户部寨地区强水敏储层压裂改造保护技术研究

针对中原油田户部寨地区Es4层位粘土矿物含量高、水敏性强这一问题,分析了压裂改造过程中粘土矿物对储层的主要损害机理,研制出了适应于强水敏储层压裂改造的复合型粘土稳定剂与酸碱度控制技术.其中粘土稳定剂在1%浓度下防膨率为92.4%,且具有耐温高、使用有效期长、与压裂液配伍性好等特点.酸碱度控制剂可有效的中和高pH值压裂液中的强碱性物质,使液体保持在弱酸性的环境下,在一定程度上减轻了水敏程度.通过上述技术的综合应用,有效地降低了地层污染,提高了压裂效果.

Reservoir protection for fracturing in strongly water sensitive reservoir in Hubusai area

Es 4 horizon in Hubusai area of Zhongyuan oilfield has high clay mineral content and is highly water sensitive. The mechanism of reservoir damage due to clay mineral during fracturing process is analyzed. A compound clay stabilizer and pH value control technique are developed for fracturing stimulation in such reservoirs. This stabilizer has an antiswelling rate of 92.4% at 1% concentration, is high-temperature resistance, has long valid period, and is compatible with fracturing fluid. The pH controlling agent can neutralize the alkali matter in high pH fracturing fluid to keep the fluid in mild acid environment and mitigate the degree of water sensitivity. The application of the above technology has lightened formation contamination and improved postfracture response.