This invention relates to controlled splitting, release and removal of at least one line from a defined section of an annulus between a tubing and a casing of a well related to the production of hydrocarbons. More specifically the present invention relates to a well completion arrangement for removing at least a portion of a line running in an annulus between a tubing and a casing in a well and a method for preparing a well for abandonment.
The main objective with the present invention is to provide an arrangement and a method for controlled removal of at least a section of at least one line in a well.
In this document the term line is meant to be any line running in an annulus between a tubing and a casing. Such a line may be a control line, a communication line, a chemical injection line and similar. The line may be used to transmit electric or fiber-optic signals, electric power, hydraulic fluid pressure, scale inhibiting chemicals and similar. For the sake of simplicity the line is commonly referred to as control line, but can be any line mentioned above.
When abandoning a well in an oil/gas field and related wells, the shutting down of the well has to be conducted according to relevant regulatory practices. The general term for such operations is “plug and abandonment”. The regulatory practices define the number and nature of barriers that need to be permanently established between the hydrocarbon carrying formation and the surface. Moreover, the practices define what equipment that can be left permanently in the well and what equipment that has to be removed.
Traditionally, plug and abandonment operations have been conducted using rigs or tailor made jack systems, cutting the tubing and the control line deep in the well, and pulling everything out to the surface. Subsequent to this, the well is cemented, and the top sections of the casing and conductors are cut and removed.
For subsea wells, the use of rigs for plug and abandonment operations becomes extremely expensive. Jack systems for similar operations does not currently exist, but may be developed in the future. Anyhow, both rig and jack operations would be very expensive to use for plugging and abandoning subsea wells.
The regulations related to plug and abandonment work do allow for the tubing to be left as part of the permanently cemented equipment left in the well. However, control lines used to communicate and/or operate downhole equipment such as sensors and flow control devices cannot be left permanently in the well, as they represent a potential for future leakage paths through the cement. The control lines are typically clamped to the outside of the production tubing, and in most cases there is no practical way of removing the control lines without cutting and pulling the tubing itself.
The invention has as its object to remedy or at least reduce one or more drawbacks of the prior art.
The object is achieved through features as specified in the description below and in the subsequent Claims.
In this document splitting will mean any kind of dividing of the line, such as cutting, clipping, pulling apart, such as pulling apart over a pre-created weakpoint or coupling in the line, squeezing apart and disconnecting by means of operating line couplings designed for this purpose.
In a first aspect of the present invention there is provided a well completion arrangement for removing at least a portion of a line running in an annulus between a tubing and a casing in a well, wherein the arrangement comprising:
- at least two clamping means spaced apart in the longitudinal direction of the tubing and fixed thereto, the clamping means being configured for fixing the line with respect to tubing;
- splitting means for releasing the line from the interval defined by at least an upper clamping means and a lower clamping means of the at least two clamping means;
- a line manipulator apparatus for activating said release of the line;
- a line retrieval apparatus for displacing into the tubing the portion of the line from said interval, thereby removing the line from the annulus.
The clamping means may constitute a portion of the tubing connecting two tubing joints, or associated crossover piping towards the tubing.
The arrangement may be provided with an allocation means for controlling the position of at least the manipulator apparatus with respect to the holding means.
The line manipulator apparatus may comprise the line retrieval apparatus.
The splitting means may be provided in at least one of the clamping means.
Alternatively, the splitting means may be provided in the manipulator apparatus.
Thus, the splitting means may be adapted to cut through a portion of the clamping means.
The line manipulator may further be provided with gripping means adapted for engaging a profile of the clamping means. The profile may be arranged adjacent of the holding means.
The retrieval apparatus may be a flow and/or pressure inducing apparatus arranged for displacing the line from the outside to the inside of the tubing. In one embodiment of the present invention the flow and/or pressure inducing apparatus is a pump located on the surface of the well.
In a second aspect of the present invention there is provided a method of preparing a well for abandonment, the method comprising the steps of:
- incorporating at least two spaced apart clamping means in a tubing during completion of the well, the clamping means being provided with a holding means for fixing a line with respect to the clamping means, the line running in an annulus between the tubing and a casing;
- providing splitting means for releasing the line at least at an upper clamping means and at a lower clamping means of the at least two clamping means;
- providing an apparatus for inducing said release of the line; and
- providing an apparatus for displacing into the tubing the portion of the line from the interval defined by at least the upper clamping means and at the lower clamping means of the at least two clamping means.
