钻井液润滑性的合理评价

研究了钻井过程中的摩擦特点，确定了用ＬＥＭ—２动态润滑仪评价钻井液润滑特性的合理使用方法，发现通过调整仪器的内置常数ＣＮＳＴ，就可使不同载荷及转速对测量结果的影响减至最小，从而使不同载荷下测得的摩阻系数Ｃｆ具有可比性．开发了一种与该仪器ＳＨＣ软件系统配套使用的全中文数据处理软件——ＬＥＭＳＳ系统，可完成对钻井液体系及一种或多种润滑剂在不同用途下的评价试验数据处理，以三种不同的图形方便直观地输出评价结果．用该仪器评价了常用钻井液体系的摩阻系数，大多数水基钻井液的Ｃｆ在０．２～０．４，但只要Ｃｆ≤０．２，就可认为其润滑性能满足工程要求．

Rational Evaluation of the Lubricity of Drilling Fluids

According to the research of the special friction property in drilling, the rational operation specification of LEM Ⅱ dynamic drilling fluid lubricity evaluation monitor (LEM) is recommended. It is found that the influences of side weight and rotary speed of friction shaft on measuring results can be reduced to the minimum through regulating the instrument constant CNST in a special formula that the paper give. And in this condition, friction coefficients (c f) under different side weight and rotary speed have the better comparability. A data processing software system (LEMSS) matching original data acquisition software system (SHC) with Chinese windows has been programmed. It can output three forms of test report chart,i.e. evaluation of a type of mud, a kind of lubricant and a comparison among several lubricants. The c f of general mud system has been measured by LEM Ⅱ. The evaluated results show that the c f of most water base drilling fluids is 0.2～0.4. But we think that the lubricity of a type of mud can not meet the need of drilling engineering unless its c f at the very most is 0.2.