Gas Well Production Evaluation Method and Application in Tight Sandstone Reservoir Based on Pressure Online Monitoring

Abstract

AbstractTight sandstone reservoirs in Member 2 of Xujiahe Formation are main development strata in Hechuan Gasfield. The reservoir seepage mechanism is complicated, and the gas wells are generally low-yield and inefficient due to the influence of liquid accumulation in the wellbore. Due to the lack of a single well measurement process, the production depends on manual splitting, it is difficult to obtain the accurate single well gas and water production, which has a great impact on the follow-up work of drainage and gas recovery. Problems such as untimely measures, deviations in process selection and unreasonable parameter design have led to poor results of drainage and gas recovery measures. By analyzing the seepage characteristics and single well production characteristics of tight sandstone reservoirs, a single well transient production calculation model based on continuous monitoring of wellhead tubing pressure was established. Moreover, considering the influence of well pattern pressure interference, a pressure interference factor was introduced to modify the model to achieve quantitative evaluation of single well production. In the field application of 10 wells in Hechuan Gasfield, comparing the calculated results with the actual test results, the errors of single well gas production and water production were lower than 10% and 15%, which can better meet the engineering application. This method can quickly and accurately determine the instantaneous production of a single well under unmetered conditions, and can provide technical support for the dynamic analysis of unstable gas wells in tight sandstone reservoirs, the optimization of the potential of measures, the formulation of measures and the evaluation of the effects of measures.KeywordsTight sandstone reservoirSeepage characteristicsOnline monitoringPressure interference factorProduction evaluation