The Roles Of Residual Oil Distribution And The Measurement Of Further Exploitation After Polymer Flooding

Along with Daqing oil field comes into high water cut epoch, the water flooding production will gradually decline, and the proportion of polymer flooding in total production will continually grow. High quality residual recoverable reserves of oil field has nearly already been used up in a short time, what remnant now is residual oil after polymer flooding in middle and high permeable formation and reserves in low permeable or untabulated stratum which difficult to exploit and need high investment. It is especially important to give further exploitation toward residual oil after polymer flooding in order to realize long-term and sustaining development. The key of it is forecast the distributing of residual oil after polymer flooding exactly. In this paper, contrasting experiments between water flooding and polymer flooding of natural core have been done. Open out the EOR mechanism of polymer flooding by nuclear magnetic resonance and core section experiment. It is extending swept volume and at the same time enhancing the microscope oil displacement efficiency. Based on physical simulation, the changing rule of microscope residual oil has been obtained and microscope residual oil of different kinds existent in water flooding has been confirmed. Distributing rule of macroscopical residual oil after polymer flooding has been ascertained combining sealing core drilling well with sedimentary microfacies. At the same time, exploitation and adjusting projects, examining well data and water flooded stratum interpretation data at the past years of three industrialization blocks that have completed polymer flooding such as one and two line of north first block, middle block of north first tract and Duandong middle block of north first tract have been cleared up in this paper. Based on subtle geology study achievement, the control extent of well spacing to reservoir has been anatomized particularly. The exploitation dynamic and effective characters of the whole process polymer flooding block and any kind of well have been completely tracked and analyzed. Effect of every adjusting method and stimulation of production and injection measure in the course of polymer flooding has been studied. The potential and distribution of residual oil have been detailed described using water injection profile, numerical simulation and interpretation data of examining well and water flooded stratum. EOR estimate of polymer flooding to the three industrialization tracts has been done using many methods. Based on in-house mechanism study and statistic analysis of field data, quantitative analysis and synthetically estimate to the effective factor of recovery efficiency have been put up.