Compositions and methods for completing subterranean wells
AssigneeSchlumberger Technology Corporation
InventorSimon James
Life of this patent
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Abstract
Disclosed are compositions and methods for providing fluid-loss control in subterranean wells. Well-completion fluids contain fine particulate additives whose glass-transition temperatures are below the anticipated bottomhole temperature. The particles soften upon injection into the well, whereupon they soften and become deformable. The particles then migrate to the borehole wall and form a seal that reduces further fluid flow from the borehole into the formation. The additive may be supplied as a powder or in the form of a liquid suspension.
Claims14
A method for reducing fluid loss in a subterranean well, the well having a borehole wall, a formation and a bottomhole temperature, comprising:
- (i) preparing a composition comprising a process fluid and a particulate additive having a glass-transition temperature lower than the bottomhole temperature and a particle size smaller than 1 micrometer, and being composed of one material;
- and
- (ii) pumping the composition into the well, wherein, after injection into the well, the particulate additive becomes deformable at a temperature below the bottomhole temperature and migrates to the borehole wall, thereby forming a seal that reduces fluid ingress through the borehole wall and into the formation.
A method for using a particulate additive in a subterranean well having a borehole wall, a formation and a bottomhole temperature, the additive comprising a material whose glass transition temperature is lower than the bottomhole temperature and a particle size smaller than 1 micrometer, and being composed of one material, comprising:
- (i) preparing a process fluid comprising cement, water and the particulate additive;
- and
- (ii) pumping the process fluid into the subterranean well, wherein the particulate additive becomes deformable and migrates to a borehole wall, forming a seal that reduces fluid ingress through the borehole wall and into the formation.
Dependencies are inferred from the claim text.