裂缝性油藏高效压裂技术研究与应用

EFFICIENT FRACTURING TECHNIQUE RESEARCH AND APPLICATION IN NATURAL FRACTURES RESERVOIR

裂缝性油藏中天然裂缝的存在使得液体滤失量大,人工裂缝延伸扩展规律复杂,压裂施工砂堵率高,如何提高该类油藏压裂效果是油藏改造领域的重大难题。针对乾北—大情字井地区裂缝发育程度,压裂引起的储层污染等进行分析并开展高效压裂技术研究,基于天然裂缝分布规律分析和油藏两个水平主应力差值与裂缝延伸净压力的关系,提出了实现支撑天然裂缝的条件和工艺技术措施;综合分析了压裂过程的伤害因素,研发出能有效降解压裂液残渣的中高温生物酶破胶剂。研究成果在乾北—大情字井地区16口井应用,增产效果明显,为裂缝性油藏压裂改造提供了新思路。

Natural fractures in reservoir lead to large amount of the fracturing liquid filtered,the complicate expanding laws of artificial fractures,and higher probability of sand’s walling up. Aiming at Qianbei-Daqingzijing region natural fractures growth degree and pollution of reservoir,efficiently fracturing technique research and application in natural fractures reservoir are carried out. According to analysis of natural fracture distribution law and the relationship between two horizontal principle stress difference and fracture extension net pressure,technology measure and conditions of supporting natural fractures are proposed. The injury factors of fracturing process are comprehensively analyzed. The gel breaker,which can effectively degrade the middle-high temperature enzyme in fracturing fluid residues,is developed. Upon the application of the research results in 16 wells of Qianbei-Daqingzijing region, the stimulation effect is obvious,which provides a new way of fracturing in natural fracture reservoir.