scholarly journals Formation of submarine gas hydrates

1994 ◽  
Vol 41 ◽  
pp. 86-94
Author(s):  
V. Soloviev ◽  
G. D. Ginsburg
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Deep Sea ◽  
Hydrate Formation ◽  
Coarse Grained ◽  
Necessary Condition ◽  
Dissolved Gas ◽  
Scale Levels ◽  
Bottom Sampling ◽  
Gas Bearing

Submarine gas hydrates have been discovered in the course of deep-sea drilling (DSDP and ODP) and bottom sampling in many offshore regions. This paper reports on expeditions carried out in the Black, Caspian and Okhotsk Seas. Gas hydrate accumulations were discovered and investigated in all these areas. The data and an analysis of the results of the deep-sea drilling programme suggest that the infiltration of gas-bearing fluids is a necessary condition for gas hydrate accumulation. This is confirmed by geological observations at three scale levels. Firstly, hydrates in cores are usually associated with comparatively coarse-grained, permeable sediments as well as voids and fractures. Secondly, hydrate accumulations are controlled by permeable geological structures, i.e. faults, diapirs, mud volcanos as well as layered sequences. Thirdly, in the worldwide scale, hydrate accumulations are characteristic of continental slopes and rises and intra-continental seas where submarine seepages also are widespread. Both biogenic and cat­agenic gas may occur, and the gas sources may be located at various distances from the accumulation. Gas hydrates presumably originate from water-dissolved gas. The possibility of a transition from dissolved gas into hydrate is confirmed by experimental data. Shallow gas hydrate accumulations associated with gas-bearing fluid plumes are the most convenient features for the study of submarine hydrate formation in general. These accumulations are known from the Black, Caspian and Okhotsk Seas, the Gulf of Mexico and off northern California.

scholarly journals A New Inhibitor to Prevent Hydrate Formation

2021 ◽  
Vol 5 (1) ◽  
pp. 1-6
Author(s):  
Bazvand M
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Deep Sea ◽  
Hydrate Formation ◽  
Cost Effective ◽  
Vinyl Pyrrolidone ◽  
Flow Assurance ◽  
Main Structure ◽  
Poly Vinyl Pyrrolidone ◽  
Prevention Methods

Due to the growing demand for energy as well as the depletion of shallow land reservoirs, it sounds more important to utilize deep sea reservoirs. Due to their special conditions, drilling and production of these reservoirs face more problems. The science that helps us avoiding problems during operation is called flow assurance. One of the important issues in flow assurance is to prevent formation of gas hydrates. One of gas hydrates preventing methods is to use of inhibitors. Using of inhibitors is a cost- effective and eco-friendly method; so, it is used more nowadays. This paper introduces a new hydrate inhibitor that has been developed from the modification of one of the most widely used inhibitors present in the industry, Poly Vinyl Pyrrolidone, to improve its efficiency. The main structure of the paper is about what is the gas hydrate and its prevention methods. Finally, compare different inhibitors with new one. The results show that hydrate formation time for all polymers is approximately the same, while a half of new inhibitor in compare with amount of others inhibitors causes the same results. This matter shows a double efficiency, and this means a saving of double Polymer consumption.

Thermodynamic Modelling of Gas Hydrate Formation in the Presence of Inhibitors and the Consideration of their Effect

2014 ◽  
Vol 14 (1) ◽  
pp. 45
Author(s):  
Peyman Sabzi ◽  
Saheb Noroozi
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Low Temperatures ◽  
Hydrate Formation ◽  
Transportation Systems ◽  
Flow Lines ◽  
Main Approach ◽  
Efficient Inhibitor ◽  
System A ◽  
Gas Hydrate Formation

Gas hydrates formation is considered as one the greatest obstacles in gas transportation systems. Problems related to gas hydrate formation is more severe when dealing with transportation at low temperatures of deep water. In order to avoid formation of Gas hydrates, different inhibitors are used. Methanol is one of the most common and economically efficient inhibitor. Adding methanol to the flow lines, changes the thermodynamic equilibrium situation of the system. In order to predict these changes in thermodynamic behavior of the system, a series of modelings are performed using Matlab software in this paper. The main approach in this modeling is on the basis of Van der Waals and Plateau's thermodynamic approach. The obtained results of a system containing water, Methane and Methanol showed that hydrate formation pressure increases due to the increase of inhibitor amount in constant temperature and this increase is more in higher temperatures. Furthermore, these results were in harmony with the available empirical data.Keywords: Gas hydrates, thermodynamic inhibitor, modelling, pipeline blockage

scholarly journals Rapid Gas Hydrate Formation—Evaluation of Three Reactor Concepts and Feasibility Study

