井下抽油泵吸入口附近腐蚀模拟试验装置研制

Development of Dynamic Simulation Test Device for the Corrosion Near Downhole Pump Suction Port

油田井下抽油泵吸入口附近套管腐蚀穿孔现象比较普遍,严重影响油田的稳产。为研究其腐蚀机制,自行设计和制造了一种井下抽油泵吸入口附近动态腐蚀模拟试验装置。该装置采用单柱塞泵和与现场一致的油套管柱结构,真实模拟了抽油泵间歇性的生产方式以及泵吸入口附近流体的流动状态,实现了不同温度、CO2分压、流速等条件下腐蚀速率的测定及腐蚀行为的研究,可为套管选材提供参考。试验结果表明,抽油泵吸入口附近腐蚀介质的流速流态是造成该处套漏的主控因素,并以CO2局部腐蚀为主,与现场套损状况一致。

The corrosion of the casing near a downhole pump suction port is common in some domestic oilfields, and it has a serious impact on the stable production of the oilfield. In order to study the corrosion mechanism, we have designed and manufactured a dynamic simulation test device for the corrosion of the casing near the downhole pump suction port. The device consists of a single plunger pump and a tube and casing strings in line with the site structure to simulate the intermittent production mode of the pump as well as the fluid flow state near the pump inlet adequately, and the corrosion velocity measurement can be made and the corrosion behavior can be studied under different temperatures, C02 partial pressures, and velocities to provide important data for the casing materials. The test results show that the flow rate and flow pattern of the corrosive medium near the oil pump suction port are the main factors of casing-leakage, and C02 local corrosion is the main way, which is in accordance with the casing damage status.