Gas Production Characteristics Research Articles

Experimental Study on Gas Production Capacity of Composite Reservoir Depletion in Deep Carbonate Gas Reservoirs

Deep carbonate gas reservoirs exhibit diverse reservoir types and complex seepage patterns. To study the gas production capabilities of different composite reservoir types, we classified the reservoirs of the fourth member of the Dengying Formation in the Anyue Gas Field into high-quality reservoirs (HRs) and poor-quality reservoirs (PRs) based on high-pressure mercury injection (HPMI) experiment results. By varying the differential pressure of the depletion experiment and the connection method, as well as the permeability and water saturation of the composite core, the effects of well location deployment, permeability ratio of the high-quality reservoir and poor-quality reservoir (PRHPR), gas well production pressure difference (GWPPD), and water saturation on the depletion gas production characteristics of the composite reservoir were studied. The research results show that (1) deploying wells on HR enables high gas production rates and ultimate recovery rates; (2) only when the PRHPR falls within a reasonable range (21.88–43.19) can the “dynamic recharge” capability of PR and the high permeability of HR be coordinated to achieve high gas recovery rates; (3) a GWPPD of 3 MPa is optimal, resulting in fast gas production rates and high ultimate recovery rates for PR; (4) high water saturation (≥50%) leads to premature water breakthrough at the well bottom, decreased gas production rate, and sealing of HR and PR reserves by formation water. Combining experimental results with field production data is our next research focus. Our future research focus will be on integrating experimental results with field production data to provide solid theoretical support for the efficient development of this type of gas reservoir.

Evaluation of Nutritive Value of Pleurotus tuber-regium Biodegraded Maize Cob using in Vitro Gas Production and Fermentation Characteristics

Evaluation of Nutritive Value of Pleurotus tuber-regium Biodegraded Maize Cob using in Vitro Gas Production and Fermentation Characteristics

Experimental Study on Edge Water Invasion of Strongly Heterogeneous Carbonate Gas Reservoirs Based on NMR Technology

Controlling the extent of water invasion in the reservoir and mitigating its detrimental effects on gas well production and natural gas recovery have long been a challenging task in the efficient development of strongly heterogeneous edge water gas reservoirs. To elucidate the edge water invasion mechanism of strongly heterogeneous carbonate gas reservoirs, this study investigates the pore throat characteristics and fluid mobility from both qualitative and quantitative aspects, leveraging natural core observations, cast thin sections, scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) tests with centrifuge experiments. A core-scale edge water invasion simulation experiment was conducted under online NMR monitoring to examine the dynamic gas production characteristics of the three types of reservoirs during the water invasion process and to elucidate the formation mechanism and distribution pattern of water-sealed gas. Research findings indicate that carbonate reservoirs typically exhibit a diverse range of pore types, including various types of fractures and cavities. Fractures significantly enhance reservoir connectivity, thereby increasing fluid mobility, but also lead to strong non-uniform water invasion. In contrast, cavities substantially improve the storage capacity of the reservoir and can retard the advancement of the water invasion front, thereby alleviating the adverse effects of water invasion. The ultimate recovery rates of fracture-type, cavity-type, and fracture-cavity cores in the water invasion simulation experiment were 29.81%, 64.87%, and 53.03%, respectively. Premature water breakthroughs in the reservoir can result in a large number of gases in matrix pores and even cavities being sealed by formation water, rendering them unrecoverable, which seriously impacts the gas recovery rate of the reservoir.

Thermal runaway and gas production characteristics of semi-solid electrolyte and liquid electrolyte lithium-Ion batteries: A comparative study

Solid-state electrolytes have attracted considerable attention as an alternative to liquid electrolytes for lithium-ion batteries. This study compares the thermal runaway and gas production of two commercially available lithium-ion batteries (i.e., the liquid electrolyte lithium iron phosphate battery (LFP-L) and the semi-solid electrolyte lithium iron phosphate battery (LFP-SS)) under different environments and states of charge (SOCs). The main findings include the following aspects: Regarding thermal runaway characteristics and gas production kinetics, LFP-SS exhibits a slower temperature rise rate but a higher per Ah pressure increase. The total gas production volume of LFP-SS is lower, but the gas production volume per Ah is approximately 1.5 times that of LFP-L batteries. The LFP-L produces gas rate per Ah more rapidly than the LFP-SS. As for the produced gas components, LFP-L has higher concentrations of H2 and hydrocarbons than LFP-SS. Concerning explosion limits, both the upper and lower explosion limits of LFP-SS are higher than those of LFP-L at 100 % SOC. However, for 110 % SOC, the upper explosion limit of LFP-SS is lower than that of LFP-L. Quantitative analysis of the safety performance of these batteries under different conditions shows that LFP-SS exhibits the best safety performance at 100 % SOC in a nitrogen environment. These results are hoped to guide battery selection and safety protection design for lithium-ion battery packs.

