氯化钙-烷基糖苷钻井液室内研究

Laboratory Study on Calcium Chloride-APG Drilling Fluid

烷基糖苷（APG）可提高聚合物的抗温抗污染能力,APG的引入可解决CaCl2钻井液流变性和滤失量控制难的问题.对CaCl2-APG水溶液的水活度和人造岩心浸泡稳定性进行研究,证明APG不但不会影响游离钙的存在,而且高浓度APG可促进CaCl2水溶液水活度的降低,确定CaCl2的适宜浓度为20％～40％.在此基础上对增黏剂、封堵降滤失剂和消泡剂优选,构建了体系配方,形成了较为稳定的高浓度CaCl2钻井液.测试了不同密度的钻井液性能,并进行综合评价,表明CaCl2-APG钻井液抗温达130℃,抑制性和润滑性良好.

Calcium chloride(CaCl2), a cost-effective mud additive, has good inhibitive capacity suitable for shale/clay-stone drilling, and its solution has low activity. Drilling fluid mixed with calcium chloride, however, has rheology and filtration rate that are difficult to manipulate, and is easy to foam. To solve these problems, Alkyl polyglucoside(APG) was introduced into the CaCl2 drilling fluid. By analyzing water activity of the CaCl2-APG drilling fluid, and testing on artificial cores, the concentration of CaCl2 needed that is best for borehole stabilization was determined. Using suitable viscosifiers, filtration reducers and defoamers, a CaCl2-APG drilling fluid that can be used at 130 ℃ was developed, with good inhibitive capacity and lubricity.