Study On Optimization Of Polymer Injection Parametres And Development Adjustments In Block La8

Nowadays, chemical flooding is one of the main oil recovery techniques at late high water-cut stage in oilfields, and domestic chemical flooding technique has been at the world forefront, which has achieved great achievements in large oilfields such as Daqing Oilfield, Shengli Oilfield, etc. Polymer flooding is a key component of chemical flooding. Polymer flooding can get a higher oil recovery by more than 10 percent than water flooding. It can effectively increase the viscosity of water phase, improve the mobility ratio of displacing phase and displaced phase, enlarge the swept volumes and improve the sweep efficiency. The distribution of remaining oil influenced by the oil layer condition and development condition is scattered and complex at the later development stage with a high increasing water-cut, and it has become a significant issue to precisely determine the distribution of remaining oil, effectively extract it and get a better development effectiveness. The three major contradictions, namely the interior layer contradiction, interlayer contradiction, and plane contradiction, have become more and more obvious, which makes it harder for remaining oil development. Therefore, it is necessary to further increase the oil recovery.The following work has been done aiming at the optimization of injection parameters and adjustments of polymer flooding in Block La8:Firstly, the current development situation of Block La8 has been analyzed, and the curves of liquid production, oil production, water-cut, injection and injection polymer concentration of the central block are plotted; the phased three-dimensional geological modeling of Block La8 based on stochastic model method has been established using Petrel software, and the structural plane and petrophysical property distribution are given; after the matching for reserves based on the geological model, the numerical model has been established through Eclipse software, and the history match of the block and single wells are completed;Secondly, the distribution of polymer concentration is analyzed and the distribution maps of polymer concentration in different layers and at different time are given to analyze the polymer development effectiveness; the remaining oil distribution is analyzed in plane and portrait aspects; the reasonable polymer consumption is studied by numerical simulation and the molecular weight, concentration and injection rate of polymer are optimized based on the current situation of the block;Finally, the schemes including the injection and production adjustment, hydraulic fracturing(implemented on oil wells only and on oil wells and the corresponding water wells), and well pattern refinement(at different time and in different ways) are simulated to predict the development effectiveness and provide a basis to efficiently extract the remaining oil.