储层水敏系统评价方法与水敏机理研究

Method for Water Sensitive System Evaluation and Study on Water Sensitivity Mechanism

摘要: 矿物晶层间距测量试验能准确分析水化膨胀的水敏矿物种类及矿物晶层间距变化程度；扫描电子显微镜不镀膜定点观察试验既能观察分析矿物的种类，又可以确定各种矿物分布的位置；孔喉半径测量试验测量水敏伤害前后孔喉半径分布，间接给出了水敏运移颗粒的半径范围和堵塞位置，以上3种主要的储层水敏微观测试评价方法，结合常用的岩心流动与物理膨胀2种宏观水敏测试评价方法，能精细分析引起水敏伤害机理、主要水敏矿物种类、伤害位置以及引起伤害的时间与程度，克服了单一方法无法精确研究水敏原因的不足之处。应用系统水敏评价方法研究S油田岩样，其结果表明该岩样产生水敏的机理主要是以运移的颗粒架桥堵塞孔喉为主，膨胀性黏土矿物水化膨胀造成孔隙半径缩小为辅。

Abstract: Mineral crystal spacing measurement experiment could accurately analyze the water swelling of the water-sensitive mineral species and mineral layer spacing changes. Scanning electron micro-scope uncoated spotting observation experiment could not only observe the types of minerals, but also determine the location of various mineral distributions. The radius of the pore throat was measured before and after the water-sensitive injury, and the radius range and the clogging position of the water-sensitive moving particles were given. Three main methods of water-sensitive micro-test evaluation of the reservoir combined with the commonly used core flow and physical expansion of two kinds of macro-water sensitivity test evaluation method, could finely analyze the mechanism of water-sensitive damage, the main water-sensitive minerals, damage location and its time and degree, which overcame the shortcoming that the original method could not accurately study the reason of water sensitivity. Water Sensitive System Evaluation was used for studying the rock samples from S Oilfield. The result shows that the main reason for the mechanism of water sensitivity is that the pore throat is blocked by the migration of the particles. The secondary reason is that the swelling of the clay minerals increases due to the expansion of clay mineral.