| US 7,575,054 B2 | ||
| Self diverting matrix acid | ||
| Michael J. Fuller, Houston, Tex. (US); Diankui Fu, Tyumen (Russian Federation); Marieliz Garcia-Lopez De Victoria, Sugar Land, Tex. (US); Slaheddine Kefi, Cottenham (United Kingdom); and Mohan K. R. Panga, Kuala Lumpur (Malaysia) | ||
| Assigned to Schlumberger Technology Corporation, Sugar Land, Tex. (US) | ||
| Filed on Nov. 16, 2005, as Appl. No. 11/280,749. | ||
| Application 11/280749 is a continuation in part of application No. 10/969110, filed on Oct. 20, 2004, granted, now 7,237,608. | ||
| Prior Publication US 2006/0118302 A1, Jun. 08, 2006 | ||
| Int. Cl. E21B 43/26 (2006.01); E21B 43/27 (2006.01); C09K 8/74 (2006.01); C09K 8/76 (2006.01) | ||
| U.S. Cl. 166—281 [166/282; 166/283; 166/307; 166/308.3; 507/240; 507/241; 507/244; 507/277; 507/934] | 20 Claims |
| 1. A method of treating a subterranean sandstone formation penetrated by a wellbore comprising
injecting into the formation a treatment fluid having a viscosity of less than about 20 cP comprising
at least one viscoelastic surfactant selected from the group consisting of cationic viscoelastic surfactants, zwitterionic
viscoelastic surfactants, and mixtures thereof, at a viscoelastic surfactant concentration insufficient for aggregation of
viscoelastic surfactant structures to form a viscoelastic fluid,
a hydrogen fluoride source selected from the group consisting of ammonium fluoride, ammonium bifluoride, polyvinylammonium
fluoride, polyvinylpyridinium fluoride, pyridinium fluoride, imidazolium fluoride, sodium tetrafluoroborate, ammonium tetrafluoroborate,
salts of hexafluoroantimony, synthetic resinous fluorine-containing polymer, and mixtures thereof, and
at least one formation-dissolving agent, wherein the viscosity of the treatment fluid increases to above about 50 cP as the
fluid passes through the formation.
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