Development and Implementation of Green Inhibitors of Gas Hydrate Formation in the Fields of Western Siberia

2021 ◽  
Author(s):  
Aleksander Voloshin ◽  
Nikolay Nifantiev ◽  
Mikhail Egorov ◽  
Robert Alimbekov ◽  
Vladimir Dokichev

Abstract The effect of biodegradable polysaccharides – sodium (NaCMC) and ethanolammonium salts of carboxymethylcellulose, dextran and arabinogalactan on the process of gas hydrate formation was studied in order to search for new "green" inhibitors of low-concentration gas hydrate formation. The ability of polysaccharides to inhibit gas hydrate formation was studied in a quasi-equilibrium thermodynamic experiment. A mixture of hydrocarbon gases with a composition typical of the composition of petroleum gas and containing 78% methane was used as a gas-hydrate-forming model medium. It was found that in concentrations of 0.005, 0.0065 and 0.008%, dextran, NaCMC and arabinogalactan as thermodynamic inhibitors exceed methanol by 170-270 times in inhibitory properties. Dextran is superior to NaCMC and arabinogalactan in terms of inhibition efficiency, reduction of gas hydrate formation rate and induction time. Since with an increase in the concentration of polysaccharides, the pressure drop of gas hydrate formation increases and the rate of formation of gas hydrates decreases according to the mechanism of action, the studied polysaccharides can be attributed to both thermodynamic and kinetic inhibitors. It is established that the molecular weight of water-soluble polysaccharides has a significant effect on their inhibitory properties. A polysaccharide with a molecular weight of 250,000 demonstrated the highest inhibitory activity among the studied samples of NaCMC, which is 400 times more effective than methanol. NaCMC with a mass of 700 thousand did not have any effect on the formation of hydrates. Among the ethanolammonium salts, the monoethanolammonium salt CMC showed the greatest effectiveness in inhibiting the formation of tetrahydrofuran hydrates. An increase in its concentration from 0.02 to 0.1% leads to an increase in the induction time required for the nucleation and subsequent growth of crystals by 10 times. When switching from mono - to di - and triethanolammonium salts of carboxymethylcellulose, the inhibition efficiency decreases. It is shown that sodium and ethanolammonium salts of carboxymethylcellulose, arabinogalactan and dextran are promising for creating new "green" highly effective inhibitors of gas hydrate formation on their basis. The results of laboratory and field tests of the preparative form of the "green" gas hydrate formation inhibitor at the fields of Western Siberia are presented. It was found that at dosages of 500 g/m3 or less, there is no formation of hydrate plugs in the annulus of wells.

2012 ◽  
Vol 616-618 ◽  
pp. 902-906 ◽  
Author(s):  
Chun Long Wang ◽  
Xue Min Zhang ◽  
Jin Ping Li ◽  
Lin Jun Wang ◽  
Liang Jiao

Predicting the driving force accurately is the key process to hydrate nucleating and growing of hydration reaction. The nucleating and growing process of hydrate is relevant to temperature, pressure and component of reactant, and the property of reaction tank and intermiscibility of reactant have notable effect on the formation process of hydrate with its nucleating position, the induction time, growth rate and hydration rate. However, the present driving force model of hydrate cannot predict nucleating area, induction time, growth rate and the reaction limit, and also can't explain the influence of some factors such as cooling rate, temperature disturbance and inlet way on the hydration reaction, it is uncertain of the process to gas hydrate nucleation. We introduced some driving force models, analyzed their merits and demerits, and looked into the distance of research direction to driving force in the future.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Qiang Zhang ◽  
Qiang Wu ◽  
Hui Zhang

In order to explore the method of accelerating hydration separation process to recover methane from mine gas, propane hydrate phase equilibrium was used to measure the equilibrium points of three kinds of mine gas in NaCl solution. Driving force was set as 1 MPa on this basis and high-pressure experimental apparatus of mine gas hydrate was used to carry out the nucleation kinetics experiments of mine gas hydrate for three gas samples in different concentrations of sodium chloride (NaCl) and sodium dodecyl sulfate (SDS) compound systems, which was to study the effect of propane and NaCl-SDS solution on nucleation process of mine gas hydrate. The results showed that induction time of multicomponent mine gas hydrate formation was shortened with the decrease of methane concentration and increase of propane concentration. The induction time of mine gas hydrate formation was shortened with the reduction of NaCl concentration and the increase of SDS concentration. It was found that methane and propane in multicomponent mine gas nucleated collaboratively, which simplified its nucleation process compared with the single component. NaCl has two kinds of functions.


