Experimental investigations on energy recovery from water-saturated hydrate bearing sediments via depressurization approach

Chong, Zheng Rong; Yin, Zhenyuan; Tan, Jun; Linga, Praveen

doi:10.1016/j.apenergy.2017.04.031

Cited by 155 publications

(85 citation statements)

References 61 publications

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“…The results indicated that the process of gas production is significantly influenced by the depressurization amplitude and the ambient temperature. Linga et al [27] confirmed that the gas production from hydrate can be enhanced by depressurization at the temperature below ice point. Song et al [28] analyzed the gas production process of hydrate by depressurization method.…”

Section: Introductionmentioning

confidence: 97%

Experimental Investigation on the Production Behaviors of Methane Hydrate in Sandy Sediments by Different Depressurization Strategies

Chen

et al. 2018

Energy Tech

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The depressurization method is one of the most promising methods for the exploitation of hydrate reservoirs and has been conducted in several field tests. In this work, the production behaviors of methane hydrate in sand sediments by different depressurization strategies were comparatively investigated using a cubic hydrate simulator (CHS) with a capacity of 5.832 L. The experimental conditions are based on the hydrate reservoirs parameters of the South China Sea. The results indicate that the hydrate dissociation rate is related to production pressure and heat conduction between the sediments and the surroundings. Some hydrate form again at the beginning of depressurization and the progress of hydrate dissociation during stable depressurization stage is basically along with the P−T curve. The cumulative amounts of gas production are almost the same, affirming it depends on the final depressurization amplitude, and less water produced when a short shut‐in period is conducted before hydrate dissociation. Compared to single‐step depressurization strategy, the multistep depressurization possesses a more well‐distributed gas production, and the sensible heat of sediments contributes less to hydrate dissociation. Despite the production period is longer, its temperature over the whole production process is higher, which has the potential to reduce the secondary hydrate formation and the damage of wellbore and sediments effectively in actual hydrate production.

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Section: Introductionmentioning

confidence: 97%

Experimental Investigation on the Production Behaviors of Methane Hydrate in Sandy Sediments by Different Depressurization Strategies

Chen

et al. 2018

Energy Tech

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“…Gleaning from our past experience with both experiments and simulations of the MH formation process in sandy media [20,23,33], we postulate that the rate of hydrate formation rate (and the corresponding heterogeneity effects on the spatial distribution of SH) can be controlled by the degree of sub-cooling (∆Tsub) applied to the closed system (laboratory apparatus) used in the excess-water method. The term ∆Tsub can be defined as the onset temperature of MH below its equilibrium temperature (Teq).…”

Section: Introductionmentioning

confidence: 99%

“…To date, various techniques have been devised to form hydrate in porous media in the laboratory, including the excess-gas method [20,21], the excess-water method [22,23], the dissolved-gas method [24] and the ice-to-hydrate method [25]. A persistent and recurring issue in all these techniques is that of spatial heterogeneity of hydrate in the core [15,20,24,26].…”

Section: Introductionmentioning

confidence: 99%

“…The numerical studies of Yin et al [33,34] analysed through history-matching (inverse modelling) laboratory data of MH formation and dissociation in a sandy core in a 1.0 L reactor, and the optimized parameters determined in the process closely matched the pressure and temperature measurements and yielded consistent predictions of heterogeneous spatial distributions of all phases. The MH formation method of Chong et al [23,35] that provided the data for the Yin et al [33,34] studies was shown to lead to significantly heterogeneous spatial distributions of SH (high SH near the reactor cooling boundary, and low SH at the reactor centre) as a result of the apparatus design. The numerical studies of Yin et al [33,34] also determined that the thermal processes associated with the reactor cooling and the warm water injection (to effect dissociation) had a considerable impact on the spatial distribution of SH in the hydrate-bearing core, as did the ambient air temperature.…”