A novel method of microscale gas migration and production characteristics simulation considering adsorption characteristics

One challenge to the effective development of coalbed methane and shale gas is the complexity of their migration mechanism and production characteristics. Recognizing this, our study has devised an indoor experimental simulation system for production characteristics of coalbed methane or shale gas with a consideration of the effect of adsorbed gas. Firstly, we carried out a theoretically-informed quantitative identification of adsorbed gas, pore-confined gas, and free gas in the production process. Then, the theory was combined with experiments to quantitatively evaluate the production rates of these gases in different occurrence states and their contribution to the yield. This paper presents an application of this new method to coal-seam samples from the Da Ningji County Block. Our research suggests that during the extraction process, a higher gas production rate would lead to a higher pressure in the eventually abandoned formation, and ultimately a lower recovery rate. Specific findings include, firstly, that before extraction, the proportion of adsorbed gas in the samples is 80%, which then gradually increases during the extraction process, eventually reaching 90% at the end of production, with an average contribution of 70% to yield. Secondly, a greater contribution of adsorbed gas to production leads to a higher ultimate recovery rate. Thirdly, the desorption rate shows an upward trend in the stable production phase, gradually decreasing during the depletion production period, but the rate of decrease slows down as the development progresses. Fourthly, a higher desorption rate in the later stage of extraction is positively correlated with a higher ultimate recovery rate. Lastly, the contribution of pore-confined gas and free gas to production exceeds 70% in the early stage before gradually declining as extraction progresses, and no relationship of significance has been found between the production rate and recovery rate in the later stage. It is hoped that our study can provide theoretical underpinning for the optimization of coalbed methane and shale gas development.

Multilayer Commingled Production Effects in Hydrate Reservoirs with Underlying Gas

Multilayer commingled production is a widely used development method to improve the production capacity of gas reservoirs. However, there is currently limited research on the gas production characteristics of multilayer commingled production in hydrate reservoirs with underlying gas. The objective of this study was to analyze the characteristics of multilayer commingled production in order to determine suitable hydrate reservoirs for such a development method. Firstly, we employed analytical solutions to the equations of fluid flow in porous media to determine the factors affecting the production capacity. Then, by employing numerical simulation and depressurization methods, the rates of gas production and gas release from hydrate dissociation in a single production well were estimated. Additionally, the production capacity ratio of multilayer commingled production and separated-layer production was proposed. The influence of different reservoir characteristics on multilayer commingled production yield was determined and plotted. When there is an interlayer between hydrates and the underlying gas, the formation pressure ratio is the decisive factor affecting the multilayer commingled production yield. When there is no interlayer, the multilayer commingled production rate will increase with an increase in the permeability ratio, hydrate saturation, and underlying gas saturation. This study provides a theoretical foundation for predicting the production capacity of hydrate reservoirs, as well as assistance in selecting the hydrate reservoirs most suitable for multilayer commingled production.

Influence of Typical Defects on Insulation and Gas Production Characteristics of Oil-Impregnated Paper Bushing

Influence of Typical Defects on Insulation and Gas Production Characteristics of Oil-Impregnated Paper Bushing

Cotton stalk decomposition with DBD low-temperature plasma: Characteristics and kinetics

DBD low-temperature plasma (DLTP) is recognized as one of the most efficient technologies for treating cotton stalks. This study investigates the impact of various conditions on the gas production characteristics of cotton stalks (CS) and delves into the DLTP decomposition kinetics of CS and CSC in oxygen-enriched (30 % O2/Ar) and CO2 atmospheres. The decomposition rates of CS followed the order CO2 > N2 > Ar. The decomposition behavior of CSC in oxygen-enriched DLTP (30 % O2/Ar) aligned well with the chemical reaction model. The activation energies for CSC decomposition at 900 °C and 1000 °C were determined to be 23.8 kJ/mol and 33.8 kJ/mol, respectively. Moreover, the reaction rate decreased at higher carbonization temperatures, which proved to be detrimental to the decomposition of CSC. The DLTP decomposition of CSC in CO2 exhibited consistency with the fitting results of the unreacted shrinking core model, revealing an observed activation energy of 19.4 kJ/mol.

