Efficient dual-function inhibitors for prevention of gas hydrate formation and CO2/H2S corrosion inside oil and gas pipelines

2021 ◽  
pp. 134098
Author(s):  
Abdolreza Farhadian ◽  
Woojin Go ◽  
Soyoung Yun ◽  
Alireza Rahimi ◽  
Mohammad Reza Nabid ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Dual Function ◽  
Gas Pipelines ◽  
H2s Corrosion ◽  
Gas Hydrate Formation ◽  
Oil And Gas Pipelines

scholarly journals A Quick-Look Model to Predict Gas Hydrate Formation in Gas Pipelines using Modified Navier-Stokes Correlation

2020 ◽  
pp. 1-11
Author(s):  
Akinsete O. Oluwatoyin ◽  
Oladipo O. Olatunji ◽  
Isehunwa O. Sunday
Keyword(s):  
Gas Hydrate ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Oil And Gas Industry ◽  
Navier Stokes ◽  
Fluid Composition ◽  
Gas Pipelines ◽  
Navier Stokes Equation ◽  
Gas Industry ◽  
Gas Hydrate Formation

Major challenges associated with the smooth production operations in the oil and gas industry that has raised technical curiosity are formation of natural gas hydrates in production facilities and flow lines which introduces significant cost to operators. Accurate modeling is therefore paramount; most existing models are based on constitutive conservation laws neglecting other dissipative energy types. To predict “if” and “where” gas hydrate would be formed in gas pipeline, the Navier-Stokes equation was modified by incorporating dissipative forces of viscosity and gravity; the equation that emerged was solved analytically to determine the hydrate formation pressure (HFP) and the position of hydrate formation along gas pipelines. The developed model, used as a quick-look tool for where and if hydrates will form revealed that when the predicted HFP is positive hydrates was formed but when it is negative hydrates were not formed. The model also showed that HFP is a function fluid composition, mass flowrate, changes in fluid and surrounding conditions and changes in elevation and direction confirming the results of earlier work done.

scholarly journals Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5664
Author(s):  
Roman S. Pavelyev ◽  
Yulia F. Zaripova ◽  
Vladimir V. Yarkovoi ◽  
Svetlana S. Vinogradova ◽  
Sherzod Razhabov ◽  
...  
Keyword(s):  
Corrosion Inhibitor ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Oxygen Demand ◽  
Oil And Gas Industry ◽  
Dual Function ◽  
Structure Property ◽  
Tert Butyl ◽  
Waterborne Polyurethanes ◽  
Gas Hydrate Formation

The design of new dual-function inhibitors simultaneously preventing hydrate formation and corrosion is a relevant issue for the oil and gas industry. The structure-property relationship for a promising class of hybrid inhibitors based on waterborne polyurethanes (WPU) was studied in this work. Variation of diethanolamines differing in the size and branching of N-substituents (methyl, n-butyl, and tert-butyl), as well as the amount of these groups, allowed the structure of polymer molecules to be preset during their synthesis. To assess the hydrate and corrosion inhibition efficiency of developed reagents pressurized rocking cells, electrochemistry and weight-loss techniques were used. A distinct effect of these variables altering the hydrophobicity of obtained compounds on their target properties was revealed. Polymers with increased content of diethanolamine fragments with n- or tert-butyl as N-substituent (WPU-6 and WPU-7, respectively) worked as dual-function inhibitors, showing nearly the same efficiency as commercial ones at low concentration (0.25 wt%), with the branched one (tert-butyl; WPU-7) turning out to be more effective as a corrosion inhibitor. Commercial kinetic hydrate inhibitor Luvicap 55 W and corrosion inhibitor Armohib CI-28 were taken as reference samples. Preliminary study reveals that WPU-6 and WPU-7 polyurethanes as well as Luvicap 55 W are all poorly biodegradable compounds; BODt/CODcr (ratio of Biochemical oxygen demand and Chemical oxygen demand) value is 0.234 and 0.294 for WPU-6 and WPU-7, respectively, compared to 0.251 for commercial kinetic hydrate inhibitor Luvicap 55 W. Since the obtained polyurethanes have a bifunctional effect and operate at low enough concentrations, their employment is expected to reduce both operating costs and environmental impact.

