Numerical simulation on gas production from inclined layered methane hydrate reservoirs in the Nankai Trough: A case study

Mao, Peixiao; Sun, Jiaxin; Ning, Fulong; Chen, Lin; Wan, Yizhao; Hu, Gaowei; Wu, N.

doi:10.1016/j.egyr.2021.03.032

Cited by 20 publications

(7 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The unusually high gas production rate on the first day was caused by an instantaneous pressure drop from 13.5 MPa to 4.5 MPa, resulting in a slightly higher cumulative gas production than the actual value. Given the similar results observed in other studies [22,37,40,41], it could be concluded that the model was accurate and has been successfully established. Based on the successful establishment of the model, a one-year simulation by the direct depressurization method was conducted using this model.…”

Section: Model Validationsupporting

confidence: 83%

“…The gas production rate then gradually decreased, reaching a value of 1.15 × 10 4 m 3 /d at the end of the first year. This decreasing trend was attributed to the slow pressure propagation, which hindered the decomposition of hydrates [41]. In contrast, the water production rate remained stable at 0.6 × 10 4 m 3 /d throughout the year.…”

Section: Characteristics Of Gas and Water Productionmentioning

confidence: 98%

See 1 more Smart Citation

Numerical Simulation of Optimized Step-Wise Depressurization for Enhanced Natural Gas Hydrate Production in the Nankai Trough of Japan

Xue,

Liu,

et al. 2023

Processes

View full text Add to dashboard Cite

The utilization of natural gas hydrates as an alternative energy source has garnered significant attention due to their proven potential. Despite the successful offshore natural gas hydrate production tests, commercial exploitation has not been achieved. This study aims to enhance the understanding of gas production behavior through simulations from a single vertical well in the Nankai Trough and assess the effectiveness of the step-wise depressurization method for gas production using TOUGH + HYDRATE. The simulation results showed that the effective permeability for the water phase decreased as the hydrates were decomposed, and the invasion of the pore water from the underburden eliminated this effect. Compared with the direct depressurization method, the step-wise depressurization method significantly increased the cumulative gas production by more than 10% and mitigated the rapid generation of gas and water production during the moment of depressurization. The results also indicated that the depressurization gradient was more sensitive to the cumulative gas production than the maintenance time of depressurization. In view of the gas and water production characteristics coupled with the challenges in carrying out the step-wise depressurization method, it is suggested that a depressurization gradient of 1 MPa and a maintenance time of 1 day should be employed.

show abstract

Section: Model Validationsupporting

confidence: 83%

Section: Characteristics Of Gas and Water Productionmentioning

confidence: 98%

Numerical Simulation of Optimized Step-Wise Depressurization for Enhanced Natural Gas Hydrate Production in the Nankai Trough of Japan

Xue,

Liu,

et al. 2023

Processes

View full text Add to dashboard Cite

show abstract

“…Among the above-mentioned approaches, depressurization has been identified as the most practical and efficient way owing to the relatively simple borehole configuration and low cost of well operation as well as the high energy output–input ratio. As a result, this approach has been applied in the short-term field tests of offshore NGH production conducted in the Nankai Trough of Japan , and the Shenhu Area of the South China Sea. , However, owing to the endothermic hydrate decomposition, gas production induced by depressurization depends largely on the ambient heat transfer in the NGH deposits . With the continuous consumption of the sensible heat of the reservoir stratum, gas production rate tends to gradually decline due to the insufficient heat supply for the hydrate decomposition process .…”

Section: Introductionmentioning

confidence: 99%

Feasibility Evaluation of a New Approach of Seawater Flooding for Offshore Natural Gas Hydrate Exploitation

