砾岩三维缝网扩展及影响因素分析——以玛湖凹陷南斜坡上乌尔禾组为例  

Analysis of 3D Fracture Network Expansion and Influencing Factors of Conglomerate:A Case Study of the Shangwuerhe Formation on the Southern Slope of Mahu Depression

作　　者：蒋庆平[1] 邹正银[1] 孔垂显[1] 李胜[1] 常天全[1] JIANG Qing-ping;ZOU Zheng-yin;KONG Chui-xian;LI Sheng;CHANG Tian-quan(Research Institute of Exploration and Development,Xinjiang Oilfield Company,Karamay 834000,China)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,克拉玛依834000

出　　处：《科学技术与工程》2021年第17期7074-7083,共10页Science Technology and Engineering

基　　金：中石油重大科技专项(2017E-0415,2017E-0405)。

摘　　要：水力压裂技术已成为玛湖致密油田开发的有效手段。然而传统的压裂模拟方法无法得到真实的三维裂缝扩展规律,并且储层的物理特征对裂缝扩展的影响还有待进一步研究。对玛湖目的层上乌尔禾组进行压裂模拟并对裂缝延伸影响因素进行分析。结果表明,乌尔禾组弹性模量值域在18~58.5 GPa,平均为32.4 GPa。泊松比值域在0.21~0.38,平均为0.31。脆性指数在21.0~89.0,平均为44.3,压裂改造可形成多分支裂缝。水平井设计方向为南北向,水平应力差在4.2~9.8 MPa,储层容易压裂改造形成复杂缝网。缝网模拟与微地震监测裂缝吻合度高达92.03%,模拟效果理想。物性特征越好其裂缝延伸拓展范围越广。弹性模量与脆性指数越大,更利于裂缝延伸,裂缝主要向高深区域及强脆性指数区域延伸,泊松比与裂缝广度呈负相关关系。最大水平地应力和最小水平地应力间接影响裂缝拓展延伸,水平应力差越小,裂缝空间展布越大。针对人工缝网的模拟有利于优化玛湖1井区水平井压裂参数及开发参数。Hydraulic fracturing technology has become an effective means to develop the Mahu tight oilfield.However,the true three-dimensional fracture propagation law cannot be given by traditional fracturing simulation methods,and the physical characteristics of the reservoir need to be studied for its influence on fracture propagation.The three-dimensional fracturing model of the Wuerhe Formation on the Mahu target layer was established to study the effects of physical and mechanical parameters on fracture propagation.The results show that the range of elastic modulus of Shangwuerhe Formation is 18~58.5 GPa,with an average of 32.4 GPa.The range of Poisson's ratio is 0.21~0.38,with an average of 0.31.The brittleness index is 21.0~89.0,with an average of 44.3.Multi-branch fractures can be formed by fracturing.The design direction of horizontal wells is north-south,and the horizontal stress difference is 4.2~9.8 MPa.The reservoir can be fractured to form multi-branched fractures.The fracture network simulation and the microseismic monitoring fracture coincide is up to 92.03%,and the simulation effect is ideal.The better the physical characteristics,the wider the crack extension and expansion range.The larger the elastic modulus and brittleness index,the more conducive to the propagation of cracks.The fractures mainly extend to high depth areas and strong brittleness index areas,and Poisson's ratio is negatively correlated with crack width.The maximum horizontal in-situ stress and the minimum horizontal in-situ stress indirectly affect the expansion and extension of fractures.The smaller the horizontal stress difference,the larger the fracture space spread.The simulation of artificial fracture network is beneficial to optimize the reasonable fracturing parameters and development parameters of horizontal wells in the Mahu tight oilfield.

关 键 词：水力压裂 缝网 数值模拟 扩展 

分 类 号：TE355[石油与天然气工程—油气田开发工程]