ANALYSIS OF IMPACT OF INJECTION WELL CAPACITY ON SELF-INDUCED HYDRAULIC FRACTURE DEVELOPMENT

Abstract

As experience in field development shows, unplanned growth of injection well cracks does not always have a positive effect on the development of oil reserves, but, on the contrary, causes premature flooding of producing wells. Currently, most of the fields are at the final stages of development, and an increase in reservoir coverage by flooding is an important task of developing oil fields. The article discusses and analyzes the effect of injection well capacity on the growth of self-induced fracturing fractures and the relationship with oil production on the example of one of the fields in Western Siberia. Using the hydrodynamic simulator and the geomechanical module, the best option was chosen and the positive effect was evaluated. An example is a production well of a highly watered stock. The reasons for the premature well flooding are considered by analyzing the graphical dynamics of capacity and flow rate of injection and production wells. As confirmation of the fracture growth or closing, the results of the adaptation of a single-layer two-phase model using the automatic hydraulic fracture are presented. The analysis of the geomechanical properties of the layers was carried out, during which the dependence of the crack length on the bottomhole pressure was determined. This dependence is compared with the results of the model adaptation. According to this adaptation of the hydrodynamic model, several variants of calculations were made in order to identify the optimal bottomhole pressure and compare this variant with the actual one. According to the data obtained, it was found that with optimal injectivity, a positive effect was observed already in the first month. The information obtained during the analysis of actual data and calculation on the hydrodynamic and geomechanical module, confirms the need to control bottomhole pressure at injection wells. Calculations show that there is a significant loss of oil production after the crack has opened. Using a calculation on the geomechanical module, optimal bottomhole pressures were given for a given injection well, at which there would be no increase in the crack of the injection well followed by watering of the production well. Calculations to determine the optimal values of the bottomhole pressure of the selected injection well can be applied to the wells of other fields.