迫使碳酸盐岩油气藏裂缝向下延伸的酸压技术　　

Acid fracturing technology forcing fracture to propagate downward in carbonate reservoirs

周福建 汪道兵 伊向艺 刘雄飞 张福祥 石阳

ZHOU Fujian WANG Daobing YI Xiangyi LIU Xiongfei ZHANG Fuxiang SHI yang

中石油勘探开发研究院廊坊分院，河北廊坊　065007 油气藏地质及开发工程国家重点实验室·成都理工大学，四川成都　610059 中国石油塔里木油田分公司，新疆库尔勒　841000

PetroChina Research Institute of Petroleum Exploration & Development, Langfang 065007, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation·Chengdu University of Technology Chengdu 610059, China

碳酸盐岩油气藏非均质性强，受钻井工艺和地质条件的限制，井眼距下部储集体较远时，常规酸压工艺难以沟通下方的储集体。从人工隔层控制裂缝延伸方向机理出发，提出上浮转向剂形成人工高阻隔层迫使酸压裂缝在纵向上向下延伸的思路，研发了一种超低密度耐高温高承压的特殊上浮转向剂TBA，其密度为0.37 g/cm3，承压140 MPa，260 ℃高温下稳定，并对上浮转向剂TBA进行了上浮规律研究，使用数模的方法对上浮转向剂TBA的上浮时间、用量进行优化，获取了有效迫使裂缝向下定向酸压控制参数，使裂缝尽可能向下延伸沟通储集体。该技术已在塔里木盆地碳酸盐岩油气藏进行了4口井酸压试验，取得了很好的效果。

Considering the strong heterogeneity of carbonate reservoirs, it is very difficult to reach the reservoir at the lower part by conventional acid fracturing due to restrictions of drilling technology and geological conditions if the borehole is relatively far away from the reservoir. This paper, based on the mechanism of artificial interlayer controlling fracture propagation path, puts forward an idea where floating type of diverting agent forms high artificial barrier layer before forcing longitudinal downward propagation of acid fracture. A special floating type of diverting agent TBA of ultra-low density and high temperature and high pressure resistance is developed, which has a density of 0.37 g/cm3, pressure-bearing capacity of 140 MPa and keeps stable at 260 ℃. The floating type of diverting agent TBA is studied with respect to the floating law, and digital modeling is used to optimize the time of floating and dosage of TBA to obtain the control parameters of acid fracturing that effectively forces the fracture to propagate downward as far as possible until reaching the reservoir. This acid fracturing technology has been tested in 4 wells in carbonate reservoirs in Tarim basin with excellent effect.