石炭系浅层低压砂岩油藏压裂方式优选  

Optimization of Fracturing Methods in Carboniferous Shallow Low Pressure Sandstone Reservoirs

作　　者：陈宏飞 曹旭升 冯海蛟 彭越 巨世昌 李斯琪 陈文顺 胥新刚 邓青玉 CHEN Hong-fei;CAO Xu-sheng;FENG Hai-jiao;PENG Yue;JU Shi-chang;LI Si-qi;CHEN Wen-shun;XU Xin-gang;DENG Qing-yu(Heavy Oil Developed Company,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China;School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;Beijing Zhongdi Jinshi Technology Co.,Ltd.,Beijing 100085,China)

机构地区：[1]中国石油新疆油田分公司重油开发公司,克拉玛依834000 [2]中国地质大学(北京)能源学院,北京100083 [3]北京中地金石科技有限公司,北京100085

出　　处：《科学技术与工程》2023年第1期173-182,共10页Science Technology and Engineering

基　　金：国家重大专项(2017E-0405)。

摘　　要：新疆油田J230区块石炭系油藏储层中部深度620 m,地层压力8.6 MPa,平均孔隙度7.26%,渗透率分布在0.01~96.1 mD,平均渗透率1.14 mD,属典型浅层低压砂岩储层。近几年,该区进行了水平井多段压裂和体积压裂开发试验,提高了油井初期产量。但是,体积压裂投资规模大,风险高,迫切需要评价不同压裂方式下的油井长期生产特征,为经济可行性评价提供参考。选取了一个典型的裂缝单元,运用数值模拟方法,开展相同支撑剂用量下常规多段压裂与体积压裂下的油井生产规律研究,预测了20年油井累计产量与采出程度。数值模拟研究结果表明:一定支撑剂用量下,不同渗透率储层对应最优压裂方式。当储层渗透率低于1 mD时,体积压裂效果好。当储层渗透率高于1 mD时,普通多段压裂效果好。在相同的支撑剂用量下,体积压裂相对于普通多段压裂具有更高的初产优势,但随着生产的进行,体积压裂的优势逐渐减弱。对于体积压裂,储层的改造程度和改造面积是决定油井长期生产的主控因素,不同渗透率储层存在最优的裂缝簇数。针对新疆油田J230区块石炭系油藏储层物性特征,建议以常规多段压裂为主,在极低渗透率区域辅以体积压裂。研究结果对于西部石炭系浅层低压油藏压裂方式优选有重要的指导意义。The carboniferous reservoir in Block J230 of Xinjiang Oilfields is a typical shallow low pressure sandstone reservoir,which has a middle depth of 620 m,the formation pressure is 8.6 MPa,the average porosity is 7.26%,the permeability ranges from 0.01 mD to 96.1 mD and the average value is 1.14 mD.In recent years,the area has undergone exhausted development tests of multi-stage fracturing and volume fracturing in horizontal wells,improving the initial oil production.However,volume fracturing has a large investment scale and high risk.Therefore,it is urgent to evaluate the long-term production characteristics of oil wells under different fracturing methods,so as to provide reference for economic feasibility evaluation.A typical fracture element was constructed to simulate the oil well production under conventional multi-stage fracturing and volume fracturing treatment with the same amount of proppants.On the basis of the numerical results,the cumulative production of oil wells in 20 years and recovery degree can be predicted.The results indicate that the optimal fracturing methods are different in reservoirs with different permeability but the same amount of proppants.The volume fracturing is better when the permeability is less than 1 mD,whereas the well production is higher with the conventional multi-stage fracturing when the permeability exceeds 1 mD.Moreover,at the initial stage,the oil production rate of volume fracturing is higher than that of conventional multi-stage fracturing,and the advantage of volume fracturing gradually weaken with the production.For volume fracturing,the degree and area of reservoir reconstruction by fracture network dominates the long-term production of oil wells,and there is an optimal number of fracture clusters in reservoirs with different permeability.According to the physical properties of the Carboniferous reservoir in the J230 block of Xinjiang oilfield,it is recommended to use conventional multi-stage fracturing as the main method,supplemented by volume fracturing in the extr

关 键 词：浅层砂岩油藏 压裂模式 裂缝参数优化 数值模拟 

分 类 号：TE343[石油与天然气工程—油气田开发工程]