临盘油田L95站钡锶垢成因及连续除垢技术研究

Formation and Continuous Removal of Barium/Strontium Sulfates Scaling at L95 Production Sites in Linpan Oilfield

石东坡 尹先清 郑延成 陈武 付家新 任朝华

SHI Dongpo，YIN Xianqing，ZHENG Yancheng，CHENWu，FU Jiaxin，REN Zhaohua

为获得有效的消除混输管线结垢技术，分析了临盘油田L95 站混输管线内的垢样和部分油井采出液水样的离子组成，研究了采出水中Ba2+和Sr2+在结垢过程中的相互促进作用与结垢机理。结果表明，垢样主要成分为BaSO4和SrSO4（摩尔比1∶1）。L95-1、L95-36 等5口油井水样中的Ba2+和Sr2+含量较高，而L95-18、L95-12 等3口油井水样中的SO42-和Sr2+含量较高，两类水样混输引起结垢。当SO42-含量为1620 mg/L 时，单一Ba2+易结垢，单一Sr2+较难结垢。Sr2+对Ba2+的结垢无明显影响，但Ba2+对Sr2+的结垢具有显著的促进作用。Ba2+对Sr2+结垢的促进作用是L95站混输管线严重结垢的重要原因。通过将L95站各油井水样输入结垢器中混合，同时加入SO42-充分结垢，总结垢率可达89.87%～92.35%，可保证剩余Sr2+和Ba2+在混输管线内不会结垢。图5 表3 参12

To achieve the effective scale removing technology in water-gathering pipelines，the scale of pipelines and ionic composition of produced water at L95 production sites in Linpan oilfield were analyzed. The interaction between Ba2+ and Sr2+ of produced water and scaling mechanism in scaling process was studied. The results showed that the scale was composed of barium sulfate and strontium sulfate in molar ratio 1∶1. The produced waters from five wells were rich in Ba2+ and Sr2+，such as L95-1 and L95-36 well，and other three wells were rich in SO42- and Sr2+，such as L95-18 and L95-12 well. Mixing these two types of produced water would lead to scale formation in gathering pipelines. When the concentration of SO42- was 1620 mg/L，barium sulfate scale was easy to form，while strontium sulfate scale was difficult to from. The concentration of Sr2+ had little influence on the scaling rate of barium sulfate scale，while the scaling rate of strontium sulfate scale increased obviously with increasing Ba2+ concentration. Thus，the effect of Ba2+ on strontium sulfate scale formation was a major cause of serious scaling in water-gathering pipelines of L95 production sites. After mixing these produced waters from various L95 production wells in a device for scale formation，the total scaling rate of barium and strontium sulfates scale was 89.87%—92.35% with enough SO42-. The remaining Ba2+ and Sr2+ could not lead to the scale formation in gathering pipelines.