Core String Parallel Experiment Study for Volcanic Rock in Xushen Gas Field

Abstract

Volcanic gas reservoir in Xushen gas field has complex microscopic pore throat structure and dense physical property, which is quite different from that of conventional high-permeability sandstone gas reservoir. It is of great significance to know its seepage mechanism for scientific and efficient development technology countermeasures. Through the parallel and series experiments of volcanic fracture cores and matrix cores, the gas flow changes of fractures and matrix cores with different permeability levels under different pressure gradients were measured, and the percolation mechanism of volcanic gas reservoirs with different pressure gradients was revealed when fractures and matrix cores were in parallel or series. The experimental results show that the fracture is the dominant channel relative to the matrix, and the supply and exhaust capacity of the fracture is much larger than that of the matrix, and the permeability of the matrix determines the supply and exhaust capacity of the series system composed of fracture and matrix