Analytical modeling of gas production rate in tight channel sand formation and optimization of artificial fracture

Abstract

Permeability variation in tight channel sand formation makes an important role in gas production. Based on the features of channel sand formation, a mathematical model has been established considering anisotropy of permeability. The analytical solutions were derived for productivity of both vertical wells and vertically fractured wells. Simulation results show that, gas production rate of anisotropic channel sand formation is less than that of isotropic formation. For vertically fractured well, artificial fracture direction, drainage radius, permeability ratio and fracture half-length have considerable influence on production rate. The optimum fracture direction should be deviated less than π/8 from the maximum permeability direction (or the channel direction). In addition, the analytical model was verified by in situ measured data. The research provides theoretical basis for the development of tight channel sand gas reservoirs.

Gas-Water Production of a Continental Tight-Sandstone Gas Reservoir under Different Fracturing Conditions

“…Thereby, it is considered that the stress difference between the target layer and the upper and lower spacers [29,30], the viscosity of fracturing fluid [31], and the fracturing displacement [32] are the relevant factors affecting vertical fracture propagation. However, the correlation among them has not been fully clarified [33][34][35][36]. In this article, a numerical fracture propagation model is established to study the hydraulic fracture propagation law of deep tight sandstone under different interlayer stress difference, fracturing construction displacement and fracturing fluid viscosity on the basis of comprehensive analysis of the geological characteristics, development status and low efficiency of stimulation and reconstruction of low permeability reservoir in Northeast Sichuan.…”