Experimental Determination of the Temperature Suppression in Formation of Gas Hydrate in Water Based Drilling Mud

Abstract

The aqueous mixtures of light gas molecules under low-temperature and high-pressure conditions are candidates to form gas hydrate clathrates. The formation of gas hydrate may lead to various problems and extra charges in natural gas production and processing. The presence of hydrate crystals forming a stable solid phase can potentially block the wells, pipes, and process facilities. To avoid such problems, hydrate formation must be studied in different conditions. In this regard, this study aims to design an experimental procedure to determine gas hydrate formation in water based drilling mud. In addition to this, the effect of different inhibitors (i.e. NaCl, methanol, and ethylene glycol) on the hydrate temperature suppression is studied. The designed apparatus is capable of determining hydrate formation conditions in both static and dynamic conditions. Based on the obtained results, among the combinations of NaCl with methanol or ethylene glycol at different concentrations, a mixture of 10 wt.% NaCl + 10 wt.% methanol shows the best inhibition effects (i.e. higher temperature suppression and longer induction time). Furthermore, the experimentally obtained temperature suppression data were fitted and compared against two different thermodynamic models. Temperature suppression variation with inhibitor concentration is described in an acceptable manner by both models.The present contribution is aimed to design an experimental procedure to determine gas hydrate formation in water based drilling mud. In addition to this, effect of different inhibitors (i.e. NaCl, methanol, and ethylene glycol) on the hydrate temperature suppression is studied. The designed apparatus is capable to determine hydrate formation conditions in both static and dynamic conditions. Based on the obtained results, among the combinations of NaCl with methanol or ethylene glycol in different concentrations, a mixture of 10 wt. % NaCl + 10 wt. % methanol shows the best inhibition effects (i.e. higher temperature suppression and longer induction time). Furthermore, experimentally obtained temperature suppression data were fitted and compared against two different thermodynamic models. Temperature suppression variation with inhibitors concentration is described in an acceptable manner by both models.