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为探求吐哈油田胜北构造粘土矿物纵向分布规律与井眼稳定性的关系，以台参２井为例系统分析了本构造泥页岩地层中高岭石（Ｋ）、绿泥石（Ｃ）、伊利石（Ⅰ）、蒙脱石（Ｓ）和伊蒙混层（Ｉ／Ｓ）矿物的分布及演变特征，测定了粘土矿物中各种阳离子（Ｋ＋、Ｎａ＋、Ｃａ２＋、Ｍｇ２＋）的可交换容量（ＣＥＣ）．研究表明，胜北构造上部地层是以Ｓ（约４０％）为主的高活性泥岩，中部大段硬脆碎泥页岩以Ｉ／Ｓ（约５０％）为主，下部地层Ｉ／Ｓ渐减至消失．Ｋ、Ｃ、Ｉ纵向分布较为均匀，基本与井径扩大率无相关性．井径扩大率与Ｉ／Ｓ含量呈明显正相关，但与Ｉ／Ｓ中的Ｓ含量却呈负相关，Ｉ纵向变化小但总含量较高（约５０％）且其中裂隙、解理发育，因此认为井眼的失稳主要是Ｉ及Ｉ／Ｓ含量较高的硬脆碎泥页岩在释放构造应力时，各种综合工程因素诱发地层崩裂和剥蚀而引起的，具有明显的时敏性．由于这种地层的ＣＥＣ特别是ＥＫ较低，因而必须主要靠封堵裂缝而不是提高钻井液中的Ｋ＋浓度来抑制井眼垮塌
In order to explore the relationship between the longitudinal distribution of clay minerals and the wellbore stability of the Shengbei structure in Tuha Oilfield, taking Tsent Well 2 as an example, the authors analyzed the contents of kaolinite (K), chlorite (C) (K +, Na +, Ca2 +, Mg2 +) in clay minerals were determined by the distribution and evolution of the illite (I), montmorillonite (S) (CEC). The study shows that the upper strata of the Shengbei Formation are highly activated mudstones mainly composed of S (about 40%), the middle and large sections of hard brittle shale are mainly composed of I / S (about 50%), and the lower strata To disappear. K, C, I longitudinal distribution is more uniform, basically no correlation with the caliper expansion rate. Well diameter expansion rate was positively correlated with I / S content, but negatively correlated with S content in I / S. I longitudinal variation was small but the total content was high (about 50%) and the development of cracks, cleavage, Therefore, it is considered that the instability of wellbore is mainly caused by various synthetic engineering factors that cause formation cracking and denudation during hard tectonic shale with high I and I / S content and obvious time-sensitivity . Due to the low EK of this formation, especially the EK, it is essential to suppress wellbore collapse mainly by plugging fractures instead of increasing K + concentrations in the drilling fluid