碳酰胺复合驱吞吐井缓蚀剂优选评价

Optimization and Evaluation of Carbamide Composite Flooding Corrosion Inhibitor for Stimulation Well

某西部油田碳酰胺复合驱吞吐井井筒温度最高可达260℃,CO_(2)分压预计为0.4 MPa,井筒管柱面临较高的腐蚀风险。为了解决井筒腐蚀问题,根据碳酰胺复合驱吞吐井井筒服役工况的特点,提出了一套适用于碳酰胺复合驱吞吐井的缓蚀剂优选评价技术流程。首先,对预选的缓蚀剂进行配伍性评价,然后,进行热滚耐温测试和电化学测试,优选出耐温性能和缓蚀性能良好的缓蚀剂,再采用高温高压釜模拟现场腐蚀工况对缓蚀剂防护效果进行评价;最后,结合碳酰胺复合驱吞吐井注—焖—采的工艺特点和不同阶段的腐蚀环境,确定了焖井降温阶段为缓蚀剂的最佳注入时机。研究结果表明,在温度180℃、CO_(2)分压0.4 MPa条件下,优选出的缓蚀剂XCN2-21可将N80管材的腐蚀速率降低至0.0441 mm/a,满足油田腐蚀控制要求。

In a western oil field,the temperature of the wellbore of a carbonamide combined flooding well can be as high as260℃,and the partial pressure of CO2 is expected to be 0.4 MPa.The wellbore string is facing a higher risk of corrosion.To solve the problem of wellbore corrosion,according to the characteristics of the service conditions of the wellbore of the carbonamide combined flooding huff and puff well,a set of corrosion inhibitor optimization evaluation technical process suitable for the carbonamide combination flooding huff and puff well is proposed.First,the compatibility of the preselected corrosion inhibitor is evaluated,and then the hot roll re sistance is performed.Temperature test and electrochemical test,select the corro sion inhibitor with good temperature resistance and corrosion inhibition performance,and then use the high-temperature autoclave to simulate the on-site corrosion conditions to evaluate the corrosion inhibitor protection effect;finally,combining the process characteristics of the injection-simmering-production of the carbonamide combined flooding huff and puff well and the corro sive environment at different stages,the optimal injection timing of the corrosion inhibitor in the cooling stage of the simmering well is determined.The research results show that under the conditions of temperature 180℃and CO2 partial pressure 0.4 MPa,the optimized corrosion inhibitors XCN2-21 can reduce the corrosion rate of N80 pipes to 0.0441 mm/a,meeting the requirements of oilfield corrosion control.