Chen

Jiang

et al. 2023

Energy Fuels

View full text Add to dashboard Cite

In this work, a new approach of seawater flooding was proposed for offshore natural gas hydrate (NGH) exploitation, whose feasibility was numerically evaluated based on a large-scale NGH reservoir situated in the Shenhu Area of the South China Sea. Then, two artificial means of well location rearrangement and hydraulic fracturing, as well as their combination, were proposed to be incorporated with seawater flooding to promote gas production from offshore NGH deposits. Simulation results indicated that seawater flooding had great advantages over depressurization and could substantially promote hydrate dissociation, effectively prevent secondary hydrate formation, and greatly facilitate gas production. Furthermore, a stable gas production period could be achieved for a long duration, which made the most significant contribution to gas production. The two artificial means of well location rearrangement and hydraulic fracturing could both promote hydrate dissociation and enhance gas recovery, but the promotion mechanisms were different. When these two methods were combined, hydrate dissociation in the whole hydrate-bearing layer could be further facilitated, and a favorable gas production rate could be obtained with a low water production and a high gas−water ratio, which demonstrated great superiority of the combined method over these two methods when used alone. Therefore, it is expected that the newly proposed approach of seawater flooding combined with well location rearrangement and hydraulic fracturing can be applied in the future commercial offshore NGH development.

show abstract

“…In addition, Konno et al proposed a cyclic depressurization method in an attempt to achieve the sustainable production of hydrate reservoirs. Wu et al . simulated the gas production process of the hydrate reservoir in the Nankai Trough and investigated the effect of well pattern layout on reservoir production.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, Konno et al 19 proposed a cyclic depressurization method in an attempt to achieve the sustainable production of hydrate reservoirs. Wu et al 20 simulated the gas production process of the hydrate reservoir in the Nankai Trough and investigated the effect of well pattern layout on reservoir production. To explore the synergistic interactions between production wells and multiple wells combined depressurization to produce gas from hydrate reservoirs were also investigated by numerical analysis and simulation.…”

Section: Introductionmentioning

confidence: 99%

Numerical Evaluation of Long-Term Depressurization Production of a Multilayer Gas Hydrate Reservoir and Its Hydraulic Fracturing Applications

Cai

Ding

et al. 2022

Energy Fuels

View full text Add to dashboard Cite

In this study, a multilayer gas hydrate reservoir model was implemented based on the geological conditions of the Shenhu area in the South China Sea (SHCS) to predict the production performance of the reservoir during long-term depressurization. Hydraulic fracturing technology was introduced to boost production, and its positive/negative impact on the production behavior of the hydrate reservoir was evaluated. Results show that hydrate dissociation is severely constrained by pressure propagation and fluid flow in the low reservoir. During production, almost half of the wellhead gas production is from the dissolved gas in seawater and the free gas contained in sediments. Massive secondary hydrate forms and gathers in the hydrate layer I and near the interface of hydrate layers. Underlying free gas is conducive to reservoir production, in which the cumulative wellhead gas production can be increased by ∼59% compared to the reservoir lacking underlying free gas. On one hand, hydraulic fracturing can significantly promote hydrate dissociation and increase the capacity of production, especially for long-distance fracture implemented in the middle part of the hydrate layer. On the other hand, high permeability in the fractured zone also provides a convenient channel for water in the sedimentary layer. After hydraulic fracturing, the production efficiency of the reservoir is still low due to the involvement of more pore water. In future, the combination of hydraulic fracturing and other auxiliary means can be considered to develop hydrate reservoirs.

show abstract

Numerical simulation on gas production from inclined layered methane hydrate reservoirs in the Nankai Trough: A case study

Cited by 20 publications

References 58 publications

Numerical Simulation of Optimized Step-Wise Depressurization for Enhanced Natural Gas Hydrate Production in the Nankai Trough of Japan

Numerical Simulation of Optimized Step-Wise Depressurization for Enhanced Natural Gas Hydrate Production in the Nankai Trough of Japan

Feasibility Evaluation of a New Approach of Seawater Flooding for Offshore Natural Gas Hydrate Exploitation

Numerical Evaluation of Long-Term Depressurization Production of a Multilayer Gas Hydrate Reservoir and Its Hydraulic Fracturing Applications

Contact Info

Product

Resources

About