Study of Factors Affecting Fouling in Near-Well Zones and Wellbores of Shale Oils

Since the development of shale oil horizontal wells in Changqing oilfield, the scaling problem in the near-well zone and wellbore area has been gradually serious, which affects the pump checking cycle and mining efficiency to a certain extent. In order to clarify the main influencing factors of corrosion and scaling in oil wells, based on the changing rules of pressure, temperature and flow rate in the near-well zone and wellbore, a scaling simulation device was designed to simulate the formation conditions, adjust the temperature, pressure and flow rate, and carry out the same-media continuous repulsion experiments, so as to study the influence of different factors on the scaling situation. The results show that the fouling amount in the near-well zone and wellbore is positively correlated with the temperature and negatively correlated with the flow rate; the fouling amount in the near-well zone is negatively correlated with the pressure, while the fouling amount in the wellbore is positively correlated with the pressure; the fouling mainly concentrates in the near-well zone and the middle and lower part of the wellbore, especially in the area of high temperature and high pressure and the area of tubing diameter change; the fouling in the wellbore is more severe than the fouling in the near-well zone.