Study On Single Well Productivity Evaluation And Control Reserve Calculation Method Of Heba Gas Reservoir In Northeast Sichuan

With the constant exploitation of natural gas,the influx of water is increasing,making the development of water-drive gas reservoirs more and more difficult.The production capacity of water-producing gas wells and single-well controlled reserves are the basis for the optimization of gas well production and drainage processes.Irrational production distribution or drainage processes often result in phenomena such as fluid accumulation in the wellbore and severely affect gas production.Therefore,it is of great practical significance for the development of gas field to study gas well productivity and reserves evaluation in Heba,northeastern Sichuan.Based on the gas-water two-phase flow theory,this paper first analyzes the gas well productivity test data in Heba,northeastern Sichuan,and considers the influence of stress sensitivity on production capacity under abnormal conditions.Based on the analysis of conventional production test data,a new method of variable-coefficient production capacity calculation was proposed.It is not necessary to carry out production test again to obtain the capacity equation with pressure changes in the formation.By understanding the basic characteristics of gas reservoirs in the Hebei area of the northeastern Sichuan Basin,variable coefficient pseudo-stability methods and pressure drop methods were used to calculate the individual well control reserves in the gas reservoirs,and compared with conventional methods for the evaluation of single wells reserves in water-producing gas wells.This design mainly completed the following work:first,based on the productivity analysis of single-phase gas wells,the gas-water two-phase seepage equations were considered,and the stress-sensitive effects were taken into account.At the same time,the gas balance of material balance equations of water-drive gas reservoirs was used to establish gas wells with variable coefficients.The productivity equation can not only obtain single well productivity but also obtain single well control reserves.Then use the calculation method of single well production capacity and dynamic reserves of water-producing gas wells to fit the actual production dynamics data and obtain its production capacity and reserves.Finally,this method was used to compare and analyze the reserves of water-producing gas reservoirs with the methods of geological reserves,unstable percolation and material balance,and the feasibility of the new method was verified.