The following describes a non-limiting example of a preferred embodiment illustrated in the accompanying drawings, in which:
FIG. 1 is a generic sectional view of a well for the production of hydrocarbons;
FIG. 2 illustrates a prior art plug and abandonment technique;
FIG. 3 illustrates a desired scenario for plugging and abandonment, which is sought by means of the invention described herein;
FIG. 4 illustrates prior art attachment techniques for securing a control line to production tubing;
FIG. 5 illustrates a generic well completion according the present invention;
FIG. 6 illustrates the same well completion as shown in FIG. 5, but where the control line has been removed;
FIG. 7 illustrates the completion from FIGS. 5-6 after the well has been cemented;
FIG. 8
a illustrates in a sectional view one embodiment of a bottom clamp further to the invention herein;
FIG. 8
b illustrates a side view of FIG. 8a seen from right to left;
FIG. 9
a illustrates the bottom clamp in FIG. 8a where a wireline manipulation tool is used to create a cut and perform an initial release operation of the control line;
FIG. 9
b illustrates a side view of FIG. 9a seen from right to left;
FIG. 10
a illustrates in a sectional view an embodiment of an intermediate clamp further to the invention herein;
FIG. 10
b illustrates a side view of FIG. 10a seen from right to left;
FIG. 11
a illustrates the intermediate clamp of FIG. 10a, and a wireline manipulation tool used to perform a release operation of the control line;
FIG. 11
b illustrates a side view of FIG. 11a seen from right to left;
FIG. 12
a illustrates a sectional view of one embodiment of a top clamp further to the invention herein;
FIG. 12
b illustrates a side view of FIG. 12a seen from right to left;
FIG. 13
a illustrates the top clamp of FIG. 12a, and a wireline manipulation tool used to perform a cut and release operation of the control line;
FIG. 13
b illustrates a side view of FIG. 13a seen from right to left;
FIG. 14
a illustrates the top clamp of FIGS. 12a-13a, after the control line has been cut and released, and shows the initial stage of the control line removal operation;
FIG. 14
b illustrates a side view of FIG. 14a seen from right to left;
FIG. 15
a illustrates a sectional view of a top clamp in another embodiment, and a wireline manipulation tool used to perform a cut and release operation of the control line;
FIG. 15
b illustrates a side view of FIG. 15a seen from right to left;
FIG. 16
a illustrates the top clamp of FIG. 15a, after the control line has been cut and released, and shows the initial stage of the control line removal operation;
FIG. 16
b illustrates a side view of FIG. 16a seen from right to left;
FIG. 17
a illustrates a sectional view of another embodiment of a top clamp further to the invention herein;
FIG. 17
b illustrates a side view of FIG. 17a seen from right to left;
FIG. 18
a illustrates the top clamp of FIG. 17a, and a wireline manipulation tool used to perform a cut and release operation of the control line;
FIG. 18
b illustrates a side view of FIG. 17a seen from right to left;
FIG. 19
a illustrates the top clamp of FIGS. 17a-18a, after the control line has been cut and released, and shows the initial stage of the control line removal operation;
FIG. 19
b illustrates a side view of FIG. 19a seen from right to left;
FIG. 20
a illustrates in a sectional view another embodiment of a top clamp further to the invention herein;
FIG. 20
b illustrates a side view of FIG. 20a seen from right to left;
FIG. 21
a illustrates the top clamp of FIG. 20a, and a wireline manipulation tool in engagement with it to perform a cut and release operation of the control line;
FIG. 21
b illustrates a side view of FIG. 21a seen from right to left;
FIG. 22
a illustrates the top clamp of FIGS. 20a-21a, after the control line has been cut and released, and the system being ready for the control line removal operation;
FIG. 22
b illustrates a side view of FIG. 22a seen from right to left;
FIG. 23
a illustrates in a smaller scale a sectional view of a larger well schematic, and the well status upon completing the manipulation step illustrated in FIG. 22a;
FIG. 23
b illustrates in a larger scale a detail of FIG. 23a;
FIG. 24
a illustrates a first step of removing the control line based on a scenario as illustrated in FIG. 23a;
FIG. 24
b illustrates in a larger scale a detail of FIG. 24a;
FIG. 25
a illustrates a second step of removing the control line based on a scenario as illustrated in FIG. 23a;
FIG. 25
b illustrates in a larger scale a detail of FIG. 25a;
FIG. 26
a illustrates a sectional view of an alternative arrangement for removing the control line based on a scenario as illustrated in FIG. 23a;
FIG. 26
b illustrates in a larger scale a detail of FIG. 26a; and
FIG. 27 illustrates a sectional view of an alternative embodiment for removing the control line based on a scenario as illustrated in FIG. 23a.
In this document positional specifications such as “upper” and “lower”, “bottom” and “top” or “horizontal” and “vertical” refer to the position of the apparatus in the figures, which may also be a natural, necessary or practical functional position.
In FIG. 1 a borehole 101 is provided with a casing 102 used for preventing the borehole from collapsing during drilling and subsequent production. In the lower section of the well, the casing 102 is cemented to the borehole 101, resulting in a section of what is referred to as casing cement 103 herein; filling the annular area between the casing 102 and the borehole 101. The casing cement 103 forms one of several required fluid barriers between the underground, hydrocarbon carrying formation and the surface.
FIG. 1 illustrates a generic well completion wherein the lower completion comprises a production liner 104, which is cemented to the borehole using liner cement 105. The liner is open towards the hydrocarbon reservoir via perforations 106. The design and configuration of the production liner 104 may vary significantly from what is illustrated herein, however this will be appreciated by a person skilled in the art and not further described herein. The production liner 104 is anchored to and forms a seal towards the casing 102 by means of a liner hanger system 107.
The upper completion comprises a production tubing 108, which is stung into the lower completion by means of a seal stinger assembly 109. In the bottom section of the tubing 108, this is terminated and forms a seal towards the casing 102 by means of a production packer 110. In the top of the well, the tubing 108 is terminated in the lower section of the wellhead 111.