A novel gas injection method with swirl flow in underground gasification for improving gas production and controlling pollution yields

Underground coal gasification (UCG) is a promising technology, which can convert deep coal seams into high calorific value gas products through in-situ controllable combustion, for the traditional coal mining technology. However, the structure of raw coal is dense, and it is difficult for the injected gasification agent to penetrate from the coal surface to the inside of coal in the gasification channel, which leads to worse gasification performance. Different from conventional straight flow injection, swirl flow injection is proposed to improve the effective contact between the gas and the coal surface to enhance the gasification reaction efficiency. In this work, various types of novel swirl nozzles were independently designed. The characteristics of gas production, temperature distribution and tar pollutant are studied with different swirl angles. As the swirl number increases from 0 to 1.41, there is a significant enhancement in the residence time of oxygen in the axial direction and a reduction of the mass transfer between oxygen and the coal wall in the radial direction. As the oxygen flow rate increases from 0.5 to 2 L/min, swirl flow injection exhibits stronger gasification performance than traditional straight flow injection, such as maximum gas calorific value and tar generation control capability.

The gas production characteristics and catastrophic hazards evaluation of thermal runaway for LiNi0.5Co0.2Mn0.3O2 lithium-ion batteries under different SOCs

Lithium-ion batteries (LIBs) are widely used as electrochemical energy storage systems in electric vehicles due to their high energy density and long cycle life. However, fire accidents present a trend of frequent occurrence caused by thermal runaway (TR) of LIBs, so it is especially important to evaluate the catastrophic hazards of these LIBs. This study conducted the adiabatic TR test coupled gas production test, Gas Chromatography-Mass Spectrometry test, and explosion limit test on a commercial LIB with Ni0.5Co0.2Mn0.3 as the cathode material at different states of charge (SOCs). The results show that the TR temperature and the maximum temperature at low SOC are lower compared to that at a high SOC. The probability of LIBs TR at less than SOC = 50 % is small and also causing less harm. For the gas production characteristics, the lower the SOC of the battery, the lower the gas production volume. The peak and steady-state gas production increase with the increase of SOC. For the mixed gases generated during TR, the content of CO2 shows a trend of decreasing with the increasing of battery SOC, while that of H2 and CO increase with the increasing of SOC. For the explosion limit of the mixed gas, the lower explosion limit and upper explosion limit decrease and increase with the increasing of SOC, respectively. Finally, based on the seven parameters related to the TR gas production of LIBs and so on, the analytic hierarchy process method was used to establish a LIB TR disaster-causing hazard evaluation system. The evaluation system can quantitatively evaluate the thermal safety of a LIB. This is instructive for establishing a comprehensive quantitative evaluation method for battery safety in practical engineering applications.

Analysis of the Production Characteristics of Heterogeneous Reservoirs Assisted by Shallow Gas by Depressurization Path

The problems of low gas production rate and low gas production restrict the commercial production of natural gas hydrate. The combined production of hydrate reservoirs and underlying shallow gas reservoirs is expected to make up for this shortcoming. Most natural gas hydrates in the formation exhibit vertical heterogeneous distribution characteristics; There is still little research on the mechanism of its impact on the characteristics of co harvesting. This work focuses on the interaction between vertical heterogeneous hydrate reservoirs and shallow gas layers, and analyzes the mechanism of the impact of depressurization pathway on the characteristics of combined production. The results indicate that before the pressure in the shallow gas layer is equal to the pressure in the hydrate layer, the change in pressure reduction method cannot significantly affect the characteristics of pressure changes in the shallow gas layer; In addition, there is a significant hysteresis effect in the pressure evolution of shallow gas layers compared to hydrate layers. Not limited to this, the presence of shallow gas layers will also weaken the impact of pressure reduction paths on the gas production characteristics of combined production, which makes the gas production characteristics at this time more inclined towards the gas production characteristics under direct pressure reduction. In summary, in order to effectively increase the temperature of shallow gas and enhance hydrate decomposition, it is necessary to flexibly adjust the pressure reduction indicators of the pressure reduction path in different mining stages. The results can lay the foundation for clarifying the mechanism of interlayer interference in multiple gas source reservoirs.

