The Research on a Driving Device for Natural Gas Hydrate Pressure Core

Precise pressure core motion, including translation and rotation, is the basis and core part of the Analysis and Transfer System of Natural Gas Hydrate Pressure Core, which is crucial to nondestructive analyses, core cutting, and transfer. This paper mainly proposes a driving device, whereby a pressure core, up to 3 m long, can be transferred from pressure core drilling tools to proceed to nondestructive analyses and transferring the cores into other chambers. The lead screw is one of the most important components of this driving device. Therefore, the modal analyses of the lead screw are performed, which can help researchers to analyze the stability of this device. The analyzed data shows that the different positions of the slider have a great impact on the natural frequency of the lead screw. Furthermore, the lead screw with a support slider has a larger natural frequency than that without a support slider. According to data analysis, we can derive that the device with the support slider has a much larger rigidity, which can contribute to the stability of the device. To verify the feasibility of this device, the deformation of the lead screw was tested by the Micro-Electro-Mechanical Systems (MEMS) accelerometer array. Experimental results show that the deformation of the lead screw with the support slider is much less than that without the support slider.

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MRI Visualization of Spontaneous Methane Production From Hydrates in Sandstone Core Plugs When Exposed to CO2

SPE Journal ◽

10.2118/118851-pa ◽

2008 ◽

Vol 13 (02) ◽

pp. 146-152 ◽

Cited By ~ 37

Author(s):

Arne Graue ◽

B. Kvamme ◽

Bernie Baldwin ◽

Jim Stevens ◽

James J. Howard ◽

...

Keyword(s):

Natural Gas ◽

Gas Hydrates ◽

Gas Hydrate ◽

Methane Production ◽

Methane Hydrate ◽

Co2 Storage ◽

Natural Gas Hydrate ◽

Hydrate Dissociation ◽

Natural Gas Hydrates ◽

The Stability

Summary Magnetic resonance imaging (MRI) of core samples in laboratory experiments showed that CO2 storage in gas hydrates formed in porous rock resulted in the spontaneous production of methane with no associated water production. The exposure of methane hydrate in the pores to liquid CO2 resulted in methane production from the hydrate that suggested the exchange of methane molecules with CO2 molecules within the hydrate without the addition or subtraction of significant amounts of heat. Thermodynamic simulations based on Phase Field Theory were in agreement with these results and predicted similar methane production rates that were observed in several experiments. MRI-based 3D visualizations of the formation of hydrates in the porous rock and the methane production improved the interpretation of the experiments. The sequestration of an important greenhouse gas while simultaneously producing the freed natural gas offers access to the significant amounts of energy bound in natural gas hydrates and also offers an attractive potential for CO2 storage. The potential danger associated with catastrophic dissociation of hydrate structures in nature and the corresponding collapse of geological formations is reduced because of the increased thermodynamic stability of the CO2 hydrate relative to the natural gas hydrate. Introduction The replacement of methane in natural gas hydrates with CO2 presents an attractive scenario of providing a source of abundant natural gas while establishing a thermodynamically more stable hydrate accumulation. Natural gas hydrates represent an enormous potential energy source as the total energy corresponding to natural gas entrapped in hydrate reservoirs is estimated to be more than twice the energy of all known energy sources of coal, oil, and gas (Sloan 2003). Thermodynamic stability of the hydrate is sensitive to local temperature and pressure, but all components in the hydrate have to be in equilibrium with the surroundings if the hydrate is to be thermodynamically stable. Natural gas hydrate accumulations are therefore rarely in a state of complete stability in a strict thermodynamic sense. Typically, the hydrate associated with fine-grain sediments is trapped between low-permeability layers that keep the system in a state of very slow dynamics. One concern of hydrate dissociation, especially near the surface of either submarine or permafrost-associated deposits, is the potential for the release of methane to the water column or atmosphere. Methane represents an environmental concern because it is a more aggressive (~25 times) greenhouse gas than CO2. A more serious concern is related to the stability of these hydrate formations and its impact on the surrounding sediments. Changes in local conditions of temperature, pressure, or surrounding fluids can change the dynamics of the system and lead to catastrophic dissociation of the hydrates and consequent sediment instability. The Storegga mudslide in offshore Norway was created by several catastrophic hydrate dissociations. The largest of these was estimated to have occurred 7,000 years ago and was believed to have created a massive tsunami (Dawson et al. 1988). The replacement of natural gas hydrate with CO2 hydrate has the potential to increase the stability of hydrate-saturated sediments under near-surface conditions. Hydrocarbon exploitation in hydrate-bearing regions has the additional challenge to drilling operations of controlling heat production from drilling and its potential risk of local hydrate dissociation (Yakushev and Collett 1992). The molar volume of hydrate is 25-30% greater than the volume of liquid water under the same temperature-pressure conditions. Any production scenario for natural gas hydrate that involves significant dissociation of the hydrate (e.g., pressure depletion) has to account for the release of significant amounts of water that in turn affects the local mechanical stress on the reservoir formation. In the worst case, this would lead to local collapse of the surrounding formation. Natural gas production by CO2 exchange and sequestration benefits from the observation that there is little or no associated liquid water production during this process. Production of gas by hydrate dissociation can produce large volumes of associated water, and can create a significant environmental problem that would severely limit the economic potential. The conversion from methane hydrate to a CO2 hydrate is thermodynamically favorable in terms of free energy differences, and the phase transition is coupled to corresponding processes of mass and heat transport. The essential question is then if it is possible to actually convert methane hydrate as found in sediments to CO2 hydrate. Experiments that formed natural gas hydrates in porous sandstone core plugs used MRI to monitor the dynamics of hydrate formation and reformation. The paper emphasizes the experimental procedures developed to form the initial natural gas hydrates in sandstone pores and the subsequent exchange with CO2 while monitoring the dynamic process with 3D imaging on a sub millimetre scale. The in-situ imaging illustrates the production of methane from methane hydrate when exposed to liquid CO2 without any external heating.

