EP3870801B1

EP3870801B1 - In-situ surface controlled sub-surface safety valves control line rectification device and method

Info

Publication number: EP3870801B1
Application number: EP19809201.7A
Authority: EP
Inventors: Pål HJERTHOLM
Original assignee: Wellmend As
Current assignee: Wellmend As
Priority date: 2018-10-22
Filing date: 2019-10-22
Publication date: 2024-02-21
Anticipated expiration: 2039-10-22
Also published as: NO345227B1; WO2020085915A1; EP3870801A1; NO20181351A1

Description

Technical Field

The present invention relates to systems and methods for rectification of wellbore hydraulic lines in-situ, typically running along the production tubing from the wellhead to a sub-surface location. Such hydraulic lines can be e.g. control lines connected to Surface controlled sub-surface safety valves (SCSSVs), such as Down Hole Safety Valves (DHSV) or Annulus Safety Valves (ASV), where connection has been lost due to a blocked or leaking control line and rectification is required for further operation of the wellbore.

Background Art

For safety reasons, wellbores are equipped with downhole safety valves (DHSV) that will isolate the part of the wellbore below the safety valve in the event of a failure or emergency. The DHSVs should operate failsafe, i.e. that the safety valve closes automatically if a failure, such as excessive pressure or drop of flow occur in the wellbore. This is typically achieved by maintaining the valve open by applying a hydraulic pressure. As soon as the pressure is lost, the valve will automatically close, and production will stop.
DHSVs operated from surface through a control line are often termed Surface controlled sub-surface safety valves (SCSSVs). In this case the control line run along the production tubing down to the safety valve.
The SCSSV is maintained in an open position by applying a hydraulic pressure from surface, all the way down to the safety valve through the control line. The safety valve may have a spring loaded flap that closes the tubing as soon as there is no hydraulic pressure to counteract the spring force.
Fig. 1 illustrates a typical prior art wellbore with an SCSSV (40) arranged in the production tubing (61). A wellhead (62) and casing strings supported by tubing and casing hangers (63, 64, 65) set in the wellhead (62) are also illustrated. The wellhead is usually installed on top of the first casing string as illustrated, but other configurations are possible. Typically, a well contains multiple intervals of casing successively placed within the previous casing run, e.g., conductor casing, surface casing, intermediate casing, production casing, and production liner. The wellhead (62) is topped with the christmas tree (not shown).
The figure is for illustration only, and the relative dimensions are not indicative of a real wellbore. Further, the lower part of the well bore has been left out.
On the surface, a safety valve control system (67) with a control panel is hydraulically connected to the surface controlled sub-surface safety valve (40) via the control line (50). Typically the control line (50) runs along the production tubing up to the wellhead (62), through the tubing hanger (63), through the wall of the wellhead (62), where it is terminated in a hydraulic block (66). After or during completion, the safety valve control system (67) is connected to the hydraulic block (66) to allow hydraulic connectivity between the safety valve control system (67) and the SCSSV (40).
Such valves are required in wellbores in most countries. In general, the safety valves are either wireline retrievable or tubing retrievable. An example of such a valve is given in Fig 2a, where the valve is in closed position, and in Fig. 2b, where it is in open position. In the safety valve (40) shown, a sliding sleeve (45) is pushed upwards by a spring (42). A fluid flowing upwards will force the flap (41) to close the tubing. Thus, the fluid is not allowed to flow upwards. The valve (40) can be opened by applying a hydraulic pressure in the fluid chamber (44) that overcomes the spring force from the spring (42). To achieve this, hydraulic fluid is pumped down the control line (44), running along the tubing, into the fluid chamber (44). When the pressure is sufficiently large, the sliding sleeve (45) will be forced downwards, and open the flap (41), as shown in Fig. 2b. As will be understood from the above, a loss or reduction of hydraulic pressure in the fluid chamber (44), will cause the valve to close.
The above is only one example of a surface controlled sub-surface safety valve. Other implementations exist, such as ball or poppet types.
One objective of the invention disclosed herein is related to preventing unintentional closing of the valve due to a failure in the valve control system.
