PRODUCTION SYSTEM FOR PRODUCING HYDROCARBONS FROM A WELL
The present invention relates to a production system (1) for producing hydrocarbons from a well (2). Said production system comprises a production casing (3), a monitoring unit adapted to measure a production outcome of the well, a first reservoir zone (6) comprising at least a first fluid (10), extending along and outside part of the production casing, a second reservoir zone (7) comprising at least a second fluid (11), extending along and outside another part of the production casing, a first inflow device arranged in the first reservoir zone having a first inflow area and being adapted to let the first fluid into the production casing at a first volume rate (VI), a second inflow device arranged in the second reservoir zone having a second inflow area and being adapted to let the second fluid into the production casing at a second volume rate (V2), wherein the first and second inflow areas of the inflow devices are adjustable, whereby the first and second inflow devices can be adjusted so that the first volume rate is equal to or higher than the second volume rate. Furthermore, the present invention relates to a well completion comprising the production system according to the invention as well as to a production method for the production of hydrocarbons from a well.
The present invention relates to a production system for producing hydrocarbons from a well. Furthermore, the present invention relates to a well completion comprising the production system according to the invention as well as to a production method for the production of hydrocarbons from a well.
BACKGROUND ARTDuring oil and gas production, it is sometimes necessary to assist the production in a well due to a high hydro-static pressure. If the well itself is not capable of generating the adequate pressure to drive oil or gas to the surface, or the well has been deliberately killed, artificial lift may be used to lift the well fluid at the upper part of the well.
By submerging a pump into a well, the pump may be used to boost the pressure or perhaps restart a dead well. The pump sets a plug or seal in the well and pumps well fluid from one side of the plug to the other to overcome the static pressure of the well fluid above the pump.
Other methods of artificial lifting use chemicals or gasses to provide the lift required to ensure an acceptable production outcome from the well. However, the known solutions overcoming the static pressure of the well fluid use external energy sources.
SUMMARY OF THE INVENTIONIt 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 production system for producing hydrocarbons from a well without using an artificial lift system, such as a pump, gas or chemicals.
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 production system for producing hydrocarbons from a well, comprising
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- a production casing,
- a monitoring unit adapted to measure a production outcome of the well,
- a first reservoir zone comprising at least a first fluid, extending along and outside part of the production casing,
- a second reservoir zone comprising at least a second fluid, extending along and outside another part of the production casing,
- a first inflow device arranged in the first reservoir zone, having a first inflow area and being adapted to let the first fluid into the production casing at a first volume rate, and
- a second inflow device arranged in the second reservoir zone, having a second inflow area and being adapted to let the second fluid into the production casing at a second volume rate,
wherein the first and second inflow areas of the inflow devices are adjustable, whereby the first and second inflow devices can be adjusted so that the first volume rate is equal to or higher than the second volume rate.
Hereby, a production system is obtained wherein the energy in the reservoir and well is used for lifting the well fluid out of the well, substantially without using external energy sources.
In an embodiment, the inflow device comprises a first outer sleeve and a second inner sleeve movable in relation to each other, the first outer sleeve having outer inflow openings arranged in rows with a different number of openings in each row, and the second inner sleeve having inner openings, whereby the inflow area of the inflow device is adjustable in that the inner openings of the second inner sleeve can be moved and aligned in relation to the outer openings of the first sleeve.
Said inflow openings may be arranged in rows along the inflow device.
Furthermore, the inner openings may be arranged with a distance between them in relation to the outer openings, whereby the inflow area of the inflow device is adjustable in that the inner openings of the second inner sleeve can be moved and aligned in relation to the outer openings of the first sleeve.
Moreover, the inner openings of the inner sleeve may be arranged with predetermined circumferenctial distances between them so that each row of outer inflow openings can optionally be opened or closed by moving the inner sleeve.
In one embodiment, the second inner sleeve may be rotatably movable in relation to the first outer sleeve.