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3615
Author(s):  
Florian Filarsky ◽  
Julian Wieser ◽  
Heyko Juergen Schultz
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Synthetic Natural Gas ◽  
Operation Conditions ◽  
Gas Hydrate Formation ◽  
Gas Conditioning ◽  
And Storage ◽  
Economic Considerations ◽  
High Storage

Gas hydrates show great potential with regard to various technical applications, such as gas conditioning, separation and storage. Hence, there has been an increased interest in applied gas hydrate research worldwide in recent years. This paper describes the development of an energetically promising, highly attractive rapid gas hydrate production process that enables the instantaneous conditioning and storage of gases in the form of solid hydrates, as an alternative to costly established processes, such as, for example, cryogenic demethanization. In the first step of the investigations, three different reactor concepts for rapid hydrate formation were evaluated. It could be shown that coupled spraying with stirring provided the fastest hydrate formation and highest gas uptakes in the hydrate phase. In the second step, extensive experimental series were executed, using various different gas compositions on the example of synthetic natural gas mixtures containing methane, ethane and propane. Methane is eliminated from the gas phase and stored in gas hydrates. The experiments were conducted under moderate conditions (8 bar(g), 9–14 °C), using tetrahydrofuran as a thermodynamic promoter in a stoichiometric concentration of 5.56 mole%. High storage capacities, formation rates and separation efficiencies were achieved at moderate operation conditions supported by rough economic considerations, successfully showing the feasibility of this innovative concept. An adapted McCabe-Thiele diagram was created to approximately determine the necessary theoretical separation stage numbers for high purity gas separation requirements.

scholarly journals Investigation on Gas Hydrates Formation and Dissociation in Multiphase Gas Dominant Transmission Pipelines

2020 ◽  
Vol 10 (15) ◽  
pp. 5052 ◽  
Author(s):  
Sayani Jai Krishna Sahith ◽  
Srinivasa Rao Pedapati ◽  
Bhajan Lal
Keyword(s):  
Crude Oil ◽  
Phase Behavior ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Rate ◽  
Water System ◽  
Hydrate Formation ◽  
Multiphase System ◽  
Gas Hydrate Formation ◽  
Water Cut

In this work, a gas hydrate formation and dissociation study was performed on two multiphase pipeline systems containing gasoline, CO2, water, and crude oil, CO2, water, in the pressure range of 2.5–3.5 MPa with fixed water cut as 15% using gas hydrate rocking cell equipment. The system has 10, 15 and 20 wt.% concentrations of gasoline and crude oil, respectively. From the obtained hydrate-liquid-vapor-equilibrium (HLVE) data, the phase diagrams for the system are constructed and analyzed to represent the phase behavior in the multiphase pipelines. Similarly, induction time and rate of gas hydrate formation studies were performed for gasoline, CO2, and water, and crude oil, CO2, water system. From the evaluation of phase behavior based on the HLVE curve, the multiphase system with gasoline exhibits an inhibition in gas hydrates formation, as the HLVE curve shifts towards the lower temperature and higher-pressure region. The multiphase system containing the crude oil system shows a promotion of gas hydrates formation, as the HLVE curve shifted towards the higher temperature and lower pressure. Similarly, the kinetics of hydrate formation of gas hydrates in the gasoline system is slow. At the same time, crude oil has a rapid gas hydrate formation rate.

Investigating the dynamics of gas hydrates in a gas dominant flow loop

2011 ◽  
Vol 51 (2) ◽  
pp. 734
Author(s):  
Yutaek Seo ◽  
Mauricio Di Lorenzo ◽  
Gerardo Sanchez-Soto
Keyword(s):  
Steady State ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Gas Flow ◽  
Transient Flow ◽  
Hydrate Formation ◽  
Hydrodynamic Condition ◽  
Gas Pipelines ◽  
Flow Loop ◽  
Offshore Pipelines