As previously mentioned, the control line typically runs along the production tubing from a control system with a control panel at a surface location down to the safety valve. Such a control line can run hundreds of meters below the seabed and typically have an inner diameter of only 4 mm.
The control lines are usually wound around the tubing to allow slack, and bent close to the terminations for fastening purposes.
The problem with lost communication to Surface controlled sub-surface safety valves (SCSSVs), such as Down Hole Safety Valves (DHSV) or Annulus Safety Valves (ASV) is in many occasions caused by clogging of the control line as a result of build-up of debris or particles.
It is well known that such control lines are subject to contamination or blocking due to debris, contamination, or particles that develop and become suspended in the control fluid. The problem can originate from reservoirs, physical wear of system components, chemical degradation, and other sources. Problems may also be related to maintenance or testing of the control line involving bleeding off pressure, which allows hydrocarbons and particles to enter the control line. This could be the case when bleeding off pressure on the control line to test its barrier integrity, or when pumping additional hydraulic fluid into the control line due to a leak.
Chemicals are in some cases used to fix leaking control lines, but this may itself cause plugging of the control line above the leakage point.
Independent of the source of the problems, blocking or leakage, or a combination of the two will inhibit fluid communication between the surface pressure source and the safety valve since it is not possible to maintain a sufficient pressure at the safety valve, and communication will in any case be limited or lost, and the safety valve will close.
US patent 4705107 A discloses a system for cleaning wells with coil tubing, a fluid motor and cutter heads. The invention allows equipment used to clean boiler tubes or heat exchangers to remove downhole deposits from the inside diameter of well tubulars
US2003094419 A1 proposes a general method for cleaning and pressure testing hydraulic control systems. The method is carried out by establishing a turbulent flow of cleaning fluid through the hydraulic control system and maintaining the turbulent flow until the hydraulic control system has been cleaned.
US patent application 2009205832 A1 propose to replace the safety valve temporarily with a separation sleeve comprising a cross-port that connects the port where the control line enters the nipple. A feed line is connected to the cross port, and pressurized solvent can be applied to the feed line, or alternatingly between the control line and the feed line to remove the blockage.
A Similar approach is taken in US2009205831 A1 wherein a method for unblocking the control line comprises removing the safety valve from the nipple; setting into the nipple a sealing tool which sealingly connects the control line and a mini tubing running down into the production tubing; and increasing the pressure of a fluid into the mini tubing to cause fluid to flow into the control line through the sealing tool.
However, the replacement of the safety valve with the separation sleeve is time consuming and requires stop in the production.
US2009050333 A1 discloses a redundant control line where the two control lines are interconnected by a connecting valve. The connecting valve allows control fluid to communicate from the first control line to the safety valve but prevents fluid communication from the second control line to the first control line. To open the valve, the second control line is exhausted to a reservoir.
US20158059 A1 discloses a similar flushing system, with a hydraulic downhole control line that runs from a hydraulic source to a surface controlled sub-surface safety valve. The hydraulic downhole control line having a directional control valve therein; and, a purge line that runs from the hydraulic downhole control line downstream of the directional control valve to a service line, where the purge line has a fluid isolation valve therein.
CN108643858A discloses a sub-surface safety valve piston inlet cleaning system. A cleaning line is installed in the control line between the surface and the piston chamber in the sub-surface safety valve. A chemical can be pumped down to clean the piston chamber. However, there is no mentioning of problems related to impurities in the control line or how to rectify the control line in such case.
These system, with separate purge lines and additional valves, require a more complex installation process than single control lines. For established and completed well bores, such systems cannot be used without a work over of the well. Further, the last section of the control line, below the interconnection of the redundant control lines, is still a single feed line to the safety valve.

