5, which is fastened to the inner face of the well tubular metal structure 2. Subsequently, the intervention downhole tool 4 having both the projection unit 3 and the downhole tool section 4a is moved so that the projection unit 3 lands on the annular edge 1, and the operational tool is activated.

[0051] The method may also be used for removing an existing landing nipple for letting a large diameter tool pass, and when the large diameter tool no longer needs to pass, a new landing nipple is created by expanding the tubular metal element 5. Even though a well completion is planned very carefully, sometimes a large diameter tool needs to pass a landing nipple, and then the landing nipple is drilled or milled out. After the large diameter tool has passed, the nipple cannot be recreated or remounted, but a new landing nipple is created by way of expanding the tubular metal element 5 at the same location can be performed so as to reestablish the landing nipple function for later use.

[0052] In some wells, a restriction is installed higher up in the well, and the method then further comprises activating the projection unit 3 to move from a retracted position to a projected position before landing the projection unit 3 on the annular edge 1. In this way, the tool is able to pass the restriction and then still be able to land on the annular edge 1 before starting the operation.

[0053] The downhole tool section comprises an expansion tool 8 for expanding the tubular metal element 5. The expansion tool 8 comprises an expansion packer 16 or a mandrel for expanding the tubular metal element 5 from the first outer diameter OD1 to the second outer diameter OD2. The packer 16 is inflatable, and the mandrel is expandable, e.g. by radially movable cones.

[0054] After the tubular metal element 5 has been expanded and thus set, the downhole tool section is released from the tubular metal element 5. The projection unit 3 is

[0055] P2975PC00then moved to land on the annular edge 1 after expansion of the tubular metal element 5.

[0056] In Fig. IB, the projection unit 3 comprises at least two projectable arms 15. As shown in Fig. 1A, the tubular metal element 5 has a first wall thickness tl of 0.5-50 mm, preferably 10-30 mm, in the first condition. When expanded, the tubular metal element 5 has a smaller thickness, i.e. a second wall thickness t2 of less than 0.5-50 mm in the second condition that is smaller than the first wall thickness tl. As shown in Fig. IB, the operational tool 7 is arranged at the predetermined distance DI from the annular edge 1, where the predetermined distance is 100-5000 mm, preferably 200-2000 mm.

[0057] The creation and setting of the landing nipple in the form of expanding the tubular metal element 5 is performed by the downhole tool section 4a comprising the tubular metal element 5. The downhole tool section 4a may be a separate tool and thus not part of the intervention downhole tool 4, and then after having released the downhole tool section 4a from the expanded tubular metal element 5, the downhole tool section 4a is retracted from the well tubular metal structure 2, and the intervention downhole tool 4 having the operational tool is introduced in the well so that the projection unit 3 lands on the annular edge 1, and the operation can be initiated.

[0058] The operational tool may comprise a milling bit, a drilling bit, a manipulation tool, a tubing punching tool, a stroking tool, a perforation tool, a tubing cutting tool or a similar tool. The tubing cutting tool may have at least two projecting arms 18 having a cutting insert / edge 19, as shown in Figs. IB and ID. The stroking tool may comprise a manipulation tool having projectable keys matching into a profile in a sliding sleeve for pulling or manipulating the sleeve between an open and a closed position. The drilling or milling bit may be arranged to be rotated around a longitudinal tool axis or in a radial axis perpendicular to the longitudinal tool axis.

[0059] After the operational tool has cut the tubing, the tension in the well tubular metal structure 2 is released in the top part. Thus, if making a second operation, the tubular metal element 5 may also be set below the intended cut so that the tubular metal element 5 is expanded, and then the tool is moved upwards. The projection unit 3 is then arranged further down the well of the downhole tool section 4a than the operational tool. After the cut has been made, the "released part" of the well

[0060] P2975PC00tubular metal structure 2 may be pulled upwards, creating an axial opening so that an annular barrier can be inserted, or a straddle or patch can be set.

[0061] In Figs. 2A and 2B, the tubular metal element 5 has a first section 9 having a first section wall thickness t3 that is larger than a second section wall thickness t4 of a second section 10 of the tubular metal element 5. The first section 9 of the tubular metal element 5 has a first inner diameter ID1, and the second section 10 of the tubular element 5 has a second inner diameter ID2, so that the first inner diameter ID1 is smaller than the second inner diameter ID2, at least in the second condition after the tubular metal element has been expanded. The first inner diameter ID1 and the second inner diameter ID2 are substantially the same in the first condition as shown in Fig. 2A, but a projection 20 in the first section 9 changes the inner diameter ID1 when the tubular metal element 5 is expanded, creating the annular edge 1, which is inclined. In Figs. 3A and 3B, the first and the second inner diameters ID1, ID2 are also the same in the first condition shown in Fig. 3A and the second condition is shown in Fig. 3B. The expansion tool 8 comprises a first expansion packer 8a and a second expansion packer 8b arranged on each side of the first section 9 so that, during expansion, only the second sections 10, 10a, 10b are fully expanded on each side of the first section 9, forming the annular edge 1. Thus, the first section 9 is expanded less than the second section 10. The annular edge 1 is therefore inclined, forming a decreasing inner diameter of the well, and in that way the annular edge 1 is formed by both the thickness t2 of the tubular metal element 5 and a distance D2 from an outer face 21 of the tubular metal element 5 to the inner face 6 of the well tubular metal structure 2, as shown in Fig. 3B. A packer may also be arranged opposite the first section 9 to expand the first section 9 but less than the second sections 10, 10a, 10b.

