Study Of Well-test And The Reasonable Test Parameters For Tight Gas Of Fractured Horizontal Wells

Tight gas reservoir has the characteristics of tight,low permeability and so on.Using horizontal well fracturing technology can significantly improve the efficiency of the gas field exploration.The productivity test and determining reasonable test parameters are important content of gas reservoir engineering and oil-gas recovery projection for tight gas of fractured horizontal wells.Researching on present situation of fracturing horizontal well production in the world represented by Daniudi tight gas field and rich test and production datas,this thesis has mainly analyzed it by the following four parts guided by the reservoir engineering and percolation mechanics theory,test characteristics of tight gas reservoir fracturing of horizontal wells,test influence factors of tight gas reservoir fracturing of horizontal wells,correcting method of single point test formula for tight gas and the rational test parameters of tight gas field for horizontal wells.The main achievements of this thesis are summarized as follows:1.According to the classification of layer and production,change characteristics of test-time,flow-back,oil-pressure and flow-rate in test phase are analyzed,concluded for the further study.2.This thesis studys the influence of flow-back rate of fracturing fluid,test-time and flow-rateon horizontal well test,and thr relationships between flow-back rate of fracturing fluid,flow-rate and open-flow and producing pressure drop which is analyzed,concluded for the further study.3.Though analyzing of liquid loading theory,This thesis studys the influence of liquid loading on reservoir pressure calculation and deliverability equation,and presents two methods of judging wellbore liquid loading,and comes to a conclusion that the fluid can cause abnormal test-data.Further,it also studys the influence of flow-back rate of fracturing fluid,test-time and flow-rate on abnormal test wells.4.To obtain new single point test formulas of different layers from the existing gas well data of single point test,considering actuating pressure gradient and combining with theoretical derivation of productivity formula and tight gas reservoirs gas flow characteristics.Finally the contrast analysis of examples shows that the method is feasible.5.For tight gas of fractured horizontal wells,this thesis calculate different flow stages time using the theoretical formula,and obtained time range of flow stages by dividing the flow phase fluidized through a large number of actual data.The results above were compared with statistical results on the basis of the statistical data of single-point test time from different layers to be verified.At last,the effects is analyzed from view of single point test time impacts on open-flow.