国内供应的重晶石砷含量多超出《GB 36600-2018 土壤环境质量 建设用地土壤污染风险管控标准（暂行）》中第二类建设用地筛选值要求，常用加重剂铁矿粉、钛铁矿粉，由于其对钻具的严重磨损、应用后可能影响电测结果以及使用后钻井液色度不达标等问题，目前已甚少使用。碳酸钙类加重剂由于其自身低密度，加重后易造成钻井液性能流变性恶化。针对上述加重剂环保性能及应用性能存在的不足，通过优选碳酸钙类加重剂，按比例复合重晶石，经过表面涂覆改性、干法活化处理等生产工艺，降低了粘度效应、解决了砷超标问题，同时利于碳酸钙类加重剂的油气层保护特性，创新形成了对油气层与环境进行双重保护的双保型加重剂。现场实施10口井，实施井均安全钻进，与邻井均值相比，机械钻速提高10个百分点，平均井径扩大率降低1.8个百分点，投产井平均单井每米产层增油0.60t，泥饼重金属砷含量达到了标准筛选值要求（低于60mg/Kg）。
The arsenic content of barite supplied in China mostly exceeds the filter value of Second type of construction land in‘GB 36600-2018 Soil environmental quality Risk control stardard of soil contamination of development land’. Iron ore powder and ilmenite powder are commonly used as weighting agents, but they wear drilling tools seriously, which affects the electrical measurement results, and the chroma of drilling fluid is not up to standard after use, so they are rarely used now. Calcium carbonate is also a common weighting agent, due to its low viscosity, the viscosity effect is obvious, which has an impact on drilling. In view of the shortcomings of the environmental protection performance and application performance of the weighting agent, choose calcium carbonate weighting agent,adding barite into it proportionally,after surface coating modification, dry activation treatment and other production processes, The viscosity effect and the arsenic content is reduced.At the same time, it is beneficial to the hydrocarbon reservoir protection characteristics of calcium carbonate weighting agents . Innovation has formed a double-protection weighting agent that protects oil and gas reservoirs and the environment.The technology has been applied to 10 wells,all wells were drilled safely. Compared with the average value of adjacent wells, the penetration rate increased by 10%, the average hole diameter expansion rate decreased by 1.8%, the average oil production per meter of single well increased by 0.60t, and the arsenic content of mud cake reached the standard screening value (less than 60mg/Kg).