Design of the Surface Flow Test System for 1st Offshore Production Test of Methane Hydrate

Abstract

Description: As a paper of the MH21 study, this paper describes the design and operation of the surface flow test system utilized for the 1st Offshore Production Test of Methane Hydrate in deep water offshore Japan in March 2013 using a dynamically positioned drill ship. The unique characteristics of this production test required a customized approach to the design of this system. As the production test was carried out for scientific research purposes, the data acquisition requirements were of paramount importance. Application: The information contained in this paper can be applied to future offshore production tests of methane hydrate using the depressurization technique. Results, Observations, and Conclusions: The surface flow test system was successfully designed, installed, commissioned and operated. Measurement and separation of the produced gas and water were effectively achieved under low temperature, low pressure, and low production rate conditions. Transportation and operation of surface flow test equipment was able to accommodate the motions of the floating drilling vessel. Two separate fluid processing trains were installed for high quality measurement of the gas and water rates. A real time data sharing system to monitor the condition of the surface system and the down hole systems implemented but shut down of the downhole equipment was not triggered automatically by surface production equipment ESD. Some non-critical data acquisition failures occurred or limitations observed during the production test. Significance of Subject Matter: It is believed that this was the first offshore production test of methane hydrate to have been conducted in the world. The design philosophy and operational experience will be useful for future production testing in similar environments.