In another embodiment, the inflow device may have an axial extension, and the inner sleeve may be slidable in relation to the outer sleeve along the axial extension.
Furthermore, the outer sleeve may have a recess in which the inner sleeve slides along the axial extension.
In yet another embodiment, the second sleeve may comprise recesses for engaging with a key tool for adjusting the inflow device.
In yet another embodiment, the inner sleeve may be slidably movable in relation to the outer sleeve.
In addition, the production system as described above may further comprise a monitoring unit adapted to measure a production outcome of the well.
Moreover, the monitoring unit may be adapted to measure a water content of the production outcome so that the inflow devices may be adjusted to obtain an optimum between production outcome and water content.
Also, the monitoring unit may be adapted to measure a volume rate of the production outcome and/or a pressure at the top of the well so that the inflow devices may be adjusted based on the volume rate and/or pressure measured at the top of the well.
In one embodiment, the inflow devices may be manually adjustable.
In another embodiment, the inflow devices may be remotely adjustable.
Furthermore, the inflow device may be operated by a magnetic source.
Moreover, the reservoir zones may be separated by annular barriers.
In an embodiment, the system may comprise a plurality of reservoir zones.
Further, a plurality of inflow devices may be arranged in the system and/or in each reservoir zone.
Said plurality of inflow devices may be arranged in the system and/or in each reservoir zone.
Also, the first fluid may be oil and the second fluid may be water or gas.
In addition, a valve may be arranged in one or more of the openings.
Furthermore, a screen may be arranged outside the openings.
In one embodiment, the inflow device may comprise a first packer, the second sleeve may be arranged in a recess of the first sleeve, and the first packer may be arranged between the first sleeve and the second sleeve.
Furthermore, the packer may extend around the inner circumferential recess and have an inner diameter which is substantially the same as that of the second sleeve.
Moreover, the packer may have a number of through-going packer channels for being aligned with first axial channels in the first sleeve.
In addition, the packer may be made of ceramics.
In an embodiment, the production casing may comprise annular barriers, each annular barrier being adapted for being expanded in an annulus between the production casing and an inside wall of a borehole downhole, and each annular barrier comprising:
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- a tubular part for mounting as part of the production casing,
- an expandable sleeve surrounding the tubular part, each end of the expandable sleeve being fastened to the tubular part by means of a connection part,
- an annular barrier space between the tubular part and the expandable sleeve, and
- an aperture in the tubular part for letting fluid into the annular barrier space to expand the sleeve,
wherein annular barriers are arranged, separating the first reservoir zone and the second reservoir zone.
Furthermore, the expandable sleeve may be made of metal.
The present invention also relates to a well completion comprising the production system as described above and a well head.
The well completion may further comprise a control unit arranged in the well head for adjusting the inflow devices.
In addition, the well completion may further comprise a key tool connected with a downhole tractor for adjusting the inflow devices.
Further, the present invention relates to a production method for production of hydrocarbons from a well, comprising the steps of:
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- determining a first reservoir zone comprising at least a first fluid,
- determining a second reservoir zone comprising at least a second fluid,
- opening a first inflow device in the first zone to let the at least first fluid into a production casing at a first volume rate,
- opening a second inflow device in the second zone to let the at least second fluid into the production casing at a second volume rate,
- monitoring a production outcome of the well, and
- adjusting the first and second inflow devices based on the production outcome so that the first volume rate is equal to or higher than the second volume rate or so that the second volume rate is higher than the first volume rate.
In said method, the monitoring step may comprise one or more of the steps of:
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- measuring a pressure at the top of the well,
- measuring a volume rate of the production outcome at the top of the well, and/or
- measuring a water content of the production outcome at the top of the well.
Also, the step of adjusting the first and second inflow devices may further comprise adjustment of at least one of the inflow devices based on the measured pressure, volume rate and/or water content at the top of the well.
Moreover, the step of step of adjusting the first and second inflow devices may be performed manually, e.g. by a key tool connected with a downhole tractor.
