Theoretical Study Of Well Testing Analysis Of Eccentric Well In Reservoir

Well test is one of the important means of dynamic description and dynamic monitoring of oil and gas reservoir and has become an important part of oil and gas exploration and development.It can be used to determine reservoir physical characteristics,reservoir boundary,pressure system,reserve forecast and production capacity of reservoir.However,the existing theory of well test analysis is based on the fact that the well is located in the center of the formation,and there is no research on the deviation center of the well.In the actual production process,due to the complexity of oilfield formation conditions and uneven distribution of well network,the well is not located at the center of the formation,so it is necessary to study the problem of eccentric well.The main content of this paper includes:(1)Basic on the continuous point source function solution in homogeneous infinite formation,using the mirror image and superposition principle and poisson equation,combined with the characteristics of the eccentric well,we can obtain the basic point source solution of the eccentric well.(2)A well testing mathematical model in homogeneous and dual-porosity oil reservoir of eccentric well considering wellbore storage effect and skin effect under different outer boundary conditions has been built.The method of Laplace transformation and point source function has been used to solve the math model.Using the programming software,the dimensionless bottom-hole pressure and its derivative double logarithmic curve for eccentric well model have been obtained.Discuss the characteristic of curve and analyze its influential factors through the control variable.(3)A well testing mathematical model in homogeneous and dual-porosity composite oil reservoir of eccentric well considering wellbore storage effect and skin effect under different outer boundary conditions has been built.The method of Laplace transformation and point source function has been used to solve the math model.Using the programming software,the dimensionless bottom-hole pressure and its derivative double logarithmic curve for eccentric well model have been obtained.Discuss the characteristic of curve and analyze its influential factors through the control variable.(4)Using Saphir,a well-test software,to calculate the results of numerical solutions of the above four models,and the numerical solution is compared with the analytical solution to figure out the result is correct or not.(5)Use the established model to interpret the field data.Through the study of the theory analysis of well test interpretation model,we can know characteristics of bottom-hole pressure dynamic response better in fractured horizontal well with different kinds of reservoir,which can provide theoretical guidance for well test interpretation in practical work.