Summary of Invention

A goal with the present invention is to overcome the problems of prior art, and to disclose a system and a method where production stops as a result of faulty control lines can be reduced.
The invention solving the above mentioned problems is an-situ surface controlled sub-surface safety valves control line rectification device, configured to mechanically rectify in-situ a control line connected to a surface controlled sub-surface safety valve, and wherein the rectification device comprises;

a rectification line feeder,
a longitudinal first rectification line, wherein the rectification line feeder is arranged to feed the first rectification line longitudinally into the hydraulic line,
wherein the first rectification line has an elastic modulus larger than 10GPa and the rectification feeder is configured to feed the longitudinal first rectification line with decreasing speed into the control line.

The invention is also a method for mechanically in-situ rectifying a surface controlled sub-surface safety valve control line connected to a surface controlled sub-surface safety valve, wherein the method comprises the steps of

feeding a longitudinal first rectification line with an elastic modulus larger than 10 GPa into the hydraulic line, and feeding the lingitudingal first rectification line with decreasing speed into the control line.

A major advantage of the current invention is that control lines can be maintained to prevent failures to e.g. the control system connected to the hydraulic line to happen, or repaired if failures have already happened without having to install additional equipment in a well work-over. This may prevent a time-consuming and costly shut-in. The result is reduced production losses and reduced capital spending.
An effect of the invention, is that the push force at the end of the rectification line is sufficiently large to remove obstacles and debris even when the hydraulic lines are hundreds of meter long and wound around the tubing.

Brief Description of Drawings

Fig. 1
[fig. 1] shows a general, prior art description of a wellbore with a surface controlled sub-surface safety valve (SCSSV).
Fig. 2
[fig. 2] Fig. 2a and 2b illustrates a surface controlled sub-surface safety valve (SCSSV) according to prior art.
Fig. 3
[fig. 3] shows a schematic view of an embodiment of the invention.
Fig. 4
[fig. 4] shows a schematic view of an embodiment of the invention.
Fig. 5
[fig. 5] illustrates some possible cross section embodiments of the longitudinal rectification line.
Fig. 6
[fig. 6] illustrates some possible cross section embodiments of the longitudinal rectification line with a hollow cross section.
Fig.7
[fig.7] illustrates in a partly sectioned view prior art, where a control line (50) is running along a production tubing (20) inside a casing string.
Fig.8
[fig.8] illustrates the same elements as in Fig. 7, and in addition a plug insertion apparatus (70) connected to the first exit block (66a).
Fig.9
[fig.9] illustrates in a partly sectioned and simplified view, the same casing string, production tubing and control line as in Fig. 7 and 8. However, the first exit block (66a) has been replaced by a second exit block (66) wherein the second exit block (66) and the extension control line (51) are configured for guiding the rectification line (20) from the rectification line feeder (10) into the control line (50).