In the lower section of the tubing 108, a permanent downhole pressure and temperature gauge 112 is mounted. This is powered and communicates to the surface by means of a control line 113.
In the top of the wellhead 111, an intervention bore 114 is blocked by two crown plugs 115. On the side of the wellhead 111, a flow line 116 is connected to a production bore 117.
The completion design may vary significantly from what is shown in FIG. 1, and there are common completion components that are not illustrated herein, such as a downhole safety valve. This is done consciously in order to simplify the drawings, hence direct the focus on the design and methods directly related to the invention described herein. Such facts will be appreciated by a person skilled in the art.
FIG. 2 illustrates relevant aspects in relation to prior art techniques for permanent plugging and abandonment of wells. In conjunction with such operations, heavy kill fluid is pumped into the well, whereupon a deep-set mechanical barrier 118 is installed. In conjunction with the killing of the well, holes 119 are punched in the tubing 108 to allow for displacement to kill fluid both on the inside and the outside of the tubing 108. As a next step, further to current practice, the tubing 108 and control line 113 is cut, normally right above the production packer 110, the cut being illustrated by the line A-A′. Then, the tubing 108 and control line 113 is hauled out of the well using traditional casing/tubing handling equipment such as tongues and control line 108 winches, or tailored jack based tubing retrieval systems on the surface.
The subsequent step in plugging and abandonment is the installation of a cement retaining device 120, before a cement column referred to as abandonment cement 121 is dumped on top of the cement retainer 120. It is a common requirement that the height of the abandonment cement 121 column must equal or exceed a particular length L. In many cases, the length L equals 50 meters. A final important requirement in this respect is that the abandonment cement 121 must fully overlap with the casing cement 103 in order to provide for the required pressure barrier function between the hydrocarbon carrying reservoir formation and the surface.
In particular on fields developed by means of subsea well solutions, plug and abandonment operations can become very expensive, as the current practice requires a drilling rig to perform the operation. An object of the present invention is to remove the need for a drilling rig to plug and abandon wells.
FIG. 3 illustrates a hypothetical situation, further to a scenario sought achieved by the invention described herein. In the scenario illustrated in FIG. 3 the tubing is not pulled out of the well. Instead, the cement is pumped down the inside or bore of the tubing 108, through the holes 119 and up the annulus between the tubing 108 and the casing 102 as illustrated in FIG. 3. The result is a column of abandonment cement 121 that fills both on the inside and the annulus on the outside of the tubing 108. Current regulations allow for such a method to be used, leaving the relevant section of tubing 108 encased by the abandonment cement 121. The only limitation is that the control line 113 cannot be left inside along the permanent cement barrier. Current regulations state that the control line 113 may form a future leak path; hence it needs to be removed prior to installing the cement 121. There is no current existing technique to remove control line 113 from the annular area between the tubing 108 and the casing 102. In order to avoid rig operations for performing the plug and abandonment work, there is a need for an arrangement and a method for cutting and removing a section of control line 113 from the interval of length L as illustrated in FIG. 3.
FIG. 4 illustrates prior art technology for attaching the control line 113 to the tubing 108. The main parts of the tubing 108 is made up of tubing joints 401 and collars 402. In normal cases, each tubing joint is approximately 12 meters long. Common practice for installing a control line 113 is to attach it to the tubing 108 using one cable clamp 403 per collar 402. There are several designs of cable clamps 403, the one illustrated herein having bands 404 surrounding the tubing, the bands 404 being located adjacent the shoulders of the collar 402. This prevents any sliding of the clamps 403 along the tubing 108 during installation in the well. The clamp 403 is commonly a hinged design, manually installed when running the well completion. The clamps 403 are mounted on the tubing 108 as illustrated, whereupon the control line(s) is/are routed into grooves 405 of the clamp 403 prior to closing this and tightening it up using torque bolts 406. As a part of this process, the control line 113 gets squeezed towards the tubing 108 via the main shoulders 407 of the clamp 403, hence securing this from any sliding movement along the length of the tubing 108. As per current practice, the removal of control line 113 from the annulus between the tubing 108 and the casing 102 is difficult, as the orientation of the control line 113 is unknown; the tubing 108 may be ex-centered inside the casing 102, the clamps 403 being made of very hard materials, difficult to cut etc. Finally, in relation to cutting the tubing 108 and the control line 113, there are regulatory requirements not to cause any damage to the casing 102, making a cutting, allocation and retrieval process for the control line 113 difficult.
According to the present invention, a well is completed in a different manner than what is performed today. More specifically, sections of the well overlapping with the interval of length L in FIG. 3, are proposed completed by means of cable clamping arrangements having distinctive characteristic in order to facilitate for releasing, accessing and removing the control line 113 over an interval that has an equal or exceeding overlap with the interval of length L in FIG. 3.
FIG. 5 illustrates a preferred embodiment of the invention. In the illustration clamping means comprising one top clamp 501, two intermediate clamps 502, 502′ and one bottom clamp 503 is illustrated. An important functionality related to these clamps 501, 502, 502′, 503 is to secure the line 113 to the tubing 108 during installation of the well completion and for the wells life. Essential functionality characteristics in conjunction with the plugging and abandonment of wells are:
- The ability to perform a controlled splitting of the line 113 (typically done in the top clamp 501, the bottom clamp 503 or both).
