Study On Porosity And Permeability Of Complex Reservoir Inversion

Inversion of Porosity and permeability is a difficulty and focus of the current exploration,according to the porosity and permeability of reservoir can be quantitative interpretation and evaluation.Paper aim at the difficulty and drastic issues with the demand of Marine complex reservoir exploration,to use the BISQ and Biot theory model and to establish complex reservoir geophysical model.Meanwhile it put forward a kind of hybrid particle swarm optimization algorithm(PSO-SA)of high efficient and powerful search ability,which joint calculate seismic data for porosity and permeability.finally,the reservoir is explained and evaluated.This paper discusses the theory of porous media,the numerical simulation method and the inversion algorithm research and development at home and abroad,and research the theory of elastic wave propagation and BISQ,Biot theory model,and set up geophysical model of porous media based on the complex reservoir.Then,this paper studies the seismic wave reflection and transmission relations in porous media,and has carried on the finite difference method of wave field simulation,and describes the slow p-wave in porous media,to illustrates the validity of the Biot theory;Based on porous media seismic wave propagation theory,paper studied forward modeling of reservoir parameters of porosity,permeability,saturation,characteristic length of jet flow with the relationship of between frequency and seismic wave velocity and attenuation,and analyzed the change trend and sensitive degree.Thus,the parameters of reservoir parameter inversion research has important guiding significance.Moreover,this paper studies the nonlinear inversion mixed particle swarm optimization based on simulated annealing algorithm,that is compared with the single particle swarm algorithm which has higher convergence speed,convergence precision and increasing stability.To the wedge model inversion,there is the expected effect.Through test and analysis,the PSO-SA algorithm calculation cost will be increased,but the global search ability and convergence precision is improved,through setting up reasonable population scale and the simulated annealing disturbance frequency,number of annealing and boltzmann factor,which can make the hybrid optimization algorithm has strong search ability.In this paper,the optimization of porosity and permeability inversion method,can avoid the complicated matrix gradient calculation.The nonlinear mapping relationship is established between seismic data and the porosity,permeability.Paper use the proposed nonlinear inversion algorithm of particle swarm hybrid optimization to deal with actual seismic data and to acquire porosity and permeability.The drawing section and plan of porosity and permeability fron inversion results,which is good tallies with the actual logging data,proved that the inversion results believable degree is higher and has obtained the good application effect.In this paper,a set of wave field numerical simulation and analysis based on the theory of porous media and nonlinear inversion method of reservoir parameters are developed.The effect of practical application shows that this method has high reliability for the inversion of reservoir parameters and provides important and accurate reservoir parameter support for oil and gas prediction.