Marine gas hydrate technology: state of the art and future possibilities for Europe

Abstract

Interest in natural gas hydrates has been steadily increasing over the last few decades, with the understanding that exploitation of this abundant unconventional source may help meet the ever-increasing energy demand and assist in reduction of CO2 emission. The CO2 emission per energy unit produced by natural gas is significantly lower than similar energy produced by combustion of coal. The production of energy from hydrates requires special attention to the phase transition dynamics of hydrates and pore scale dynamics as well as higher reservoir dynamics. In any event, most of all conventional gas technology for completing the production system is well known technology. One of the main challenges is to address the dynamics of the hydrate phase transition as efficiently as possible. As such, the most important challenges related to production from hydrates is in the understanding of the multi scale coupled dynamics and how to perform efficient interactions with the in situ hydrates for technically, economically and environmentally safe production. Better understanding of the dynamic characteristics of the system within THMC simulations, will allow improvement of the technology chain, from exploration through production to monitoring; which appears to be less well developed for gas production from hydrate sediments. For any potential method of hydrate production or combined CO2 storage and production, it is critically important to develop a deeper understanding of the geomechanical implications. This would assist avoiding geohazards risks associated with future production wells, as well as assessment of natural occurring of geohazards situations. Various academic groups and companies within the European region have been heavily involved in theoretical and applied research of gas hydrate for more than a decade. To demonstrate this, Fig. 1.1 shows a selection of leading European institutes that are actively involved in gas hydrate research. A significant number of these institutes have been strongly involved in recent worldwide exploitation of gas hydrate. The most important worldwide tests and production sites are summarized in Table 1.1. Despite the state of knowledge, no field trials have been carried out so far in European waters. The MIGRATE project (COST action ES1405) aimed to pool together expertise of a large number of European research groups and industrial players to advance gas-hydrate related activity with the ultimate goal of preparing the setting for a field production test in European waters. This MIGRATE report presents an overview of current technologies that are being used, and could be used, with relation to gas hydrate exploration (Chapter 2), production (Chapter 3) and monitoring (Chapter 4), with an emphasis on European activity. This requires covering various activities within different disciplines, all of which contribute to the technology development needed for future costeffective gas production. The report points out future research and work areas (Chapter 5) that would bridge existing knowledge gaps, through multinational collaboration and interdisciplinary approaches.