Numerical Study of Reactive Flow in Fractured Carbonate Rock

Frontiers in Earth Science

Qingfu Zhang¹  Xu Zhou²  Haibin Su²  Jianrong Lv²  Zhaoqin Huang³  Hongchuan Xing³ 

[1] Exploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongyig, China;Research Institute and Exploration and Development, XinJiang Oilfield Company, PetroChina, Karamay, Xinjiang, China;School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, China;

关键词: fractured carbonate rock;    two-scale model;    the discrete fracture model;    reactive flow;    numerical simulation;   

DOI  :  10.3389/feart.2021.765139

来源: DOAJ

【 摘 要 】

Acidizing technology is an effective reformation method of oil and gas reservoirs. It can also remove the reservoir pollution near wellbore zones and enhance the fluid transmissibility. The optimal injection rate of acid is one of the key factors to reduce cost and improve the effect of acidizing. Therefore, the key issue is to find the optimal injection rate during acid corrosion in fractured carbonate rock. In this work, a novel reactive flow mathematical model based on two-scale model and discrete fracture model is established for fractured carbonate reservoirs. The matrix and fracture are described by a two-scale model and a discrete fracture model, respectively. Firstly, the two-scale model for matrix is combined with the discrete fracture model. Then, an efficient numerical scheme based on the finite element method is implemented to solve the corresponding dimensionless equations. Finally, several important aspects, such as the influence of the injection rate of acid on the dissolution patterns, the influence of fracture aperture and fracture orientations on the dissolution structure, the breakthrough volume of injected acid, and the dynamic change of fracture aperture during acidizing, are analyzed. The numerical simulation results show that there is an optimal injection rate in fractured carbonate rock. However, the fractures do not have an impact on the optimal acid injection rate, they only have an impact on the dissolution structure.

【 授权许可】

Unknown