Patent Application
20090205832
Various downhole devices use control lines for their operation. As shown in
Operators must make a number of time-consuming and labor-intensive measures to remedy a clogged or blocked control line 40. For example, operators may have to work over the well and deploy a new safety valve. To avoid the problem altogether, operators may alternatively run a subsurface controlled safety valve instead, but regulations may prevent use of such a valve in a given well. In addition, operators may use a velocity valve in well that does not require control from the surface via a control line. Such velocities valves, however, decrease the production and can be difficult to check once deployed.
In
To clear the control line 40, operators then deploy a separation sleeve 100 as shown in
As shown, a male member 110 of an automatic connector positioned on the pod 106 communicates with the cross-port 108 and extends upward into the passage 101. While the sleeve 100 is in position, any effluents of the well can circulate through the sleeve's internal passage 101 and pass the pod 106, as shown in the end section of
With the sleeve 100 in position, operators then deploy a capillary string 60 through the tubing 10 as shown in
Once connected, the capillary string 60 communicates with the sleeve's port 54 via the cross-port 108 in the pod 106. Operators then inject pressurized solvent through the capillary string 60. The solvent reaches the cross-port 108 and fills the sleeve's port 54 as shown in
To inject the solvent, a system for clearing the control line 40 can be used as schematically illustrated in
Operators use one or more well control panels 200 to apply solvent (e.g., diesel) or other fluid from a solvent reservoir, into the capillary feed line 60, to the control port 54, and into the control line 40 to act against any blockage or clogging. The pressurized solvent can be applied up to the point that the blockage is removed, or it can be passed through the feed line 60 all the way through the control line 40 once any blockage is broken to clear the line of remaining debris. To further work on the blockage, the well control panel 200 can apply pressure alternatingly between the control line 40 and the feed line 60 if the solvent proves slow in relieving the blockage. As opposed to solvent, the well control panel 200 could apply hydraulic fluid through the feed 60 to break the blockage. In addition, once the blockage is cleared, the well control panel 200 can cycle control fluid through the control line 40 and the feed line 60 to flush the control line of debris.
Once the blockage is cleared, operators can reverse the procedures used to install the sleeve 100 in the landing nipple 50. For example, operators disconnect the feed line 60 from the male connector 100 on the sleeve 100 and remove the line 40 from the tubing 10. Then, using wireline procedures, operators remove the sleeve 100 from the nipple 50 and tubing 10 so that the surface controlled safety valve can be redeployed into the nipple 50 using techniques known in the art.
As discussed above, the sleeve 100 can have locking contours 102 for engaging the nipple's lock profiles 52. In an alternative arrangement shown in
Although the present disclosure has been directed to clearing a control line of a safety valve, it will be appreciated that the disclosed apparatus can be used with any downhole component to which a control line connects, including, but not limited to, a remotely operated sliding sleeve, a pressure relief valve, or other downhole device. Although chevrons (e.g., 105 and 107) are described above, it will be appreciated that other devices to sealably engage the sleeve 100 in the nipple 50 can be used, such as elostomer O-rings, packing elements, or crimp seals. Components of the control line clearing apparatus disclosed herein are preferably composed of materials suitable for a well environment and are preferably constructed using accepted practices for the well environment.
The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.
