MH Gas Field Test Interpretation Model And Application Research

MH gas field is cut by fault, which is a small fault-block condensate gas reservoir. Based on the theory of percolation mechanics, in view of the MH production data and characteristics of gas field reservoir, a mathematical model of well test interpretation is established for the MH field, and the data of actual measured pressure in the gasField is analyzed, the research achievements is of important significance on the reservoir evaluation and production performance.(1)The mathematical model of well test interpretation is established considering effect of wellbore storage, skin effect and wellbore fluid phase separation, and the Laplace space solution of dimensionless bottom hole pressure on infinite boundary, circular closed boundary, the circular constant pressure boundary is gained by Laplace transformation. The dimensionless bottom hole pressure and its derivative and the dimensionless time double logarithmic curve are calculated and draw by the Stehfest Laplace inversion algorithm, and the characteristics of well test curve and its influencing factors are analyzed.(2)The mathematical model of well test interpretation on compound gas reservoir considering effect of wellbore storage, skin effect and wellbore fluid phase separation effect is established and calculated. The dimensionless bottom hole pressure and its derivative and the dimensionless time double logarithmic curve are calculated and draw by the Stehfest Laplace inversion algorithm, the impact of the well test curves, mobility ratio, diffusion coefficient ratio, and complex radius on the well test curves.(3)The calculation method on the dynamic pressure at the bottom of gas well hole considering the fault boundary (Straight line fault, Parallel to the fault, Rectangular fault, U fault, Rectangular fault) is studied by the mirror image principle and superposition principle, and the effect of fault form and the distance between the fault and the well on the well test curves are studied.(4)Based on the results of the theoretical model research, the well test data of MH gas filed is fitted by the corresponding mathematical model for well test interpretation, and the reservoir parameters is gained.By the detailed study of the interpretation model of well test on homogeneous gas reservoir and composite gas reservoir considering fault boundary, the reservoir characteristics and dynamic flow can be well understood on the technical support for efficient and reasonable development for the gas field.