The Forecast And Control Of Dynamic Targets With Polymer Flooding

Polymer flooding has been gained industrialized application on large scale in the Chinese oil field since the bottom of last century. In order to select displacement tracts under polymer flooding and displacement occasion, predict displacement effect and ascertain optimum control projects above the ground, based theoretic research and pilot tests and combined gained data of actual exploitation, this paper systematically studies prediction and control methods of dynamic indexes such as pressure, output and etc under polymer flooding.1 .This paper establishes predicting models of displacement pressure under polymer flooding of single injection and production well, studies one injection well pressure change situation with one production well, determines pressure distributing among injection and production well and corresponding relation between output and flow pressure of well bottom, so forms theoretic thought in establishing mathematic models of displacement oil under polymer flooding at center of pressure. According to forecast effects of random selected displacement oil well pressure under polymer flooding and output predict results, this method has high predicting precision, and roundly incarnates complex factors in actual production process, predicts oil well influent trends in different production phases, and provides dependable bases for optimum select of displacement oil well pumps under polymer flooding and adjustment of work parameter.2.This paper adequately considers heterogeneity, especially many characteristics at simultaneously exploiting multi-well and multi-layer, establishes predict models of displacement pressure distributing under polymer flooding to heterogeneity and asymmetry distributing oil field, and forms foreland boost theory and connection between injection pressure and injection quantity of flooding liquor. Based of above method, we can select optimally occasion of shot holes and mended holes with injection and production well, enlarge areas of displacement oil under polymer flooding, and improve effect of oil flooding.3.Aimming at the characteristic of polymer injection system having large scale, more variables and parameters, and correction and varies of structures, methods of theoretic analyze and system identification is used, mathematic models of polymer injection stations, injection allocation rooms and pipelines basic units are built. Afterwards, The hierarchical coordination theory of largescales systems is applied, large polymer injection system is divided into a series of subsystems, sub-area basic mathematic models are established, and usual models adapt for optimum operation are gained. With the model, we can expedite convergent speed of iterative operation and reduce modeling and program workload of large polymer injection system.4. Optimum scheme of polymer flooding system above ground is determined, basic theory of subsystems searching optimum is put forward, optimum running policy of large polymer flooding system is formed, control object function and restrict conditions of polymer flooding system is defined, solving models are built, iterative arithmetic is studied, iterative steps of subsystems and large systems is given, validity of optimum policy and astringency of control arithmetic are proved, and a integrated optimum control theory with large polymer flooding system is established accordingly.5.This paper selects Daqing oil field as object, marked off sub-area with polymer flooding system above ground according to low and high pressure, and solves the number of start-up pumps in pump station. In order to accord with actual situation of polymer injection system, the paper had iterative calculation to whole pipeline networks, gains pressure and flux of each knot in networks. Considering affect of some injection station staggered stopped run, networks united method which made total subsystems number reduced is studied and applied without altering arithmetic. The running effect of programmed software based above arithmetic indicates that the metho...