Study On Non-Stop Pump Desanding And Sand Cleaning Technology In Offshore Oil Wells

The efficient exploitation of offshore oil wells is of great significance to provide a solid foundation for China's economic development. China's offshore oil development has been for decades, and the China's offshore oil development and onshore oil fields are similar to the existence of oil well sand production problem. According to the general technical requirements, the oil field usually used "strict guard"approaches such as sand control pipe to sand control. But this kind of sand control method can reduce oil well output capacity, in addition, with the increase in mining time, the sand filter screen that was often used in oil field will be damaged after being used for a period of time, causing the sand still be into the pump, causing wear and tear, resulting in pump maintenance cycle shortened and the cost increase. In order to improve the recovery rate, the traditional way of "strict guard" sand control had shifted to the manner of "moderate sand". "Moderate sand" control measures relaxed the control of sand into the wellbore, allowing part of the smaller size of the sand discharged with the produced fluid. Therefore,this sand control measures solved the problem of "strict guard" sand control scheme's lower offshore oil field output capacity that was caused by too strictly limited oil well sand production. But at the same time, this measure also made the sand content increase in produced fluid, causing wear and tear, resulting in pump maintenance cycle shortened and the cost increase.This article mainly aims to overcome the existing oil desanding deoxidization technical defects, putting forward a kind of non-stop pump desanding and sand cleaning technology in offshore oil wells. In terms of desanding, using the design of the hydrocyclone desander for oil sands separation and the isolated sand fall into the bottom. The purified fluid is lifted to the platform through the electric submersible pump, thus extending the life of the submersible pump. In order to avoid the accumulation of sand in the bottom resulting in sand buried oil and electric submersible pump problems, we use the jet pump that is down into the down hole with the electric submersible pump to remove the bottom sand. Make use of the portion of the output electric submersible pump high pressure produced fluid as a power fluid to the jet pump, and the sand will be raised from the bottom to the platform wellhead,eliminating the need for offshore platform to provide power of the device to ease the offshore oil platform space constraints.This article dealt with the oil well condition of a certain block in the sea: oil well depth of 1500m, size of 7 inches casing pipe, electric submersible pump under the pump depth of 800m, sinking degree of 400m, electric submersible pump's normal production capacity of 300m3/d, so as to study on non-stop pump desanding and sand cleaning technology. In order to optimize the cyclone desander, the flow optimization analysis was carried out using fluent software. The results showed that when the flow rate of the desander was 300m3/d, the diameter of the inlet width of 16mm and the diameter of ?120mm could meet the requirement of high efficiency separation in oil well condition.Finally, the simulation studied on the effect of different working conditions on the efficiency of the cyclone desander was carried out.The structure parameter optimization of jet pump which was used to clean bottom sand of the well was optimized by fluent software and orthogonal test. The results showed that the jet pump with area ratio of 0.25, throat mouth distance of 3.45 mm, throat length of 36.8 mm, thenozzle cone Angle of 14°, throat inlet Angle of 60° had better performance sand pump. In addition, this paper discussed the effect on the performance of pumping sand particle diameter.In order to meet the calculation convenience, to improve the efficiency of jet pump's design under different conditions, to easy users to do the trial of the jet pump's parameters such as pump depth, the power fluid volume under different working conditions, this article used python programming to realize the development of jet pump structure design software.