A Study Of Residual Oil Distribution Of Main Reservoir Group Of Daqing Oil Field After Polymer Flooding

Polymer flooding has played a great role for the high yield and stable yield for Daqing oil-field. At the present time, Daqing oil-field have already entered extremely high water cut period, and production yield for water flooding continuously descends. For the sake of continual development of oil-field, the proportion of area and oil layer for polymer flooding will keep on an increase according to future programming of Daqing oil-field.The study of residual oil distribution for polymer flooding is important to make fully use of the residual oil potential, to enhance oil recovery further, and to direct the succeeding exploitation of areas for polymer flooding since all those measures, such as potential using, APS compound flooding, multiple foam flooding, microbial flooding and surfactant flooding need to predict remaining oil well and truly.This dissertation mainly studied the following contents:1. The mechanism study of enhanced oil recovery for polymer flooding: through contrast!ve experiments of natural core for water flooding and polymer flooding by means of nuclear magnetic resonance equipment and fluorescence ground slice analysis technology, the research shows that not only the spreading volume is expanded but also the displacement efficiency is enhanced, however the displacement efficiency of water flooding is bigger than that of polymer flooding under special circumstances .1. On the basis of physical simulation, the microscopic residual oil variety is gotten, and the proportion of different types of microscopic residual oil that exist during the period of water flooding is ascertained for polymer flooding, furthermore the microscopic residual oil distribution rules are given for different parts of water-invasion intensity which is high, middle or low.3. Vertical residual oil distribution rules are presented by the contrastive data analysis from two obturated coring wells in Duanxi, which are for water flooding and polymer flooding respectively, and the explanation is combined with sedimentary micro-faces. Different micro-faces affect residual oil distribution variously, and residual oil in different parts of the same micro-faces verifies with permeability, perfect degree of injection-production system, and well spacing.4. Residual oil reserve and residual recoverable reserve of BeiYiErPaiXi area are given with different sedimentary unit, different permeability, and different thickness by means of numerical simulation, in the mean time, macroscopic residual oil distribution rules are shown for polymer flooding.