Optimized dual-gas co-production from hydrate reservoirs with underlying gas through depressurization & well closure cycling: An experimental evaluation

The regular depressurization method for the exploitation of natural gas hydrate, while effective in gas production, carries a high risk of hydrate regeneration and significant reservoir shrinkage. In this study, the hydrate reservoirs containing underlying gas were synthesized by controlling the initial water distribution, and confining pressure was applied to replicate sub-seafloor conditions. An innovative cyclic depressurization (DP) + well closure (WC) cycling scheme was implemented to facilitate the joint production of hydrate and underlying gas. The heat transfer, gas production, and sediment deformation characteristics during dual-gas co-production were compared and examined considering different DP and WC duration. The findings clearly indicate that the DP + WC cycling method yielded significantly superior results compared to the regular DP approach. Specifically, it achieved effective CH4 recovery rates 1.83–2.33 times higher, temperature recovery rates 1.2–1.3 times greater, and a reduced the duration of reservoir contraction. More importantly, the extent of influence on these factors could be controlled by adjusting DP or WC duration. A discovery like this offers diverse gas production approaches tailored to various hydrate reservoir requirements. Overall, this study provides preliminary evidence that the DP + WC cycling method allows for the simultaneous attainment of efficient production and reservoir security, highlighting its potential significance for gas production from hydrate reservoirs containing underlying gas.

Effect of hydrothermal carbon on biogas production from agricultural waste by anaerobic fermentation

In this study, biogas residue was used as raw material to prepare biogas residue by hydrothermal carbonization at 190℃ with different treatment time. The effects of hydrothermal carbon addition on gas production characteristics during medium temperature anaerobic fermentation (straw, straw + chicken manure, chicken manure) were studied, and the differences of surface formation of biogas residue hydrothermal carbon were observed by SEM. The results showed that the duration of gas generation peak was prolonged in the straw + chicken manure fermentation group and the chicken manure fermentation group after adding biogas residue hydrothermal charcoal, and the total gas production in the 8h, 12h and 24h hydrothermal charcoal groups increased more (P < 0.05), and the total gas production increased 39.2% at most. There was no significant difference in cumulative gas production among groups in straw fermentation group. According to the actual production, the optimal HTC process for anaerobic fermentation is 8 h at 190℃.

Study on the effect of low-temperature cycling on the thermal and gas production behaviors of Ni0.8Co0.1Al0.1/graphite lithium-ion batteries

With their high energy density and long cycle life, lithium-ion batteries (LIBs) are currently the most promising electrochemical energy storage system for electric vehicles. However, their safety and cycling performance can be significantly compromised in low-temperature environments due to lithium plating and other factors. Therefore, it is essential to study the safety of aging batteries. In this study, we focused on a commercially available high-specific-energy Ni0.8Co0.1Al0.1 cathode system battery and simulated the aging of the battery by long-term cycling at 0 ℃. This study compares and analyzes the samples on the basis of the previous ones in terms of heat production power, thermal runaway (TR) characteristics and gas production characteristics. It reveals the influence of low-temperature aging on the comprehensive performance of lithium batteries in a more comprehensive way. The results show that the charging pattern of all three characteristics is related to the aging degree of the battery. In terms of the thermal characteristics, the relative change in specific heat capacity of the aged battery is only between 0.32 % and 1.08 % compared to that of a fresh battery, so the effect of ageing on the specific heat capacity of the battery is negligible. The average heat generation power of batteries with different state of health (SOH) is not monotonically increasing with the decrease of SOH, the threshold of dramatic increase is SOH = 80 %. In terms of TR characteristics, the onset temperature of exothermic reactions (TOER) of aged batteries is significantly lower than that of fresh batteries. With the decrease of SOH, TOER also decreases gradually. Compared with batteries with different SOHs, the more seriously aged the battery safety valve opens earlier, and the TR occurs earlier. In terms of the TR gas production characteristics, the more severely aged the battery, the earlier the safety valve opens compared to a fresh battery. The most gas is produced when SOH = 70 %, which increases the risk of catastrophic damage.

