Experimental Studies On Different Developments Of Low Permeability Heavy Oil Reservoirs

With the consistent improvement of oil field technology, low permeability heavy oil reservoir has become a research hotspot at home and abroad. The low permeability heavy oil reservoirs have characteristic of both low permeability oil reservoirs and heavy oil reservoirs, so it brought huge difficulty to this kind of oil field development. The development methods is of great importance. According to the characteristics of O oilfield, experimental studies on different development methods in low permeability heavy oil reservoirs for artificial full diameter cores were done using the percolation mechanism equipment for heavy oil.According to the oilfield situation, the paper set up an experiment method for low permeability heavy oil reserviors. The comparison of development effect among natural energy exploition, hot water flooding, steam flooding and steam stimulation was made, and the paper researched the effect of permeability, viscosity and other parameters on developmen methods. Experiments show that, for low permeability heavy oil reservior, the effect of natural energy exploition is good. The bottomhole pressure should be maintained 2~3MPa lower than bubble point pressure. The higher the solution gas-oil ratio, the higher the recovery; when the pressure decreasing magnitude is 1MPa, the highest recovery factor would appear. The recovery factor had a good linear relationship with the logarithmic of mobility, the depleted recovery factor of middle-low permeability heavy oil reservoirs could be predicted by the theory chart provided. Hot water flooding is situable for the reservior with viscosity of 50~150mPa.s and permeability higher than 10 mD. It could enhance oil recovery about 45%. The injection speed is 84.96 m3/d. Steam stimulaiton after natural energy exploition is the most siutable method. It is applicable to reservior with viscosity higher than 300 mPa.s. The peak of oil production appeared at 2 and 3 cycle. The steam injection rate is 192~240m3/d. It could enhance oil recovery about 26~36%. The steam flooding after steam stimulaiton is suitable only when the permeability is high with the EOR 25~30%. With the increase of permeability and viscosity, the recovery of all the development methods increased.