Additionally, the step of adjusting the first and second inflow devices further may be performed remotely from the top of the well.
Finally, the step of adjusting the first and second inflow devices further may be performed wirelessly.
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
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.
DETAILED DESCRIPTION OF THE INVENTIONThe production system 1 also comprises a first reservoir zone 6 comprising at least a first fluid 10, extending along and outside the production casing 3, and a second reservoir zone 7 comprising at least a second fluid 11, extending along and outside the production casing. Furthermore, a first inflow device 8 is arranged in the first reservoir zone 6, having a first inflow area and being adapted to let the first fluid 10 into the production casing 3 at a first volume rate V1, and a second inflow device 9 is arranged in the second reservoir zone 7, having a second inflow area and being adapted to let the second fluid 11 into the production casing 3 at a second volume rate V2. The first and second inflow areas of the inflow devices 8, 9 are adjustable, whereby the first and second inflow devices 8, 9 can be adjusted based on the production outcome so that the first volume rate V1 is equal to or higher than the second volume rate V2.
Hereby, it is obtained that the production of hydrocarbons from the well 2 may be optimised by adjusting the inflow volume rates of the inflow devices 8, 9 to the instantaneous requirement based on either the volume rate of the production outcome, the pressure at the top of the well 2, the water content of the production outcome, or a combination thereof. Thus, by means of the present system, it is possible to create lift of the fluids in the well by adjusting the inflow volume rates of the fluids and thereby avoid using artificial lift or at least substantially reduce the use of artificial lift.
In the event that the first fluid 10 comprises more water or gas, it may be used for driving the second and heavier fluid 11, and thus, artificial lift higher up the well may be avoided. Similarly, the second fluid may have a higher content of water which is normally shut off by hindering its inflow into the casing, however, the second fluid may be useful for mixing with the first fluid to ease the flow of the well of the first fluid.
In the production system 1 shown in
In
Another embodiment of the inflow device 8 is shown in
An additional embodiment of the inflow device 8 is shown in
The inflow device 8 of
In other embodiments, the inflow device may have a different number of rows and a different number of inflow openings in each row. Thus, the embodiment shown in
The inner sleeve 23 is shown in
In the same manner as described above, the inflow device 8 comprises an inner sleeve 23 or tubular which is rotatable within the outer sleeve 22 or tubular. The inflow device 8 is shown in a cross-sectional view of a radial extension of the inflow device 8. The outer sleeve 22 has four rows of inflow openings, 24, 28, 29, 30. In the first row 24, there are seven inflow openings, as shown in
In
In
In
In
In
In
In
In
In
In
In
In
In
In
In
The sequence of adjustments shown in
The inflow device also comprises a second sleeve 42 or tubular having a first end 43 near the outlet 53 and a second end 44 and, in this view, six inner openings 25. Even though the second sleeve 42 or tubular only shows six inner openings 25, the number of inner openings is actually the same as in the first sleeve 40 or tubular, i.e. 12 inner openings.
Furthermore, the second sleeve 42 or tubular is rotatable within the first sleeve 40 or tubular, and the second sleeve 42 has a second wall 45 having twelve second axial channels (not shown) extending in the second wall 45 from the first end 43 to the inner opening 25. Thus, each inner opening 25 has its own second axial channel.
The second sleeve 42 or tubular is arranged in an inner circumferential recess 46 in the first wall 41 of the first sleeve 40 or tubular, meaning that when the second sleeve 42 or tubular is arranged in the recess, the second sleeve 42 or tubular will not decrease the overall inner diameter of the inflow device and thereby of the production casing.
