The Study Of Method Of Sand Production Prediction Of Gas Well Considering The Impact Of Production

During the development process of gas reservoir, some serious problems of sand production have often been faced, and substantial manpower and resources will be required to input on researching and controlling, sand production will bury the well bores, abrade the ground and underground equipments, result in cut or stop production, casing failure and so on, seriously it can cause the gas well abandoned. Through theoretical research, it can be found that to predict sand production of gas well can effectively reduce or avoid the hazards of sand production. As the complexity of movement and nature of the underground gas, the sand prediction of gas well is different, in addition to considering the reservoir geologic conditions, we must combine the production conditions and the gas flow patterns etc. to carry on the study of sand prediction theory.On the base of studying the affecting factors and mechanism of sand production of domestic and foreign gas wells, the different affecting factors and mechanism of sand production have been cleared. First, the sand production prediction model of bare-hole gas well has been established combined with the Mohr-Coulomb criterion, by analyzing the distribution of rock stress around the well bore, respectively, considering the formation fluid pore pressure, shapes of Darcy Flow and Non-Darcy Flow of the gas, the impact of the friction drag force generated by the fluid flow. The formation stability index S has been introduced to simplify the forecasting results, the influence rule of rock compressive strength, ground stress, Poisson's ratio, ? m constant on sand prediction has been studied. Then, the spherical cavity model of the perforated completion has been established, the solving formulas of the critical bottom hole flowing pressure and the critical gas production have been given; the sand production prediction model of perforated gas well has been established combined with the Drucker-Prager failure criterion, by analyzing the distribution of rock stress around the perforation in cylindrical eyehole model, the solving formula of discriminant index S of sand production has been given.Summarizing the sand prediction methods of gas well, the sand production prediction system software has been developed, combined with the visual programming language Microsoft Visual Basic 6.0 and SQL2000 database system, this has provided to the sand predicting work some convenience, achieved the digitization of the forecasting results, the uqwntf of the data management, the automation of the production management.