The present invention relates to a method of sealing a well. In particular embodiments, the method comprises installing a permanent fluid-tight barrier for well abandonment.
Traditional plug and abandonment operations require that the entire production tubing and associated cabling is pulled from the wellbore prior to installation of a cement plug. However, the removal of the tubing is a costly and time-consuming exercise as it requires a drill rig on site. There also associated safety risks.
It is therefore an aim of the present invention to provide an alternative method of sealing a well which helps to address the afore-mentioned problems.
In accordance with a first aspect of the present invention there is provided a method of sealing a well comprising:
Embodiments of the invention therefore provide a method for sealing a well which does not require the entire production tubing and control cables to be removed prior to forming a seal in the well. The method employs a wireline-conveyed stinger provided inside the tubing and arranged to extend over the interval provided with openings so that the sealant may flow out of the bottom end of the stinger and through the openings to seal the A-annulus between the tubing and adjacent casing. Conveniently, each step in the method may be performed using wireline and the method may be carried out whether or not control lines are originally present in the location for the well seal.
In certain embodiments, the method may further comprise removing any adjacent control lines in the location for the well seal.
It will be understood that, in practice, there will be heavy fluid in the A-annulus and in the tubing below the stinger and this will create a pressure differential causing the sealant which is pumped down an upper portion of tubing and through the stinger to flow upwards on exiting the stinger. If the method was employed without a stinger across the open section, the sealant would only flow through the upper openings due to the pressure from below. The provision of a stinger therefore ensures that the sealant is placed across the entire section of open tubing.
It will be understood that a stinger is normally a piece of tubular which is provided on a lowermost section of a tubing string to sting into another section of tubular (or a fluid or a seal) in order to perform a task such as sealing, pumping, verifying a location or opening valves etc. Alternatively, a small diameter tubing may be inserted along the entire length of the tubing. It is therefore an advantage of the present invention that the stinger is located only in the area of interest using wireline, thereby reducing the time and cost for the operation.
The stinger may have a fixed length or may be extendable. The length of the stinger may depend upon on the lubrication length available and/or the length of the interval to be sealed off.
In certain embodiments, the stinger may be telescopic. In which case, a plurality of telescopic sections may be held in a compacted configuration by a mechanism (e.g. shear screws, latches, detent rings, etc.) configured to release when a pre-determined pressure is applied, thus causing the telescopic sections to extend. Seals (e.g. O-rings or the like) may be provided between each telescopic section to ensure the joins are fluid-tight.
The telescopic stinger may comprise a valve across an end which is lowermost when the stinger is extended. The valve may be configured to adopt a closed position when fluid is pumped down into the stinger to apply pressure to the release mechanism to open each telescopic section. Once the stinger is suitably (e.g. fully) expanded, a greater pressure may be applied (e.g. above hat required to release the mechanism) in order to open the valve for pumping sealant into the tubing and casing.
The one or more openings may be formed by removing a relatively large section of the tubing (e.g. by milling). Alternatively, the one or more openings may be formed by slicing or perforating one or more holes in a section of the tubing.
The method may further comprise the use of a high viscous pill deployed through the stinger to clean the location before forming the seal.
Typically, the seal may be provided over an interval of approximately 50 m. Accordingly, the one or more openings may be provided over a similar length of interval and the stinger may also be of a similar length (when extended).
The step of setting the stinger in the location for the seal may comprise use of a packing element and slips to hang the stinger off the tubing at a position above the one or more openings.
The step of forming the seal may comprise forming a temporary or permanent plug in the well. The sealant may therefore comprise cement.
The method may further comprise providing a transverse support ledge in the tubing below the one or more openings so as to ensure that the sealant is retained within the location for the well seal (e.g. if the well pressure alone is not sufficient for this purpose).
According to a second aspect of the invention, there is provided a wireline-deployed stinger for use in the method according to the first aspect of the invention.
According to a third aspect of the invention, there is provided a telescopic stinger for use in the method according to the first aspect of the invention.
Specific embodiments of the present invention will now be described with reference to the accompanying drawings, in which:
As shown in
As shown in
A valve 48 is provided across an end which is lowermost when the stinger 40 is extended. The valve 48 is configured to adopt a closed position when fluid is pumped down into the stinger 40 so as to apply pressure to the shear screws 44 to open each telescopic section 42. Once the stinger 40 is fully expanded, a greater pressure is applied to open the valve 48 for pumping sealant 30 into the tubing 12 and casing 14 as per
It will be appreciated by persons skilled in the art that various modifications may be made to the above-described embodiments without departing from the scope of the present invention, as defined by the claims. It will also be appreciated that features described in relation to one embodiment may be mixed and matched with features of another embodiment.
Number | Date | Country | Kind |
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1317000.6 | Sep 2013 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/070279 | 9/23/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2015/044151 | 4/2/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
3324017 | Perry | Jun 1967 | A |
3556220 | Schwegman | Jan 1971 | A |
6073694 | Crawshaw | Jun 2000 | A |
6595289 | Tumlin | Jul 2003 | B2 |
20020023754 | Buytaert | Feb 2002 | A1 |
20020170713 | Haugen | Nov 2002 | A1 |
20030150614 | Brown et al. | Aug 2003 | A1 |
20060219407 | Livingstone | Oct 2006 | A1 |
20080190612 | Buchanan | Aug 2008 | A1 |
20090260817 | Gambier et al. | Oct 2009 | A1 |
20090280912 | Buchanan | Nov 2009 | A1 |
20100006282 | Dirdal | Jan 2010 | A1 |
20130319671 | Lund | Dec 2013 | A1 |
20150267500 | Van Dongen | Sep 2015 | A1 |
Number | Date | Country |
---|---|---|
0346961 | Dec 1989 | EP |
2325479 | Nov 1998 | GB |
WO 2006053896 | May 2006 | WO |
WO 2012105852 | Aug 2012 | WO |
Number | Date | Country | |
---|---|---|---|
20160230499 A1 | Aug 2016 | US |