Research progress and challenges of natural gas hydrate resource evaluation in the South China Sea

Abstract

As an efficient clean energy, natural gas hydrate (NGH) has become a hot topic in recent researches. Since 1990s, China has made great achievements and progress in NGH exploration in the South China Sea (SCS), including determination of the favorable distribution areas and favorable strata thickness, identification of the dual source for accumulation, evaluation of the prospective gas contents, verification of the widespread existence, and confirmation of the technical recoverability of NGH resources. However, there are three major challenges in the NGH studies. First, all the 24 national key and major projects in the SCS focused on trial production engineering and geological engineering in the past 20 years, while 8 of the 10 international NGH research projects focused on resource potential. Second, resource evaluation methods are outdated and some parameter selection are subjective. Third, the existing resource evaluation results are low-level with a great uncertainty, and cannot be used to guide NGH exploration and production or strategic research. To improve the evaluation of NGH resources in the SCS, future researches should focus on four aspects: (1) improve the research on the criterion of the objective existence of NGH and the method of prediction and evaluation; (2) apply new theories and methods from the global NGH research; (3) boost the research on the difference and correlation of the conditions of hydrocarbon migration and accumulation in different basins; (4) innovate the theory and method of NGH resource potential evaluation.