Study On The Enhanced Liquid Mechanism In High Water Cut Stage Of Putaohua Oil Layer Of Shengping Oilfield

In Putaohua oilfield of Daqing the eighth oil production factory, as the less layer number of single well and poor production replace capacity, the well production decreases, the water cut rises fast and the efficiency and utilization ratio are low after the main layer postwaterflood, which cause recovery percent of partly block is low, composite water cut is high and the difficulty of further improving water flooding displacement efficiency is great. Shengping oilfield has entered into high water cut stage, so it is urgent to explore new ways of raising water flooding displacement efficiency technology. Therefore, it is essential to study the enhanced liquid mechanism in the high water cut stage of Putaohua oil layers of Shengping oil field, which points out a new clue and approach for improving oilfield development result in high water cut stage of low permeability oilfield in the peripheral part of Daqing and implementing the redevelopment of maturing field.On the basis of analysis of the reservoir characteristic and fluid property and the current waterflooding development, according to existing research results, combining the petroleum reservoir engineering method and the laboratory physical simulation experiment method, the enhance liquid mechanism is studied, the feasibility of implementing enhanced liquid in Shengping oilfield is demonstrated and the reasonable opportunity of enhanced liquid is between 60% and 95% water cut and the best opportunity is 65% ; the relationship of liquid withdraw rate and oil recovery rate is further studied and based on Logistic cycle, a model of relationship between water cut and time is established, through the field historical data fitting, the reasonable oil recovery rate of the next year is determined that is 0.66%; the inflow performance lower limit curve of different water cut stages is plotted, the maximum liquid and oil production and other main technical indices are given; under the condition of bound water, threshold pressure gradient of natural core of various permeability are determined by indoor experiment; through homogeneous core and heterogeneous core experiments, the relationship between water cut and degree of reserve recovery and the changing law of the oil displacement efficiency at different injection pressure, injection rate and PV conditions are studied, and the best displacement rates of the homogeneous and heterogeneity core experiments are optimized that is respectively 25ml/h and 20ml/h.