甲基硅酸盐抑制粘土水化性能及机理

Clay Hydration Inhibit Performance and Mechanism of Methylsiliconate

摘要:

泥页岩水化分散是引起钻孔孔壁失稳，导致缩径、掉块、坍塌等孔内事故的主要原因，泥页岩抑制剂一直是复杂地层钻进技术研究的热点。通过对甲基硅酸钾、甲基硅酸钠、氯化钾、硅酸钠、硅酸钾5种抑制剂对粘土沉降稳定性、水化膨胀及造浆效果等性能测试，结果表明甲基硅酸盐具有良好抑制性；通过红外光谱、X射线衍射、水接触角和光学显微镜对甲基硅酸钾的抑制性作用机理进行了探讨。明确了钾离子的抑制性与表面疏水膜结构协同是甲基硅酸钾抑制粘土水化和防塌作用的原因。

Abstract:

The shale hydration and dispersion are the major factor which reasonable for the wellbore instability and the accidents such as tight hole, stuck pipes and borehole collapse. Compare to sodium methylsiliconate, potassium chloride, sodium silicate and potassium silicate, potassium methylsiliconate exhibit better shale inhibition, through clay settlement test, bentonite inhibition tests and linear swelling tests. The shale inhibition mechanism of potassium methyl-silicate was investigated by infrared spectroscopy, X-ray diffraction, water-contact angle and optical microscope. The excellent inhibition effect and collapse preventing of potassium methylsiliconate is attributable to the synergistic effect of potassium cation and hydrophobic membrane structure formed on the surface by methylsiliconate anions.