Sand production prediction of deep gas wells in Bashijiqike Formation of the Keshen block

Abstract

In order to effectively prevent the occurrence of sand production during the gas well production, rock mechanics tests were carried out for a deep tight sandstone gas reservoir in Bashijiqike Formation of the Keshen blockk, and the logging prediction models of mechanics parameters were established. At the same time, considering the effect of reservoir pressure and stimulation measures, based on the analysis of stress state of borehole wall and using M-C criterion, the calculation model of the critical production pressure of gas well was established to achieve the purpose of guiding production and improving the gas well production. The results show that the relationship between rock mechanic parameters with acoustic wave and volume density of the Bashijiqike Formation reservoir was studied, and the response mechanism of rock mechanics parameters was revealed, thus the logging calculation model of rock mechanics parameters was established. Based on the drilled fracturing and logging data, the multi-parameter prediction method of the formation pore pressure and the in-situ stress calculation model were established. The critical production pressure has also been significantly reduced, and the risk of sand production in gas wells increased significantly. After water immersion and acid fracturing, the compressive and elastic modulus of the rock samples decreased obviously, and the maximum decrease of the critical production pressure of the reservoirs in the study area reached 9 MPa. In order to ensure the safe production, it is necessary to supplement formation energy or take more effective sand control measures in the study area. The research results can provide guiding significance for gas well production allocation in this area.