CO2-saturated Salinity Environment Effects on Ni-Mo Alloys at Gas Hydrate Formation Temperatures

2019 ◽  
Author(s):  
Christopher Ozigagu ◽  
Ting Zhou ◽  
Stephen Sanders ◽  
Teresa Golden
Keyword(s):  
Corrosion Resistance ◽  
Deep Water ◽  
Gas Hydrate ◽  
Surface Characterization ◽  
Oil And Gas ◽  
High Salinity ◽  
Hydrate Formation ◽  
Test Solution ◽  
Low Salinity ◽  
Gas Hydrate Formation

Corrosion and gas hydrate formation are flow assurance problems that can cause serious safety problems in deep water environments. One aspect that has been given less attention is the corrosion behavior of materials in salinity environment where gas hydrate formation and CO2 (sweet) corrosion can both occur. This type of environment is common in oil and gas deep water environments. The aim of this work is to investigate the effects of CO2-saturated salinity environment on Ni-Mo alloys at gas hydrate formation temperatures using electrochemical, SEM/EDX, and XRD surface characterization techniques. The immersion test solutions were sweet low-salinity (CO2 + 1 wt% salt + 5 oC) and sweet high- salinity (CO2 + ~24 wt% salt + 5 oC) environments, respectively. The as-deposited Ni-Mo alloy coating has the highest corrosion resistance of 33.28 kΩ cm2. The corrosion resistance dropped to 14.36 kΩ cm2 and 11.11 kΩ cm2 after 20 hrs of immersion in the sweet low-salinity and sweet high-salinity test solutions respectively. From grazing incidence XRD, the (111) reflection peak of the Ni-Mo coating was depressed and broaden after immersion in both test solutions due to increase in oxide layer formation on the surface of the Ni-Mo coating. SEM revealed a cracked surface morphology after immersion in sweet high-salinity test solution and elemental analysis shows the presence of oxygen after immersion in both test solutions. The oxygen content increased from 1.70 wt% after immersion in sweet low-salinity test solution to 2.37 wt% after immersion in sweet high-salinity test solution.

New «green» inhibitors of gas hydrate formation for the oil and gas industry based on polysaccharides

2021 ◽  
pp. 33-40
Author(s):  
V.A. Dokichev ◽  
◽  
A.I. Voloshin ◽  
N.E. Nifantiev ◽  
M.P. Egorov ◽  
...  
Keyword(s):  
Gas Hydrate ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
Field Tests ◽  
Oil And Gas Industry ◽  
Quasi Equilibrium ◽  
Green Inhibitor ◽  
Gas Industry ◽  
Gas Hydrate Formation ◽  
Thermobaric Conditions

The thermobaric conditions for the formation of gas hydrates in the presence of the sodium salt of carboxymethylcellulose, dextran, and arabinogalactan were studied in a quasi-equilibrium thermodynamic experiment. It is established that polysaccharides slow down the rate and change the conditions of gas hydrate formation of a mixture of natural gases, showing the properties of a thermodynamic and kinetic inhibitor with technological efficiency exceeding methanol by 170-270 times when used in the same dosages. The results of the development of a «green» synergistic inhibitor of gas hydrate formation «Glycan RU» on their basis are presented, which includes a combination of thermodynamic and kinetic inhibitors. Pilot field tests of «Glycan RU» were carried out at the wells of the Priobskoye, Prirazlomnoye, Ombinsky, Zapadno-Ugutskoye oilfields. It was found that at dosages of 1000 g/m3 and 500 g/m3, there is no formation of hydrate plugs in the annulus. «Glycan RU» is recommended for industrial use by the technology of periodic injection and/or continuous dosing through wellhead dispensers. Keywords: carboxymethylcellulose; dextran; arabinogalactan; polysaccharides; «green» inhibitor of gas hydrate formation; «Glycan RU».

