Understanding the status and the relative content of water in shale is of great significance for shale gas and oil reserve estimations and production predictions. In this work, a facile and efficient method to quantitatively determine the status and relative content of water in shale is proposed. As shale composition significantly influences the distribution and status of water, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis were conducted; the results showed that shale composition is very complex, thus suggesting that is rather difficult to efficiently analyze the water in shale. Because the weight loss during a TG experiment not only contains water but also complicated organic hydrocarbons, it is impossible to obtain the status and relative content of water in shale by TG. In the present investigation, thermogravimetry-mass spectrometry (TG-MS) technology was employed to solve this problem, and the water ion currents of MS were utilized to record the removal behavior of water in shale. The integral area of the water ion current curves within different temperature ranges corresponds to the status (free, bound and structural water) and relative content of water. The TG-MS results indicate that the structural water content in the six typical shale samples is all greater than 50% of the total water. Among the six shale samples, the structural water content varies from 71.24% to 57.37%. At the same time, free water is the least abundant, and most of the free water contents of the shale samples contribute less than 10% of the bound water contents. A retort method was utilized to verify the effectiveness of the TG-MS method, and the results indicate this method is efficient and reliable. The results show that TG-MS technology can efficiently determine the removal behavior of water in shale, and the different statuses of water can be qualitatively described by using this method. This work provides a simple and effective method to explore the status of water and its relative content in shale.

了解页岩中水的状态和相对含量对页岩气和油储量的估算和产量预测具有重要意义。在这项工作中，提出了一种简便有效的方法来定量确定页岩中水的状态和相对含量。由于页岩成分显着影响水的分布和状况，因此进行了X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）分析。结果表明，页岩的组成非常复杂，因此很难有效地分析页岩中的水分。由于TG实验中的失重不仅包含水，而且还包含复杂的有机碳氢化合物，因此无法通过TG获得页岩中水的状态和相对含量。在本次调查中，利用热重-质谱（TG-MS）技术解决了这一问题，并利用MS的水离子流记录了页岩中水的去除行为。在不同温度范围内，水离子电流曲线的积分面积对应于状态（游离水，结合水和结构水）和水的相对含量。TG-MS结果表明，六个典型的页岩样品中的结构水含量均大于总水量的50％。在六个页岩样品中，结构含水量从71.24％到57.37％不等。同时，游离水最少，页岩样品的大部分游离水含量不足结合水含量的10％。利用干馏法验证了TG-MS方法的有效性，结果表明该方法有效，可靠。结果表明，TG-MS技术可以有效地确定页岩中水的去除行为，并可以定性地描述水的不同状态。这项工作为探讨页岩中水的状态及其相对含量提供了一种简单有效的方法。