抗240℃超高温水基钻井液室内研究

针对中国大陆科学钻探松科2井深部高温层段钻井作业需要,通过研制出高温稳定剂MG-H2,引入抗高温抗盐的凹凸棒土,优选抗高温降滤失剂,设计出一套以钠膨润土和凹凸棒土为黏土相的低固相抗240℃超高温的水基钻井液配方。MG-H2是采用反相乳液聚合方式研制出的一种油包水型高温稳定剂,其具有球状高分子柔性搭接、增强悬浮稳定性作用和半刚性微粒黏度特性,能实现对钻井液黏度、润滑、滤失性能的综合控制。优选出的3种降滤失剂及其加量配比为3%Lockseal+1%硅氟降滤失剂+1.5%Soltex。综合性能评价结果表明,该抗高温钻井液经过240℃高温老化后性能稳定,具有良好的流变性能和滤失造壁性能,抑制和润滑性能满足钻井需要,能抗10%膨润土、5%Na Cl和1%Ca Cl2的污染。为松科2井下阶段抗260℃超高温钻井液的研制奠定了良好基础。

Laboratory Study on Ultra High Temperature Water Base Mud

A high temperature water base drilling fluid was formulated with sodium bentonite and attapulgite, and a high temperature water-in-oil stabilizer, MG-H2 which is synthesized through emulsion polymerization. Laboratory evaluation of the drilling fluid showed that, after aging at 240℃, the drilling fluid still retained satisfactory rheology and filtration properties. It had good inhibitive capacity and was resistant to contamination caused by the introduction of 10% clay, or a combination of 5% NaCl and 1% CaCl2. It also had good lubricity at high temperature. The formulation of this high temperature drilling fluid lays the foundation for the formulation of an ultra-high temperature drilling fluid, say, 260℃, for the drilling of the Well Songke-2.