Description of Embodiments

In the following description, various examples and embodiments of the invention are set forth in order to provide the skilled person with a more thorough understanding of the invention. The specific details described in the context of the various embodiments and with reference to the attached drawings are not intended to be construed as limitations. Rather, the scope of the invention is defined in the appended claims.
Some of the embodiments described below are numbered. In addition, dependent or related embodiments defined in relation to the numbered embodiments are described. Unless otherwise specified, any embodiment that can be combined with one or more numbered embodiments may also be combined directly with any of the dependent embodiments of the numbered embodiment(s) referred to.
The examples provided are related to in-situ rectification of control lines for surface controlled sub-surface safety valves (SCSSV). However, the same rectification device, or an adapted rectification device, e.g. a rectification line with other dimensions due to the diameter of the hydraulic line in question, can be used for rectification of other types of hydraulic lines installed in the wellbore.
Figure 1 illustrates a wellbore with surface controlled sub-surface safety valve (SCSSV) according to prior art as explained above, and Fig. 2 illustrates a SCSSV according to prior art.
When the control line used to operate the SCSSV becomes clogged or otherwise filled with debris overtime, it is not possible to maintain pressure inside the control line all the way down to the safety valve, and the SCSSV will close. It is in this situation, or preferably before the control line is so clogged that the SCSSV closes automatically, that the current invention can be used to rectify or clean material and debris from the inside of the control line.
According to a first embodiment of the invention, illustrated in Figure 3 of the drawings showing a schematic illustration, the hydraulic control line (50) runs along the outside of the tubing (61), supported by the tubing hanger (63), between the SCSSV (40) and the wellhead (62). The SCSSV (40) and the control line (50) are part of the completion string in the wellbore.
In the event that it has been decided to rectify the control line (50), the control line rectification device (1) is connected to the control line (50), e.g. by disconnecting the control system (67) from the hydraulic block (66) located at the wellhead (62) outside the pressure barrier. An extension control line (51) may be used between the rectification device and the hydraulic exit block (66).
The rectification device (1) comprises a rectification line feeder (10) and a longitudinal first rectification line (20) , wherein the rectification line feeder (10) is arranged to feed the first rectification line (20) longitudinally into the control line (50). The first rectification line (20) is in an embodiment sufficiently long to reach down to the SCSSV (40).
The first rectification line (20) may in a dependent embodiment have an elastic modulus larger than 10GPa, which has proven to be advantageous for preventing lock-up situations and provide the required force at the end of the first rectification line (20) in real life situations where the control line is several hundred meters long and sometimes curled and wound.
In a second embodiment that may be combined with the first embodiment above, the rectification line (20) has a hollow cross section (22), and the rectification device (1) is arranged to provide a fluid flow internally through said first rectification line (20).
This can be used to circulate fluid in the control line (50) to wash out debris, impurities and pollution from the control line (50). Pressure may be set up from the surface by connecting a fluid pump to the end of the rectification line (20).
The first rectification line (20) may be made in metal, such as steel, polymeric or composite material.
According to a third embodiment that may be combined with any of the embodiments above, an outer cross section (CS) of the first rectification line (20) has at least three protrusions (21a, 21b, 21c) arranged to slide along an inner surface of the hydraulic line (50).
In a related embodiment the outer cross section (CS) of the rectification line (2) is a polygon, and the at least three protrusions (21a, 21b, 21c) are corners of the polygon arranged to slide along an inner surface of the hydraulic line (50).
In a fourth embodiment, that may be combined with any of the embodiments above, the inner and/or outer cross section of the first rectification line (20), is uniform along the a first length of the first rectification line (20), wherein the first length is the length arranged to be fed into the hydraulic line (50).
As seen in Fig. 4, where the dashed circle is illustrating an enlargement of the section where the rectification line (20) enters the control line (50), the transverse cross section of the first rectification line (20) has protrusions (21a, 21b, 21c....) that are arranged to slide along an inner surface of the control line (50). Although a cross section with six protrusions is shown for the first rectification line (20) in this Figure, other cross sections with three or more protrusions can be used to obtain the desired effect of the invention. Some non-limiting examples of hollow cross sections are shown in Fig. 5a, 5b, 5c, 6a, 6b and 6c. Other shapes and combinations are possible.