Study on the kinetic characteristics and control steps of gas production in coal spontaneous combustion under the oxidation path

The low-temperature oxidation of coal involves multiple gas production paths including desorption, pyrolysis and oxidation. These paths interfere with each other, resulting in unclear kinetic characteristics of CO and CO2 production in coal oxidation and incomplete mechanism of gas production. Therefore, this paper proposed a method that can effectively exclude the effects of desorption and pyrolysis on gas production and adopted this method to explore the kinetic characteristics of CO and CO2 production under different paths. Besides, with the aid of microscopic characterization methods, the kinetic steps controlling gas production and the mechanism of gas production were analyzed. The experimental results demonstrate that the proposed method can effectively eliminate the effects of desorption and pyrolysis, and can obtain the kinetic characteristics of gas production under the oxidation path that can reflect the intrinsic characteristics of low-temperature oxidation of coal. Based on the difference method, the activation energies of CO and CO2 produced under the oxidation path are 59.49 kJ/mol and 60.09 kJ/mol, which activation energies are almost the same, suggesting that CO and CO2 are likely to be produced from the same precursor. The gas production in low-temperature oxidation is a process in which methylene groups in coal react with oxygen to generate oxygen-containing intermediates which then decompose to produce CO and CO2. The reaction of methylene groups with oxygen is the control step of gas production kinetics in coal spontaneous combustion, resulting in the same apparent activation energies of CO and CO2 production in the stable phase under the oxidation path.

Thermal runaway propagation behavior and gas production characteristics of NCM622 battery modules at different state of charge

Due to the complex thermal runaway propagation behavior of lithium-ion battery modules and the generation of a substantial amount of combustible mixed gases during the process, their safety performance is compromised, hindering their large-scale application in the fields of energy storage and automotive industries. Therefore, in this paper, the thermal runaway propagation behavior and gas production characteristics of Li (Ni0.6Co0.2Mn0.2) O2 battery modules with different state of charge were investigated in closed space. The results show that no thermal runaway occurred in the battery module when the state of charge was below 25% in closed space. With the decrease of the state of charge, both the internal thermal propagation speed and the surface temperature of the lithium-ion battery were reduced. The total gas production volume from 17.48 mol to 6.17 mol when the state of charge was reduced from 100% to 50%. The main gases produced during thermal runaway were CO2, CO, H2, CH4, and C2H4. With the decrease of the state of charge, the content of CO2 increased, the content of C2H4 and CO decreased, and the content of H2 and CH4 remained unchanged with the state of charge. The results contribute to safety measures for preventing thermal runaway accidents in lithium-ion batteries, offering guidance for the secure design of lithium-ion battery packs, and thus enhancing the overall safety of lithium-ion batteries.

Study on the oxidized gas production characteristics and spontaneous combustion tendency of pre-oxidized water-soaked coal in lean-oxygen environments.

The oxidation characteristics and spontaneous combustion (SC) tendency of raw long-flame coal (RC), water-soaked 200-day coal (S200), pre-oxidized water-soaked coal at 200°C (O200S200), and pre-oxidized soaked coal at 300°C (O300S200) in an oxygen-poor environment were investigated using a programmed warming system. The results show that pre-oxidation water-soaked treatment (PWT) promotes the coal-oxygen complex reaction and increases the rate of coal oxygen consumption (OCR) and the rate of carbon and oxygen compound production. The rate of CO and CO2 production of the water-soaked (WS) coal increased by 0.329mol·(cm3·s)-1 and 0.922mol·(cm3·s)-1, respectively, compared with that of the original coal sample. PWT reduces the activation energy of coal in the low-temperature oxidation stage (the maximum difference can be up to 110.99kJ/mol) and enhances the oxidizing and heat-releasing capacity. There was a synergistic effect between the pre-oxidation (PO) and WS treatment, and the lowest comprehensive determination index of the SC propensity of coal in O200S200 samples was 831.92 which was 4.72 lower than that of RC samples, presenting a more SC tendency. Low oxygen concentration has an inhibitory effect on the oxidation characteristic parameters of coal, and the apparent activation energy of the low-temperature oxidation stage of pre-oxidized water-soaked coal (PWC) increased to 206.418kJ/mol at 3% oxygen concentration. The lower the oxygen concentration of the anoxic environment, the lower the risk of SC of the coal samples. The results of the study can provide theoretical guidance for the identification and prevention of SC disasters in coal seams with shallow burial and close spacing.

SMART LIVESTOCK FOR SCIENCE…12 months later

The fourth issue of Slovak Journal of Animal Science 2023 gives to me the opportunity to overview our scientific publishing activity after the first 12 months together. Along four issues, our Journal has been faced with many different aspects of animal farm production, among them mainly circular economy strategy, non-conventional feed resources, and community-based livestock programs. All these different aspects have a common point: boost and develop the livestock farming system, in terms of competitiveness and profitability. Looking at the different articles collected and published during this year, the incorporation of locally available novel feed resource alternatives can promote circular economy concepts, increase food security, and improve sustainable livestock production. By exploiting locally accessible resources, the inclusion of these materials in animal feed nutrition has significant potential to enhance livestock performance, lower production costs, and promote bioeconomy concepts.
 On the other hand, analysis of genomic data is an important resource for the effective management of small and endangered animal populations. The research activity of scientists has deeply been focused on developing breeding programs able to conserve animal biodiversity and monitor animal biodynamics.
 
