Polyester diverting agents for low-temperature oil wells

Abstract

A hydraulic fracturing method for recovering oil from a low-temperature subterranean oil formation is disclosed. Before, during, or after inducing hydraulic fracturing within the formation, a particulate, degradable polyester diverting agent is introduced into the formation in an amount effective to improve oil production from the formation. The diverting agent is allowed to degrade, and oil is recovered. The diverting agent has a melting point greater than the average temperature of the formation and is selected from: (i) ethylene glycol succinates; (ii) acid-terminated ethylene glycol succinates; (iii) acid-terminated polyglycolic acids; (iv) acid-terminated polylactic acids; (v) mixtures of any of (i) through (iv) with a half acid ester; and (vi) mixtures of polylactic acids or polyglycolic acids with a half acid ester. These easily synthesized classes of particulate polyester diverting agents degrade more effectively than polylactides under the conditions present in low-temperature wells and should help to enhance well productivity.

Dependencies are inferred from the claim text.