The present invention relates to a method and apparatus for sealing an annulus around a drill-pipe when drilling down-hole, both in cased and open hole.
At the time of writing there are no commercially available tools to allow a drilled well to be fully or partially sealed in open-hole, while drilling, without use of complex electronics, battery-operated devices or wired pipe.
X Drilling Tools produce a tool known as LossMaster™ that comprises a drill-string anchor and packer for sealing between the drill-string and casing but not in open-hole. The tool uses ball-activated slips to anchor the tool to the casing and then uses weight to expand the packer.
Furthermore, external casing packers (ECPs), which expand when filled with cement, are known for isolating zones between a casing and a wellbore during production but not when drilling.
Traditional techniques also do not permit communication with tools/sensors both above and below the seal when set.
It is therefore an aim of the present invention to provide to a method and apparatus for sealing an annulus around a drill-pipe when drilling down-hole, which helps to address the afore-mentioned problems, even if placed above a Measurement While Drilling (MWD) pulser and/or turbine which can provide a pressure measurement from below the packer/sealing element.
In accordance with a first aspect of the present invention there is provided a method of sealing an annulus around a drill-pipe when drilling down-hole comprising:
Embodiments of the invention therefore provide a simple and cheap method for sealing an annulus around a drill-pipe when drilling down-hole. The method can be used to quickly solve issues when they arise, for example, due to massive losses, influx (i.e. kick) or cross-flow between two well segments. In particular, the method can be used to dramatically improve a well-control situation when drilling in areas with a narrow operational window.
In effect, the method can be used to quickly and easily deploy a temporary barrier or plug in the wellbore when required, while drilling, in order that a well situation can be appropriately evaluated and a decision made as to whether to take remedial action or permanently abandon the well.
Advantageously, the method can be used in open-hole as it does not require the drill-pipe to be anchored before the packer is set. The method also involves only a simple mechanically-activated valve which can easily be operated while drilling fluid is circulating as one or more balls can be dropped through the drill-pipe along with the drilling fluid. Furthermore, the use of drilling fluid (which will already be circulating in the drill-pipe as part of the drilling process) to hydraulically inflate the packer adds to the speed and efficiency of the method. In addition, the method can be implemented leaving the bore of the drill-pipe substantially open for access down-hole. This allows cables for communication or control to continue through the bore, unencumbered. Alternatively, cables can be built into the wall of the drill-pipe/tool in the region of the packer.
The method may further comprise the step of closing said one or more ports after the packer has been inflated. The step of closing said one or more ports may comprise use of a ball-activated valve. This may be a further ball-activated valve to the one mentioned previously or may be further use of the same ball-activated valve—in which case, the step may comprise increasing the pressure on the ball-activated valve. Thus, a single ball-activated valve may be provided for opening and closing the one or more ports to the packer.
The step of providing a deflated packer on a drill-pipe when drilling down-hole may comprise providing a tool on the drill-pipe that comprises an external body housing the one or more ports to the packer and supporting the packer; and an internal sleeve constituting the ball-activated valve. The sleeve may comprise a transverse valve seat with one or more holes configured for receipt of one or more balls and a longitudinal body having at least one aperture therein which is alignable with the one or more ports in the tool body for inflating the packer. The tool body may comprise one or more further ports located upstream of the packer to allow flow into the annulus above the packer.
The step of opening the one or more ports to the packer may comprise dropping one or more balls into the drill-pipe such that the one or more balls locate in the one or more holes in the valve seat. The method may then comprise increasing the pressure above the valve seat (e.g. by increasing the flow rate of drilling fluid into the drill-pipe or this may occur naturally due to the transverse holes in the sleeve being closed by the balls) to force the sleeve to move downstream within the tool body. When the at least one aperture in the sleeve body is aligned with the one or more ports in the tool body, drilling fluid circulating through the drill-pipe will be caused to flow into the packer to inflate the packer due to differential pressure. Once the packer is inflated, a pressure gradient above and below the valve seat may cause the sleeve to move further downstream within the tool body in order to close off the one or ports to the packer and/or to open the one or more further ports in the tool body, upstream of the packer, to allow flow into the annulus above the packer. Additionally or alternatively, movement of the sleeve to close the ports to the packer and open the ports to the annulus may be instigated by dropping one or more further balls. The one or more further balls may be of a different size to the initial one or more balls (e.g. the further ball/balls may be larger).
The method may further comprise measuring the pressure upstream and/or downstream of the packer. The pressure may be measured using known sensors.
Advantageously, the ball-activated valve may be actuated by a plurality of relatively small balls (i.e. when compared to the diameter of the drill-pipe) since these can be more easily circulated through the drill-pipe with the drilling fluid than a large ball. More specifically, the use of small balls will allow passage through tools such as a Measurement While Drilling (MWD) tool which may be located upstream of the packer.
