Study On Evaluation Method Of Low Permeability Gas Reservoir Productivity In Xihu Depression

In recent years,the level of oil and gas resources has been gradually improved,and the degree of exploration and development has been increasing.As a result,the reserves of conventional oil and gas resources have been decreasing,and the low permeability gas reservoir has become the main force of increasing production efficiency.The S-gas reservoir in the Xihu depression is a typical low porosity and low permeability gas reservoir.Due to its poor physical properties,drilling and completion of the reservoir damage and other reasons,there is a phenomenon in S-gas reservoir.The well logging results show a good level,while the test capacity is very low,and the test success rate is not high,which makes production is difficult to get evaluated effectively and correctly.In order to understand the reservoir better,fully exploit reservoir potential,facilitate production conveniently,it's important to have a systematic and applicable productivity evaluation method.Based on the comprehensive investigation and comprehensive understanding of domestic and international production capacity evaluation methods,the seepage characteristics of S-gas reservoirs are analyzed.and the equivalent seepage resistance method is used to establish a variety of well types(vertical wells,Horizontal wells,directional wells)in a variety of completion methods(openhole completion,naked eye perforation completion,casing perforation completion,fracturing completion,etc.)under the production capacity prediction model,and its calculation accuracy verification.On the basis of this,the influence law of well type,completion mode and various process parameters on production capacity is studied and summarized.The epidermis coefficient is decomposed and the main factors causing damage to the reservoir are analyzed the reason.The results show that the proposed method is less than 15% and can meet the needs of field calculation.Integrated theoretical research results,the "low permeability gas production capacity prediction and test method optimization" software has been established.A set of comprehensive production productivity evaluation method has been compiled,which can evaluate the production produtivity from three aspects and choose the test method in a number of ways.