Well tools utilizing swellable materials activated on demand

Abstract

A well tool includes a generally tubular mandrel with a flow passage extending longitudinally through the mandrel, and a flow controller which initially prevents a fluid from contacting a swellable material, but which permits the fluid to contact the material in response to manipulation of pressure in the flow passage. Another well tool includes a swellable material, a generally tubular mandrel, and a conduit wrapped circumferentially about the mandrel, the conduit containing a fluid which, upon contact with the swellable material, causes the material to swell. A method of actuating a well tool in a well includes manipulating pressure in a flow passage extending through a tubular string, thereby opening at least one flow control device of the well tool which selectively permits fluid communication between a reservoir of the well tool and a swellable material of the well tool, whereby a fluid in the reservoir contacts the swellable material.

Description

technical field [0001] The present disclosure generally relates to equipment used and operations performed in connection with subterranean wells and, in the examples described below, more particularly provides drilling tools that utilize on-demand swellable materials. Background technique [0002] In the past, swellable materials have been used in drilling tools to perform multiple functions. For example, swellable materials may be used in packer sealing elements to provide downhole self-driving packer assemblies. When a suitable fluid contacts the swellable material, the material swells and seals the annulus in the well. [0003] However, if fluid is already present in the well, the swellable material may start to swell as soon as it is installed in the well, which can cause a number of problems. For example, the material may swell prematurely, which will prevent the packer assembly from being properly positioned in the well. [0004] Techniques have been developed to de...

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Problems solved by technology

[0004] Techniques have been developed to delay the swelling of swellable materials, but generally these techniques yield some imprecise delay times and can be conveniently initiated only once (such as when the swellable material is installed in a well)

It has also been proposed to induce swelling in response to pressure applied to the annulus surrounding the drilling tool, but it is not possible or convenient to apply pressure if the drilling tool is used in open hole, or in perforated or leaking casing to the annulus

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