In some embodiments, a measurement tool such as a MWD tool or a Logging While Drilling (LWD) tool may be located downstream of the packer. In which case, the one or more balls required to activate the ball-activated valve need not pass through the measurement tool and therefore the size of the one or more balls is not restricted accordingly (so, for example, a single large ball could be employed). However, in this case, it is desirable to provide a communication and/or control channel through the drill-pipe from the measurement tool to the surface. Accordingly, the present (packer) tool may comprise a communication and/or control channel there-through (e.g. through a bore of the tool or built into a wall of the tool).
In some embodiments, two or more packers may be employed and may be activated in accordance with the first aspect of the invention. In which case, a measurement tool (e.g. a MWD tool) may be provided between the two or more packers.
A one-way valve (e.g. ‘float’) may be provided to seal off the bore of the drill-pipe. The one-way valve may be located upstream of the packer.
The drill-pipe may be configured so that a top-section located upstream of the packer can be disconnected and pulled out of the borehole. Disconnection of the top-section may be achieved by further increasing the pressure in the drill-pipe or by use of a further ball-activated valve (e.g. using a larger ball). The bottom hole assembly (BHA) up to and including the packer may be left in the borehole and the well cemented shut.
It may be desirable to deflate or destroy the packer (e.g. once a well situation is under control). This may be performed by changing the pressure gradient in the region of the packer or by destroying the packer (e.g. by pulling or rotating the drill-string). Once the packer is deflated/destroyed drilling can continue and/or the drill-pipe (including the BHA) can be pulled to the surface.
The packer may be located a maximum of approximately 20 m from a drill bit.
According to a second aspect of the invention, there is provided an apparatus for sealing an annulus around a drill-pipe when drilling down-hole comprising:
The external body may comprise one or more further ports located upstream of the packer to allow flow into the annulus above the packer.
The apparatus may comprise a communication and/or control channel there-through (e.g. through a bore of the external body or built into a wall of the external body).
The apparatus may comprise a one-way valve (e.g. ‘float’) to seal off a bore of the external body.
The apparatus may comprise a disconnection mechanism configured to disconnect the apparatus from the drill-pipe.
The apparatus of the present invention may be considered to be a drill-string packer sub or drill-pipe packer tool.
By way of example, specific embodiments of the present invention will now be described with reference to the accompanying drawings, in which:
With reference to
More specifically
In the position shown in
Once the packer 16 is inflated, the system is pressured up to shift the valve 20 to a lower position to close the packer ports 18 and thereby keep the packer 16 fully inflated as per
As above, the method illustrated in
Although not illustrated in either embodiment, if desired, the apparatus 10, 40 could be disconnected from the upper portion of the drill-pipe 14 to allow the upper portion to be removed and the wellbore to be cemented closed. Alternatively, the packer 16 could be destroyed or deflated after use so that drilling can continue. Furthermore, it will be understood that in embodiments of the invention, a control and/or communication channel may be provided through the apparatus 10, 40 (e.g. built into the wall of the external body 26) so that pressure can be measured below the packer and communicated to the surface.
The method and apparatus disclosed herein can further be described by the following numbered paragraphs:
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. Furthermore, features described in relation to one embodiment may be mixed and matched with features described in relation to another embodiment.
Number | Date | Country | Kind |
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1508619.2 | May 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NO2016/050099 | 5/20/2016 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2016/186519 | 11/24/2016 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2862562 | Hughes | Dec 1958 | A |
3503445 | Cochrum et al. | Mar 1970 | A |
4889199 | Lee | Dec 1989 | A |
4941534 | Berzin | Jul 1990 | A |
5109925 | Stepp et al. | May 1992 | A |
5375662 | Echols, III et al. | Dec 1994 | A |
5488994 | Laurel et al. | Feb 1996 | A |
20050011678 | Akinlade et al. | Jan 2005 | A1 |
20100294512 | Assal | Nov 2010 | A1 |
20100314126 | Kellner | Dec 2010 | A1 |
20160258280 | Murphree | Sep 2016 | A1 |
Number | Date | Country |
---|---|---|
0 819 830 | Jan 1998 | EP |
2 219 615 | Dec 1989 | GB |
2 309 722 | Jun 1997 | GB |
WO 2011060493 | May 2011 | WO |
Entry |
---|
International Search Report, issued in PCT/NO2016/050099, dated Aug. 1, 2016. |
United Kingdom Combined Search and Examination Report, issued in Priority Application No. 1508619.2, dated Jul. 24, 2015. |
United Kingdom Further Search Report, issued in Priority Application No. 1508619.2, dated Jan. 28, 2016. |
Written Opinion of the International Searching Authority, issued in PCT/N02016/050099, dated Aug. 1, 2016. |
Number | Date | Country | |
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20180163502 A1 | Jun 2018 | US |