The Boundary Element Method In Well Test Analysis In Applied Research

Reservoir geometry and heterogeneities and interference between wells significantly influence the flow field and the pressure transient response in underground reservoir fluid flow. It is very important to study the theory of transient fluid flow and method of well testing interpretation in complex reservoir. According to development practice of these special oil reservoirs, combined the foundational theory of fluid flow through porous media with boundary element method, focusing on the establishing, solving, and computing of the mathematics modal, the analysis theories of well testing in these special reservoirs have been studied in detail by combining fluid mechanics, modern mathematics and modern computation technology. The main works presented in this paper are as followings:(1) The mathematics model of well testing interpretation has been established and solved for homogeneous reservoir with arbitrary geometries, which accounts for wellbore storage and skin effect. On the basis of verifying the result of BEM with the analytical solution of regular shape reservoir, the influence of reservoir geometries, the permeability of boundary, and interwell interference to the bottom hole pressure performance have been analyzed.(2) The mathematics model of dual porosity reservoir with arbitrary geometries has been established and solved, which accounts for the influence of wellbore storage effect and skin effect. Compared with the analytical solution of reservoir with regular geometries, the influence to the performance of bottom hole pressure caused by reservoir geometries, the permeability of boundary, interwell interference, storativity ratio and interporosity flow parameter has been analyzed.(3) The mathematics model of dual porosity reservoir which has arbitrary geometries has been established and the influence of wellbore storage effect and skin effect and impermeable or constant pressure subregion has been taken into account. The influence to the performance of bottom hole pressure that caused by reservoir geometries, interwell interference, and the location and size of impermeable zones or constant zones has been analyzed.(4) The mathematics model of dual porosity composite reservoir which has arbitrary geometries has been eatablished and solved, which concerns the influence of wellbore storage effect and skin effect. The influence to well bottomhole pressure in inner or outer regions caused by mobility ratio and storativity ratio has been analyzed.At last, a set of complete well testing interpretation methods and flowing theory in complex reservoir based on boundary element method has been presented in this dissertation, which has improved and enriched the reservoir engineering theories. The methods proposed in this paper can be used to recognize or evaluate such parameters as the property of reservoir boundary, the length and permeability of fault, the location and range of Ientoid shale, the variety of container rock or fluid properties, the driving range and the advancing front injected fluid.