Offshore pipelines transporting hydrocarbon fluids have to be operated with great care to avoid problems related to flow assurance. Of these possible problems, gas hydrate is dreaded as it poses the greatest risk of plugging offshore pipelines and other production systems. As the search for oil and natural gas goes into deeper and colder offshore fields, the strategies for gas hydrate mitigation are evolving to the management of hydrate risks rather than costly complete prevention. CSIRO has been developing technologies that will facilitate the production of Australian deepwater gas reserves. One of its research programs is a recently commissioned investigation into the dynamic behaviour of gas hydrates in gas pipelines using a pilot-scale 1 inch and 40 m long flow loop. This work will provide experimental results conducted in the flow loop, designed to investigate the hydrate formation characteristics in steady state and transient flow. For a given hydrodynamic condition in steady state flow, the formation and subsequent agglomeration and deposition of hydrate particles appear to occur more severely as the subcooling condition is increasing. Transient flow during a shut-in and restart operation represents a more complex scenario for hydrate formation. Although hydrates develop as a thin layer on the surface of water during the shut-in period, most of the water is quickly converted to hydrate upon restart, forming hydrate laden slurry that is transported through the pipeline by the gas flow. These results could provide valuable insights into the present operation of offshore gas pipelines.

Insights into CO2 Capture by Flue Gas Hydrate Formation: Gas Composition Evolution in Systems Containing Gas Hydrates and Gas Mixtures at Stable Pressures

2018 ◽  
Vol 6 (5) ◽  
pp. 5732-5736 ◽  
Author(s):  
Aliakbar Hassanpouryouzband ◽  
Jinhai Yang ◽  
Bahman Tohidi ◽  
Evgeny Chuvilin ◽  
Vladimir Istomin ◽  
...  
Keyword(s):  
Co2 Capture ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Flue Gas ◽  
Hydrate Formation ◽  
Gas Mixtures ◽  
Gas Composition ◽  
Gas Hydrate Formation

scholarly journals Numerical Simulation on the Dissociation, Formation, and Recovery of Gas Hydrates on Microscale Approach

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5021
Author(s):  
Mar’atus Sholihah ◽  
Wu-Yang Sean
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Pore Networks ◽  
Mechanisms Of Formation ◽  
Pressure Concentration ◽  
Micro Modeling ◽  
Multi Phase ◽  
Saturation Rate ◽  
Process Method

Investigations into the structures of gas hydrates, the mechanisms of formation, and dissociation with modern instruments on the experimental aspects, including Raman, X-ray, XRD, X-CT, MRI, and pore networks, and numerical analyses, including CFD, LBM, and MD, were carried out. The gas hydrate characteristics for dissociation and formation are multi-phase and multi-component complexes. Therefore, it was important to carry out a comprehensive investigation to improve the concept of mechanisms involved in microscale porous media, emphasizing micro-modeling experiments, 3D imaging, and pore network modeling. This article reviewed the studies, carried out to date, regarding conditions surrounding hydrate dissociation, hydrate formation, and hydrate recovery, especially at the pore-scale phase in numerical simulations. The purpose of visualizing pores in microscale sediments is to obtain a robust analysis to apply the gas hydrate exploitation technique. The observed parameters, including temperature, pressure, concentration, porosity, saturation rate, and permeability, etc., present an interrelationship, to achieve an accurate production process method and recovery of gas hydrates.

Distribution and fractionation of light hydrocarbons related to gas hydrate occurrence and biogenic production at Hikurangi Margin (IODP Site U1517), New Zealand

2020 ◽  
Author(s):  
Katja Heeschen ◽  
Stefan Schloemer ◽  
Marta Torres ◽  
Ann E Cook ◽  
Liz Screation ◽  
...  
Keyword(s):  
New Zealand ◽  
High Resolution ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Isotopic Fractionation ◽  
Close Relation ◽  
Coarse Grained ◽  
Accretionary Wedge ◽  
Light Hydrocarbons ◽  
Slide Mass