[0062] In order to enhance the sealing ability of the tubular metal element 5, the tubular metal element 5 comprises at least one sealing part arranged on an outer face of the tubular metal element 5. Furthermore, at least one groove may be arranged in the outer face of the tubular metal element 5, and the sealing part is arranged in the groove. The tubular metal element 5 may further comprise a back-up element arranged in the groove adjacent to the sealing part to back up the sealing part during expansion.

[0063] The use of the terms "first", "second", "third" and "fourth", "primary", "secondary", "tertiary", etc., does not imply any particular order, but are included to identify

[0064] P2975PC00individual elements. Moreover, the use of the terms "first", "second", "third" and "fourth", "primary", "secondary", "tertiary", etc., does not denote any order or importance, but rather the terms "first", "second", "third" and "fourth", "primary", "secondary", "tertiary", etc., are used to distinguish one element from another. Note that the words "first", "second", "third" and "fourth", "primary", "secondary", "tertiary", etc., are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering.

[0065] Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

[0066] It is to be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

[0067] It is also to be noted that the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements.

[0068] It should further be noted that any reference signs do not limit the scope of the claims.

[0069] A stroking tool is a tool providing an axial force. The stroking tool comprises an electric motor for driving a pump. The pump pumps fluid into a piston housing to move a piston acting therein. The piston is arranged on the stroker shaft. The pump may pump fluid out of the piston housing on one side and simultaneously suck fluid in on the other side of the piston.

[0070] By "fluid" or "well fluid" is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By "gas" is meant any kind of gas composition present in a well, completion or open hole, and by "oil" is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil and water fluids may thus all comprise other elements or substances than gas, oil and / or water, respectively.

[0071] By "annular barrier" is meant an annular barrier comprising a tubular metal part mounted as part of the well tubular metal structure and an expandable metal sleeve surrounding and connected to the tubular metal part defining an annular barrier space.

[0072] P2975PC00The expandable sleeve of the annular barrier may be an expandable metal sleeve.

[0073] By "casing" or "well tubular metal structure" is meant any kind of pipe, tubing, tubular, liner, string, etc., used downhole in relation to oil or natural gas production.

[0074] In the event that the tool is not submergible all the way into the casing, a downhole tractor can be used to push the tool all the way into position in the well. The downhole tractor may have projectable arms having wheels, wherein the wheels contact the inner surface of the casing for propelling the tractor and the tool forward in the casing. A downhole tractor is any kind of driving tool capable of pushing or pulling tools in a well downhole, such as a Well Tractor®.

[0075] Although the invention has been described above in connection with preferred embodiments of the invention, it will be evident to a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.

[0076] P2975PC00

Claims

Claims1. A method for creating a landing nipple having an annular edge (1) in a well tubular metal structure (2) on which a projection unit (3) of an intervention downhole tool (4) may land, comprising:- lowering a downhole tool section (4a) comprising a tubular metal element (5) having a first outer diameter (OD1) in a first condition into an existing well to a predetermined position,- expanding the tubular metal element from the first condition to a second condition having a second outer diameter (OD2) in which the tubular metal element abuts an inner face (6) of the well tubular metal structure, creating the annular edge in the well,- landing the projection unit on the annular edge, and- performing an operation by an operational tool (7) at a predetermined distance (DI) from the annular edge.

2. A method according to claim 1, further comprising retracting the downhole tool, changing a condition of the operational tool and reintroducing the downhole tool until the projection unit lands on the annular edge, continuing the operation.

3. A method according to claim 1 or 2, further comprising activating the projection unit to move from a retracted position to a projected position before landing the projection unit on the annular edge.

4. A method according to any of the preceding claims, further comprising releasing the downhole tool section from the tubular metal element after expansion of the tubular metal element.

5. A method according to any of the preceding claims, further comprising moving the projection unit to land on the annular edge after expansion of the tubular metal element.

6. A method according to any of the preceding claims, wherein the downhole tool section comprises an expansion tool (8).P2975PC007. A method according to any of the preceding claims, wherein the tubular metal element has a first wall thickness (tl) of 0.5-50 mm, preferably 10-30 mm, in the first condition.

8. A method according to any of the preceding claims, wherein the tubular metal element has a second wall thickness (t2) of 0.5-50 mm in the second condition that is smaller than the first wall thickness.

9. A method according to any of the preceding claims, wherein the predetermined distance is 100-5000 mm, preferably 200-2000 mm.

10. A method according to any of the preceding claims, further comprising retracting the downhole tool section from the well tubular metal structure.

11. A method according to any of the preceding claims, further comprising introducing the intervention downhole tool after expansion of the tubular metal element.

12. A method according to any of the preceding claims, wherein the operational tool is a milling bit, a drilling bit, a manipulation tool, a tubing punching tool, a stroking tool, a perforation tool, a tubing cutting tool or a similar tool.

13. A method according to any of the preceding claims, wherein the tubular metal element has a first section (9) with a first inner diameter (ID1) and a second section (10) with a second inner diameter (ID2), the first inner diameter being smaller than the second inner diameter, at least in the second condition.

14. A method according to claim 13, wherein the first section is expanded less than the second section.

15. A method according to claim 13, wherein the first section has a first section wall thickness (t3) that is larger than a second section wall thickness (t4) of the second section.P2975PC00

Images