Title: Productivity and feasibility analysis of gas production from subsea sediment bearing with natural gas hydrate

Authors: Zhiwu Gong; Liang Zhang; Haiqing Cheng; Yanyong Wang; Di Qi; Shaoran Ren

Addresses: School of Petroleum Engineering, China University of Petroleum (Huadong), No. 66, Changjiang West Road, Huangdao District, Qingdao, Shandong 266580, China ' School of Petroleum Engineering, China University of Petroleum (Huadong), No. 66, Changjiang West Road, Huangdao District, Qingdao, Shandong 266580, China ' Research Institute of Petroleum Exploration and Development, Liaohe Oilfield, CNPC, Panjin, 124000, China ' School of Petroleum Engineering, China University of Petroleum (Huadong), No. 66, Changjiang West Road, Huangdao District, Qingdao, Shandong 266580, China ' School of Petroleum Engineering, China University of Petroleum (Huadong), No. 66, Changjiang West Road, Huangdao District, Qingdao, Shandong 266580, China ' School of Petroleum Engineering, China University of Petroleum (Huadong), No. 66, Changjiang West Road, Huangdao District, Qingdao, Shandong 266580, China

Abstract: A dynamics-model of natural gas hydrate (NGH) dissociation was established based on experimental results, which can be used for numerical simulation studies of gas production from subsea sediment bearing with hydrate. Three phases (aqueous, hydrate-solid and gaseous) and three components (water, methane hydrate and methane) were considered in the reservoir simulation model of gas hydrate. Comparisons between the numerical simulation and the experimental results were made to verify the simulation model. The reservoir model was then used to analyse the productivity of typical wells for gas production from hydrate via depressurisation, which was compared with that of conventional gas, tight gas and coalbed methane reservoirs to reveal the main features and feasibility of subsea NGH development. The simulation results indicated that, at similar reservoir scales, NGH reservoirs with hydrate saturation greater than 0.3 can have higher gas productivity than typical tight gas and coalbed methane reservoirs. That means gas production from NGH in subsea sediment can be feasible using the current technologies if reservoirs or formations with high hydrate saturation can be found, while its economics may be of further consideration. [Received: November 26, 2014; Accepted: April 15, 2015]

Keywords: natural gas hydrate; NGH reservoirs; reservoir simulation; gas productivity; tight gas; coalbed methane; hydrate dissociation; feasibility analysis; gas production; subsea sediment; dynamic modelling; numerical simulation; gas wells; depressurisation.

DOI: 10.1504/IJOGCT.2016.074773

International Journal of Oil, Gas and Coal Technology, 2016 Vol.11 No.3, pp.229 - 248

Received: 04 Dec 2014
Accepted: 15 Apr 2015
Published online: 17 Feb 2016 *

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