The Theoretical and Experimental Research on Rapid Sampling Technology for Marine Gas Hydrate

Abstract

The rapid sampling technology for marine gas hydrate (RSTGH) is proposed to improve the efficiency of hydrate resource evaluation. RSTGH mainly consists of a hydraulic reverse circulation sampling (HRCS) apparatus and mud cooling sys-tem. It can be verified from lab tests that 800 L/min of mud circulation at 24 (cid:158) C could be cooled to − 6 (cid:48) 1 (cid:158) C within 45 min. Furthermore, the experiment of HRCS was carried out offshore, and the average core recovery rate was 86% in unconsoli-dated formation. Through simulation, the temperature of the mud outlet was stable at − 1 (cid:48) 21 (cid:158) C after circulating for 9 h in a 1,200 m well, with the temperature of the mud inlet at − 5 (cid:158) C and a flow rate of 800 L/min. It provides a new method for the rapid evaluation of marine hydrate resources.