任丘雾迷山组储层、水、结垢中微量元素赋存特征

对任丘油田雾迷山组白云岩76块岩样、17口井的水样和任436井结垢进行了Sr,Ba等微量元素的测试，利用PHREEQM消化水化学模拟软件对微量元素所组成矿物的溶解与沉淀在不同温度、没CO2分压条件下进行了模拟，并探讨了微量元素在其中的分布特征和迁移规律。结果表明，岩石中微量元素的分布受沉积环境及后期水岩作用的控制，潮下高能环境中形成的锥状迭层石、核形岩、凝块中石中微量元素含量高，如Sr含量最高达0．03％；而形成于潮上带低能环境中的粉晶、粉晶白云岩中Sr含量低，一般0．002％－0．003％；好的储层由于后期溶滤作用，岩石中微量元素含量降低；与之相反，好的储层其油田水中元素富集；结垢中微量元素含量比岩石、油田水中的含量高数百倍甚至数千倍，表明在结垢过程中伴随着强烈的浓缩作用，其中重晶石（Ba-SO4)、玉髓（SiO2)、石英（SiO2)的溶解与沉淀取决于温度条件，而对CO2分压的变化不敏感；天青石（SrSO4)随着CO2分压的减小和温度的升高其饱和指数逐渐升高，直至产生沉淀。

Occurrence of Trace Elements in Reservior, Oilfield Water, and Scaling of Wumishan Formation, Renqiu, China

dolomite samples, the water sample from 17 wells, and the sample of water scaling from the No.436 well were tested for trace elements Sr and Ba in Wumishan formation of Renqiu oil field. The dissolution and precipitation of minerals composed of these trace elements at different temperatures and under different pressures of CO 2 were simulated using the PHREEQM software. The distribution and migration of the trace elements were discussed. The result shows that the distribution of trace elements was controlled by the sedimentation environment and the post stage water rock interaction. Minerals formed in a high energy environment of subtidal zone have a high content of trace elements. The Sr, for example, may reach as high as 0.03%; While those formed in a low energy environment of suprallitoral zone have a low content of Sr, only 0.0028%. For the scaling, the content of Sr may be as high as 0.69% and that of Ba is 0.09%, much higher than that in rocks and in water of the oil field, indicating that there exists a strong condensation action in the scaling process.