海拉尔盆地复杂岩性储层压裂增产技术

Complex lithologic reservoir fracturing production stimulation technique in Hailaer Basin

海拉尔盆地是一个多断块、多储集类型的油田,储层物性条件差,岩性变化复杂,常规水力压裂技术不能适应复杂多变储层类型的需要。针对兴安岭群含凝灰质储层早期砂堵的问题,在研究其水力压裂裂缝启裂与延伸特征的基础上,开发成功了水基冻胶外相油内相乳化压裂液体系,具有与兴安岭群含凝灰质储层配伍性强、乳化与破乳完全、低滤失、流变性能好、地层伤害程度低、可降低支撑剂嵌入等特点,使压裂成功率和压裂增油效果大幅度提高;针对布达特群古潜山变质岩储层裂缝孔洞多储集介质发育、厚度大、储隔层应力差异小的特点,研究成功将储层地质条件、地应力条件和压裂液性能等紧密结合,在压裂施工风险分析基础上进行施工参数优化,根据测试压裂分析结果完善、确定主压裂施工设计的方法,实现了真正的个性化设计。同时,应用切实可行的现场控制技术,实现了微裂缝数量、裂缝高度、压裂液滤失量和施工摩阻的可控性,提高了布达特群储层压裂施工的成功率。

Hailaer basin is a multi-fault block and multi-reserve type oilfield with poor reservoir properties and complex lithologic changes. Conventional hydraulic fracturing technology can not meet the needs of various reservoir types. Aiming at the early stage sand plugging problem of marlaceous reservoir in Xing’anling Group, based on study of fracture opening and extension features of its hydraulic fracturing, a water base gel fracturing liquid system with oil as outer phase and emulsified in inner phase is successfully developed. It has the following features: good compatibility with marlaceous reservoir in Xing’anling Group, complete emulsification and emulsion breaking, low filtration, good rheological behavior, low formation damage degree, and proppant embedment reduction. Fracturing success ratio and fracturing stimulation effect can be greatly enhanced. Aiming at the features of fracture and pore space multi-reservoir media development, large thickness and small difference of reservoir and barrier interlayer stress in ancient burial hill metamorphic rock reservoir in Budate Group, a design method has been successfully developed through combining reservoir geologic conditions, earth stress conditions and fracturing fluid performance, optimizing operation parameters based on fracturing operation risk analysis, perfecting and determining major fracturing operation design according to micro-fracture analysis result. True individualized design has been achieved. At the same time, feasible field control technology is applied to achieve the controllability of microfracture quantity, fracture height, fracturing fluid filter loss and operation frictional resistance, and to improve the success ratio of fracturing operation in Budate Group.