Performance of horizontal wells in composite tight gas reservoirs considering stress sensitivity

Advances in Geo-Energy Research

article

Kui Zhao¹  Peng Du¹ 

[1] Qingdao Jari Industry Control Technology

关键词: Heterogeneity;    stress-sensitivity;    unsteady fluid exchange;    mathematical model;    flow regimes;    sensitivity analysis;   

DOI  :  10.26804/ager.2019.03.07

来源: Yandy Scientific Press

【 摘 要 】

Tight gas reservoir (TGR) plays an important role in unconventional oil and gas resources. The existing seepage models for TGR rarely consider the effects of heterogeneity, stress-sensitivity, and the unsteady fluid exchange between matrix and fracture. Heterogeneity is common for tight gas reservoir which should be carefully considered in geological model. The stress-sensitivity effect of fracture is an important factor influencing the transient flow behavior of TGR. Ultra-low porosity and permeability cause the unsteady flow between matrix and fractures systems. So this paper introduced a mathematical model for the horizontal well in a dual-porosity composite tight gas reservoir with considering the stress-sensitivity effect and unsteady flow between matrix and fractures systems. Some mathematical methods including the finite Fourier cosine transform, perturbation technique, Laplace transform, superposition principle, Stehfest numerical inversion algorithm are used to solve the nonlinear partial differential equation. Different flow regimes are divided based on pressure transient analysis curves. The sensitivity analysis of related parameters is studied according to pressure transient analysis and rate transient analysis curves. The presented model and obtained results in this paper give better understanding on pressure and rate transient behaviors of composite TGR.

【 授权许可】

Unknown