Research On The Law Of Horizontal Well Effusion And Foam Drainage And Gas Production

Penglai Town, Shaxi temple, and other gas reservoirs in the West Sichuan gas field, which is a typical gas reservoir of tight sandstone with low permeability, strong heterogeneity and high water saturation. With the continuous progress in the development of the gas field, relatively high-quality reserves in shallow layer has been basically used through vertical wells and directional wells, and increasing reserves and production of oil and gas field mainly rely on the reservoir that have the characteristics of "super low porosity and low permeability", and it is difficult to use. for difficult producing reserves, formed development way of horizontal well.For horizontal well, have "two unclear" in production process-unclear effusion mechanism, wellbore flow did not have a clear understanding, "two not supporting"-well bore flow pattern identification technology is not complete, the water drainage and gas production technology is not complete, those lead to the problem of horizontal well pressure and production rapidly decline; first of all, combined with the characteristics of body structure for horizontal well in Western Sichuan gas field, according to the similarity principle, developed the horizontal wellbore visualization simulation device and carried out physical model experimental study; had a clear understanding of the horizontal wellbore flow, first mastered the horizontal wellbore liquid loading rules, cleared the drainage of horizontal well is change the flow pattern of the inclined section and reduce pressure drop loss for inclined section. Secondly, analysed influencing factors on the flow pattern of wellbore, and based on the measured data and the experimental data, had a optimization for wellbore pressure drop prediction model of each section by the computer simulation, build a horizontal wellbore pressure drop the combination forecasting model; used multivariate regression analysis method of mathematical statistics, combined the wellhead oil casing pressure, gas production data with average and maximum pressure gradient, studied the correlation between parameter above and the ratio of wellbore flow, established the production data discrimination method based on field experience; thus realized the prediction of the critical liquid carrying flow rate, pressure gradient and flow parameter analysis for liquid drainage measures of horizontal wellbore, provided the technical foundation for targeted selection implementation. At last, with the characteristics of horizontal well production, the technology of foam drainage gas production in Western Sichuan gas field is introduced, including the optimization of the filling parameter and filling method, and the evaluation of the application effect in Western Sichuan gas field.