Jimmie Brown Lawson - Houston TX Robert June Faircloth - Houston TX George Neal Iken - Houston TX
Assignee:
Shell Oil Company - Houston TX
International Classification:
C02F 514
US Classification:
252175
Abstract:
A scale inhibitor solution composition comprising water; an organophosphorous scale inhibitor selected from the group consisting of nitrilotri(methylene phosphonic acid), diethylenetriaminepenta-(methylene phosphonic acid) and salts thereof with monovalent cations; and sodium chloride in a concentration of between about 12 and about 14% by weight of the scale inhibitor solution.
Jimmie B. Lawson - Houston TX Robert J. Faircloth - Houston TX George N. Iken - Houston TX
Assignee:
Shell Oil Company - Houston TX
International Classification:
E21B 4312 E21B 4322
US Classification:
166279
Abstract:
A method to place anionic scale inhibitors in formations containing CaSO. sub. 4 is provided. The solution dissolves CaSO. sub. 4 when injected into the formation containing CaSO. sub. 4 causing calcium salts of the scale inhibitor to precipitate at a rate and to an extent that exceeds that resulting when an inhibitor solution not containing the salt is used. Precipitation of the calcium salt of scale inhibitor is maximized because salt reduces its solubility.