针对钻井工程中泥页岩井壁易失稳的问题,近年来开发并应用的聚胺强抑制水基钻井液,被认为是最接近油基钻井液性能的新型水基钻井液。其中,聚胺页岩水化抑制剂作为该钻井液的关键处理剂,具有独特的分子结构和优异的抑制性能。通过抑制膨润土造浆试验、三次页岩滚动分散试验、X射线衍射分析黏土层间距和Zeta电位测试等试验,对比评价了聚胺与传统阳离子钻井液抑制剂小阳离子的抑制性。同时,考察了聚胺、小阳离子与膨润土及常用钻井液处理剂的配伍性。结果表明,与小阳离子相比,聚胺更能有效抑制黏土水化膨胀和抑制泥页岩水化分散,并具有长期稳定作用。聚胺与膨润土及各种钻井液处理剂配伍性良好,克服了阳离子钻井液配伍性差的问题。
A novel polyamine highly inhibitive water-based drilling fluid has been developed and applied recently aiming to keep the wellbore stability in shale formation during drilling,and its property is close to that of oil-based drilling fluid.As the critical additive of the system,polyamine high shale hydration inhibitor has its unique molecular structure and excellent inhibitive properties.The inhibition comparison between polyamine and conventional minor cation inhibitor in cationic drilling fluid was evaluated by testing bentonite inhibition,tertiary shale hot rolling dispersion,X-ray diffraction to analyze the interlayer spacing of clay and zeta potential,etc.The compatibility of the two inhibitors with bentonite and common additives was tested.Results show that polyamine is more effective and stable to suppress clay hydration and shale dispersion than minor cation.Polyamine is also compatible with various additives,eliminating the problems of compatibility for cationic drilling fluid.