关键词: 试井分析, 垂直裂缝, 有限导流, 椭圆流, 模型

Abstract: The approximate solutions of the elliptical flow model for wells with vertical fractures with a finite conductivity are further studied.It is found that there is a greater difference between the calculations given in this paper and the Cinco－ley's calculations.It is made clear that the weighting factor W is the function of the dimensionless fracture conductivity coefficient F_CD and other parameters.The relation curve for F_CD and W with the dimensionless wellbore storage coefficient,C_WD=0,and the fracture skin factor,S_f=0,is presented.The computation dimensionless pressure is compared with the results presented by Cinco－ley.It is concluded that the calculations much approach to the Cinco－ley's ones when F_CD>=1,and the calculations are incorrect when F_CD<1.The improved formula are proposed finally.Analyses of two examples show that the modified solutions not only keep the advantages of high speed of calculation as the old solutions,but the computation results are reliable.The approximate solutions of the elliptical flow model are practical.Although the approximate solutions of the elliptical flow model for the homogeneous reservoirs are studied,the study method can be of good use for the modification of the approximate solutions of the elliptical flow model in the dual porosity reservoirs.

Key words: well test analysis, vertical fracture, finite conductivity, elliptical flow, model