Section: Introductionmentioning

confidence: 99%

“…Most laboratory studies of core behaviour up to now have only focused on the morphology and the characteristics of fluid flow during MH formation [37][38][39], and far fewer have addressed the heat transport behaviour and the kinetics of the hydrate formation reaction in cores. Practically all hydrate formation studies have been conducted by either exposing the core-containing vessel to a constant low temperature [20,29] or by rapid cooling of the vessel in a step that lowers the temperature below the equilibrium level [23,35,40]. There is limited information on the system behaviour and the phase spatial distributions induced by a different cooling process (e.g., slow cooling rate and low degree of sub-cooling).…”

Section: Introductionmentioning

confidence: 99%

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Effectiveness of multi-stage cooling processes in improving the CH4-hydrate saturation uniformity in sandy laboratory samples

et al. 2019

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Laboratory-created samples of methane hydrate (MH)-bearing media are a necessity because of the rarity and difficulty of obtaining naturally-occurring samples. The hypothesis that the inevitable heterogeneity in the phase saturations of the laboratory samples may lead to unreliable and non-repeatable results provided the impetus for this study, which aimed to determine the conditions under which maximum uniformity can be achieved. To that end, we designed four experiments involving different multi-stage cooling regimes (in terms of their duration and number of stages) to induce MH formation under excess-water conditions. In the absence of direct visualization capabilities, we analysed the experimental results by means of numerical simulation, which provided high-resolution predictions of the spatial distributions of the phase saturations in the cores and enabled the estimation of the parameters controlling the kinetic MH-formation behaviour through history-matching. Analysis of the numerical results indicated that, under the conditions of the experiments and with the design of the reactor, significant heterogeneities in phase saturation distributions were observed in all cases, leading to the conclusion that it is not possible to obtain cores with uniform phase saturation. Additionally, contrary to expectations, heterogeneities increased with the number of cooling stages and the duration of cooling, and this was attributed to imperfect insulation of the upper part of the reactor. A set of simulations involving perfect insulation of the reactor top confirmed the validity of this assumption: (a) predicting the formation of high-uniformity MH-bearing cores that became more homogeneous as 1 The short version of the paper was presented at ICAE2018, Aug 22-25 (2018), Hong Kong. This paper is a substantial extension of the short version of the conference paper.2 the number of cooling stages and the length of the cooling period increased; and (b) providing important information for the improvement of the standard design of the experimental apparatus for the laboratory creation of MH-bearing cores using the excess water method.

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Research Development in the Traditional Methods and Water Flow Erosion for Natural Gas Hydrate Production: A Review

Sun

Chen

Zhu³

et al. 2022

Energy Tech

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Natural gas hydrates are considered a possible sustainable energy source. Various methods have been proposed and developed in the past few decades to exploit hydrate. The purpose of this paper is to review the research advances, application potential, and limitations of hydrate production methods, including four traditional methods (depressurization, thermal stimulation, inhibitor injection, and CO2 replacement), and novel water flow erosion. For the four traditional methods, there still exist many bottlenecks to achieve commercial hydrate production owing to a series of problems such as vast sand production, ice generation, hydrate reformation, lower energy efficiency, and huge water production. For the water flow erosion method, it can be a novel strategy to promote hydrate decomposition by introducing the chemical potential difference and accelerating mass transfer. Significantly, if the traditional methods assist with water flow erosion, the problems such as insufficient decomposition driving force and ice generation are prevented. However, there is always a gap between the experimental results and the practical application of the water flow erosion method. Therefore, future work should be undertaken to investigate the selection criteria of suitable water flow rates for different reservoirs and the ecological security of the hydrate reservoir during the water flow erosion process.

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Experimental investigations on energy recovery from water-saturated hydrate bearing sediments via depressurization approach

Cited by 155 publications

References 61 publications

Experimental Investigation on the Production Behaviors of Methane Hydrate in Sandy Sediments by Different Depressurization Strategies

Experimental Investigation on the Production Behaviors of Methane Hydrate in Sandy Sediments by Different Depressurization Strategies

Effectiveness of multi-stage cooling processes in improving the CH4-hydrate saturation uniformity in sandy laboratory samples

Research Development in the Traditional Methods and Water Flow Erosion for Natural Gas Hydrate Production: A Review

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