Drilling fluid concentrates
AssigneeAlbright & Wilson UK Limited
InventorKevan Hatchman
Life of this patent
Estimating the term…
Abstract
A pourable concentrate suitable for forming structured surfactant drilling muds on dilution with aqueous electrolyte comprises: a) from 30 to 80% by weight, based on the weight of the composition, of surfactant consisting of at least 25%, based on the weight of the surfactant, of an anionic surfactant, from 0 to 70% by weight, based on the total weight of surfactant, of an alkanolamide, and from 0 to 20% based on the total weight of surfactant, of other non-ionic surfactant and/or amphoteric surfactants; b) from 3 to 60% by weight of the composition of a compound of the formula RHX where R is hydrogen or a C1-6 alkyl group and X is a random or block copolymeric chain comprising a total of from 3 to 20 ethoxy and propoxy units in a relative numerical proportion of 0 to 10:1; and c) up to 65% by weight of water.
Claims9
A lamellar, spherulitic or L2 phase composition consisting essentially of:
- (A) from 45 to 80% by weight of the composition of surfactant consisting essentially of at least 50% based on the total weight of surfactant of C10-20 alkyl 1-20 mole ethoxy sulfate, up to 50% by weight of C10-20 alkyl mono- or di-ethanolamide and up to 20% by weight of the surfactant of other non-ionic surfactants selected from the group consisting of ethoxylated C10-C20 alcohols, fatty acids, fatty amines, glyceryl esters, sorbitan esters and amine oxides, and/or amphoteric surfactants;
- (B) from 6 to 40% by weight based on the weight of the composition of a C2-4 alkyl ethoxy/propoxy copolymer, the copolymeric portion having an ethoxy to propoxy mole ratio of from 1:3 to 3:1 and a mean molecular mass of 300 to 800;
- and
- (C) water.
A drilling fluid comprising the composition of claim 1 and 2-10 parts by volume, based on the volume of said composition, of sea water and an effective amount of up to 25% by weight of an added electrolyte.
Dependencies are inferred from the claim text.