Research On Seepage Field Of Changing Low Permeability Reservoir Well-net For Wuliwan No.1 Oil Field

Due to the production Wells in low permeability reservoir are required fractured, the seepage field is different with higher permeability reservoir. This paper conducted physical simulation and numerical simulation for three networks of Wuliwan no.1 field. Through the research of the seepage field of low permeability reservoir, we get the law of the distribution and formation mechanism of the residual oil, what offer references for the later production adjustment. By theory of multi-well interference and means of image theory and potential superposition principle, this paper gets three units for three well-nets, and then flat panel visual simulation is carried. After that we carry through numerical simulation. Through this study we get the following conclusions:1.It is radial flow near the injection wells in the low permeability reservoir, and the waterflood front is fan-shaped forwarding. When the waterflood front get to the fracture of production well, the injection water breakthrough along the fracture. Sooner the production well produces water, and the FWCT rapidly increase. In the process of simulation, we can see that the waterflood front on both sides of the fracture produces significant separation.2. Bottom hole pressure near the injection wells is very high, and there will be got an inverted pressure drop funnel. Bottom hole pressure near the production wells is very low, and there will be got a pressure drop funnel. For the inverted nine-spot pattern, pressure drop funnel of the brim wells is more obvious than corner wells' And there will get low pressure at the direction of the connection of production wells.3. The streamlines occurred change near the fractures, and they concentrate to the fracture, the fluid flow into the fracture and then along the fracture into the production well. The streamlines is sparse away from the injection wells and production wells, where will tend to form large not swept remaining oil for lack of hydrodynamic. The results of numerical simulation show that when the FWCT is 70%, the Rectangular pattern's areal sweep efficiency is 62.74%, the Diamond-shape inverted nine-spot pattern's areal sweep efficiency is 67.88%, and the Square-shape inverted nine-spot pattern's areal sweep efficiency is 68.42%.