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A novel mathematical method for evaluating the wellbore deformation of a diagenetic natural gas hydrate reservoir considering the effect of natural gas hydrate decomposition

Natural Gas Industry B ◽

10.1016/j.ngib.2021.04.009 ◽

2021 ◽

Author(s):

Qiangui Zhang ◽

Zhaoxiang Wang ◽

Xiangyu Fan ◽

Na Wei ◽

Jun Zhao ◽

...

Keyword(s):

Mathematical Method ◽

Natural Gas ◽

Gas Hydrate ◽

Natural Gas Hydrate ◽

Hydrate Decomposition ◽

Hydrate Reservoir ◽

Gas Hydrate Reservoir

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Oedometer test of natural gas hydrate-bearing sands: Particle-scale simulation

Journal of Natural Gas Science and Engineering ◽

10.1016/j.jngse.2020.103631 ◽

2020 ◽

Vol 84 ◽

pp. 103631

Author(s):

Haitao Zhang ◽

Jinfeng Bi ◽

Xianqi Luo

Keyword(s):

Natural Gas ◽

Gas Hydrate ◽

Natural Gas Hydrate ◽

Oedometer Test

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Natural Gas Hydrate Formation Using Saline/Seawater for Gas Storage Application

Energy & Fuels ◽

10.1021/acs.energyfuels.1c00399 ◽

2021 ◽

Vol 35 (7) ◽

pp. 5988-6002 ◽

Cited By ~ 1

Author(s):

Hari Prakash Veluswamy ◽

Praveen Linga

Keyword(s):

Natural Gas ◽

Gas Hydrate ◽

Hydrate Formation ◽

Gas Storage ◽

Natural Gas Hydrate ◽

Gas Hydrate Formation

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A Comprehensive Review on Well Completion Operations and Artificial Lift Techniques for Methane Gas Production from Natural Gas Hydrate Reservoirs

Energy & Fuels ◽

10.1021/acs.energyfuels.1c01437 ◽

2021 ◽

Author(s):

Chandan Sahu ◽

Rajnish Kumar ◽

Jitendra S. Sangwai

Keyword(s):

Natural Gas ◽

Gas Hydrate ◽

Gas Production ◽

Natural Gas Hydrate ◽

Comprehensive Review ◽

Methane Gas ◽

Well Completion ◽

Artificial Lift ◽

Hydrate Reservoirs

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Evaluation and re-understanding of the global natural gas hydrate resources

Petroleum Science ◽

10.1007/s12182-021-00568-9 ◽

2021 ◽

Vol 18 (2) ◽

pp. 323-338

Author(s):

Xiong-Qi Pang ◽

Zhuo-Heng Chen ◽

Cheng-Zao Jia ◽

En-Ze Wang ◽

He-Sheng Shi ◽

...

Keyword(s):

Natural Gas ◽

Gas Hydrate ◽

Oil And Gas ◽

Material Balance ◽

Energy Resource ◽

Resource Assessment ◽

Future Trend ◽

Natural Gas Hydrate ◽

The Future ◽

Recoverable Resources

AbstractNatural gas hydrate (NGH) has been widely considered as an alternative to conventional oil and gas resources in the future energy resource supply since Trofimuk’s first resource assessment in 1973. At least 29 global estimates have been published from various studies so far, among which 24 estimates are greater than the total conventional gas resources. If drawn in chronological order, the 29 historical resource estimates show a clear downward trend, reflecting the changes in our perception with respect to its resource potential with increasing our knowledge on the NGH with time. A time series of the 29 estimates was used to establish a statistical model for predict the future trend. The model produces an expected resource value of 41.46 × 1012 m3 at the year of 2050. The statistical trend projected future gas hydrate resource is only about 10% of total natural gas resource in conventional reservoir, consistent with estimates of global technically recoverable resources (TRR) in gas hydrate from Monte Carlo technique based on volumetric and material balance approaches. Considering the technical challenges and high cost in commercial production and the lack of competitive advantages compared with rapid growing unconventional and renewable resources, only those on the very top of the gas hydrate resource pyramid will be added to future energy supply. It is unlikely that the NGH will be the major energy source in the future.

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