摘要
对于低渗透砂泥互层储层,为沟通更多砂岩层并增加泄油面积,通常采用斜井结合水力压裂技术进行开发。与直井和水平井相比,斜井中水力裂缝的起裂、转向形态复杂,而近井区域的裂缝复杂程度决定了压裂效果。针对储层中砂泥互层的情况,利用物理模拟实验,研究了砂泥互层中不同钻完井参数及地应力条件下水力裂缝起裂、转向和垂向扩展形态。研究结果表明:方位角和水平应力差对裂缝扩展能力有很大影响,当方位角较大,水平应力差较小时,近井区域裂缝扭曲程度大,数量多,不利于裂缝垂向扩展和施工后期加砂;泥岩层会阻碍裂缝垂向扩展,砂岩层与泥岩层之间应力差越高,阻碍作用越大,裂缝越不容易从砂岩层进入泥岩层。根据实验所得结论,提出了组合及分层压裂的判断依据。
In low permeability reservoir with sand and mud interbedding, deviated well combined with hydraulic fracturing technology is applied to communicate more sand layers and increase well drainage area. Compared with fractures in vertical and horizontal wells, fractures in deviated wells always initiate and propagate in a more complex geometry. The complexity of fractures near wellbore determines the stimulation effect. In this paper, hydraulic frac- turing simulating experiments in sand and mud interbedding reservoir are conducted to study the initiation, reorient- ation and propagation in vertical direction of hydraulic fracture in deviated well. The experiment results show that azimuth angle and horizontal stress difference influence the ability of fracture propagation seriously, and a larger azimuth angle and smaller horizontal stress difference will result in multi fractures with large twisting extent, which will go against fracture propagation in vertical direction and sand adding. Mud layers will hinder fracture propaga- tion in vertical direction, and a larger stress difference between sand layer and mud layer will add the hindering effect. According to the conclusion of the experiments, the judgement basis for combination fracturing or layer fracturing is proposed
出处
《科学技术与工程》
北大核心
2015年第26期54-59,共6页
Science Technology and Engineering
基金
国家自然科学基金资助项目(51574260
51490651
51234006)
中国石油大学(北京)科研基金项目(2462015YQ0203)资助
关键词
砂泥互层
斜井
水力压裂
裂缝扩展
sand and mud interbedding deviated well hydraulic fracturing fracture propagation