 In the last Editorial article of 2023, I am going to introduce the contents of the articles collected and published in the fourth issue of 2023 year.
 Formelova et al. performed a study to evaluate the effect of dried hempseed cake (by-product of oil production) supplementation (5% - EG1 and 10% - EG2) to rabbit feed mixture on livestock performances, quality of meat, digestibility of nutrients and animal health status. All obtained data let Authors to recommend the inclusion of hempseed cake up to 10% in rabbit diet without any negative effect on animal welfare, livestock performance and quality of meat.
 Osaiyuwu et al. organized a study to provide useful information for the creation of sustainable breeding programmes and developing a sustainable use and conservation strategy aimed at developing highly producing Muscovy ducks in Nigeria; consequently, increasing the food security index of the nation and source of income for small-scale farmers. In general, the ducks from all seven ecogeographic locations were rather homogeneous than heterogeneous.
 Mekonnen et al., had the prime objective to survey and characterize the husbandry practices of the different indigenous sheep populations. Authors concluded the study claiming a need of feed development, shift to modern husbandry practices, access to veterinary services, indigenous sheep conservation through utilization, control of inbreeding, ram-to-ewe ratio, fattening and castration should be of future attention of farmers and stakeholders.
 Ajayi et al., to justify the use of duckweed as an alternative and novel aquatic-derived fodder in ruminants' feeding strategies, performed preliminary investigation via in vitro gas production technique. The study assessed the nutrient and mineral potential, secondary metabolites and in vitro gas production characteristics of duckweed to estimate the short-chain volatile fatty acids, metabolizable energy, organic matter digestibility and apparent in vitro dry matter degradability. In conclusion, duckweed from earthen fish ponds is fairly degradable in vitro, and the nutrient contents elucidate its forage value for ruminants.
 Editorial Team looks forward to evaluating your submitted contributions and providing all necessary support to Authors in order to best serve animal science and the scientific community, with commitment to research integrity and the highest publishing ethics. Enjoy the reading!

Experimental Study on Permeability and Gas Production Characteristics of Montmorillonite Hydrate Sediments Considering the Effective Stress and Gas Slippage Effect

Summary Gas permeability in hydrate reservoirs is the decisive parameter in determining the gas production efficiency and gas production of hydrate. In the South China Sea (SCS), the gas flow in tight natural gas hydrate (NGH) silty clay reservoirs is significantly affected by the gas slippage effect and the effective stress (ES) of overlying rock. To improve the effectiveness of hydrate exploitation, it is necessary to understand the influence of gas slippage in hydrate reservoirs on the permeability evolution law. For this paper, the gas permeability characteristics and methane production of hydrate montmorillonite sediments were studied at different pore pressures and ESs. Experimental data revealed that the gas permeability of montmorillonite samples before methane hydrate (MH) formation is seriously affected by the Klinkenberg effect. The gas permeability of montmorillonite sediments before hydrate formation is generally smaller than that after hydrate formation, and the gas slippage effect in the sediments after hydrate formation is weaker than that before hydrate formation. With the change in ES, the intrinsic permeability of sediment has a power law relationship with the simple ES. The ES law coefficient n was determined using the response surface method to eliminate the influence of gas slip on gas permeability. As pore pressure decreases and MH decomposes, montmorillonite swelling seriously affects gas permeability. However, the gas slippage effect has a good compensation effect on the permeability of montmorillonite sediments after MH decomposition under low pore pressure. The multistage depressurization-producing process of MH in montmorillonite sediments is mainly 3 MPa depressurization-producing stage and 2 MPa depressurization-producing stage. In this paper, the influence mechanism of gas slippage effect of hydrate reservoir is studied, which is conducive to improving the prediction accuracy of gas content in the process of hydrate exploitation and exploring the best pressure reduction method to increase the gas production of hydrate in the process of exploitation.

Gas Production Characteristics of Partial Discharge in Needle-plate Electrodes under Typical Vibration Conditions in a UHV Shunt Reactor

Gas Production Characteristics of Partial Discharge in Needle-plate Electrodes under Typical Vibration Conditions in a UHV Shunt Reactor