Numerical Simulation of Gas Production from Natural Gas Hydrate Using a Single Horizontal Well by Depressurization in Qilian Mountain Permafrost

In November 2008, gas hydrate samples were recovered during the scientific expedition conducted in the Qilian Mountain Permafrost. It is expected that this area will become a strategic area of gas hydrate production in China. However, the evaluation of the hydrate deposits in the area as a potential energy resource has not been completed. Using numerical simulation and currently available data from site measurements, we preliminarily estimate the gas production potential of these hydrate reservoirs. The cumulative volume of the produced CH4 at the well in the early production period (0–10 years) is more than 50% of the total gas production from the well. The gas hydrate dissociation mainly occurs in the vicinity of the horizontal well and along a cylindrical interface. There is a ringlike structure of ice around the horizontal well during the gas production process. With the decrease of the gas production rate, the ice starts to melt from the bottom to the top under the influence of the geothermal gradien...

[1]  J. Carcione,et al.  Estimation of gas‐hydrate concentration and free‐gas saturation at the Norwegian‐Svalbard continental margin , 2005 .

[2]  Scott J. Wilson,et al.  Regional long-term production modeling from a single well test, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope , 2011 .

[3]  K. Kvenvolden.  Gas hydrates—geological perspective and global change , 1993 .

[4]  Martinus Oostrom,et al.  STOMP Subsurface Transport Over Multiple Phases, Version 4.0, User’s Guide , 2006 .

[5]  George J. Moridis,et al.  Gas production from a cold, stratigraphically-bounded gas hydrate deposit at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Implications of uncertainties , 2011 .

[6]  K. Rose,et al.  Simulations of Variable Bottomhole Pressure Regimes to Improve Production from the Double-Unit Mount Elbert, Milne Point Unit, North Slope Alaska Hydrate Deposit , 2011 .

[7]  George J. Moridis,et al.  The use of huff and puff method in a single horizontal well in gas production from marine gas hydrate deposits in the Shenhu Area of South China Sea , 2010 .

[8]  Van Genuchten,et al.  A closed-form equation for predicting the hydraulic conductivity of unsaturated soils , 1980 .

[9]  George J. Moridis,et al.  Numerical studies of gas production from several CH4 hydrate zones at the Mallik site, Mackenzie Delta, Canada , 2004 .

[10]  Stephen A. Holditch,et al.  Natural gas-hydrates — A potential energy source for the 21st Century , 2007 .

[11]  George J. Moridis,et al.  Depressurization-induced gas production from Class 1 hydratedeposits , 2005 .

[12]  George J. Moridis,et al.  Evaluation of Gas Production Potential from Marine Gas Hydrate Deposits in Shenhu Area of South China Sea , 2010 .

[13]  Youhai Zhu,et al.  Gas hydrate occurrences in the Qilian Mountain permafrost, Qinghai Province, China , 2011 .

[14]  George J. Moridis,et al.  Numerical Studies of Gas Production From Class 2 and Class 3 Hydrate Accumulations at the Mallik Site, Mackenzie Delta, Canada , 2004 .