Natural Gas Hydrates to Enable the Safe, Sustainable, and Economical Production of Offshore Petroleum Reserves

Abstract

Abstract This research presents a novel approach using Natural Gas Clathrate Hydrates (NGH) for the production of natural gas from deep-water petroleum reserves. Liquefied Natural Gas (LNG) has limitations associated with its enormous capital cost (requiring significant production capacity), inherent hazards, and environmental impact. Storage and transport of natural gas must address the economic, safety and environmental requirements, as a whole, by designing the supply chain as an end-to-end process. The solution is the production of NGH at depths where the in situ pressure and temperature inherently favor the formation in situ, based on thermodynamics and kinetics. The remaining system is then created in order to manage these products. The engineering design, safety analysis and business case are assessed concurrently in order to optimize the system and meet all of the requirements. Containment technology, originating from space exploration, is adapted so that it will be strong, durable, flexible and lightweight. The processing rate and dimensional parameters are selected to mitigate system losses and energy dissipation during long distance ocean transport. The resulting proposed process is economically assessed to be significantly cheaper for the production of natural gas. It can be applied for small production rates and replace operations which flare gas byproducts. Theoretically, it could be scaled for the production of large natural gas fields. The proposed system presents an inherently safer system as the hazards inherent with compressed natural gas (CNG), LNG and pipeline are eliminated by design. There is no handling of compressed or cryogenically cooled fluids, and the transfer from platform to carrier is eliminated. Consistent with the industry direction to move crude oil processing to the bottom of the ocean, the new process can be managed autonomously and avoid the hazards associated with adverse weather conditions. A resulting by-product from this new process is significantly-desalinated water originating in the deep ocean away from man-made pollutants. It is proposed that this by-product can either be post-processed to yield potable water or used as-is, replacing consumption of local resources. The proposed system can be utilized to produce natural gas reserves which would otherwise be considered as stranded reserves. It can serve markets which are too small or ports are too shallow to handle the delivery of LNG from standard carriers. A Patent Cooperation Treaty application on this proposed method was filed and received a favorable preliminary review by the United States Patent and Trademark Office; claims were found to be novel and useful.