Distributed Parameter System Identification And Optimal Control, And Application In The Simulation Of Geological History

The quantitative research of petroleum geology provides a new way for the exploitation of petroleum and gas. In this paper the geology history numerical simulation model and recognition of deep basin gas accumulations and prediction of quantities of accumulated gases are discussed applying the theory of identification and optimal control of distributed parameter system, in which the forming process of oil-bearing basin is the main research object, in order to simulate the dynamic forming process of stratums especially oil-bearing stratum in geology history in the time and space concept, further to investigate the history of petroleum forming, transmitting,accumulating and predict the distributing rule and scope of petroleum, and offer an rapid, quantitative, exact, general choice for the researcher of petroleum geology.Porosity is the major parameter in the changing course of geological characters. In the second chapter the mudstone porosity non-linear parabolic partial differential equation and its initial and boundary condition are established according to the depositional covering mechanism and the physical and chemical principles in petroleum geology, and the dynamic boundary is dealt synchronously.In the third chapter we convert this non-linear equation to a linear one through some approximation in geology. Then the distributed parameter system identification model is introduced based on this equation. After dealing with the boundary condition according to the theory of domain decomposition, the optimal control model is constructed, in which the porosity equation is the state equation and the data of field survey is the optimal guide line. At last the algorithm of three dimensional geology history numerical simulation is given.The model and algorithm are successfully applied in the "973" National Major Fundamental Research/Development Project of "Formation, enrichment and distribution prediction of oil and gas in superimposed basin of China" in the fourth chapter, The numerical results show the distribution area and the quantity of accumulated gas.A brief presentation of the software system for predicting the distributed area and the quantity of accumulated deep basin gas is given in the last chapter. This software system is designed according to the model of three dimensional geology history numerical simulation algorithm of identification and optimal control of distributed parameter system and the force and matter balance principles of deep basin gas.