- The ability to perform a controlled release of the line 113 (typically done in the top clamp 501 and bottom clamp 503 in conjunction with a splitting/cutting operation, and for some embodiments in the intermediate clamps 502, 502′
- The ability to remove at least a majority of the line 113 from an interval equal to or exceeding, and overlapping with the interval L as described above—in a controlled manner.
There are several conceptual ways of achieving the above—some examples are described in relation to the subsequent figures of this document.
In one embodiment of the invention, all of the control line 113 is removed in one go. For this embodiment, the intermediate clamps 502, 502′ are designed to allow for the controlled release of the control line 113 from the tubing at these locations, without cutting the control line 113.
In another embodiment, the control line 113 is removed sequentially. In one associated embodiment the control line 113 is removed in sections that for the most overlap with the length of the associated tubing joints. In this case, the intermediate clamps 502, 502′ may not be relevant to use. In one related embodiment the top clamp 501 and bottom clamp 503 is merged into one uniform design, providing for both the ability to split the relevant section of control line 113 as well as removing this from the interval of relevance.
It should be emphasized that the clamps 501, 502, 502′, 503 described herein are not needed for attachment of control line 113 along the entire well interval. They are only required for the interval where the control line 113 needs to be cut/split, released and removed in conjunction with a plug and abandonment operation.
FIG. 6 illustrates the scenario where the control line 113 has been removed from the relevant interval by means of the techniques proposed herein. Do note that this normally takes place at a time where the initial steps of a plug and abandonment operation is finished, hence the holes 119 are punched in the tubing 108 and the deep set mechanical barrier 118 is installed.
FIG. 7 illustrates the scenario where the relevant interval has been cemented; this is the new abandonment scenario further to the philosophy and techniques proposed herein. One final step of the abandonment process not illustrated herein is related to the removal of the x-mas tree 111, the flow line 116 and the upper sections of the casing 102.
As mentioned above, the exact design and number of the novel clamps that are proposed herein may vary. In one embodiment of the invention, the operation of relevant clamps such as the top clamp 501, intermediate clamp(s) 502, 502′ and bottom clamp 503 to perform the required plug and abandonment steps (such as splitting, releasing and accessing the control line) is achieved by means of wireline manipulation techniques. In another embodiment, the operation is conducted by means of system manipulation via the control line 113. In still another embodiment, the components are operated by means of mechanical systems, such as mechanical counters and activation mechanisms, operated by manipulating tubing pressure, annulus pressure or both according to a pre-defined interval of pressure impulses defined by amplitude, duration, frequency and similar. In one embodiment, the operation is conducted by means of a combination of the above techniques.
FIG. 8
a and FIG. 8b illustrates one embodiment of a bottom clamp 503 associated with one embodiment of the invention. Do note that the figures serve the purpose as non-limiting examples and illustrations only.
FIG. 8
a illustrates a sectional view of the bottom clamp 503 seen from the side, whereas FIG. 8b illustrates the same section, uncut and as seen from the front looking from right to left in FIG. 8a towards the side where the control line 113 is attached.
For this embodiment, the bottom clamp 503 replaces the collar 402 of FIG. 4, meaning that the tubing joints 401 are screwed directly into the bottom clamp 503. Variations may apply, such as using crossovers to the tubing and similar. This will be appreciated by a person skilled in the art and not further described herein.
For this embodiment, the purpose of the bottom clamp 503 is merely to provide for a controlled method of cutting the control line 113. In order to do this, the control line is located in a groove 801 in the bottom clamp 503, and fixed to the bottom clamp 503 using holding means in the form of a block element 802 secured with bolts 803. Finally, the bottom clamp 503 includes allocation means in the form of an allocation and orientation profile 804 for a wireline tool to be used in the plug and abandonment operation. The profile 804 may be of similar design and shape as orientation/allocation wedges used in conjunction with installation of gas lift valves in side pocket mandrels. This will be appreciated by a person skilled in the art and is no further referred to herein.
FIG. 9
a and FIG. 9b illustrate the process of cutting the line 113 for the given embodiment of the bottom clamp 503. Here, a line manipulation apparatus in the form of a tailored wireline tool 901 is positioned correctly by means of an allocation bolt 902 orienting the tool 901 with respect to the allocation profile 804. Note that the wireline tool 901 is shown in a side view in FIG. 9a and not in a sectional view as the clamp 503 and tubing 108. Then, a splitting means in the form of a transverse cutter element 903 is used to create a transverse cut 904 of the line 113 just above the block element 802. By means, the section of line 113 that is located above the bottom clamp 503 has been split and released, and can now be pulled upwards.
FIG. 10
a and FIG. 10b illustrate one embodiment of an intermediate clamp 502 associated with a similar embodiment of the invention as FIGS. 8-9. The main difference from the bottom clamp 503 of FIGS. 8-9 is that in FIG. 10, the control line 113 is attached to the clamp 502 by a holding means shown as a hinged block element 1001.
FIG. 11
a and FIG. 11b illustrate the process of releasing the control line 113 from the intermediate clamp 502 for this given embodiment of the invention. Similar to the process described in FIGS. 8-9, a wireline 901 tool is applied for this purpose. The wireline tool 901 may be the same as the one described in FIGS. 8-9 using different tool modules, or a different tool. However, in this document, number references for similar wireline tool modules are kept constant for simplicity purposes.
