Patent ID: 7854802
Filing Date: 2010-12-21
Classification: C04B,C09K

Abstract:
1. A method for stabilizing cement slurry against degradation due to exposure to oil-based fluids, comprising the steps of: providing a cement slurry; mixing the cement slurry with a surfactant blend comprising a first non-ionic surfactant having a hydrophilic-lipophilic balance of between about 10 and about 15, a second non-ionic surfactant having a hydrophilic-lipophilic balance of between about 2 and about 6, and an anionic surfactant, wherein the anionic surfactant comprises an ammonium sulfate lauryl ether having between about 3 and about 15 moles of ethoxylene oxide; and positioning the cement slurry in a location exposed to oil-based fluid whereby the surfactant blend forms an emulsion with oil from the oil-based fluid.