盐家油田油水井结垢原因探讨  

An Investigation on Reasons of Water Scaling in Oil Production and Water Injection Wells at Yanjia Oil Field

作　　者：张兴[1] 黄敏[1] 卢明昌[1] 罗丽[1] 张新丽[1] 刘凯[1] 聂艳[1] 

机构地区：[1]中国石化胜利油田公司东辛采油厂,山东东营257094

出　　处：《油田化学》2006年第1期19-22,共4页Oilfield Chemistry

摘　　要：对地层温度65～75℃的盐家油田油水井近井地带、井底、井筒发生严重结垢的原因进行了分析探讨。7口油井采出的地层水均为NaCO3型水．矿化度6．4～10g／L，HCO3浓度高（1．6～3．7g／L），Ca^2＋＋Mg^2＋浓度较低；1口水源井水及1口水井注入水为CaCl2型水，矿化度32～33g／L，Ca^2＋＋Mg^2＋浓度高（3．1～3．8g／L）而HCO3浓度低；采用CaCO3饱和指数法和CaSO4热力学溶解度法预测，在70℃下所有水样均有CaCO3结垢趋势，除3口油井采出的地层水外，均有CaSO4结垢趋势。3口油井采出的地层水与水源水在25℃按不同比例混合后，悬浮物含量大幅度上升。在70℃放置7天后再次大幅度上升，烘干的悬浮物易溶于稀盐酸．其主要成分为碳酸盐．说明注入水、地层水不配伍。1口电泵采油井和1口注水井油管垢样含盐酸可溶物（碳酸盐）超过90％。讨论了碳酸盐、硫酸盐垢的生成条件：温度、压力及pH值。图1表4参3。The reasons of serious water scale deposition in nearbore zones, bottom, and wellbore of oil production wells （OPWs） and water injection wells （WIWs） at Yanjia oil field of reservoir temperature 65-75℃ are investigated. The formation waters （FWs） from 70PWs are characterized by water type NaHCO3, TSD in range 6.4-10.0 g/L, high HCO3^- concentration, 1.6-3.7 g/L, and mild Ca^2＋ ＋ Mg^2＋ concentration; the injection waters （IWs） from a water source well and an injection well - water type CaCl2, TSD in range 32-33 g/L, high Ca^2＋ ＋ Mg^2＋ concentration, 3.1-3.8 g/L, and low HCO3^- concentration; all these waters above mentioned at 70℃ tend to CaCO3 scaling as predicted by using CaCO3 saturation index, SI, and, besides of FWs from 30PWs, to CaSO4 scaling as predicted by using thermodynamical solubility of CaSO4, S. For the mixture of FWs from 30PWs and the source well water at different ratio, the content of suspended substances is increased dramatically at 25℃ comparing with that for the FWs and the source well water alone and increased significantly again in 7 day of standing at 70℃, which indicates inoompatibility of the FWs and the IWs; the suspended substances isolated and dried dissolve readily in dilute hydrochloric acid and hence are composed mainly of carbonates. The inorganic precipitates taken from a deep electric pumping well and a water injection well contain 〉90% of acid soluble substances （carbonates）. The conditions for carbonate and sulfate scale formation such as temperature, pressure and pH value are discussed.

关 键 词：注入水 采出地层水 水质分析 配伍性 结垢趋势预测 碳酸盐垢 硫酸盐垢 结垢条件 胜利东辛油田 

分 类 号：TE358.5[石油与天然气工程—油气田开发工程] TE357.6