Again, the wireline tool 901 is positioned correctly by means of an allocation bolt 902 orienting the tool with respect to the allocation profile 804. Then, a longitudinal cutter element 1101 is applied in a pattern illustrated by arrow 1102 to create a longitudinal cut 1103 of the hinged block element 1001 as illustrated in FIG. 11b. Thus, when a section of the control line 113 has been split and released above the lower block element 802 as illustrated in FIGS. 9a and 9b, the section of control line 113 that is located above the bottom clamp 503 and the intermediate clamp 502 can now be pulled upwards. By means, the hinge 1001 does no longer impose any holding force on the control line 113. In one embodiment, the hinge 1001 is designed to open somewhat when cut, for example by pre-tensioning it against a shoulder when tightening the bolts 803. The cutting element 1101 as well as other cutting elements described herein may be selected from the group comprising: mechanical means such as blade/saw/grinder type cutters; plasma cutters; chemical cutters; explosive cutters or a combination of one or more thereof. This will be appreciated by a person skilled in the art and is no further referred to herein.
In an alternative embodiment (not shown), the block element 1001 of the intermediate clamp 502 has a saw-tooth surface on the side that imposes force on the control line 113. By means, this allows for one-way travel of the control line 113, and no cutting exercise is required to operate this, simplifying the total operation of releasing and removing the control line 113 from the interval of interest. This saw-tooth surface allows displacement of the control line 113 in one direction, but not in the opposite direction. A similar saw-tooth surface can also be applied on the part of the intermediate clamp 502 that the control line 113 rests on, or on both the block element 1001 and the clamp 502.
The control line 113 associated with the top clamp 501 and/or bottom clamps 503 could also be designed having a self-disconnect system to remove the need to cut or manipulate the line 113 loose from the clamp being in the opposite end of where it is intended to pull/push the control line 113 out of the annular segment in question.
As would be appreciated by a person skilled in the art, combinations of the above features could also be included in relevant embodiments, such as the inclusion of a saw-tooth or similar one-way feature of block elements 802 shown in FIGS. 8 and 9 associated with top- or bottom clamps 501, 503.
FIG. 12
a and FIG. 12b illustrate one embodiment of a top clamp 501 associated with a similar embodiment of the invention as in FIGS. 8-11. As for the bottom clamp 503 of FIGS. 8-9, the control line 113 is attached to the clamp 502 by means of a block element 802.
The main difference is that the top clamp 501 is provided with a pulling profile 1201 on its internal wall, adjacent to the block element 802.
FIG. 13
a and FIG. 13b illustrate the process of releasing the control line 113 from the top clamp 501 for the given embodiment of the invention as described in FIGS. 8-11, and moreover the process of removing the control line 113 from the relevant section of the well. Here, the wireline tool 901 is positioned in a similar way to what was described for the previous figures. A latching/gripping element 1301 of the wireline tool 901 is operated to engage with the pulling profile 1201. A multi directional cutter 1302 is applied to make a rectangular shaped cut 1303, surrounding the entire block element 802. A groove 1304 is included in the arrangement to provide for space between the cutting element and the control line 113. The intention with the space is to avoid accidentally cutting the control line 113 below the block element 802. The reason for avoiding cutting the control line below the block element 802 will be apparent by studying FIGS. 14a and 14b. Such protection against accidental cutting could be sought in various ways. This would be appreciated by someone skilled in the art and is no further referred to herein. The rectangular cut 1303 may be difficult to make in one go, whilst the latching element 1301 is engaged to the pulling profile 1201. In one embodiment, one or more of the cutting operations required to create the cut 1301 is/are performed prior to engaging the latching element 1301 to the pulling profile 1201, whereas the remaining cutting operations are performed after engagement.
FIG. 14
a and FIG. 14b illustrate the process of removing the control line from the relevant section in the well for this given embodiment, following the operative steps described in FIGS. 8-13. Here, the latching element 1301 is retracted into the body of the wireline tool 901, bringing the pipe segment defined within the rectangular shaped cut 1303 holding the block element 802 with it. As the block element 802 still exerts a strong holding force on the control line 113, this can now be pulled out by means of the wireline tool 901. In one embodiment, the control line is pulled all the way to the surface and displaced of. This embodiment may entail a challenge with respect to wireline lubricator space required to bring out a >50 meter long object. In another embodiment, the wireline is used to lower the control line 113 segment to a location below the interval L to be cemented (see FIG. 7) and drop it, hence dispose of it in that section of the well. Thus, in FIG. 14a the wireline tool 9001 is both a manipulation apparatus and a retrieval apparatus arranged for bringing or displacing the portion of the line 113 from the outside to the inside of the tubing 108.
FIG. 15
a and FIG. 15b illustrate a slightly different arrangement and method to achieve the same result as described in relation to FIGS. 12-14. Here, the top clamp 501 is provided with a wedge ring 1501 which has a wedge protrusion 1502 as an integral part of it. When installed, the wedge ring 1501 is compressing a spring 1503, which again forces the wedge protrusion 1502 down abutting the block element 802. By means, when making a similar square cut 1303 as illustrated in FIG. 14b, the wedge protrusion biased by the spring 1503 will urge the piece that is cut loose inwards towards the center or bore of the tubing 108. This is illustrated in FIGS. 16a and b. A potential benefit with this embodiment is that the tubing piece that is cut loose now can be collected by means of a collector module 1504 of the wireline tool. Such a collector module 1504 may provide a more simple design and hence more reliable than the latching element 1301 of the previous embodiment. Moreover, the collector module 1504 may not cause the same spatial conflicts with the cutter 1302 when creating the cut 1303 as could be the situation with the latching element 1301.
