Study On The Interpretation Method Of Formation Pressure In Polymer Flooding Of 5-Spot Well Pattern

In this paper, we study blocks west development zone in northern sal figure of pure oil region. The block polymer injection development since 2010, after the oilfield comprehensive investment development, the well pattern in mining area, well spacing density is big, narrowing the distance between the well, inter well interference is more and more serious, nearly 70% of pressure buildup curve not a straight line segment, using conventional well test method is measured by the average formation pressure on the high side and inaccurate, explain the formation pressure, there is a big error affects the overall understanding of blocks and deployment, does not apply to water drive development conditions, the interpretation of the formation pressure under the condition of polymer flooding. Therefore, can find out the accurate interpretation area well pattern of average formation pressure for polymer flooding method, as the primary problems needs to solve.Form, this article analyzed pattern on supply pressure and drain of the reservoir area and the pressure solution and the effect of viscosity of polymer flooding is analyzed on the cause of the average formation pressure, and the change law of viscosity of polymer solution in between oil and water Wells. In the polymer flooding model to join the relation between the effective viscosity, so as to solve the problem of non-newtonian fluid viscosity is not constant. From the direction of the inter well influence in the area of well pattern, specific analysis and explain the conventional well test interpretation method is not suitable for the cause of the area of well pattern and explain the reason of the result on the high side. Put forward the five point well pattern of average formation pressure interpretation theory, based on the superposition principle of potential is deduced from the well potential, deduces the relationship between the various pressure, as well as in the five point well pattern of the relationship between the radius, Solving method of average formation pressure in considering the pattern shape, the influence of the surrounding oil Wells; Extrapolation is established in the late point pressure and the calculation method of using the extrapolation points at the end of the pressure solution of formation pressure, extrapolation is given at the end of the physical significance of point pressure, well test pressure build-up curve is given no straight segment, the interpretation method of formation pressure; Considering the distribution of power law fluid in formation viscosity difference, the power law fluid approximation considered the viscosity changes of Newtonian fluid, thus deduced the consider Newton fluid viscosity distribution to solve formation pressure for polymer flooding, the interpretation of the method.