Effect of heating and shearing history on Changqing waxy crude oil condensation point

Through the simulation of thermal history of the heat stations,shearing action of pumping stations in long-distance pipeline,we carried out an experimental study on waxy crude oil of Changqing oilfield with the shearing an heating action history,analyzed the effect of shearing and heating action on the condensation point of waxy crude oil,and came to the conclusion that heating history is the main factor affecting waxy crude oil. Contrary to medium temperature heat treatment,high temperature heat treatment reduces condensation point of waxy crude oil greatly. Shearing action is the other important factor which affects condensation point of waxy crude oil. Contrary to the shearing rate lower than 200 s-1,the shearing history with shearing rate higher than 400 s-1would reduce condensation point of waxy crude oil. After both the heating and shearing history action,short time,low or middle shearing rate action would result in a minor influence on the condensation point of waxy crude oil which is on the contrary to high or low temperature heating action. But long time shearing action would reduce condensation point of waxy crude oil greatly,and the integration of high temperature action and high shearing rate treatment would be the best effect on reducing condensation point of waxy crude oil. And lastly the appropriate temperature of heat treatment should be higher than 60 ℃ in long pipage transportation of Changqing waxy crude oil,pump shearing rate should be higher than 200 s-1.