Patent ID: 6326335
Filing Date: 2001-12-04
Classification: C09K,Y10S,Y10T

Abstract:
A microcapsule containing from about 5% to about 80% of oil field chemical selected from the group consisting, of:(A) scale inhibitor;(B) corrosion inhibitor;(C) biocide;(D) chemicals to limit the presence of solid hydrocarbons;(E) scavengers for H.sub.2 S and/or O.sub.2 ;(F) demulsifier;(G) clay stabilizer;(H) surfactant;(I) acidizing agent; and(J) mixtures thereof,said microcapsules having a wall comprisinga gelatin;an effective amount of weighting agent;an effective amount of a chelating agent selected from the acids and salts consisting of:(1) a compound having the generic formula:R.sup.5 --[O--CH(COOH)CH(COOH)].sub.n R.sup.5wherein each R.sup.5 is selected from the group consisting of H and OH and n is a number from about 2 to about 3 on the average;(2) a compound having the generic formula:R--N(CH.sub.2 COOH).sub.2wherein R is selected from the group consisting of:--CH.sub.2 CH.sub.2 CH.sub.2 OH; --CH.sub.2 CH(OH)CH.sub.3 ; --CH.sub.2 CH(OH)CH.sub.2 OH; --CH(CH.sub.2 OH)2; --CH.sub.3 ; --CH.sub.2 CH.sub.2 OCH.sub.3 ; --CO--CH.sub.3 ; --CH.sub.2 --CO--NH.sub.2 ; --CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 ; --C(CH.sub.2 OH).sub.3 ; and mixtures thereof;(3) nitrilotriacetic acid;(4) ethylenediamine and polyethylenediamine polyacetic acids; and(5) mixtures thereof.