Study On Water Injection Development Method Of Daqing Peripheral Typical Oilfield With Fractured Horizontal Wells

Now multi-stage fractured horizontal well is an effective technology to develop low permeability and tight reservoirs. It is accepted widely by many large oilfields and they start to do some experimental research gradually. Although the initial production is high, multi-stage fractured horizontal wells are developed in elastic recovery and the production declines fast. It is necessary to supple the reservoir energy effectively in order to keep stable yield. This thesis uses reservoir engineering method combined with numerical simulation technology to research on the effects of different permeabilities between common fracturing and crack net fracturing of multi-stage fractured horizontal well production. Meanwhile, based on Daqing peripheral oilfield, a typical multi-stage fractured horizontal well area was chosen to build detailed geological model to do some research of numerical simulation about the water injection parameters optimization and development law of current well pattern to evaluate the development effect. The main research results are summarized as follows:1.Using low permeability reservoir multi-stage fractured horizontal well unsteady state production forecasting software to study on the fractured horizontal well production in low permeability and tight reservoirs with different factors and different permeabilities. The results show that the fracture number has a big effect on horizontal well production in lower permeability reservoirs and the fracture number has a small effect on horizontal well production in higher permeability reservoirs.2.Based on reservoir engineering method and numerical simulation technology, horizontal well production with micro cracks in low permeability and tight reservoirs is researched to prove that hydrofracturing crack length has a big effect on the production, and the hydrofracturing crack conductivity, micro crack linear density and action width have small effects on the production in lower permeability reservoirs. The hydrofracturing parameters and micro crack parameters have small effects on the production in higher permeability reservoirs.3.Using Petrel to build detailed geological model of typical area. I have completed the production history matching of developed stage and analysed the remaining oil saturation distribution characteristic and the reservoir pressure change situation in this area. I have also forecasted the dynamic production effects. The results show that the typical area is not built an effective driving pressure system and it’s necessary to optimize the well pattern and water injection energy supplement adjustment.4.The fractured horizontal well group’s cyclic waterflooding styles, periods, injection-production ratios and water injection intensities of different water cut stages have been optimized by numerical simulation method and I applied the optimized cases to the actual geological model to forecast the development indexes. Comparing the water cut and recovery percent of the typical area in 20 years comprehensively, the final optimized development case is symmetric cyclic waterflooding and the injection wells open for 1 month then shut down for 1 month. The injection-production ratio is 1.4.