塔河油田托甫台区块碳酸盐岩油藏裂缝闭合认识与探索

Fracture closure of carbonate reservoir in Tuofutai area of Tahe Oilfield

马国建 蒋林 程洪

Ma Guojian Jiang Lin Cheng Hong

中国石化 西北油田分公司 塔河采油三厂, 新疆轮台 841604

Tahe No.3 Oil Production Plant, SINOPEC Northwest Company, Luntai, Xinjiang 841604, China

塔河奥陶系碳酸盐岩油藏具有埋藏深,上覆地层压力高的特点,地层裂缝在此条件下容易发生闭合.结合岩石裂缝临界闭合流体压力的计算得出托甫台区块裂缝闭合临界流体压力为37~42 MPa,通过生产数据及生产现象对比,得出区块裂缝闭合现象真实存在.结合碳酸盐岩油藏实际,得出影响裂缝闭合的主要因素有油藏埋深、裂缝倾角、裂缝走向与最大主应力夹角.在生产过程中通过减小生产压差、注水等保压开采措施能够一定程度减缓裂缝闭合速度,酸化措施能够重新刻蚀裂缝使油井重新获得一定导流能力.

In the Tahe Oilfield, the Ordovician carbonate reservoirs are deep-buried with high overburden pressure, which might cause fracture closure. The critical fluid pressure of fracture closure was 37-42 MPa in the Tuofutai area. The comparisons between production statistics and production phenomenon proved the existence of fracture closure. The main factors influencing closure included reservoir burial depth, fracture dip and the angle between fracture trend and maximum principal stress. During production process, some pressure-maintaining measures such as reducing pressure drop and injecting a amount of water could slow crack closing speed. Acidification measures could benefit oil wells to regain some diversion capacity by etching fractures.

https://doi.org/10.11781/sysydz2014S1061