One main benefit with the embodiments described in FIGS. 8-16 is that the clamp modules do not introduce any new leakage points to the completion than what already exist between tubing joints and collars as per current practice. However, the embodiments shown in FIGS. 8-16 requires relatively sophisticated wireline tooling to operate. In the following section, alternative embodiments, in particular embodiments that do not require pipe cutting modules are illustrated.
FIG. 17
a and FIG. 17b show an alternative embodiment of the top clamp 501. A pulling profile 1201 is integrated in a modular pipe wall segment 1701, which is initially integrated in the top clamp 501. A seal 1702 provides for the barrier integrity between the inside and outside of the tubing 108. The pipe wall segment 1701 is fixed to the top clamp 501 by a locking means, which in the embodiment shown is a lock pin 1703 initially located in a locking position inside a lock groove 1704. For the illustrated embodiment, the lock pin 1703 forms an integral part of lock ring 1705, which is initially held in a lower (locking) position by lock spring 1706. Finally, for this embodiment the top clamp 501 includes a splitting means in the form of a cutting module 1707, such as a cutting blade.
FIG. 18
a and FIG. 18b illustrate the initial operating step of the top clamp 501 embodiment from FIG. 17 at a stage where plug and abandonment activities have been initiated. As described for the embodiment above, a tailored wireline tool 901 is positioned correctly by means of an allocation bolt 902 orienting the tool with respect to the allocation profile 804. Then, a latching/gripping element 1301 of the wireline tool 901 is operated to engage with the pulling profile 1201. The next step is to unlock or release the pipe wall segment 1701 from the top clamp 501. This is done by operating a lock manipulation module 1801 of the wireline tool 901. For this embodiment, the lock manipulation module 1801 engages with the lock ring 1705 and pushes this upwards, as indicated by arrow 1802. This causes the lock pin 1703 to disengage from the lock groove 1704. Upon removing the lock function, the pipe wall segment 1701 can be disengaged from the top clamp 501 by means of operating the latching/gripping element 1301 of the wireline tool 901. When pulling the wall segment 1701 inwards, the cutting module 1707 cuts the control line 113. This is further illustrated in FIG. 19a and FIG. 19b. Subsequently, the control line 113 can be pulled out of the well, alternatively removed from the well interval to be cemented and disposed of elsewhere in the well.
Again, it is emphasized that details shown in this document illustrate possible system functions only. For example, the number and design of locks related to the embodiment shown in FIGS. 17-19 may vary, and may in alternative embodiments vary significantly from what is illustrated herein, however the functionality remains similar.
FIG. 20
a and FIG. 20b show yet another embodiment of the top clamp 501. A portion of the control line 113 runs through a sealed cavity 2001 defined by an outer cover lid 2002, the body of the top clamp 501, and an inner mandrel 2003. The inner mandrel 2003 seals against the cavity 2001 by means of mandrel seals 2004, 2004′. The cover lid 2002 seals against the cavity by means a cover seal 2005 and line seals 2006, 2006′. The line seals 2006, 2006′ surround the control line 113, to form a seal around this.
Experts in the art will appreciate that the task of obtaining 100% tight seals may be challenging from design, operational and material related perspectives. In one embodiment of the invention, the seals 2006, 2006′ (as well as the other seals described herein) may therefore not be pressure proof seals, but rather functioning as efficient flow restrictors, enabling the operation of pumping the control line 113 out of the annulus between the tubing 108 and casing 102 using techniques to create a pressure differential across seals 2006, 2006′. This is explainer further in the following paragraphs.
FIG. 20
a discloses a mandrel 2003 provided with a wireline engagement profile 2007. The top clamp 501 is provided with a mandrel recess 2008 to allow for a defined longitudinal displacement of the mandrel 2003.
Inside the cavity 2001, the control line 113 is attached to the mandrel 2003 by means of an attachment clamp 2009. Also, inside the cavity 2001, the control line 113 is thread through a cutting module 2010 that forms an integral part of the cover lid 2002.
In a preferred embodiment, the segment of control line 113 inside the cavity 2001 has a stop system associated with it, preventing it from being pumped into the annulus on the outside of the tubing 108. Such a stop system could involve one-way, saw-tooth profiled surfaces where the control line 113 is resting against the lid 2002 or the solid body of the top clamp 501. Alternatively, such a stop system be achieved by providing geometrical anomalies on the control line 113, such as for example arranging stop rings on the line, that have a size that does not allow for the control line 113 to be pumped backwards through the line seals 2006, 2006′ and into the annulus.
FIG. 21
a and FIG. 20b illustrate the engagement of a mandrel manipulation wireline tool 2101 to the engagement profile 2007 of the mandrel 2003. More specifically, engagement dogs 2102 of the wireline tool 2101 are in engagement with the profile 2007.
