Conoco Inc.

E.i. Dupont De Nemours and Company

Karl E Bennett

Paul C Yates

Richard A Harmon

Jeff J Jurinak

Larry D Johansen

Walter M MacKinlay

Chandra L Mowery

John L Fitzjohn

A process for sealing casing leaks comprises cleaning out the annulus between the tubing and the casing, situating a gelable mixture in the annulus at the loci of the leak in the casing, pressuring the mixture through the leak into the formation and effecting gelation of the mixture. Optionally, the remaining gelable mixture may be circulated out of the annulus. Gelable mixtures can be comprised of various organic and inorganic gel polymers.

Method for patching casing leaks

A process for selectively plugging permeable zones in subterranean formations or for plugging subterranean leaks which comprises injecting into the permeable zone or the site of the subterranean leak an aqueous solution containing 1 to 70 weight percent of a non-aggregated colloidal silica sol having a particle size in the range between 4 and 100 nm and a pH in the range between about 1 and 10, and causing said solution to gel in said zone or at said site.

Colloidal silica-based fluid diversion

Growing community of inventors

Hockessin, DE, United States of America

Karl E Bennett