塔河缝洞型碳酸盐岩储层裂缝扩展规律数值模拟  

Numerical simulation of fracture propagation in Tahe fracture-vuggy carbonate reservoirs

作　　者：李越 牟建业[1] 张士诚[1] 马新仿[1] 段贵府 LI Yue;MOU Jianye;ZHANG Shicheng;MA Xinfang;DUAN Guifu(College of Petroleum Engineering in China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]中国石油勘探开发研究院,北京100083

出　　处：《中国石油大学学报（自然科学版）》2022年第6期135-142,共8页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家科技重大专项(2016ZX05014-005-012)。

摘　　要：塔河油田是典型的超深层缝洞型碳酸盐岩油藏,其储层包含大量的天然裂缝和不规则溶洞。由于其结构的复杂性,使缝洞型碳酸盐岩储层裂缝扩展机制与常规储层不同。为了探究水力裂缝在缝洞介质条件下的裂缝扩展规律,基于UFM模型并借助Kinetix软件平台进行数值模拟研究。结果表明:溶洞的存在造成了局部地应力场方向的改变,并在周围形成一个高应力隔层,导致裂缝在溶洞附近受到排斥作用而发生偏离转向,较大的或不规则形状的溶洞都会增大这种排斥作用,而较高的地应力差、洞内流体压力或充填程度均会减弱这种排斥作用;使用中高黏度压裂液并尽可能提高排量有利于水力裂缝向溶洞靠近;在适当的缝间距条件下,缝间的应力阴影效应也会减弱溶洞对水力裂缝的排斥作用;天然裂缝对水力裂缝的扩展路径具有重要影响,应充分利用天然裂缝的导向作用来实现对溶洞储集体的开发。Tahe Oilfield is of typical ultra-deep fracture-cavity carbonate reservoir,which contains numerous irregular cavities.Due to the complexity of its structure,the mechanism of fracture propagation of the fracture-cavity carbonate reservoir is different from that of the conventional reservoirs.In order to investigate the formation and propagation of hydraulic fractures in the fracture-cavity reservoirs,in this study,a numerical simulation study was carried out based on the UFM model and using the software platform Kinetix.The simulation results show that the existence of natural karst caves can change the in-situ stress distributions and cause a local stress concentration,which can result in a diversion of the fracture propagation path.Large and irregularly shaped caves can increase this repulsion.However,low in-situ stress,high in-situ stress difference,high fluid pressure in the cave or strong mechanical properties of the filling can weaken the repulsive effect.Using moderate to high viscosity fracturing fluid and increasing the fluid displacement as much as possible are beneficial for hydraulic fracture to approach to the karst caves.Meanwhile,applying appropriate fracture spacing,the interference between fractures can weaken the repulsion effect of karst caves on hydraulic fractures.Natural fractures have an important influence on the propagation path of hydraulic fractures,which should be fully utilized to form a fracture network among the caves of reservoir.

关 键 词：缝洞型碳酸盐岩油藏 UFM模型 地应力场 天然裂缝 裂缝扩展 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]