<p>The investigation of the gas hydrate system and hydrocarbon distribution were targets of IODP expeditions 372 and 375 on the Hikurangi Margin offshore New Zealand. Isotopic and molecular signatures clearly indicate a biogenic signature of methane at all sites drilled along a section crossing the accretionary wedge and basin sediments. The gas void and headspace samples from depth of a few meters up to 600 m below the seafloor have varying amounts of light hydrocarbons with high amounts of methane and changing ratios of C<sub>2</sub>:C<sub>3</sub>. The best example is the high-resolution profile gained from gas voids collected at Site U1517. Drilling at U1517 reached through the creeping part of the Tuaheni Landslide Complex (TLC), the base of the slide mass, and the Bottom Simulation Reflector (BSR) just above the base of the hole. Whereas gas hydrates could not be observed macroscopically, the distribution of gas hydrates was determined by logging while drilling (LWD) and pore water data revealing the occurrence of gas hydrates at roughly 105 – 160 mbsf with elevated saturations in thin coarse-grained sediments. The application of cryo-Scanning Electric Microscopy (cryo-SEM) on samples preserved in liquid nitrogen enabled the visualization of gas hydrates.</p><p> </p><p>At Site U1517 the high-resolution void sampling reveals molecular and isotopic fractionation of hydrocarbons in close relation to the gas hydrate occurrences and allows for drawing conclusions on the recent history of the gas hydrate system and absence of free gas transport from below at the site. The molecular and isotopic composition further indicates ongoing propanogenesis.</p>

Modeling of the Kinetics of the Gas Hydrates Formation on the Basis of a Stochastic Approach

2019 ◽  
Vol 291 ◽  
pp. 98-109
Author(s):  
Vasyl Klymenko ◽  
Vasyl Gutsul ◽  
Volodymyr Bondarenko ◽  
Viktor Martynenko ◽  
Peter Stets
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Total Mass ◽  
Hydrate Formation ◽  
Stochastic Approach ◽  
Whole Process ◽  
Time Period ◽  
Proposed Model ◽  
Separation Of Gas Mixtures ◽  
Kinetics Of

Recently, more attention has been paid to the development of gas hydrate deposits, the use of gas-hydrated technologies, suitable for energy-efficient transportation of natural gas, the separation of gas mixtures, production and storage of cold, desalinating of seawater, etc. Hydrate formation is one of the main processes of gas-hydrate technological installations. In the article a model is proposed that describes the kinetics of the formation of hydrate in disperse systems, which are characteristic for real conditions of operation of gas-hydrate installations, on the basis of a stochastic approach using Markov chains. An example of numerical calculations is presented on the basis of the proposed model of the dynamics of the total mass of gas hydrates, and changes in the velocity of their formation and size distribution at different values of the nucleation constants and growth rate of the gas hydrates, and results of these calculations are analyzed. It is shown that the rate of formation of hydrate has a maximum value in half the time period of the whole process. The obtained results of the calculations of the dynamics the total mass of gas hydrates are in good agreement with the results of calculations by the equation of kinetics Kolmogorov-Avrami. The proposed model can be applied to the inverse problem: the determination of the nucleation constants and the rate of growth of gas hydrates by the results of the dynamics of the formation of hydrate and the changes in the fractional composition of the generated gas hydrates.

Numerical Studies of Gas Hydrate Formation and Decomposition in a Geological Reservoir

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
M. Uddin ◽  
D. Coombe ◽  
D. Law ◽  
B. Gunter
Keyword(s):  
Kinetic Model ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Co2 Sequestration ◽  
Numerical Study ◽  
Hydrate Formation ◽  
Gas Production ◽  
Ch4 Production ◽  
Hydrate Reservoir ◽  
Gas Hydrate Formation

Numerical modeling of gas hydrates can provide an integrated understanding of the various process mechanisms controlling methane (CH4) production from hydrates and carbon dioxide (CO2) sequestration as a gas hydrate in geologic reservoirs. This work describes a new unified kinetic model which, when coupled with a compositional thermal reservoir simulator, can simulate the dynamics of CH4 and CO2 hydrate formation and decomposition in a geological formation. The kinetic model contains two mass transfer equations: one equation converts gas and water into hydrate and the other equation decomposes hydrate into gas and water. The model structure and parameters were investigated in comparison with a previously published model. The proposed kinetic model was evaluated in two case studies. Case 1 considers a single well within a natural hydrate reservoir for studying the kinetics of CH4 and CO2 hydrate decomposition and formation. A close agreement was achieved between the present numerical simulations and results reported by Hong and Pooladi-Darvish (2003, “A Numerical Study on Gas Production From Formations Containing Gas Hydrates,” Petroleum Society’s Canadian International Petroleum Conference, Calgary, AB, Jun. 10–12, Paper No. 2003-060). Case 2 considers multiple wells within a natural hydrate reservoir for studying the unified kinetic model to demonstrate the feasibility of CO2 sequestration in a natural hydrate reservoir with potential enhancement of CH4 recovery. The model will be applied in future field-scale simulations to predict the dynamics of gas hydrate formation and decomposition processes in actual geological reservoirs.

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