Numerical Simulation Study Of Volume Fracturing In FN4 Ultra-Low Permeability Reservoir

With the sustained expansion of China’s economic weight and the burgeoning demand for energy,while the conventional oil and gas resources are declining and the contradiction between supply and demand is sharpening.Accordingly,the unconventional resources represented by ultra-low permeability reservoirs will become the alternative.So far,the "horizontal well + volume fracturing" has enabled the successful development of this new energy.However,there are several difficulties to be solved,such as the seepage characteristics of volume fracturing horizontal well,key points of simulation,sensitivity analysis and optimization of the volume fracturing parameters,which affecting the productivity and development,even the overall deployment for volumetric fracturing horizontal wells.Therefore,revealing the seepage characteristics of volume fracturing horizontal well,summarizing the key points of simulation,deriving the sensitivity and optimization scheme of parameters and making the overall deployment of volume fracturing horizontal wells are of great significance to enhance the national strategic security of energy.According to the reservoir geology,seismic and logging data of the ultra-low permeability reservoir in FN4 of the Xinjiang Oilfield,this paper established the geological model,physical model and mathematical model of the volumetric fracturing horizontal well.Then,key points of simulation were summarized,considering the artificial fractures and characteristics of low-permeability reservoirs.Besides,with the homogeneous model and numerical simulation orthogonal test,the sensitivity of eight parameters influencing production capacity and development were found.Further,seven volume fracturing parameters of the FN4 sub-model,including horizontal well direction,well spacing,horizontal section length,fracture length,fracture interval,fracturing fluid volume and discharge capacity,were optimized by CMG and DK-LS-LGR.In the last,referring to the above design for the parameter optimization,the overall deployment for volume fracturing horizontal wells in FN4 model was further studied.Based on the detailed theoretical analysis and numerical simulation studies of the volume fracturing of ultra-low permeability reservoirs in the FN4 of Xinjiang Oilfield,the future exploration and development of ultra-low permeability reservoirs will be guided and accelerated by these research achievements to some degree.