Experimental Study On Three - Dimensional Physical Model Of Carbon Dioxide Throughput In Horizontal Wells Of NP Heavy Oil Reservoir

G104-5block of NP oil field belong to small fault block oil reservoir, it has active edge and bottom water. This block oil reservoir has strong isolation, poor connecting between wells, well control small areas, oil layer is thin, and water-cut rise fast. Furthermore, the oil has its feature:the high viscosity, density and asphaltenes, the low freezing point. All of the above reason results to difficulty to be stably developed for the field and low primary recovery. The theoretic study of CO2huff and puff has become mature and the technology has been widely applied, thus CO2huff and puff is one of the effective techniques to improve recovery to such reservoirs.In this paper, for the first time use the three-dimensional physical simulation to study CO2huff and puff, derived the scaling criteria of CO2huff and puff. Achieve the model and the oil field proportional similar, reflect the effect of reservoir flooding accurately. Use the three-dimensional physical simulation, test and verify CO2huff and puff results, select the optimal scheme, guide oil field application. Provide the evidence to rational develop G104-5block, and provide the assistance to research the theory of control water and increase oil production, provide the reference for our country to widely use the CO2huff and puff to exploit heavy oil reservoir. The main studies are as follows:(1) The paper evaluated the measure results for71wells that have been conducted CO2huff and puff, aiming at some problems in the field operation, such as the process parameters: injection volume, soak time, injection speed and so on, only relying learn from other oil reservior experience. So there need do the study of CO2huff and puff in horizontal wells, especially the three-dimensional simulation study. Establish a scientific process parameters suit this oil reservoir is very necessary.(2) Analyzed the reason of ineffective and poor effective measures in part of wells. Further more, proposed the suggestions:in the fractured formation, propose firstly plugging and then injecting CO2, oil layer is thin and high water content is not suitable for CO2huff and puff, and so on.(3) Built the math model of the CO2huff and puff in horizontal well, derived scaling criteria of CO2huff and puff in horizontal, thus determined dimensionless parameters for the three-dimensional physical simulation experiment, use the dimensionless parameters change the field parameters into the model parameters.(4) Use the dimensionless parameters design and make two groups of three-dimensional physical models. The three-dimensional physical model is similar to G104-5block Ng reservoir for geological characteristics, horizontal well location and length.(5) Aim at the operation parameters that influenced the effect of CO2huff and puff. Conduct the three-dimensional physical simulation. By the experimental results select the optimal scheme. By the scaling criteria change the model parameters into oil field parameters, the results show:the experimental results fully in comply with the oil field data, and it can guide the oilfield application..(6) Do an experiment of GAW (CO2) injection flooding, analysis the result of experiment, compare with the CO2huff and puff, deeply understand the CO2huff and puff mechanism of control water and increase oil production, provide another scheme of rational exploit G104-5block ofNP oil field.(7) According to three-dimensional physical simulation experiment and the results of some another experiments, summarized the mechanism of CO2huff and puff can control water and increase oil production. Include:expand the volume of oil; reduce the viscosity of oil; formed the inside solution gas drive; CO2huff and puff can control water and unclog the oil flow paths.