The second sleeve 42 or tubular is rotatable in relation to the first sleeve 40 or tubular at least between a first position, in which the first channel 27 and second channel (not shown) are aligned to allow fluid to flow from the reservoir into the production casing via the first end 43 of the second sleeve 42 or tubular, and a second position (the position shown in
The inflow device 8 also comprises a first packer 47 which is arranged between the first sleeve 40 or tubular and the first end 43 of the second sleeve 42 or tubular. The packer 47 extends around the inner circumferential recess 46 and has an inner diameter which is substantially the same as that of the second sleeve or tubular. The packer 47 has a number of through-going packer channels 48 corresponding to the number of first axial channels, i.e. in this embodiment twelve, the packer channels 48 being aligned with the first axial channels 27. The packer is fixedly connected with the first sleeve or tubular so that the packer channels 48 are fluidly connected with first axial channels. The packer is ring-shaped, and the through-going packer channels 48 extend through the packer along the axial extension of the first sleeve or tubular.
The packer 47 is preferably made of ceramics, whereby it is possible to make the contact surfaces of the packer 47 smooth, which enhances the sealing properties of the packer 47, since the smooth contact surface may be pressed closer to the opposite surface which is the first end 43 of the second sleeve 42 or tubular. However, in other embodiments, the packer may be made of metal, composites, polymers or the like.
Furthermore, a second packer 49 is arranged between the first sleeve 40 or tubular and the second end 44 of the second sleeve 42 or tubular. However, in another embodiment, the second packer is omitted, whereby the second end 44 of the second sleeve 42 or tubular faces the first wall of the first sleeve 40 or tubular.
In
Furthermore, the second sleeve 42 or tubular may comprise at least one recess 51 accessible from within, the recess 51 being adapted to receive a key tool (not shown) for rotating the second sleeve 42 or tubular in relation to the first sleeve 40 or tubular.
The adjustment of the inflow devices 8, 9 may be performed manually, e.g. by inserting a downhole tool having a key tool into the production casing and moving the downhole tool to the inflow device which needs to be adjusted. The inflow devices 8, 9 may also be operated by a magnetic source.
The inflow device 8 of
In other embodiments, the inflow devices may be remotely adjustable, e.g. by wireline or wireless control.
The inflow device 8 is adapted to be inserted and form part of the production casing 3, thus forming a cased completion (not shown). Accordingly, the ends of the inflow device 8 are adapted to be connected with another casing element by conventional connection means, for instance by means of a threaded connection.
In the embodiments described above, the outer openings are shown as openings per se. However, the outer openings may comprise flow restrictors, throttles or valves, such as inflow control valves (not shown).
Even though the above-mentioned embodiments have been described primarily in relation to rotatable movement of the inner sleeve in relation to the outer sleeve, the inner sleeve may be slidably movable in relation to the outer sleeve.
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.
By a casing is meant any kind of pipe, tubing, tubular, liner, string etc. used downhole in relation to oil or natural gas production.
In the event that the tools are not submergible all the way into the casing, a downhole tractor can be used to push the tools all the way into position in the well. A downhole tractor is any kind of driving tool capable of pushing or pulling tools in a well downhole, such as a Well Tractor®.
Although the invention has been described in the above in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
Claims
1-22. (canceled)
23. A production system for producing hydrocarbons from a well, comprising: wherein the first and second inflow areas of the inflow devices are adjustable, whereby the first and second inflow devices can be adjusted so that the first volume rate is equal to or higher than the second volume rate, wherein the inflow device comprises a first outer sleeve and a second inner sleeve movable in relation to each other, characterised in that the first outer sleeve having outer inflow openings arranged in rows with a different number of openings in each row, and the second inner sleeve having inner openings, whereby the inflow area of the inflow device is adjustable in that the inner openings of the second inner sleeve can be moved and aligned in relation to the outer openings of the first sleeve.
- a production casing,
- a first reservoir zone comprising at least a first fluid, extending along and outside a part of the production casing,
- a second reservoir zone comprising at least a second fluid, extending along and outside another part of the production casing,
- a first inflow device arranged in the first reservoir zone, having a first inflow area and being adapted to let the first fluid into the production casing at a first volume rate, and
- a second inflow device arranged in the second reservoir zone, having a second inflow area and being adapted to let the second fluid into the production casing at a second volume rate,
24. A production system according to claim 23, wherein the inner openings are arranged with a distance between them which is different from a distance between the outer openings, whereby inflow area of the inflow device is adjustable in that the inner openings of the second inner sleeve can be moved and aligned in relation to the outer openings of the first sleeve.
