W11-4N油田海管在线清垢作业现场试验

为了验证在线清垢剂的清垢效果。解决W11-4N油田海管结垢堵塞问题，开展了为期45d的低含水输送海管在线清垢现场试验工作。结果表明．清垢作业试验获得成功。清垢达到了预定目标。海管进口压力和海管进出口压差均大幅下降，降幅均约为130kPa。且在作业后期稳定在此数值左右；清垢作业结束时。海管输送液分离水样中Ca抖浓度下降并稳定在520-600mg·L^-1,接近作业前期浓度（500-580mg·L^-1）；清垢作业完成后，拆卸发球阀外观结垢已彻底清除．且无明显腐蚀迹象．海管输送液分离水样中Fe抖浓度稳定在0．2～0．3mg·L^-1,清垢作业期间海管腐蚀速率比加清垢剂前大大降低；清垢作业的返出液对油水分离处理无明显影响；清垢作业完成后，W11-4N油田生产稳定,外输6英寸海管保持日输送液量为1330m^3，海管输送压力稳定正常。

Test of On-Line Scale Removing Work for Sub-Sea Pipeline in W11-4N Oilfield

In order to validate efficiency of on-line scale removing agent and solve the problem of scale clog in sub-sea pipeline in W11-4N Oilfield,a 45-day on-line scale removing work has been carried out. The result shows that the test is very successful and the scaling effect meets the expected goal. The entry pressure of pipe-line decreases and the pipeline pressure difference between entry and exit both decreases by about 130 kPa. At the end of scale removing,Ca^2＋ concentration decreases to 520-600 mg·L^-1 in the splitting sample from the sub-sea pipeline,close to 500-580 mg·L^-1 before production. After scale removing, the scale on the surface of ball valve detached is removed without obvious corrosive signs. Fe^2＋ concentration in the splitting sample from the sub-sea pipeline is 0.2-0.3 mg·L^-1. During scale removing,corrosive rate decreases far more than that before adding scale removing agent. Returned fluid of scale removing has no obvious effect on the separation of oil and water. After scale removing,W11-4N Oilfield maintains its steady production with the daily oil volume of 1330 m^3 by the 6-inch pipeline and steady pressure of pipeline.