Research And Application Of Well Test Interpretation In Daniudi Gas Field Compact Sandstone Gas Reservoir

A great deal of experimentation has shown that compact sandstone gas reservoir impounded strong stress sensitive characteristics.We should set up the new well test model which can consider stress sensitive characteristics.First we set compact sandstone differential equation with the stress sensitive characteristics,Second we use the novel point source function and the perturbation theory to set and solute the compact sandstone gas reservoir vertical well test model and also the compact sandstone gas reservoir special well test model,Third we analysis the influence of the compact sandstone gas reservoir well test model.(1) The compacted sandstone core samples of Daniudi Gas Reservoir would produce media deformation in stress sensitivity experiment which has periods of a pressurization and a pressure reducing.This kind of deformation can only partially resume, which means damage caused by overlying strata pressure change to permeability is irreversible. On the basis of experiment, establishing the compacted sandstone gas reservoir well test interpretation model considering stress sensitivity is very necessary.(2) By bringing in the concept of permeability modulus, this article establishes the basic equations of gas flow considering stress sensitivity of compacted sandstone gas reservoir, uses non-point source function and perturbation equation to simplify and solve percolation equation, uses VC programming to get well bottom pressure response function engraving, divides flow stages of compacted sandstone gas reservoir vertical well test well model, and analyzes the influences which the wellbore reservoir coefficient, skin factor, stress sensitive coefficient give to double logarithmic curves.(3) On the basis of compacted sandstone reservoir basic equations of gas flow, this article uses non-point source function and perturbation equation to establish well test interpretation model of compacted sandstone gas reservoir special well, such as dual medium vertical Well, part perforating Well, fracturing Well and horizontal Well, divides flow stages, and analyzes the influential factors.(4) On the basis of research on compacted sandstone reservoir well test theory considering stress sensitivity, combining the part test data of the Daniudi Gas Reservoir, uses well test model this paper established to fit accurately. The results and the practical coincide degrees higher.