Challenges, Uncertainties, and Issues Facing Gas Production From Gas-Hydrate Deposits

Abstract

Summary The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas-hydrate (GH) petroleum system; to discuss advances, requirements, and suggested practices in GH prospecting and GH deposit characterization; and to review the associated technical, economic, and environmental challenges and uncertainties, which include the following: accurate assessment of producible fractions of the GH resource; development of methods for identifying suitable production targets; sampling of hydrate-bearing sediments (HBS) and sample analysis; analysis and interpretation of geophysical surveys of GH reservoirs; well-testing methods; interpretation of well-testing results; geomechanical and reservoir/well stability concerns; well design, operation, and installation; field operations and extending production beyond sand-dominated GH reservoirs; monitoring production and geomechanical stability; laboratory investigations; fundamental knowledge of hydrate behavior; the economics of commercial gas production from hydrates; and associated environmental concerns.

Production Performance Analysis of Class II Hydrate-Bearing Layers Based on an Analytic Aquifer Model

“…According to these mechanisms, the main development methods can be divided into depressurization, thermal stimulation, inhibitor injection, and CO 2 replacement, among which the depressurization method is currently the most economical method (Wei et al, 2018). Moridis et al investigated HBLs and divided them into three classes (Moridis et al, 2011a). Class I HBLs comprise an overlying hydrate layer and an underlying free gas layer.…”

“…Over the past few years, many researchers have investigated the performance of Class II HBLs using the experimental and simulation methods. Based on the geological parameters of HBLs in Malik, Canada, Moridis et al (2011a;2011b) carried out numerical simulation studies and compared the performance of the depressurization method under different perforation schemes. The results show that the method involves a gas production interval within the water layer, and heating of the outer surface of the wellbore gives the best performance.…”

Joint interpretation of geophysical field experiments in the danube deep-sea fan, Black Sea

“…Since the first indications of the globally occurrence of marine gas hydrates (GH) it has been speculated that such deposits could serve as an additional energy resource due to the large amount of methane (CH 4 ) gas locked up in gas hydrates (Moridis et al 2011;e.g. Boswell and Collett 2011;Boswell et al 2015).…”

On the path to the digital rock physics of gas hydrate bearing sediments – processing of in-situ synchrotron-tomography data

“…Two of such difficult environments are certainly marine and permafrost strata that are host to crystalline gas-water compounds known as gas hydrates (GHs) (Sloan and Koh, 2008). Composed predominantly of methane, GHs are a target of intensive geophys-K. Sell et al: On the path to the digital rock physics of gas hydrate-bearing sediments ical surveys, drilling and well-logging operations aiming at the identification and quantification of natural deposits of this unconventional source of hydrocarbons (Sloan and Koh, 2008;Boswell and Collett, 2011;Moridis et al, 2011). The identification of potential deposits with remote sensing methods largely relies on high electric resistivity or characteristic seismic anomalies in which the increased velocity of seismic wave is coupled with high attenuations (Best et al, 2010;Guerin and Goldberg, 2005;Matsushima et al, 2015;Priest et al, 2006).…”