Heavy oil cold production gathering process after reducing viscosity through reinjection of hot water in Changji Oilfield

The reservoirs in Changji Oilfield feature high viscosity of crude oil and mid-low permeability. The long-distance pipeline gathering process would face problems like high back-pressure at wellhead and oil gelled in pipe. While the gathering process using road tanker to transport the wellhead's tank-packed oil to central processing station would encounter problems including difficulty in unloading oil from the road tanker, high energy consumption in tank electric heating, high freight of loading/unloading oil, inconvenience of inspection management and disruption of continuous production of crude oil and so on. In view of these problems, the gathering process using reinjection of hot water to reduce the viscosity is applied in Changji Oilfield to realize heavy oil's pipeline gathering, and the operation cost of per ton is reduced by 46%. This paper discusses the problems of this process found in the actual operation and puts forward solving methods, such as free of thinner, each water reinjection station worked with gas-fired water-bath heaters, associated gas to displace CNG as the fuel of phase change heater, which has gained both economic and social benefits.