FIG. 22
a and FIG. 22b illustrate the wireline tool 2101 pulling the mandrel 2003 upwards. This results in the cavity 2001 being opened towards the bore of the tubing 108. In the same process, the clamp 2009 with the control line 113 attached to it moves upwards with respect to the cutting module 2010, resulting in the control line 113 being cut by the cutting module 2010. For the illustrated embodiment, this entails a loose end 2201 of the control line 113 being positioned adjacent to an opening 2202 between the cavity 2001 and the bore of the tubing 108.
In one embodiment, similar features as those shown in FIGS. 20-22 are associated with the bottom clamp 503 rather than the top clamp 501. In such embodiments, the top clamp 501 may only have features related to splitting and releasing the control line 113 inside it, and no feature for creating the said opening 2202 between the cavity 2001 and the bore of the tubing 108. One reason for swapping the said functionalities between the top clamp 501 and the bottom clamp 503 is that it may be desired to pump the control line 113 downwards into the well during the subsequent operational step(s).
One such scenario is described in FIG. 23a and FIG. 23b illustrating the resulting status of the well and control line system after the operation of a bottom clamp 503 according to a method as illustrated in FIG. 20-22. The control line system is defined by the control line 113 having one loose end 2201 exposed to the bore of the tubing 108, the seal 2006 forming a seal between the bore of the tubing 108 and the annulus between the tubing 108 and the casing 102. For this embodiment and given status of the well operation, the control line 113 has been split and released in the top clamp 501, and also released from the intermediate clamps 502, 502′. An “x” is used to illustrate the fact that these modules have been operated according to said functions, despite the control line 113 still being illustrated to run through them.
FIG. 24
a and FIG. 24b illustrate one technique for retrieving the control line 113 further to a scenario defined in FIG. 23. In FIG. 24a and FIG. 24b a control line collecting wireline tool 2401 is intervened into the well. The tool 2401 comprises a lower collector chamber 2402, with at least one collector port 2403 being positioned adjacent to the loose end 2201 of the control line 113. The lower collector chamber 2402 module also includes a lower packer element 2404 and an upper packer element 2405 that, when in a “control line 113 retrieval position”, straddles the opening 2202 of the bottom clamp 503 illustrated in FIG. 22a, including the seal 2006. The wireline tool 2401 also includes a suction chamber 2406 containing a gas, typically air, at a low pressure, equal or close to atmospheric pressure. The collector chamber 2402 and the suction chamber 2406 are initially separated by a piston 2407.
When the wireline tool 2401 is correctly positioned, as illustrated in FIG. 25a and FIG. 25b, and the packer elements 2404, 2405 are engaged to the tubing 108, the piston 2407 is released. Methods for releasing such pistons will be appreciated by a person skilled in the art and is therefore not described in any further details herein. Now, the piston 2407 travels up into the suction chamber 2406, due to the pressure difference between the suction chamber 2406 and the surroundings. As the packer elements 2404, 2405 forms an enclosure as illustrated in the figure, the control line 113 is forced towards the inside of the tubing 108 and the collector chamber 2402, driven by the high pressure being present in the annulus between the tubing 108 and the casing 102. The result is a separated control line segment 2501 being collected into a collector chamber 2406 in a controlled fashion.
This embodiment and method may have a challenge in relation to detecting whether or not all of the control line 113 has been removed from the interval L (se FIG. 3). In one embodiment, monitoring of pressure in the annulus between the tubing 108 and the casing 102 is used to detect pressure change indications verifying that all the control line 113 has been removed from the relevant interval.
FIG. 26
a and FIG. 26b illustrate a slightly different embodiment of the wireline collector tool 2401. Here, the piston 2407 has been replaced by a channel 2601, located above the upper packer element 2405. Instead of using an atmospheric suction chamber 2406 as illustrated in FIG. 24a and FIG. 24b, the control line is removed from the interval L (see FIG. 3) by pumping fluids down the annulus between the tubing 108 and the casing 102 using a surface pump (not shown), whilst opening valves on the top of the well, allowing for a return of the same fluid via the bore of the tubing 108. By means, the control line 113 will be pumped out of the interval L and into the collector chamber 2402 of the wireline tool 2401. In one embodiment of the invention, the channel 2601 includes a filter (not shown) to prevent the control line 113 being pumped out of the wireline tool 2401.
For the method of pumping out the control line 113 by pumping down the annulus; in one embodiment of the invention, the pressure patterns on the surface is monitored, on the pump side or on the return side or both, to observe for a pressure change associated with the control line 113 no longer plugging the center channel of the seal 2006. For scenarios where the well is completed with multiple control lines 113 the entry to the channel of the seal 2006 may be provided with a ball or similar that is adapted to drop into and plug the channel when the line 113 is pumped out of it. This would entail a pressure change when all the lines are pumped out of the interval, and the system channels is plugged by components that are prevented from moving. Alternative so called tell-tale systems indicating when the control line has been fully removed from the interval could be envisaged. Such tell-tale systems would be appreciated by a person skilled in the art.
Do note that the deep set barrier 118 forms a sealed enclosure towards the bottom section of the well, providing for a pumping/circulation pattern as described above, and preventing unwanted so called bullheading of fluids into the reservoir.
