高压DSC在气体水合物形成及分解机理研究中的运用

Application of High Pressure DSC Using in Gas Hydrate＇s Formation and Decomposition

随着海底矿物开采越来越普遍，技术人员面对越来越复杂的钻探技术挑战。特别是极端条件下的深海开采，开采矿产之前，要先处理好表层的可燃冰。通过PVT仪器直接目测来观察气体水合物的形成是一种比较常用的方法。通过记录测量过程中的温压变化来确定气体水合物的形成热力学条件。但是笨重的PVT仪使得实验受限制，并且实验过程中不能有固体微粒出现。本文通过微量热法来确定水合物的成分，研究形成及分解机理，测量比热容。为了满足高压微量热试验需求，法国塞塔拉姆公司特别提出了完全革新的测试手段（法国石油学会专利技术），运用高压MICRODSC来建立气体水合物的形成热力学模型及生成动力学理论，表征水合物相变与时间、温度、压力的对应关系。MicroDSCVII是研究气体水合的专业高压微量热仪，一经推出就广受好评，样品量为0．7ml的全新样品池，并可与专业的高压控制面板相接，最大压力可以达到1000bars，温度范围为-45℃andl20℃。目前，高压MicroDSCVII已经被运用于各种条件下的气体水合物研究，诸如：气体水合物的形成机理，特别是甲烷气体水合物的研究；气体水合物在海底沉积物中的成藏机理；石油开采中水合物形成的抑制；天然气运输及储存过程中气体水合物的形成；冷藏过程中的气体水合的形成及分解等。

With the more and more common developing of seabed mineral mining, the technicians have to face more com- plex challenges of drilling technology. Especially the deep-- sea mining under extrerneconditions, before the processing, is needed to deal with the combustible ice on the surface layer. It is the common method that uses the PVT instrument to ob- serve the formation of the gas hydrate directly. But the bulky PVT asked no solid particles during the whole experiment. In this paper it determines the composition of hydrate by Microcalorimetry to study the formation, decomposition and the meas- urement of heat capacity. To fulfill the requirements of high pressure Microcalorimetry test, Setaram proposes an innovative test method （patented by French Petroleum Institute）, to use MICRO DSC to establish thermodynamic model and generate kinetic theory of gas hydrate formation for characterize the corresponding relationship of the phase change with time, tempera- ture and pressure. The Micro DSC VII is a new instrument to study the gas hydrate, once it＇s been launched gains widely ac- claims from customers. The volume of the whole new sample cell is 0. 7ml, and can be contacted to the high--pressure con- trol panel, the maximum pressure can reach 1000bars, and the temperature range is from --45℃ to 120℃. At present, the high pressure Micro DSC VII has been applied to the study of gas hydrates under various conditions, such as： the formation of gas hydrates, especially for methane; accumulation mechanism of gas hydrate in marine sediments; inhibition of hydrate for mation in oil exploration; formation of gas hydrate of gas during transportation and storage process; formation and decomposi- tion in refrigeration process.