摘要
大庆朝阳沟低渗透水驱油田一些注水井注水压力不断上升,采油井井底结垢,垢样含63.4%CaCO3、22.0%Fe2O3、14.6%有机物及其他。讨论了生成CaCO3垢的基本化学反应。实验测定并发表了温度分别为25、50、75、90℃±0.1℃,压力分别为0.1、9、19、29MPa(测量误差±5%,0.1MPa时除外)时,CaCO3在蒸馏水中的溶解度数据(单位mg/L)。概括性地讨论了相同离子和盐对CaCO3溶解度的影响。基于测得的溶解度数据及注入水、地层水矿化离子种类和含量,认为在朝阳沟油田,注水井井底温度25℃、压力约19MPa(注水压力9MPa),只要严格控制注入水的离子种类和含量,一般不会产生CaCO3结垢;采油井井底温度约45℃,压力≤0.2MPa,易产生CaCO3结垢。图2表1参2。
At water flooding Chaoyanggou oil fields in Daqing, the water injection pressure in a lot of wells increases continuously and scale is formed in the bottom of production wells with scaling substances: 63.4% CaCO3, 22.0% Fe2O3, and 14.6% organics and others. The basic chemical reactions for CaCO3 scale creation are presented. The solubility of CaCO3 (in mg/L) in distilled water is determined and published for temperatures 25,50,75 and 90℃±0.1 C and pressures 0.1,9,19, and 29 MPa (with relative measuring error±5% besides of the case of 0.1 MPa), respectively. The similar ion and the salt coexisted as influencing factors for CaCO3 scaling are discussed in general. Based on the solubility data determined and the species and concentrations of ions in the injection and formation waters, its is ascertained that at Chaoyanggou oil fields in the bottom of injection wells with temperature ～25℃ and pressure ～19 MPa (injection pressure 9 MPa) CaCO3 scale does not appear commonly if the species and concentrations of scaling ions in injection water are under proper control; in the bottom of production wells with termperature ～45℃ and pressure ≤0.2 MPa CaCO3 scale creates readily.
出处
《油田化学》
CAS
CSCD
北大核心
2003年第1期4-6,共3页
Oilfield Chemistry
关键词
碳酸钙
溶解度
高温高压条件
结垢
注水油藏
大庆朝阳沟油田
calcium carbonate
solubility
high temperature and high pressure
calcium carbonate scaling
water flooding reservoirs
Chaoyanggou oil field in Daqing