FIG. 27 illustrates an embodiment where no wireline tool is used to collect the control line 113 that has been pumped out. Instead, for this embodiment, the control line 113 is allowed to free-fall to a section of the well where it is left permanently. In one embodiment of the invention, the control line 113 falls to a section of the well that does not overlap with the interval L to be cemented. In one embodiment of the invention, a wireline tool 901 is used to force the control line 113 down and bundle it to a more compact form, ensuring that it does not overlap with the interval L to be cemented.
In another embodiment of the invention, similar techniques are used to displace the control line 113 to other locations inside the tubing 108, as well as to other locations inside the annulus between the tubing 113 and the casing 102. The important aspect is that the control line 113 originally located across the interval “L” of FIG. 3 has been removed from the interval, and to a location where it does not conflict with the subsequent cementing operations as well as other subsequent operations of the well abandonment operation.
In some scenarios, a well may be completed with multiple control lines 113. Control lines 113 may also be one or a combination of electric and hydraulic control lines 113. For the removal of hydraulic control lines 113, pumping and/or suction techniques described herein, such as the techniques described in FIGS. 22-26, may not be directly applicable, as a hydraulic control line 113 is hollow, and will allow flow through the bore therein. For such cases, it may be required to provide for a method of sealing the bore of the line 113 prior to utilizing pumping or suction methods to remove it from the interval L. In one embodiment, the arrangement and method for cutting the control line 113 segment to be removed in the opposite end of the loose end 2201 adjacent to the opening 2202 as illustrated in FIG. 22, would include a method for sealing off the control line 113 in such an opposite end. In one embodiment, such method for sealing would entail mechanical deformation of the control line 113. In another embodiment, check valve functionality is activated at this instance. For the latter case, the method for splitting“cutting” the control line 113 may not be mechanical cutting, but rather a controlled disconnection of the control line 113 at a point designed in order to facilitate for this (i.e. a line coupling designed for such purposes), meaning that the control line 113 as well as the surrounding well mechanics and manipulation devices have been designed for performing a controlled disconnection and sealing of the control line 113 at such point. Techniques for this would be appreciated by a person skilled in the art.
As a final remark, it should be emphasized that the method according to the invention provides for retrieving or producing out the control line 113 in both the top as well as the bottom end of the indicated top/intermediate/bottom clamp 501,502,503 assembly, and that the functionality of the clamp systems 501, 502, 503 as described in the examples provided herein could be interchanged, so that for alternative embodiments the functionality shown for the top clamp 501 herein would apply for a bottom clamp 502 and vice versa. Moreover, the invention provides for sequential removal of the relevant length of control line, such as sectional movement of control line 113 between two and two clamps 501, 502, 503, respectively—potentially removing the need for intermediate clamps 502, 502′. In the latter case, the term “release of control line 113” referred to herein would not be associated with the release of control line 113 from an intermediate clamp 502, but the release from a top clamp 501 or bottom clamp 503. In one embodiment the release activity takes place simultaneously to the cutting/splitting activity. To achieve splitting, release and removal of control line(s) 113 from the annulus between the tubing 108 and the casing 102, features as described or illustrated herein, as well as any combination of described features could form part of relevant embodiments.
In one embodiment of the invention, the operation of relevant clamps such as the top clamp 501, intermediate clamp(s) 502/502′ and bottom clamp 503 to perform the required plug and abandonment steps, such as cutting/splitting, releasing and removing the control line 113, is achieved by means of wireline manipulation techniques. In another embodiment, the operation is conducted by means of system manipulation via one or multiple control line(s) 113 in a similar way to how so-called smart well components of wells are manipulated. As an example, the mandrel 2003 of FIG. 20 could be manipulated to provide for the cutting/splitting, release and removal of control line 113 by operations controlled via the control line 113 using known actuating techniques such as hydraulic, electro hydraulic or electric actuation, or other techniques appreciated by a person skilled in the art. In still another embodiment, relevant components are operated by means of mechanical systems, such as mechanical counters and activation mechanisms, operated by manipulating tubing pressure, annulus pressure or both according to a pre-defined interval of pressure impulses defined by amplitude, duration and similar. Norwegian patent application NO 20110246 filed by the present applicant describes one such arrangement and technique. In one embodiment the above operations are conducted using wireless techniques, and that autonomous, remotely operated downhole arrangements perform one or more of the required cut/split, release and remove operations. In one embodiment, the operation is conducted by means of a combination of the above techniques. Provided an otherwise equal parameter comparison; the latter described methods (the methods not requiring wireline manipulation) would be preferred over methods that require wireline manipulation, as the cost of conducting a wireline operation can become somewhat high in comparison.
In one embodiment, the clamping means 501, 502, 503 are not in the form of collars that replaces the collar 402 of FIG. 4. In some embodiments they may be designed in a similar fashion as prior art cable clamps 403 illustrated in FIG. 4. For such embodiments, the clamping means 501, 502, 503 and holding means 802, 1001, 2009 may be merged into one common functionality. Moreover, for such cases, the collars 402 may be provided with external orientation profiles to enable the mounting of the clamping means 501, 502, 503 with an orientation that provides for the use of techniques described herein, and internal orientation profiles 804, 2007; 902, 2102 for the orientation of manipulation devices as described herein.
Patent Application
20140326470
