Evaluation Of Cold Injury Degree Of High Condensate Oil Reservoir And Study On Measures To Improve Recovery Efficiency

Shen 84-An 12 block is the main block of high-condensate oil in Liaohe Oilfield,which has the characteristics of high wax content and high freezing point.The development of conventional water injection will cause paraffin to precipitate out of the crude oil and block the reservoir medium,causing irreversible reservoir s damage.At present,the 12 high-condensate oil reservoirs in Shen 84-An are in the late stage of water injection development,and the development challenges such as difficulty in water injection and low oil recovery rate need to be solved urgently.In this paper,the waxing point,freezing point and melting wax point of gas-containing high-condensed oil were measured by laser method at different pressures,and the effect of pressure and shear rate on the rheology of crude oil was studied using a high-pressure capillary viscometer.High shear rate can inhibit wax crystals Inter-connected with each other to effectively reduce the viscosity of crude oil;through the inversion of wax deposition amount at different temperatures,the wax deposition amount prediction model was established to quantitatively evaluate the degree of cold damage of high-condensate oil reservoirs at different temperatures.Laboratory experiments of hot water flooding with different temperatures and ternary compound flooding were conducted to evaluate the reservoir development effect,and the feasibility of ternary compound flooding to improve the recovery of high-condensate oil was evaluated.It is recommended that the reservoir should be kept above the saturation pressure and high oil recovery rate during the development process,and the early water injection temperature should not be lower than3℃ below the wax precipitation point.Increasing the temperature of the injection liquid is conducive to the coordination of hot water and ternary It has certain guiding significance for the efficient development of the site.