压裂支撑剂性能测试方法不确定度评定

Uncertainty Analysis for the Testing Methods of Fracturing Proppant Performance

支撑剂是保障水力压裂施工效果和油井生产的关键材料,其质量受到支撑剂测试石油行业标准SY/T 5108-2014的严格控制,但该标准不包含有关最终测量不确定度方面的内容。不确定度对于检测实验室质量控制、实验室间差异和不同产品特性差异至关重要。为此将4个支撑剂样品分发到60余家支撑剂实验室,获得的测试数据用于计算标准可重复性和再现性标准差和不确定度。研究表明,标准中的酸溶解度和浊度具有较高不确定度,且随测量值的增大不确定度值增加,当测量值达到临界值7%和150 FTU时,不确定度分别可达1.5%和13 FTU;破碎率的最高不确定度约为2.2%;圆度和球度的不确定度为0.1,随测量值的增大不确定度值减小;绝对密度的误差来源于不同制造商设备的系统差异。此研究为支撑剂性能评价标准修订和工程技术人员正确理解应用支撑剂性能测试结果提供技术支撑。

Proppant is a key material to ensure the effect of hydraulic fracturing job and oil well production.Its quality is under the strict control of SY/T 5108-2014,an petroleum industrial standard of proppant testing.But this standard does not cover the final measurement of uncertainty.Uncertainty is of significant importance for the quality control of testing laboratories,the differences between laboratories and the differences in product characteristics.Therefore,the samples of four kinds of proppant were sent to more than 60laboratories,and the test data obtained were used to calculate the standard deviation and uncertainty in standard repeatability and reproducibility.The results show that acid solubility and turbidity in SY/T 5108-2014 are highly uncertain,and the uncertainty increases with the increase in measured values.When the measured solubility is 7%of the critical value,and the measured turbidity is 150 FTU,the uncertainty can reach 1.5%and 13 FTU,respectively.The maximum uncertainty in crushing percentage is about 2.2%,and the uncertainty in roundness and sphericity is 0.1.The uncertainty decreases with the increase in measured values.The error of absolute density comes from systematic differences in the equipment of different manufacturers.This study provides technical support for revising the evaluation standard of proppant performance,as well as engineering and technical staff to correctly understand and apply the test results of proppant performance.