The Research And Application On Molecular Deposition Film Flooding Technology In Niu 12S₁^m Block

MD (Molecular Deposition) film flooding is a new tertiary oil recovery technology. In the early test,some of our oil fields have achieved good yield. Liaohe Oil field Niu 12Si oil group was in trial mining in 1983, and formally put into development in November,1984.Before using MD film flooding, water cut was 93.99%, and production declined. By changing the displacing medium, MD film flooding technology is proposed. The performance of MD film is evaluated. Through laboratory experiment, the injection parameters are optimized. Combined with the experimental results and actual situation, the MD film flooding scheme in the Niu 12Sim is made, and the oil displacement effect is analyzed.The first and second chapters of this paper mainly introduce the mechanism of the MD film flooding technology and research development.The third chapter evaluate some physical and chemical properties of MD film,and some of its oil displacement mechanism is verified. In the fourth chapter, the oil-water relative permeability curve is tested and drawn through the displacement model of experiment, and the oil displacement efficiency is tested in order to understand the characteristic of the displacement.In the chapter fifth, through a series of flow experiments, the MD film flooding displacement efficiency is determined under different conditions, and the injection parameters are optimized.In the sixth chapter, oil displacement solution is made and implemented, and the displacement efficiency is analyzed and evaluated.The surface tension of MD film and CTAB solution of different concentrations are determined.Compared with CTAB solution, the surface tension of MD film does not change with the concentration of the solution basically, proving it not surface active substance.The viscosity of different concentrations of MD film and HPAM solution is determined. The viscosity of MD film solution has little change with concentration.MD film has good thermal stability and corrosion resistance.The adsorption quantity of MD film is tested on the surface of the oil sand. Adsorption of MD film increases with the increase of the solution concentration. When the concentration is 800mg/L, the saturated adsorption amount is 11.68 mg/g, and the adsorption equilibrium time is about 8 hours.The MD film solution to surface wettability change is researched by the contact angle method. MD film solution can make lipophilic glass surface shift towards hydrophilic, and hydrophilic towards weak.The wettability of core slices is researched. before processed by MD film, most of the core are lipophilic. After processed by MD film, contact angle decreases, and the surface wettability is shifted towards hydrophilic. After processing, the wettability of the core slices of intermediate wet or hydrophilic is changed to weak hydrophilic. Its change is smaller than the lipophilic ones.The relative permeability curve of the core by water flooding and MD film flooding is tested by steady state method.The residual oil saturation of MD film flooding is reduced by 7.4%than water flooding,and the oil displacement efficiency increases by 7.2%.The isotonic point of the curve moves to the right, and oil-water two phase zone widened, indicating that the injection of MD film made crude oil flow easier,so it improves the oil displacement efficiency.Through a series of MD film oil displacement efficiency experiments, oil displacement effect of different cores is tested. In laboratory experiment, oil displacement efficiency of the reverse rhythm in-homogeneous cores is the largest rise compared with water flooding, which related to its internal heterogeneity. The oil displacement efficiency of natural cores can be increased by 10%than water flooding.In the process of oil displacement, water cut declines and injection pressure drops.In order to determine the optimal injection parameters, laboratory oil displacement efficiency experiments are tested. Firstly, the partition coefficient of MD film in the water-oil is determined in Niul2 area, and the results show that the "dissolution" quantity in the crude oil is small. The concentration increases will not make the "dissolution" quantity increase a lot. Then,compared with the oil displacement efficiency of different MD film concentration as 50 mg/L,100 mg/L,200 mg/L,400 mg/L,600 mg/L,800 mg/L,1000 mg/L, or 1500 mg/L, the laboratory experiment shows that good effect was achieved in 600 mg/L, and the oil displacement efficiency increases by 8.97%; When water cut are 60%,70%,80%,90%,98%, MD film is injected. The oil displacement efficiency increases with the decrease of water cut, suggesting that the earlier injecting, the better the results; Compared the oil displacement efficiency under four different ways of injection:continuous injection, high concentration and small slug, low concentration and large section of the plug, stepwise slug, the results show that the way of low concentration and small slug or continuous injection is better. Also the effect of salinity on oil displacement efficiency is investigated, the results show that salinity effect on oil displacement efficiency is not big, and salinity increase will increase the oil displacement efficiency in small amplitude.This paper introduces the situation of reservoir structure and present development of Niu 12S1 in Liaohe oil field. Combined with the laboratory experiment and field practice, it determines the concentration 700 mg/L and continuous injection 60 days.The injected amount is 68.It totally. Produced fluid does not contain MD film. Most Wells begin to see the effect in a month. During the review period, accumulated oil yield is 1461.6t and gas 98.3465×104m3.Injection pressure is dropped a little, and the water cut is generally lower.Phase input-output ratio is 1:4.3.