SWELL-BASED INFLATION PACKER
An isolation packer. The packer is both an inflation packer and swell-based. That is, an outer shell or bladder may be utilized in conjunction with internal swell material. In advance of inflation, a void or cavity may be disposed between the inner surface of the shell and an outer surface of the swell material. Thus, fluid inflation of this void may result in an inflation that becomes swell-material filled until the void is eliminated leaving behind a more unitary and swollen packer of enhanced reliability.
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Embodiments described relate to inflation packers for use in downhole isolation. In particular, inflation packers are disclosed which are configured with a conventional or non-conventional shell equipped to accommodate novel media for inflation. More specifically, emerging downhole swell-based materials may be accommodated by the shell in a manner that provides synergistically improved seal capacity to the packer.
BACKGROUNDExploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming, and ultimately very expensive endeavors. As a result, over the years, a significant amount of added emphasis has been placed on well monitoring and maintenance. Once more, perhaps even more emphasis has been directed at initial well architecture and design. All in all, careful attention to design, monitoring and maintenance may help maximize production and extend well life. Thus, a substantial return on the investment in the completed well may be better ensured.
In the case of well monitoring and logging, mostly minimally-invasive applications may be utilized which provide temperature, pressure and other production related information. By contrast, well design, completion and subsequent maintenance, may involve a host of more direct interventional applications. For example, perforations may be induced in the wall of the well, debris or tools and equipment removed, etc. In some cases, the well may even be designed or modified such that entire downhole regions are isolated or closed off from production. Such is often the case where an otherwise productive well region is prone to produce water or other undesirable fluid that tends to hamper hydrocarbon recovery.
Closing off well regions as noted above is generally achieved by way of setting one or more inflatable packers. Such packers may be set at downhole locations and serve to seal off certain downhole regions from other productive regions. Delivering, deploying and setting packers for isolation may be achieved by way of coiled tubing, or other conventional line delivery application. Alternatively, isolation may be pre-determined, for example, where packers are secured at set positions about a tubular in advance of its installation in the well. Regardless, subsequent packer deployment or inflation may be fairly sophisticated, given the amount of precision involved. For example, proper packer inflation may be quite challenging, given the high and variable temperature and pressure extremes often present downhole which can affect fluid inflation.
At present, packer inflation is achieved in a single shot, one-way manner. For example, a rupture disk and piston assembly may be utilized in conjunction with a one-way check valve for inflation of the packer to a predetermined pressure. That is, the packer assembly may be exposed to sufficient pressure for rupturing of the disk in a manner that triggers piston based fluid inflation of the packer to the predetermined amount. At such time the valve may be permanently turned off to hold the packer in a sealingly inflated state in the well.
Unfortunately, over time, the inflated packer is unlikely to remain in sealing engagement with the well wall. That is, due to natural leakage, downhole pressure or temperature changes, or even dehydration at the packer well wall interface, a conventional inflation packer is unlikely to maintain a seal beyond about 5-7 years or so. This is problematic given that the intended life of the well is more likely in the range of more than twenty years.
A variety of measures may be undertaken in order to address inflation packer failure during the life of the well. For example, direct intervention in the form of re-inflation may be attempted. However, given standard packer configurations follow-on placement and deployment of a new packer is generally a more viable alternative. Further, in some circumstances a cementing intervention may be attempted whereby cement is deposited at the location of the failing packer in hopes of reintroducing a seal at the location.
Unfortunately, all of the above-noted measures come with considerable drawbacks. Namely, a significant amount of time and expense is required to shut down operations, rig and re-rig equipment at the oilfield surface, and run an intervention. Once more, regardless of the particular remedial intervention attempted, restoration of completely functional seal to its original form is unlikely.
As an alternative to inflation packers, swell packers may be utilized. So, for example, issues associated with packer deflation may be avoided. Unfortunately, however, such packers are nevertheless subject to degradation over time in the face of harsh downhole conditions. So, for example, it remains unlikely that such packers would remain effective for say, an intended twenty year well life. As a result, operators are likely left with the option of costly follow-on remedial interventions or ultimately foregoing reliable isolation whether inflation packer or swell packers are utilized.
SUMMARYA downhole isolation packer is detailed. The packer includes a shell configured for placement about a tubular for downhole use. A swellable material is located within a cavity of the shell. Further, the packer is configured with an inner fluid void taking up space in the cavity between an inner surface of the shell and an outer surface of the swellable material.
Embodiments herein are described with reference to certain types of downhole packers. For example, these embodiments focus on the use of packers for isolating certain downhole regions in conjunction with the use of production tubing. However, a variety of alternative applications may employ such swell-based packers, such as for well stimulation, completions, gravel packing, or isolation for water injection. Additionally, alternative packer-like devices, such as plugs, chokes, flow control valves and restrictors may take advantage of materials and techniques disclosed herein for use in a well or any other suitable conduit. Regardless, embodiments of packers disclosed herein are configured for inflation in a manner that incorporates an internal swell-based material.