2021 ◽  
Author(s):  
Khalik Mohamad Sabil ◽  
Omar Nashed ◽  
Bhajan Lal ◽  
Khor Siak Foo

Abstract Nanofluids are known of having the capability to increase heat and mass transfer and their suitability to be used as kinetic gas hydrate promoters have been recently investigated. They have favorable properties such as high thermal conductivity, large surface area, recyclable, ecofriendly, and relatively cheap that are favorable for kinetic gas hydrate promoters. However, the nanomaterials face challenges related to their stability in the base fluid. Therefore, it is crucial to investigate the impact of surfactant free nanofluid on hydrate formation and dissociation kinetics. In this work, COOH-MWCNT suspended in water is used to study the effect of surfactant free nanofluid on CO2 hydrates formation kinetic and stability. Kinetic study on CO2 hydrates formation as well as self-preservation are conducted in a stirred tank reactor. The kinetic experiments are carried out at 2.7 MPa and 274.15 K. The induction time, initial gas consumption rate, half-completion time t50, semi completion time t95 are measured to evaluate the effect of COOH-MWCNT. Furthermore, the dissociation rate was calculated to assess the impact of COOH-MWCNT on self-preservation at 271.15 K and atmospheric pressure. The results are compared with that of sodium dodecyl sulphate (SDS). The study of CO2 hydrates formation kinetic shows that the induction time is not affected by COOH-MWCNT. The impact of nanofluid is more pronounced during the hydrate growth. The initial formation rate is the highest at 0.01 wt% of COOH-MWCNT whereas 0.01 and 0.03 wt% shows the same and shortest t50. However, t95 found to be decreased with increasing the concentration. The effect of COOH-MWCNT is attributed to the strong functional group. Self-preservation results shows CO2 hydrates are less stable in the presence of COOH-MWCNT. The result of this work may provide significant finding that can be used to developed kinetic gas hydrate promoter based on nanofluid that work better than SDS to eliminate gas hydrate formation in oil and gas pipeline.


2015 ◽  
Vol 93 (9) ◽  
pp. 992-997
Author(s):  
Xuemei Lang ◽  
Pingping Lv ◽  
Shurui Xu ◽  
Baoyao Li ◽  
Shuanshi Fan ◽  
...  

Within the oil and gas industry, low-dosage hydrate inhibitors (LDHIs) are a proven technology to control hydrates. Besides hydrate inhibitors, wax inhibitors (WIs) are frequently injected to prevent wax buildup in the crude oil pipeline. However, little attention has been focused on the effect of wax inhibitors on the performance of LDHIs. In this study, performance tests of 3 LDHIs in the presence of wax inhibitors were carried out for a 67% CH4/33% CO2 gas hydrate formation. Using the isothermal cooling method at pressures of 9 MPa and temperatures of 4 °C (subcooling is 9 °C), the results showed that the induction time of CH4-CO2 gas hydrate formation with LDHI/WI was shorter than the system with only LDHI. During the growth period, when the concentration of the WIs was 1 mass%, the growth time of the system with LDHI/WI was prolonged. Taking the induction time and the growth time into consideration, it was found that WIs had a more negative impact on the kinetic hydrate inhibitor performance at low dosage. The effect of WIs at high concentration could be negligible.


2020 ◽  
Author(s):  
Amir Saberi ◽  
Abdolmohammad Alamdari ◽  
Ali Rasoolzadeh ◽  
Amir H. Mohammadi

Abstract It is necessary to understand all the prerequisites, which result in gas hydrate formation for safe design and control of a variety of processes in petroleum industry. Thermodynamic hydrate inhibitors (THIs) are normally used to preclude gas hydrate formation by shifting hydrate stability region to lower temperatures and higher pressures. Sometimes, it is difficult to avoid hydrate formation and hydrates will form anyway. In this situation, kinetic hydrate inhibitors (KHIs) can be used to postpone formation of gas hydrates by retarding hydrate nucleation and growth rate. In this study, two kinetic parameters including natural gas hydrate formation induction time and the rate of gas consumption were experimentally investigated in the presence of monoethylene glycol (MEG), L-tyrosine, and polyvinylpyrrolidone (PVP) at various concentrations in aqueous solutions. Since hydrate formation is a stochastic phenomenon, the repeatability of each kinetic parameter was evaluated several times and the average values for the hydrate formation induction times and the rates of gas consumption are reported. The results indicate that from the view point of hydrate formation induction time, 2 wt% PVP and 20 wt% MEG aqueous solutions have the highest values and are the best choices. It is also interpreted from the results that from the view point of the rate of gas consumption, 20 wt% MEG aqueous solution yields the lowest value and is the best choice. Finally, it is concluded that the combination of PVP and MEG in an aqueous solution has a simultaneous synergistic impact on natural gas hydrate formation induction time and the rate of gas consumption. Furthermore, a semi-empirical model based on chemical kinetic theory is applied to evaluate the hydrate formation induction time data. A good agreement between the experimental and calculated hydrate formation induction time data is observed.


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