Analysis And Research On Dynamic Productivity Of Puguang Gas Field

Influenced by factors such as well depth,high deviation,high hydrogen sulfide content and interwell interference,some gas well test data show abnormal phenomena such as pressure build-up curve dropping at later stage and negative slope of productivity test data,which lead to pressure recovery and productivity test data can not be interpreted,resulting in difficulties in gas well(reservoir)performance analysis.On the basis of the research of Puguang main body test data and the summary of geological results,this study evaluates the quality of the data by statistical analysis of the static pressure gradient test data,flow pressure gradient test data,pressure build-up test data,pressure drop test data,productivity test data,gas production profile test data and saturation test data in Puguang gas field,and carries out secondary interpretation according to production activity.Based on the comprehensive interpretation of gas reservoir productivity data,the productivity equations of different structural parts are determined.According to the flowing pressure of gas wells,the current productivity equation of gas wells is calculated,and the influencing factors of gas well productivity are analyzed.Through the above research,the following understandings are obtained:(1)The data obtained from static pressure gradient test,flow pressure gradient test,pressure build-up test,pressure drop test,productivity test,gas production profile test and saturation test in Puguang gas field are accurate and available,and the data quality is good.(2)Gas production profile data and water saturation test data can be mutually validated,which can explain the contribution of each formation to gas well production and determine the position of gas well water production layer,deduce the variation law of formation pressure and gas well open flow,and consider that the open flow of gas well has a power exponential relationship with formation static pressure.(3)The main body of Puguang presents the pressure distribution characteristics of "high pressure,low pressure at the edge of the structure",and the relationship between wellhead oil pressure and cumulative production is exponential decline.Water content declined in the early stage of development,but increased in the later stage.After water flooding,production and oil pressure declined rapidly in the process of water flooding.(4)In the process of development,the rate of decline of open flow in gas wells is different at different structural locations,and the rate of decline of open flow in low structural locations is the fastest;with the decline of formation pressure,open flow decreases;reservoir physical properties have a significant impact on open flow in gas wells;(5)The order of influence degree of single layer productivity of gas well is gas saturation,formation pressure,reservoir thickness,porosity and permeability.Therefore,gas saturation,formation pressure and reservoir thickness are the main factors affectingthe single layer productivity of gas wells,and these factors should be given priority in the optimization of gas well productivity.