最小二乘法在聚合物有效物含量评价方法研究中的应用

摘要

In order to thoroughly eliminate influence of various salts and measuring genuine polymer effective content,the feasibility of evaluation of effective content in polymer fluid loss additives of drilling fluid by alcohol–acid cleaning method was explored. The result showed that by this modified method,not only the alkali residue and water soluble inorganic salts can be effectively removed,but also acid soluble inorganic salts(such as carbonates)can be removed effectively from specimen. Since apparent linear relations exits between amounts of calcium carbonate addition and sample effective content,the least square method,guide sample reverse measurement and extraplolation method were employed to ensure the accuracy and reliability of the new method.Now the method has become Sinopec Company’s norm“Technical Norm of Polymer Fluid Loss Additive for Drilling Fluid”(Q/SHCG 35–2012).%　　为了彻底排除各种无机盐杂质的影响，真实地评价聚合物产品的有效成分含量，研究了醇酸共洗法测试钻井液用聚合物类降滤失剂有效物的可行性。该方法不但可有效地去除样品中的残留碱、水溶性无机盐类，同时还可以有效地去除样品中的酸溶性无机盐（如碳酸盐等）。在进行实验数据处理时，考虑标准碳酸钙的加入量与样品有效物含量测试结果间有较明显的线性关系，运用最小二乘法及加标回测外推法等统计学工具，最大限度地降低了测试结果的不确定度，提高了方法的准确度与可靠性，形成了较完善的钻井液用聚合物类降滤失剂产品有效物含量的评价方法。目前该方法已成功地应用于Q／SHCG 35–2012《钻井液用合成聚合物降滤失剂技术要求》等多个石化行业一级企业技术标准。