深层低渗储层压裂工艺优化技术

目前低渗油气储量的动用离不开压裂改造。在压裂过程中，受现有压裂技术的影响，压裂液的滤饼和对支撑剂充填层的污染不可避免地直接影响压裂效果，造成产量增加不明显或增产有效期短等问题。针对东濮凹陷低渗储层压裂改造中高温、高闭合应力的特点，文章开发研制了低伤害压裂液体系，包括低伤害羟丙基胍胶及OB-991和OB-992两种压裂液，生产的高强度支撑剂在69 MPa下破碎率小于7%，其性能指标满足深层低渗储层压裂改造的需要。文章还从污染机理入手，开展了水力裂缝缝面处理技术研究，筛选的多种压裂缝面处理剂具有降解压裂液残渣幅度大，对压裂液伤害堵塞物溶解率大于80%的特点。将这些技术应用于现场试验，取得了较好的增产效果，共实施17口井现场施工，累计增油上万吨，增产天然气数百万立方米，取得了明显的经济效益。

OPTIMIZATION OF FRACTURING TECHNIQUES FOR DEEP RESERVOIRS WITH LOW PERMEABILITY 1)

Fracturing stimulation is indispensable for lo w permeable reservoirs to develop now. During fracturing process, since the filt er cake of fracturing fluid and the pollution of proppant filling caused by the existing fracturing techniques, the fracturing results are directly affected, wh ich makes the production increase unobvious and the effective period of producti on increase short. Aiming at the characteristics of high temperature and high cl osing stress of the low-permeable reservoirs in Dongpu depression, the low-dama ge fracturing fluid system, including the low-damage hydroxypropylguar gum and the 2 fracturing fluids of OB-991 and OB-992, is developed. The high strength proppant available now has the breaking ratio of less than 7% under 69 MPa., whi ch performance meets the requirements of fracturing stimulation for deep reservo irs with low permeability. According to the mechanism of pollution, the technica l study is conducted for fracture face processing of hydraulic fracturing. Sever al fracture face processing agents are selected, which can resolute the fracturi ng fluid residues greatly and have the resolution rate of more than 80% for the fracturing fluid pluggers. The techniques are used for field test and good resul ts of production increase are achieved. With the techniques, 17 wells are fractu red. The accumulative production increase reaches more than ten thousands tons f or oil and several millions cubic meters for gas. Obvious economic benefits are obtained.