In an embodiment the cross section (CS) of the first rectification line (20) has 4, 5, 6, 7, 8 9, 10, 11 or 12 protrusions.
The illustrations in Fig. 5 show rectification lines (20) illustrated inside a control line (50). From the left, these rectification lines have a cross section with three, four and seven main protrusions (21a, 21b, 21c, 21d, 21e, 21f, 21g).
A protrusion is defined as a main protrusion only if it can reach the inner diameter of the control line (50), i.e. if it can slide along the inner surface. Thus, the left rectification line (20) of Fig. 5 has a minor protrusion in addition to the three main protrusions, but the minor protrusion cannot reach the inner diameter of the control line due to the geometry, and is therefore not considered a protrusion for the purpose of the invention.
A main protrusion may have zero or more edges. Zero indicates that it has a rounded outer surface. The middle rectification line of Fig. 5 has two edges on each of its vertical main protrusions, while the horizontal protrusions are curved. Preferably a rectification line has at least one protrusion with at least one edge.
The embodiments of rectification line cross sections should be seen as exemplary embodiments only. Other cross sections with other combinations of protrusions, and edges, solid or tubular, will fall within the scope of the invention, as defined by the claims.
In embodiments that may be combined with any of the embodiments above, the elastic modulus is larger than 20, 30 or 50 GPa.
Fig. 3 illustrates some more details of the rectification line feeder (10) that can be comprised in a further embodiment. It contains a termination block (11) arranged to terminate the extension control line (51) connected to the hydraulic exit block (66) on the wellhead in the opposite end.
It further comprises at least four feeding wheels (12) arranged in pairs, where the two wheels (12) of each pair is located on opposite sides of the rectification line (20), and arranged to move the rectification line (20) into the termination block (10a) and further into the extension control line (51) and the control line (50). The feeding wheels (12) are arranged to move and guide the rectification line (20) between the pairs of feeding wheels (12) by rotating and gripping the control line (20). The position of the feeding wheels (12) may be adjustable to accommodate different types of rectification lines (20) with different cross sections, and to adjust pressure against the rectification line to obtain the friction required for forcing the rectification line forward and into the hydraulic line (50). In an embodiment the feeding wheels (12) have a circular groove arranged to guide the rectification line (20), and further to improve the friction by interacting with a larger surface of the interaction line (20). Different sets of feeding wheels (12) with different circular grooves may be used for rectification lines (20) with different cross sections.
The feeding wheels (12) are driven by one or more feed motors (13). In an embodiment the one or more feed motors (13) are electrically powered. The feed motor may use any kind of transmission for driving the feeding wheels (12), such as belts, cog wheels, etc. as will be understood by a person skilled in the art.
In an embodiment the rotational speed of the feeding wheels (12) is synchronized. This can be a mechanical synchronization, e.g. by gears where the same motor is used to drive all wheels, or a synchronization controlled by a control loop in a control system if the wheels (12) are driven by individual motors.
The termination block (11) holds the extension control line (51) and will have to set up a counterforce similar in size to the force applied to the rectification line (20) by the rectification line feeder (10). It is therefore important that the termination block (11), and additional support blocks (11a) along the path of the rectification line (20), e.g. in between the feeding wheels (12) prevents lateral movement of any part of the rectification line (20) before it enters the extension control line (51).
The control line can be several hundred meters long and the rectification line (20) may be of approximately the same length. In an embodiment, that may be combined with any of the embodiments above, the control line rectification device therefore comprises a reel (30) for storing the rectification line (20). However, when the line is wound up on the reel (30) it is no longer straight. Since the rectification line has to be stiff to withstand radial deformation, it will also be difficult to enter into the narrow control line if it is bent.
In an embodiment, that may be combined with any of the embodiments above, the rectification device (1) comprises a line straightener (15) arranged to straighten the rectification line (20) as it is fed into the control line (40) from the reel (30).
More details of the line straightener (15) is shown in Fig. 4. In an embodiment it comprises first and second straighteners (16, 17), arranged in series between the reel (30) and the line feeder (10), and arranged to straighten the rectification line (20) in perpendicular, lateral directions.
