Composition and placement process for oil field chemicals
AssigneesConoco Inc., E. I. DuPont de Nemours and Company
InventorsLisa A. Cantu, Marvin E. Yost
Life of this patent
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Abstract
Oil field chemicals are incorporated in microcapsules of the condensation product of hydroxyacetic acid or the co-condensation product of hydroxyacetic acid and other compounds containing hydroxy-, carboxylic acid-, or hydroxycarboxylic acid moieties. The microcapsules are then introduced into an oil well bore and/or subterranean oil formation where the microcapsules dissolve over a period of time and release the oil field chemicals.
Claims9
A process for the continuous release of an oil field chemical within a subterranean hydrocarbon bearing formation or wellbore penetrating such formation comprising:
- (a) placing said oil field chemical in a polymeric microcapsule comprising the condensation product of hydroxyacetic acid monomer or hydroxyacetic acid co-condensed with up to 15 percent by weight of other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, said product having a number average molecular weight of from about 200 to about 4000;
- (b) dispersing such polymeric microcapsules containing such chemical in a wellbore fluid which at ambient conditions is a non-solvent for such polymeric microcapsules and contained chemical;
- and
- (c) introducing said wellbore fluid containing said microcapsules into a wellbore or subterranean formation through a wellbore;
- then
- (d) allowing water and temperature at formation conditions to degrade said microcapsules to form water soluble and oil soluble components;
- and thereby
- (e) continuously releasing said chemical from said degraded microcapsules.
A composition comprising an oil field chemical incorporated in a polymeric microcapsule comprising the condensation product of hydroxyacetic acid monomer or hydroxyacetic acid co-condensed with up to 15 percent by weight of other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid- containing moieties, said product having a number average molecular weight of from about 200 to about 4000.
Dependencies are inferred from the claim text.