具有恒流变特性的深水合成基钻井液

Synthetic-Based Drilling Fluid with Constant-Rheology Used in Deepwater Drilling

合成基钻井液(SBM)以其特有的环保性能及机械钻速高、井壁稳定性好等特点,已成为国际上海上油气钻探的常用钻井液体系。但是在深水钻探作业中,由于温度和压力对流变性的影响常导致井漏和当量循环密度(ECD)不易控制。为了解决该技术难题,近年来国外首先研制出一类新型的具有恒流变特性的合成基钻井液(CR-SBM),其流变性,特别是动切力、静切力和低剪切速率下的黏度等参数基本上不受温度压力的影响。阐述了该新型钻井液的典型组成及性能特点,对比了传统SBM和CR-SBM在不同温度、压力下的流变性、抗岩屑污染和毒性测试结果,并介绍了国外CR-SBM的现场应用情况。

The synthetic-based mud（SBM） has been increasingly used for deepwater drilling in China and overseas because of its environmental protection,high rate of penetration and excellent wellbore stability.However,its rheological properties vary with the temperature and pressure,which may cause lost circulation and inaccurate control of equivalent circulation density（ECD） during deepwater drilling operations.In order to solve these problems,a new type of constant-rheology synthetic-based mud（CR-SBM） has been firstly developed overseas.The rheological parameters,especially the yield point,gel strength and viscosity at low shear rates of the CR-SBM,are not changing with change of the temperature and pressure.This paper summaries the typical composition and properties of the CR-SBM.The measured data of rheology properties,solids contamination and sediment toxicity testing of CR-SBM at different temperature and pressure are compared with conventional SBM,respectively.The results of field applications of this drilling fluid are also presented in this paper.