North China Cattle Low Permeability Gas Reservoir Fracturing Reasonable Production Of Gas Research

When fractured gas well in low permeability gas reservoir is tested by conventional productivity test, the formation pressure is commonly not in pseudo-steady state. Because of short test time, the measured flow rate is great, the bottom-hole flowing pressure is high, the open flow potential is little larger than practical.. Then the productivity and reasonable production of fractured gas well in low permeability gas reservoir of Daniudi in North China are hardly evaluated by conventional productivity test.Facing the problem that the rational proration of gas well in low permeability gas reservoir of Daniudi in North China is difficult to determine, a suit of new method has been presented. In this method, parameters for fractured gas wells are provided by well test analysis; Base on matching the well head flowing pressure, the productions of gas wells are forecasted by the unsteady flow formula of fractured gas well; With the stable productivity formula of fractured gas well, the productivities of gas wells are evaluated, then the productions are allocated by empirical method; Combined with the productions came form the stable productivity formula, the numerical simulation is finished, it predicts the stable production; Finally, compared the results of all above methods with the result of single-point, the important knowledge that the rational proration of fractured gas well in low permeability gas reservoir of this area is found. Therefor, the following studies are done: (1) All kinds of gas well productivity testing design methods and testing data analyzing methods are discussed, and their merits and demerits are analyzed. (2) The experimental study of reservoir's physical and percolation property; (3) The finite-conductivity vertically fractured gas well model and its solving process are reviewed, the bottom-hole pseudo-pressure solution of each flow phase are gained. (4) The analysis of pressure build-up test of 10 gas wells and numerical well logging of 7 fractured gas wells are finished. (5) By the bilinear flow solution of finite-conductivity vertically fractured gas well, which is combined with the arithmetic of average temperature and average compressibility, the well head flowing pressures are calculated and matched by program. Subsequently, it forecasts the well head flowing pressures and stable production time of 6 fractured gas wells under different allocated production, and the outputs kept producing for 3 years of wells under constant well head flowing pressure. (6) With the stable productivity formula of fractured gas well, the productivities of 10 gas wells are calculated by program, then the productions are allocated by empirical method. (7) The numerical simulation of 10 gas well are finished, it predicts the stable production time of gas well under different allocated productions and well head flowing pressure, and the outputs kept producing for 3 years of wells under constant well head flowing pressure. (8) Contrasted with the results of single-point productivity evaluation, gas production forecast of fractured gas well during unsteady flow, the productivity evaluation by the stable productivity formula of fractured gas well, the study of single-well numerical simulation.Through our research, following conclusions are acquired:...