Self-Destructing Filter Cake
AssigneeSchlumberger Technology Corporation
InventorsDean Willberg, Keith Dismuke
Life of this patent
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Abstract
A composition and method are given for self-destructive fluid loss additives and filter cakes in wellbores and subterranean formations. The fluid loss additives and filter cakes are formed from a mixture of particulate solid acid-precursors, such as a polylactic acid or a polyglycolic acid, and particulate solid acid-reactive materials, such as magnesium oxide or calcium carbonate. In the presence of water, the solid acid-precursors hydrolyze and dissolve, generating acids that then dissolve the solid acid-reactive materials. The composition is used in oilfield treatments such as drilling, completion and stimulation where it disappears when it is no longer needed without the use of mechanical means or injection of additional fluids.
Claims14
An oilfield treatment composition comprising a mixture of a solid acid-precursor and a solid acid-reactive material.
An oilfield treatment method in which a filter cake is formed and at least partially destroyed on a subterranean formation surface comprising:
- a) preparing an oilfield treatment fluid comprising:
- i) a solid acid-precursor, and
- ii) a solid acid-reactive material;
- b) injecting said oilfield treatment fluid into a wellbore penetrating said formation, causing said fluid to contact said formation surface;
- c) forming a filter cake on said formation surface;
- and
- d) allowing at least a portion of said solid acid-precursor to hydrolyze, whereby at least a portion of said solid acid-reactive material dissolves.
A method for forming and at least partially destroying a filter cake comprising the steps of formulating a fluid comprising a composition comprising a solid acid-precursor and a solid acid-reactive material, causing said fluid to contact a surface, and allowing said solid acid-precursor to hydrolyze, whereby at least a portion of said acid-reactive material dissolves.
Dependencies are inferred from the claim text.