Optimization Of Volumetric-fracturing Parameters For Horizontal Wells In Tight Oil Reservoirs

Tight oil is another hotspot of unconventional oil and gas exploration and development in the world after shale gas.It is regarded as "black gold" by the petroleum industry.In recent years,tight oil exploration and development has been extremely active.As an important form of energy supply,tight oil resources have been discovered in most countries and regions in the world.However,the development of tight oil is a typical capital-intensive process,so parameter optimization can minimize the trial-and-error costs of fracturing and provide support for cost reduction and efficiency improvement.In this paper,volumetric-fracturing parameters optimization of horizontal wells in tight reservoirs are carried out from the aspects of volumetric fracturing production capacity prediction,sensitivity of volumetric fracturing capacity and main controlling factors,single well parameter of volumetric fracturing and multi-well parameter optimization.Firstly,the prediction model of productivity of fractured seam network was established by using embedded discrete fracture model(HFM).The capacity after volumetric fracturing was quantitatively described.The model was fitted with CMG numerical simulation software,The fitting effect is better,which proves the applicability of the modified model.Based on the productivity prediction model,firstly,the single factor influencing productivity was analyzed from two aspects of geological factor and fracture factor,then the RSM method was used to sort out the importance of single factor,and the influencing factors of volumetric fracturing capacity Then by comparing different algorithms,CMA-ES algorithm is optimized to optimize single-well fracture parameters(fracture spacing,fracture conductivity,half-fracture length,fracture inclination).Finally,a field model was applied to the examples to get better results and proved the feasibility of this optimization method.Through the research of this paper,the superiority of the embedded discrete fracture model in simulation of the seam network is proved firstly,and then the univariate analysis details the eleven factors including the geological factors and the crack factors Productivity and the matrix porosity,formation pressure coefficient,matrix permeability,fracture conductivity,half-crack length,and crack spacing as the main control factors by RSM method.Then compared the traditional optimization method and the intelligent optimization method proposed in this paper,the advantage of the intelligent optimization method in this paper is reflected from the three aspects of cumulative oil production,NPV,and computer.contrasting the different sewing methods and found that the dumbbell type is a good fabric seam Way.