25. A production system according to claim 23, wherein the inner openings of the inner sleeve may be arranged with predetermined circumferenctial distances between them so that each row of outer inflow openings can optionally be opened or closed by moving the inner sleeve.
26. A production system according to claim 23, further comprising a monitoring unit adapted to measure a production outcome of the well.
27. A production system according to claim 26, wherein the monitoring unit is adapted to measure a water content of the production outcome so that the inflow devices may be adjusted to obtain an optimum between production outcome and water content.
28. A production system according to claim 26, wherein the monitoring unit is adapted to measure a volume rate of the production outcome and/or a pressure at the top of the well so that the inflow devices may be adjusted based on of the volume rate and/or pressure measured at the top of the well.
29. A production system according to claim 23, wherein the reservoir zones are separated by annular barriers.
30. A production system according to claim 23, wherein the first fluid is oil and the second fluid is water or gas.
31. A production system according to claim 23, wherein the inflow device comprises a first packer, the second sleeve is arranged in a recess of the first sleeve, and the first packer is arranged between the first sleeve and the second sleeve.
32. A production system according to claim 31, wherein the packer extends around the inner circumferential recess and has an inner diameter which is substantially the same as that of the second sleeve.
33. A production system according to claim 31, wherein the packer has a number of through-going packer channels for being aligned with first axial channels in the first sleeve.
34. A production system according to claim 31, wherein the packer is made of ceramics.
35. A production system according to claim 23, wherein the production casing comprises annular barriers, each annular barrier being adapted for being expanded in an annulus between the production casing and an inside wall of a borehole downhole, and each annular barrier comprising: wherein annular barriers are arranged, separating the first reservoir zone and the second reservoir zone.
- a tubular part for mounting as part of the production casing,
- an expandable sleeve surrounding the tubular part, each end of the expandable sleeve being fastened to the tubular part by means of a connection part,
- an annular barrier space between the tubular part and the expandable sleeve, and
- an aperture in the tubular part for letting fluid into the annular barrier space to expand the sleeve,
36. A production system according to claim 35, wherein the expandable sleeve is made of metal.
37. A well completion comprising the production system according to claim 23 and a well head.
38. A well completion according to claim 37, further comprising a control unit arranged in the well head for adjusting the inflow devices.
39. A production method for production of hydrocarbons from a well by means of the production system according to claim 23, comprising the steps of:
- identifying a first reservoir zone comprising at least a first fluid,
- identifying a second reservoir zone comprising at least a second fluid,
- opening a first inflow device in the first zone to let the at least first fluid into a production casing at a first volume rate,
- opening a second inflow device in the second zone to let the at least second fluid into the production casing at a second volume rate,
- monitoring a production outcome of the well, and
- adjusting the first and second inflow devices based on the production outcome so that the first volume rate is equal to or higher than the second volume rate or so that the second volume rate is higher than the first volume rate.
40. A method according to claim 39, wherein the monitoring step comprises one or more of the steps of:
- measuring a pressure at the top of the well,
- measuring a volume rate of the production outcome at the top of the well, and/or
- measuring a water content of the production outcome at the top of the well.
41. A method according to claim 39, wherein the step of adjusting the first and second inflow devices further comprises adjustment of at least one of the inflow devices based on the measured pressure, volume rate and/or water content at the top of the well.
42. A method according to claim 39, wherein the step of adjusting the first and second inflow devices is performed manually, e.g. by a key tool connected with a downhole tractor.
Type: Application
Filed: Dec 21, 2012
Publication Date: Dec 4, 2014
Inventor: Jørgen Hallundbæk (Graested)
Application Number: 14/363,880
International Classification: E21B 43/14 (20060101); E21B 43/16 (20060101);