The Research Of Steam Injection And Hot-water Injection In Cao Tai Buried Hill Construction Cracks High-condensate Oilfield

In recent years, the method of hot-water injection and steam injection are widespread used as an oil recovery method in heavy oil and condensate oil field exploitation, and have been successfully settled out a number of questions which can not be resolved by the conventional injection methods.Hot-water injection and steam injection are methods of oil recovery which use the high-temperature water or steam as a medium, tarry the heat generated on the ground into the oil reservoirs. To reduce oil viscosity and improve oil mobility, thereby enhancing the oil recovery.Cao Tai Oilfield cracks is a typical high-condensate cracks oil field, according to the geological features and the crude oil physical characteristics of Cao Tai Oil Field, applied methods such as indoor core experiments and numerical simulation and so on, do research on the flow characteristics of the high-condensate reservoirs, optimized the parameters of steam injection and hot-water injection strengthening exploitation, in addition, studied the adaptability of the steam injection strengthening exploitation. The research found that the changes in rheological properties of the crude oil made the seepage process of the high-condensate oil more complicated. Temperature is one of the most decisive factors of the seepage characteristics of high-condensate oilfield. When the experimental temperature is higher than the abnormal point , the crude oil was Newtonian fluid; When the temperature is lower than the abnormal point, crude oil was non-Newtonian fluid. At the same time, if the temperature was lower than the abnormal point, the oil phase permeability was declined when the temperature dropped. The impact factors of the development effect of the steam injection and hot-water injection include geological factors such as oil viscosity, the effective thickness , the reservoir coefficient, the original oil saturation, porosity and oil content ; as well as the process parameters such as the amount of steam injection, the air injection velocity , well braised time, gas injection cycle and steam dry degrees, the speed, temperature, time of water injection. Because the cracks was developed in Cao Tai oilfield, high injection speed will lead to cross flow, earlier breakthrough, and reduce the swept volume .So, 150ml / D is the most appropriate results of numerical simulation of integrated optimization. The reasonable steam injection parameters of Cao Tai oilfield are: the amount of steam injection is 2000ml, the after cycle of steam injection with a to a 10% decline, cycle throughput should not more than five times , steam dry degrees is 70 to 80%, the velocity of steam injection is the 150ml / d or so.The results will provide an effective foundation for the exploitation Cao Tai oilfield .