三元复合驱采油井结垢物质组成分析研究  

Chemical and Mineral Composition Analyses of Scale Substances Formed in Producing Wells of ASP-Combinational Flooding Reservoir

作　　者：王贤君[1] 谢朝阳[2] 王庆国[2] 

机构地区：[1]中国矿业大学资源系,北京100083 [2]中国石油大庆油田公司采油工程研究院,黑龙江大庆163453

出　　处：《油田化学》2003年第4期307-309,330,共4页Oilfield Chemistry

摘　　要：使用X射线衍射、扫描电镜、电子能谱、电子探针、化学分析等方法,分析研究了大庆油田三元复合驱试驱区2口采油井中垢的矿物组成和化学组成。垢样中所含的化学元素有硅、铝、钙、铁、钠、钡;化合物有SiO2(67.7%～71.4%)、Al2O3(3.49%～5.56%)、CaO(6.22%～9.04%)、Fe2O3(～2.45%)、BaO(2.0%～12.0%,一口井垢样),这些氧化物合计占垢样总质量的～80%。垢样中有吸附水存在。垢样的主要矿物成分为非晶质二氧化硅、六方球状方解石、普通方解石,次要矿物有碎屑石英、长石、粘土颗粒,还鉴定出多种微量矿物。介绍了主要矿物和前2种次要矿物的形态、成分、结构特征。结垢类型主要为非晶SiO2垢。根据一口井的数据,在三元复合驱过程中,由于发生水岩反应,油井采出水中Ca2+、Mg2+和HCO-2浓度由102mg/L增至3.0×103mg/L,Si离子浓度3消失,CO2-由465mg/L增至2366mg/L(水驱时为129mg/L),pH值由8.5升至11.27。图4表3参2。The chemical and mineral composition of scale substances (SSs) formed in 2 producing wells at a pilot ASP-combinational flooding area in Daqing are investigated by using XRD, SEM, ESCA, electron probe, chemical analysis, and others. The scale samples contain chemical elements Si, Al, Ca,Fe, Na, and Ba, etc and chemical compounds SiO_2( 67.7—71.4%), Al_2O_3 (3.49—5.56%), CaO ((6.22)—9.04%), Fe_2O_3 (～2.45%), and BaO (2.0—12.0%, for one well) and these oxides constitute ～80% of total mass of the SSs. There exists adsorption water in the SSs. The basic minerals of the scale samples are amorphous silica, vaterite, and calcite; the minor minerals—classtic quartz, feldspar, and particulated clay; the micro minerals are identified in tiny quantities. The morphological, compositional and structural features of the basic and the minor (quartz and feldspar) minerals are presented. The scale formed is of amorphous silica type. Owing to rock/water reactions in reservoir formations in the course of ASP-flooding, Ca^(2+), Mg^(2+), and HCO^-_3 in produced water disapear, CO^(2-)_2 concentration increases from 10~2 to 3.0×10~3 mg/L, concentration of Si ion increases from 465 to 2 766 mg/L (129 mg/L in the course of water flooding) and the pH value increases from 8.5 to 12.7 according to the data for a producing well.

关 键 词：油井 结垢 物质组成 X射线衍射 扫描电镜 三元复合驱油 化学驱油 

分 类 号：TE358.5[石油与天然气工程—油气田开发工程] TE357.46