The first straightener (16) comprises a first set (16a) of two or more straightener wheels arranged in line, and a second set (16b) of two or more straightener wheels arranged in line, wherein the straightener wheels of the first and a second set (16a, 16b) are arranged to contact opposite sides of the rectification line (30), respectively.
In the same way the second straightener (17) comprises a third set (17a) of two or more straightener wheels arranged in line, and a fourth set (17b) of two or more straightener wheels arranged in line, wherein the straightener wheels of the third and fourth set (17a, 17b) are arranged to contact opposite sides of the rectification line (20), respectively.
The first and second straighteners (16, 17) are in an embodiment rotated 90 degree relative each other, so that the straightener applies forces to the rectification line from four different lateral directions, i.e. 0 and 180 degree from the first straightener and 90 and 270 degree from the second straightener.
In an embodiment it is one more straightener wheel in the first set or second set of straightener wheels (16a, 16b) than in the other set (16a, 16b) of the first straightener (16).
In an embodiment it is one more straightener wheel in the first set or second set of straightener wheels (17a, 17b) than in the other set (17a, 17b) of the second straightener (22).
In order to most efficiently rectify the control line (50), different rectification lines (20) with different cross sections may be run down the control line (50) sequentially.
E.g. a first run with one of the rectification lines (20) illustrated in the upper part of Fig. 5. The goal of the first run will be to apply as much force as possible on the end of the rectification line (20) to partly or completely open up the control line (50).
The control line should not be damaged or otherwise disabled by the rectification device and process. In an embodiment the rectification device (1) therefore comprises a control system (100) arranged to control a feed force of the rectification line feeder (10) when it is feeding the rectification line (20) into the control line (50).
The control system may use the power used by the motor as an indication of the push force and limit power to the motor when a threshold power is reached.
The in-situ surface controlled sub-surface safety valves control line rectification device (1) of any of the claims above, wherein the rectification device (1) is configured for pumping a dissolving agent through the first rectification line (20), and to dissolve a previously inserted temporary plug (71) in the hydraulic line (50) with the dissolving agent.
In an embodiment that may be combined with any of the embodiments above, the rectification device (1) is configured for pumping a dissolving agent through the first rectification line (20), and to dissolve a previously inserted temporary plug (71) in the hydraulic line (50) with the dissolving agent.
The invention is also a method for in-situ rectifying a surface controlled sub-surface safety valve control line (50).
In a first method embodiment a the method comprises the step of feeding a longitudinal first rectification line (20) into the hydraulic line (50).
the first rectification line (20) may in a dependent embodiment have an elastic modulus larger than 10 GPa.
In an second method embodiment that may be combined with the first method embodiment above and any of its dependent embodiments, the method comprises the step of straightening the longitudinal first rectification line (2) as it is fed into the hydraulic line (50) from the reel (30).
In a dependent embodiment, straightening is performed by running the longitudinal first rectification line (2) through first and second straighteners (16, 17), arranged in series, and arranged to straighten the rectification line (20) in perpendicular, lateral directions.
In a third method embodiment that may be combined with any of the method embodiments above and any of its dependent embodiments, the method comprises the step of feeding the longitudinal first rectification line (20) with decreasing speed into the hydraulic line (50).
Experiments have shown that decreasing speed may increase the reach of the first rectification line (20).
In a fourth method embodiment that may be combined with any of the method embodiments above and any of its dependent embodiments,, the rectification line (20) has a hollow cross section (22) as explained above, and the method comprises the step of circulating fluid in the hydraulic line (50) by providing a fluid flow internally through said first rectification line (20).
A line feeder (10) as disclosed previously may be used also for any of the method embodiments.
The method embodiments may comprise straightening the longitudinal rectification line (2) as it is fed into the control (2) line from the reel (30) by a line straightener (15) as disclosed previously.
In a fifth method embodiment that may be combined with any of the method embodiments above, the control line (50) runs through a wall of a casing or tubing and is terminated inside a first exit block (66a) outside the casing or tubing, wherein the method comprises;

