A Completion System Application for the World's First Marine Hydrate Production Test

TLDR

Methane hydrate production methods are considered feasible by industry across geological, geophysical, petrophysical, and reservoir/production engineering perspectives. This paper aims to present the application of a depressurization‑based completion system in a methane hydrate production well and to review its design, key components, and lessons learned. The completion system employs an electrical submersible pump with real‑time downhole monitoring, separating fluid and gas streams to the surface using natural and artificial separation techniques. The world’s first subsea methane hydrate completion system was installed and its production test successfully executed in the eastern Nankai Trough off central Japan in March 2013.

Abstract

Abstract The world's first subsea methane hydrate completion system was installed and its production test successfully executed in the eastern Nankai Trough area off the east coast of central Japan in March 2013. A variety of methane hydrate production methods exist and have been recognized by the industry as being feasible in producing methane hydrate from the view point of geology, geophysics, petrophysics and reservoir/production engineering. This paper describes one of these methods and provides some background and detailed engineering required in the development of a completion design, the interface and qualification testing necessary to mitigate some key challenges and risks associated in the development of a methane hydrate completion and production system. The completion system demonstrated in this paper utilizes an Electrical Submersible Pump (ESP) in conjunction with real-time downhole monitoring whilst producing separated fluid and gas flow streams to surface, combining natural and artificial separation methods. The objective of this paper is to present the application of the completion system in a methane hydrate production well by the depressurization method. It will review the completion system and key production string component, as well as the lessons learned from the production test.