Studying Of Productivity And Optimized Well Pattern For Horizontal Wells In Low Permeability Reservoirs

Now, the exploratory development of low-permeability oil and gas is one of the main trends of global oil and gas development, which have become the main battlefield of oilfield exploration. However, the difficulty, such as non-response or poor-response of inject water, low-levels of production (most well stable at It or less), low recovery, poor development results and high cost conditions would be a technical challenge in the exploitation of low permeability reservoirs. In this dissertation, it carries out production forecasting with Longitudinal fracture, the optimization design of single factor in well pattern the overall fracture parameters of well network, advanced injection and other aspects of the application of horizontal wells in low permeability, obtaining the following conclusion and the understanding:1) Summarized the method of forecasting the early stages production in low permeability reservoirs with horizontal wells, and analyzed domestic application and development of well pattern and advanced injection in low permeability reservoirs.2) According to many academics about productivity formula of horizontal wells, sorted out horizontal well productivity calculation methods under various conditions for low permeability reservoirs.3) Considering the shortcomings of early breakthrough time and water cut rising faster with transverse fractures, recommended longitudinal fractures along a horizontal well avoiding the quickly water.4) Based on the parameter of formation and fluid in Zhou 6 Wellblock in Daqing Oilfield, and with the index of oil production per day, recovery, water content,used the reservoir Numerical simulation to evaluate fractured horizontal well performance for scale of the injection well, the number of fractures,the position of fracture.5) Based on the fracture parameters in well patterns, from composed of different levels of standard length, well spacing, row spacing, the number of fractures, and a half crack length of water wells by orthogonal optimized design method, summarize the parameters as that:Form the relationship between water content and the effective recovery and the range analysis method, we derived:standard length, row spacing have greater impact on the well network, followed by the number of fractures, well spacing, well semi-crack length on smaller, so The optimum level of each factor level were length of 600m, row spacing of 80m, the number of fractures are 4, well spacing of 50-80 m, well semi-crack length of 50-70m.6) According to the experience of similar reservoir conditions and numerical simulation, we have a water injection technology research.of rational bottom hole pressure, the maximum injection pressure of injection wells, advanced injection timing, the maintaining level of formation pressure, reasonable injection-production ratio, reasonable production rate.