Patent Application
20120090857
Fluidic systems, such as, tubular systems employed in earth formation boreholes for purposes such as hydrocarbon recovery and carbon dioxide sequestration, for example, at times employ swellable members to create seals between tubulars. Such swellable members may swell in response to being exposed to fluids that induce swelling of the swellable member. Polymeric materials, including various elastomers, swell when exposed to water, oil, brine and natural gas, for example. The swellable material itself largely controls the rate of swelling of members made of the material once exposure to a swell inducing fluid has been initiated. This natural swell rate, however, can progress at unpredictable rates that can sometimes interfere with operations. Since greater control is always a goal for operators in the downhole industry, inventions providing such control are always well received.
Disclosed herein is a swell controlling arrangement that includes a swellable member configured to swell upon exposure to a swell inducing fluid, and an acidic material that is configured to form an acidic environment. The swell controlling arrangement is configured to preferentially expose the swellable member to the acidic environment when the swellable member and the acidic material are exposed to the swell inducing fluid.
Also disclosed herein is a swell controlling arrangement that includes a swellable member configured to swell in a swell inducing fluid, and an acid forming material disposed at the swellable member configured to form acid that is preferentially exposed to the swellable member over the swell inducing fluid.
Further disclosed is a method of controlling swelling of a swellable member. The method includes, forming an acidic environment, exposing a swellable member to the acidic environment, and positioning the swellable member and the acidic environment within a swell inducing fluid.
Further disclosed is a swellable member including a polymeric body configured to swell upon exposure to a swell inducing fluid, and an acidic material disposed at the polymeric body configured to retard a rate of swelling when the polymeric body is exposed to the swell inducing fluid.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed arrangement, apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
The polymeric swellable member 14 of this embodiment, being an acrylate polymer, swells at a rate in response to exposure to, water, oil, brine, natural gas and combinations of two or more of the foregoing. The polymeric swellable member 14 swells at a slower rate when preferentially exposed to an acidic environment 20. This reduction in swell rate is particularly pronounced when the acidic environment 20 includes an organic acid, such as one or more of, lactic acid, acetic acid, formic acid, citric acid, oxalic acid and uric acid, and the acidic environment 20 has a pH level in the range of 3 to 6. As such the swell controlling arrangement 10 disclosed herein retards the swelling or, stated another way, it slows a rate of swelling.
The swell controlling arrangement 10, as illustrated in
Additionally, dilution of the acidic environment 20, and a corresponding change in swell rate, could be made to accelerate upon rupturing of the film 50. The film 50 could be made to rupture when the swellable member 14 has swelled to a selected size. Such a configuration would provide an operator with additional control over timing associated with fully swelling the swellable member 14. In order to assure integrity of the film 50 until rupturing is desired, the film 50 can be protected from abrasion during running into the borehole 26 through such things as being radially dimensionally smaller than surfaces longitudinally adjacent thereto, for example.
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While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
