aqueous based drilling fluid composition and method for reducing reactivity of clays and shale in drilling operations

摘要

Summary "aqueous-based drilling fluid composition and method for reducing reactivity of clays and shale in drilling operations" hydration of clays and shale in drilling operations can be inhibited by employing an aqueous-based drilling fluid comprising a shale hydration inhibiting agent having the formula: (i) r is an alkyl group having from 1 to 6 carbons, r1 may be the same or different from re and is an alkyl group having from 1 to 10 carbons or a hydroxy alkyl group comprising n number of carbons, where n is an integer from 1 to 10 and n - 1 hydroxyl groups; R2 is an alkyl group having from 1 to 6 carbons; r3 may be the same as or different from r2 and is an alkyl group having from 1 to 10 carbons or an alkyl hydroxy group comprising n number of carbons, where n is an integer from 1 to 10 en-1 hydroxyl groups, provided that r3 does not equals r1; and x is an anion. The shale hydration inhibiting agent should be present in aqueous based drilling fluid in sufficient concentration to reduce reactivity, such as swelling of clays and shale, when exposed to water based drilling fluids. 1/1