Referring now to
The above noted swell material 130 may include any number of polymer particle types and configurations as are often employed in conventional swell packers and as detailed further below. Additionally, the shell 110 may also be of a traditional non-swell polymeric material such as a conventional non-reactive rubber as is often employed in conventional inflation packers. However, in one embodiment the shell 510 may also be made up of swellable polymer (see
By way of comparison to the swell-based inflation packer 100 of
With specific reference to
With specific reference to
Continuing now with reference to
The swell-based inflation of the packer as depicted in
Continuing with reference to
A variety of options are available for the swell material 130 such as polymers drawn from a betaine group prepared by inverse emulsion polymerization. Additional fillers, vulcanizing agents and other substances may be incorporated into the material 130 along with particular concentrations of cations and/or anions grafted thereto so as to tailor the sensitivity of the swell. From a structural standpoint, non-elastomeric polymers, fillers, plasticizers, and various fibers may also be incorporated into the swell material 130.
Referring now to
Continuing with reference to
Referring now to
With specific reference to
With specific reference to
Referring now to
In the embodiment of
Referring now to
Swelling of the swell material within the packer may take place until the material cohesively reaches an outer shell of the packer, thereby sealably isolating the target location with a structurally uniform inflated and swollen packer (see 695). Furthermore, achieving this type of isolation may be further aided by use of a shell which is also constructed of swell material as noted at 675.
Embodiments described hereinabove provide a manner by which packer reliability may be substantially enhanced, thereby extending useful packer life as well. Thus, the amount of time and expense dedicated to remedial interventions and/or packer replacements for conventional inflation or swell packers may be kept to a minimum. Further, in some cases, the combination of inflation and swell-based materials may also be utilized to speed up inflation.
The preceding description has been presented with reference to presently preferred embodiments. Persons skilled in the art and technology to which these embodiments pertain will appreciate that alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle, and scope of these embodiments. For example, whereas the inflated and swollen device detailed herein is provided in the form of a packer for downhole isolation, other types of devices for alternative applications may be involved. Along these lines, such devices may be directed at marine applications, or water and sewage line repairs. Furthermore, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.
Claims
1. A downhole isolation device for placement in a well, the device comprising:
- a shell for disposing about a downhole mandrel; and
- a swellable material disposed within a cavity of said shell, the device having an inner fluid void between an inner surface of said shell and an outer surface of said material.
2. The device of claim 1 wherein said shell is of a non-swell polymeric material.
3. The device of claim 2 wherein said shell material is a non-reactive rubber.
4. The device of claim 1 wherein said shell is configured to protect said swellable material from exposure to downhole exposure.
5. The device of claim 1 wherein said swellable material is of one of bead, pellet and powder form.
6. The device of claim 1 wherein said swellable material includes at least one solid band thereof about the mandrel.
7. The device of claim 1 wherein said shell is of a swellable polymer to reduce a swell period of the device.
8. The device of claim 7 wherein the swellable polymer is swellable upon exposure to a wellbore type fluid.
9. A downhole isolation packer comprising:
- a shell for disposing about a downhole tubular; and
- a swellable material disposed within a cavity of said shell, the packer having an inner fluid void between an inner surface of said shell and an outer surface of said material.
10. The packer of claim 9 wherein said tubular is production tubing.
11. A method of providing fluid isolation at a target location of a conduit, the method comprising:
- delivering a swell-based inflation device to the target location;
- inflating a fluid void of the device with an inflation fluid;
- swelling an interior swell material of the device with the fluid to achieve the isolation.
12. The method of claim 11 wherein the fluid isolation is employed in one of a downhole wellbore application, a marine application, water line repair and sewage line repair.
13. The method of claim 12 wherein the downhole wellbore application comprises utilizing one of a water-based fluid, an oil-based fluid, a diesel fluid, and a wellbore type fluid as the inflation fluid for said inflating.
14. The method of claim 12 wherein the downhole wellbore application is configured to provide a substantially effective seal in a wellbore for a period exceeding about 7 years.
15. The method of claim 11 wherein said inflating comprises supplying a predetermined amount of the inflation fluid to the void in a one-way manner.
16. The method of claim 15 wherein the predetermined amount of the inflation fluid is pressure determined.
17. The method of claim 11 wherein said swelling takes place over the course of a swell period as the swell material takes up the inflation fluid.
18. The method of claim 17 wherein a duration of the swell period is tailored based on the types of swell material and inflation fluid employed.
19. A method of providing fluid isolation at a target location in a wellbore of a well, the method comprising:
- delivering a swell-based inflation packer to the target location;
- inflating a fluid void of the packer with an inflation fluid;
- swelling an interior swell material of the device with the fluid; and
- swelling a shell of the packer exterior the swell material with the fluid to reduce a swell period of the packer.
20. The method of claim 19 wherein the fluid is a wellbore type fluid and the shell is swellable upon exposure thereto at a surface within the packer and at an opposite surface exposed to the wellbore.
Type: Application
Filed: Sep 2, 2011
Publication Date: Mar 7, 2013
Applicant: SCHLUMBERGER TECHNOLOGY CORPORATION (SUGAR LAND, TX)
Inventor: Barton Sponchia (Cypress, TX)
Application Number: 13/224,945
International Classification: E21B 33/12 (20060101);