setting a plug (71) in the control line inside the casing or tubing by pumping a first amount of a curable plug material into the exit block,
allowing the curable plug material to cure during a time interval,
replacing the first exit block (66a) with a second exit block (66),
feeding the first rectification line (20) into the hydraulic line (50), through the second exit block (66) wherein the first rectification line (20) is tubular,
pumping a dissolving agent through the first rectification line (20) to dissolve the plug (71).

In a first dependent embodiment, the method comprises pressure testing the plug (71) after the time interval, and setting a new plug (71) in the control line inside the casing or tubing by pumping a first amount of a curable plug material into the exit block, if the pressure testing did not succeed.
In a second dependent embodiment, that may be combined with the first dependent embodiment, the method comprises feeding the first rectification line (20) past the region where the plug (71) was set after the plug (71) is dissolved.
In a third dependent embodiment, that may be combined with the any of the dependent embodiments, the method comprises connecting a plug insertion apparatus (70) to the first exit block (66a) before setting the plug (71), wherein the plug insertion apparatus (70) is configured to feed the first amount of a curable plug material into the first exit block (66a) and further into the control line (50) by applying a pressure until the counteracting pressure resulting from compressibility on the far side of the plug prevents further introduction of the plug (71).
An embodiment illustrated in Fig. 7, 8 and 9, will be further explained below:
Fig. 7 illustrates in a partly sectioned view prior art, a control line (50) is running along a production tubing (20) inside a casing string. In the upper part, near the wellhead, and above a seal assembly (68) the control line (50) is wound around the production tubing before passing through the casing string and terminating inside a first exit block (66a). In normal operation the hydraulic control system is connected to the first exit block (66a).
In Fig. 8 a plug insertion apparatus (70) is connected to the first exit block (66a). The plug insertion apparatus (70) is arranged to insert a plug (71) into the control line (50). The plug (71) is inserted under pressure and can be pressed a certain length into the hydraulic control line (50) due to the compressibility of the fluid in the control line (50). After a certain time the plug has cured and the sealing of the plug can be tested by applying fluid under pressure, either from the plug insertion apparatus (70), or another leakage detection apparatus. If the plug is sealing according to specifications, the first exit block (66a) can be removed.
The hydraulic control system has either been replaced by the plug insertion apparatus (70), or otherwise disabled or blocked, if it is connected on a different hydraulic termination on the first exit block (66a).
In Fig. 9, the first exit block (66a) has been replaced by a second exit block (66) wherein the second exit block (66) and the extension control line (51) are configured for guiding the rectification line (20) from the rectification line feeder (10) into the control line (50). The rectification line feeder (10) has been described previously, and could be e.g. according to the embodiments shown in Fig. 3 or 4. The rectification line (20) is in this case tubular, and connected in the far end to a fluid source and a pump, allowing fluid to be pumped into the rectification line (20). In Fig. 9 the rectification line (20) has been fed all the way to the plug (71), and the plug can now be dissolved by pumping a dissolving fluid through the rectification line (20). Outside the casing string, a drain passage, such as the drain termination (72) in the second exit block (66), allows return fluid to exit the control line (50). The rectification line (20) can now be fed further into the control line (50) as the plug dissolves and optionally deeper into the control line for further rectification, as described previously.
The second exit block (66) comprises in this embodiment an adaptation block (73) that is specific for the installation and the control line terminating outside the casing.
The plug (71) arranged temporarily in the control line (50) may in an embodiment be a multipart curable sealing, with a density of 1 to 1,25 SG, a viscosity of 2500 to 10000 Cp. In a two component sealant the first resin may be a silicone base and the second a hardener or catalyst that works to cure or crosslink the sealant when the two resins are mixed before injection into the control line. The dissolver may be based on e.g. chlorinated hydrocarbons, such as ethyl acetate.
The invention is defined by the features specified in the appended claims.

Claims

An in-situ surface controlled sub-surface safety valves control line rectification device (1) configured to mechanically rectify in-situ a control line (50) connected to a surface controlled sub-surface safety valve, and wherein the rectification device comprises;
- a rectification line feeder (10),

