Abstract:

Tahe Oilfield is an ultra-deep and ultra-heavy carbonate oil reservoir, which needs to mix with dilute oil to decreasing viscosity The mechanical lifting method is mainly hydraulic feedback heavy-oil pump and heavy oil electric pump. As the development of heavy oil enters the middle-high water cut period, the existing processes are facing the problems of water-cut emulsification, corrosion and scaling, high abnormal rate and poor economic benefit. It is urgent to seek more efficient and economical recovery technology. According to the lifting characteristics of heavy oil wells with water cut, the solution is found from the thought of process optimization and technology substitution. The screw pump is optimized to replace the old pumps, and the water-soluble viscosity reducer is used to replace the dilute oil. Therefore the heavy oil recovery technology by the combination of ground driven by screw pump and water soluble viscosity reducer is formed. Through the application of 6 wells, the average lean ratio decreased by 0.3, for single well per day in average, 4.9 tons of dilute oil are saved, and 3.8 tons of oil are increased. The success of the field application proves that this technology has the advantages of strong adaptability, good application effect and outstanding economic benefit for water-bearing heavy oil wells, and further widen and improve the technical system of high efficiency development of heavy oil.

Key words: ultra-heavy oil, sulfur resistance, screw pump, water soluble viscosity, heavy oil recovery