Experimental study on dissociation of hydrate reservoirs with different saturations by hot brine injection

Li, Shuxia; Wang, Zhiqiang; Xu, Xinhua; Zheng, Ruyi; Hou, Jirui

doi:10.1016/j.jngse.2017.07.032

Cited by 39 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The enlarged view of Figure 3 indicates that the pressure had a slight increase in runs 2 and 3 during the depressurization. This may be because methane was wrapped in the NaCl solution, which would deform and squeeze when passing through the pipeline and valve, resulting in great flow resistance during the flow of the produced liquid, and in serious cases, resulting in temporary pipeline “blockage” (Jamin effect) [ 33 ]. Figure 3 also exhibits that the rates of the pressure decrease of runs 1–3 were essentially coincident during the depressurization.…”

Section: Resultsmentioning

confidence: 99%

Study on Hydrate Production Behaviors by Depressurization Combined with Brine Injection in the Excess-Water Hydrate Reservoir

Zeng

Zhang

Chen

et al. 2022

Entropy

View full text Add to dashboard Cite

Depressurization combined with brine injection is a potential method for field production of natural gas hydrate, which can significantly improve production efficiency and avoid secondary formation of hydrate. In this work, the experiments of hydrate production using depressurization combined with brine injection from a simulated excess-water hydrate reservoir were performed, and the effects of NaCl concentration on hydrate decomposition, temperature change, and heat transfer in the reservoir were investigated. The experimental results indicate that there is little gas production during depressurization in a excess-water hydrate reservoir, and the gas dissociated from hydrate is trapped in pores of sediments. The high-water production reduces the final gas recovery, which is lower than 70% in the experiments. The increasing NaCl concentration only effectively promotes gas production rate in the early stage. The final cumulative gas production and average gas production rate have little difference in different experiments. The NaCl concentration of the produced water is significantly higher than that which is in contact with hydrate in the sediments because the water produced by hydrate decomposition exists on the surface of undissociated hydrate. The high concentration of NaCl in the produced water from the reactor significantly reduces the promoting effect and efficiency of NaCl solution on hydrate decomposition. The injection of NaCl solution decreases the lowest temperature in sediments during hydrate production, and increases the sensible heat and heat transfer from environment for hydrate decomposition. The changes of temperature and resistance effectively reflect the distribution of the injected NaCl solution in the hydrate reservoir.

show abstract

Section: Resultsmentioning

confidence: 99%

Study on Hydrate Production Behaviors by Depressurization Combined with Brine Injection in the Excess-Water Hydrate Reservoir

Zeng

Zhang

Chen

et al. 2022

Entropy

View full text Add to dashboard Cite

show abstract

“…A different reactor used to inject hot brine was designed by the College of Petroleum Engineering in China University of Petroleum (East China). The reactors were cubes with a length and width of 350 mm, a height 60 mm, 16 temperature sensors, and 16 electrode probes, which were arranged in the upper and lower parts, respectively . A simulation experiment was conducted on the continuous injection of hot brine.…”

Section: Reactors For Gas Production Researchmentioning

confidence: 99%

Progress on Laboratory-Scale Reactors for Simulating Gas Production from Hydrate Reservoir

et al. 2021

View full text Add to dashboard Cite

Enormous laboratory efforts have been made to establish a better understanding of gas production behaviors from hydrate reservoirs. This involves an artificial synthesis and decomposition of hydrate samples in various reactors. The reactors should play a crucial role in the behaviors of hydrate formation and decomposition as well as their feasibility to scale-up. Therefore, a comprehensive summary of the current equipment is necessary. In this work, typical reactors used to study gas production behaviors from hydrate-containing sediments are introduced, involving their sizes, sensors, pressure and temperature controlling systems, and special features; the significant findings based on these reactors are also discussed. Through the results of laboratory experiments, the state of hydrate reservoirs and the changes in their characteristics during the production process can be understood; this may involve the kinetics of hydrate decomposition and its influencing factors and the seepage process of multiphase flow in sediments. Consequently, the primary control factors and control methods that affect the gas production rate and environmental safety can be given. The real-time measurement of hydrate reservoir temperature, pressure, sonic velocity, resistivity, stress, and other parameters can be determined; thus, the research on natural gas hydrate in the laboratory requires very strict equipment for support. Nevertheless, the space of the indoor simulated reactors was limited; the diameter of the largest reactor was no more than 2 m, which is not comparable to the actual reservoir. Therefore, it is still very challenging to upscale the laboratory findings to guide the on-site operation; multiscale approaches involving numerical simulation are of crucial importance as well.

show abstract

“…The natural gas hydrate is widely distributed throughout the world, and the reserves are very rich . The reserves are predicted from 3.1 × 10 15 m 3 to 7.6 × 10 18 m 3 (Nanhai 2017), and the reserves of hydrates in different regions are also different . It is necessary to accurately determine the gas hydrate saturation .…”

Section: Analyzing the Basic Physical Properties Of Hydrate Sedimentsmentioning

confidence: 99%

Application of X‐Ray Computed Tomography Technology in Gas Hydrate

Zheng

Tang

et al. 2019

Energy Tech

View full text Add to dashboard Cite

Clathrate hydrates are formed by water molecules and natural gas molecules under a certain temperature and pressure. Natural gas hydrates are mainly distributed in the marine sediments and the permafrost in nature. As a kind of potential clean energy, determining the structural characteristics of hydrates in sediments is the prerequisite for the safe and economic exploitation of natural gas hydrate. X‐ray computed tomography (CT) is a potential method to nondestructively detect the occurrence of natural gas hydrate. The basic physical properties such as porosity, hydrate saturation, and sediment permeability of the hydrate‐bearing sediments are analyzed by calculating the CT numbers or combining with the network model. Therefore, the X‐ray CT is used to study the hydrates produced in the laboratory and the hydrates formed in the nature by scientists all over the world. By summarizing the previous research, this article focuses on the important role of X‐ray CT in the hydrate research from the following three aspects: analyzing the basic physical properties of hydrate sediment, identifying the occurrence mode of hydrate in sediments, and measuring the hydrate formation and decomposition process. In response to the research progress and future research directions, relevant suggestions had been put forward.

show abstract

Experimental study on dissociation of hydrate reservoirs with different saturations by hot brine injection

Cited by 39 publications

References 18 publications

Study on Hydrate Production Behaviors by Depressurization Combined with Brine Injection in the Excess-Water Hydrate Reservoir

Study on Hydrate Production Behaviors by Depressurization Combined with Brine Injection in the Excess-Water Hydrate Reservoir

Progress on Laboratory-Scale Reactors for Simulating Gas Production from Hydrate Reservoir

Application of X‐Ray Computed Tomography Technology in Gas Hydrate

Contact Info

Product

Resources

About