- a longitudinal first rectification line (20), wherein the rectification line feeder (10) is arranged to feed the first rectification line (20) longitudinally into the control line (50), wherein the first rectification line (20) has an elastic modulus larger than 10GPa and the rectification line feeder is configured to feed the longitudinal first rectification line (20) with decreasing speed into the control line (50).
The in-situ surface controlled sub-surface safety valves control line rectification device (1) of claim 1, wherein the rectification line (20) has a hollow cross section (22), and the rectification device (1) is arranged to provide a fluid flow internally through said first rectification line (20).
The in-situ surface controlled sub-surface safety valves control line rectification device (1) of claim 1 or 2, wherein the first rectification line (20) is made in metal or polymeric material.
The in-situ surface controlled sub-surface safety valves control line rectification device (1) according to any of the claims above, wherein an outer cross section (CS) of the first rectification line (20) has at least three protrusions (21a, 21b, 21c) arranged to slide along an inner surface of the control line (50).
The in-situ surface controlled sub-surface safety valves control line rectification device (1) according to any of the claims above, wherein the rectification line feeder (10) comprises at least four feeding wheels (12) arranged in pairs, where the two wheels (12) of each pair are arranged to be located on opposite sides of the rectification line (20).
The in-situ surface controlled sub-surface safety valves control line rectification device (1) according to claim 5, comprising first and second straighteners (16, 17), arranged to straighten the rectification line (20) in perpendicular, in lateral directions.
The hydraulic line rectification device (1) according to claim 6, wherein the first straightener (16) comprises; - a first set (16a) of two or more straightener wheels arranged in line, and - a second set (16b) of two or more straightener wheels arranged in line, wherein the straightener wheels of the first and a second set (16a, 16b) are arranged to contact opposite sides of the rectification line (20), respectively.
The in-situ surface controlled sub-surface safety valves control line rectification device (1) of any of the claims above, wherein the rectification device (1) is configured for pumping a dissolving agent through the first rectification line (20), and to dissolve a previously inserted temporary plug (71) in the control line (50) with the dissolving agent.
A method for in-situ mechanically rectifying a surface controlled sub-surface safety valve control line (50) connected to a surface controlled sub-surface safety valve, wherein the method comprises the steps of feeding a longitudinal first rectification line (20) with an elastic modulus larger than 10 GPa into the control line (50), and
feeding the longitudinal first rectification line (20) with decreasing speed into the control line (50).
The method of claim 9, wherein the longitudinal rectification line (2) is stored on a reel (30) and the method comprises the step of straightening the longitudinal first rectification line (2) as it is fed into the control line (50) from the reel (30) wherein straightening is performed by running the longitudinal first rectification line (2) through first and second straighteners (16, 17), arranged in series, and arranged to straighten the rectification line (20) in perpendicular, lateral directions.
The method of any of the claims 9 to 10, wherein the rectification line (20) has a hollow cross section (22), and wherein the method comprises the step of circulating fluid in the control line (50) by providing a fluid flow internally through said first rectification line (20).
A method of any of the claims 9 to 11, wherein the control line (50) runs through a wall of a casing or tubing and is terminated inside a first exit block (66a) outside the casing or tubing, wherein the method comprises; - setting a plug (71) in the control line inside the casing or tubing by pumping a first amount of a curable plug material into the exit block, - allowing the curable plug material to cure during a time interval, - replacing the first exit block (66a) with a second exit block (66), - feeding the first rectification line (20) into the control line (50), through the second exit block (66) wherein the first rectification line (20) is tubular, - pumping a dissolving agent through the first rectification line (20) to dissolve the plug (71).
The method of claim 12, comprising pressure testing the plug (71) after the time interval, and setting a new plug (71) in the control line inside the casing or tubing by pumping a first amount of a curable plug material into the exit block, if the pressure testing did not succeed.
The method of claim 12 or 13, comprising feeding the first rectification line (20) past the region where the plug (71) was set after the plug (71) is dissolved.
The method of any of claims 12 to 14, comprising connecting a plug insertion apparatus (70) to the first exit block (66a) before setting the plug (71), wherein the plug insertion apparatus (70) is configured to feed the first amount of a curable plug material into the first exit block (66a) and further into the control line (50) by applying a pressure until the counteracting pressure resulting from compressibility on the far side of the plug prevents further introduction of the plug (71).