摘要
大庆油田NaOH/ORS 41/HPAM三元复合驱区块的采油井结垢严重。简要分析了这些采油井结垢的原因,对取自2口采油井井下的4个垢样进行了分析。垢样的主要化学成分有:有机物(原油和聚合物)、CaO、MgO等;主要矿物成分为非晶质二氧化硅和六方球状方解石、普通方解石及硫酸钡等;次要矿物成分为碎屑状石英、长石、粘土和黄铁矿等;垢由粗粒层和胶泥状细粒层交替沉积而成;垢的主要类型为硅垢和碳酸钙垢。在垢分析的基础上研制了一种清垢剂,其总体配方(质量百分数)为:10%～15%复合酸(氢氟酸、盐酸、有机酸)+6%～8%垢转化剂+8%～12%螯合剂+2%～4%表面活性剂+4%～6%缓蚀剂+水。该清垢剂45℃时对大庆各区块油井垢的溶蚀率不小于80%,溶蚀反应可在2h内完成,腐蚀速率仅为0.80g/m2·h。用该剂处理了结垢严重的4口采油井,单井每次用量为10～20m3,清垢效果良好,检泵周期大大延长。图1表4参2。
Severe scaling problems appear in production wells of reservoirs flooded by NaOH/ORS41/HPAM combinational solution in Daqing. The reasons for scale formation are discussed concisely and 4 scale samples taken from 2 wells are analysed. It is found that the main chemical constituents of the scale are organic substances (crude oil and polymers), CaO, MgO, and others; the main mineral constituents are vaterite, calcite, barium sulfate, etc, and the secondary minerals - clastic quartz, feldspar, particulated clay, pyrite, etc; the scale consists of coarse grain and cementitious fine grain layers precipitated alternatively; basically the scale are of siliceous and calcium carbonate types. On the basis of scale analysis a scale removing fluid is developed and its general formula is (by mass): 10-15% mixed acid (HF, HCl, and organic acids) +6-8% scaleconverter+8-12% chelating agent+2-4% surfactant+4-6% corrosion inhibitor + water. The dissolution rate in the fluid of scale samples from wells of various reservoirs in Daqing is not less than 80% at 45℃, the dissolution reaction completes in 2 hrs and the corrosion rate of the fluid is of 0.8 g/m2·h only. Treating 4 wells with scaling troubles by this fluid in 10-20 m3 per welltime results in satisfactory precipitate removal and in significantly prolonged periods between two pump maintainment/repair jobs.
出处
《油田化学》
CAS
CSCD
北大核心
2003年第1期1-3,共3页
Oilfield Chemistry
关键词
结垢
采油井
三元复合驱油藏
产品研究
开发
油井清垢
大庆油田
scaling
production wells
ASP-flooding reservoirs
scale removing agent
research and development of chemical
scale removal
Daqing oil fields
