The Research On Distributing Orderliness Of The Hong75area’s Stratum Stress

The Hong75blocks in Fuyu oil layer is a typical ultra-low permeability fracturedreservoirs, due to the differences in the long-term water development and geologicalcharacteristics makes the uneven distribution of reservoir pressure, and resulted in a greaterdifficulty to the selected of the drilling fluid of adjust wells density and the development ofadjacent program. In this paper, in the light of flow characteristics of the fractured ultra-lowpermeability reservoir of Hong75blocks in Fuyu oil layer, established nonlinear flow model of speciallow-permeability matrix in Fuyu reservoir and consider the coupled dual medium model of crack andmatrix rock. Then proposed the limited formation pressure element calculation method of fracturedultra-low permeability reservoir under the complex boundary conditions in adjustment zone and had beencoupled FEM equations formation pressure distributed of matrix systems and fracture systems forweakened flow equation weighted residual method. Analysis the impact of the distribution to the formationpressure and crack or fault to the formation pressure distribution in Hong75blocks in Fuyu oil layer,obtained the spread range of injection pressure and the dynamic changes of formationpressure after shut-in in Fuyu oil layer. Five single well formation pressure predictionaccuracy rate of90.40%on average, to meet the accuracy requirements of the project. On thisbasis, use this method conducted formation pressure simulation in all Hong75blocks, it canprovide the necessary basis the selected of the drilling fluid of adjust wells density and thedevelopment of adjacent program.