摘要
针对连续介质理论研究水力压裂需预设裂缝界面单元的不足,引入离散元—颗粒流方法模拟低渗透储层的水力压裂行为。采用圆形颗粒模拟低渗透储层,通过Navier-Stokes方程描述压裂液的流体运动,建立了考虑流固耦合作用的低渗透储层水力压裂颗粒流数值模型。分析了颗粒间平行连接断裂的失效判据,讨论了基于N-S方程的低渗透储层水力压裂PFC-CFD流固耦合求解方法,揭示了不同参数对水力压裂裂缝起裂及延伸行为的影响。结果表明:起裂压力与最小水平主应力、颗粒法向接触刚度、颗粒法向及切向连接强度近似呈正比例关系,而裂缝最大长度及宽度与上述参数呈反比例关系;起裂压力、裂缝长度、宽度与最大水平主应力、切向接触刚度基本不相关。
Aimed at the shortcoming of macroscopic continuum theory in investigating hydraulic fracturing by presetting crack interface element, the particle flow method of micro-mechanical discrete element theory was introduced to simulate mechanical behavior of hydraulic fracturing for low permeability reservoir. The reservoir was simulated as round particle, while the fluid movement of the fracturing fluid was described by Navier-Stokes equation, and particle flow numerical model of hydraulic fracturing for low permeability reservoir was established considering fluid-solid coupling. Fracturing criteria for contact-bond model were analyzed, and PFC-CFD fluid-solid coupling solution for hydraulic fracturing in low permeability reservoir was discussed based on N-S equation, and the effects of different parameters on the fracturing behavior were discovered. The results showed that the fracture initiation pressure is proportional to the minimum horizontal stress, particle normal contact stiffness, particle normal and tangential connection strength, while the fracture length and width are inversely proportional to above parameters. In addition, the initiation pressure, fracture length and width are independent of maximal horizontal stress and tangential contact stiffness.
作者
李然
易新斌
王天一
卢海兵
姜馨淳
姜伟
王海
孙磊
尚大磊
王征
LI Ran;YI Xinbin;WANG Tianyi;LU Haibin;JIANG Xinchun;JIANG wei;WANG hai;SUN Lei;SHANG Dalei;WANG Zheng(Petro-China Zhejiang Oilfield Company,Hangzhou 310023,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China;China petroleum Bohai drilling engineering Company LTD,Langfang 065007,China;China petroleum Great Wall drilling engineering Company LTD,Panjin 124000,China)
出处
《石油科学通报》
2022年第4期576-583,共8页
Petroleum Science Bulletin
基金
页岩气国家专项示范工程项目“走滑山地页岩气储层高效改造设计方法与工艺技术”(2017ZX05063004-015)资助。
关键词
水力压裂
细观模拟
颗粒流
平行连接模型
参数分析
hydraulic fracturing
numerical simulation
particle flow code
contact-bond model
fluid-solid coupling