Modeling of Gas Hydrate Formation in a High Pressure Reactor

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Ajay Mandal ◽  
Sukumar Laik
Keyword(s):  
Kinetic Model ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Oil And Gas ◽  
Hydrate Formation ◽  
System A ◽  
Gas Hydrate Formation ◽  
Simple Kinetic Model ◽  
Geometric Variables ◽  
Order Rate Equation

Gas hydrates are now gaining importance in oil and gas industries because they are considered a future source of energy and a means for the transport of natural gas. On the other hand gas hydrates create problems by plugging the pipelines during transportation. Obviously, predicting the conditions in which hydrates are formed would be valuable. In the present study, experiments were performed to observe the conditions, which favor the formation of an ethane gas hydrate. The results of the hydrate formation are elucidated with the help of a conceptual kinetic model. An empirical correlation is developed to predict the rate of formation of the hydrate in terms of the operating and geometric variables of the system. A simple kinetic model based on the dissolved ethane gas is also developed which shows that the hydrate formation follows the first order rate equation.

scholarly journals An Experimental Study on the Formation of Natural Gas Hydrate With Thermodynamic Inhibitors

2021 ◽  
Vol 9 ◽  
Author(s):  
Na Wei ◽  
Cuiying Xie ◽  
Wantong Sun ◽  
Haitao Li ◽  
Lin Jiang ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Natural Gas ◽  
Gas Hydrate ◽  
Oil And Gas ◽  
Volume Concentration ◽  
Hydrate Formation ◽  
Natural Gas Hydrate ◽  
Gas Hydrate Formation ◽  
Supercooling Degree ◽  
Cavity Structure

Gas hydrates formed in the conditions of high pressure and low temperature in deep sea and in the process of oil and gas transportation, natural gas hydrate (NGH), will seriously affect the safety of drilling and completion operations and marine equipment and threaten the safety of drilling platform. How to prevent the hydrate formation in the process of oil and gas production and transportation has become an urgent problem for the oil and gas industry. For this reason, in view of the formation of NGH in the process of drilling and producing marine NGH, the phase equilibrium calculation research of NGH formation was carried out, the mathematical model of gas hydrate formation phase equilibrium condition was established, and the experimental research on NGH formation was carried out through adding different thermodynamic inhibitors. The experimental phenomena show that, first, the stirring speed has little effect on the inhibition of hydrate formation. Second, when the pressure is 10 MPa and the volume concentration of inhibitor is 1, 3, 5, and 7%, the supercooling degree of hydrate formation is 1.81, 8.89, 11.09, and 9.39°C, respectively. Third, when the volume concentration of inhibitor is 1, 3, 5, and 7%, the induction time of hydrate formation is 10328, 14231, 19576, and 24900 s, respectively. As the polymer molecules in the inhibitor reduce the activity of water in the system and fill the cavity structure of the hydrate, they reduce the generation conditions of NGH and break the original phase equilibrium conditions when NGH is generated, thus forming NGH at a lower temperature or higher pressure.

scholarly journals Research into phase transformations in reservoir systems models in the presence of thermodynamic hydrate formation inhibitors of high concentration

2021 ◽  
Vol 230 ◽  
pp. 01014
Author(s):  
Nazar Pedchenko ◽  
Ivan Zezekalo ◽  
Larysa Pedchenko ◽  
Mykhailo Pedchenko
Keyword(s):  
Phase Transformations ◽  
Gas Hydrate ◽  
Oil And Gas ◽  
Solid Phase ◽  
Three Dimensional ◽  
Hydrate Formation ◽  
Oil And Gas Industry ◽  
Difficult Problem ◽  
High Concentration ◽  
Gas Hydrate Formation

Gas hydrates have been and still remain a difficult problem in the oil and gas industry, solution of which requires considerable efforts and resources. In this work, the mechanism of phase transformations at negative temperatures in the formation of the solid phase is preliminarily studied using the reservoir system models consisting of a gas mixture and a solution of gas hydrate formation inhibitor of thermodynamic action with high concentration in distilled water. A system of three-dimensional lighting and image magnification is used to visually detect phase boundaries by creating optical effects. Thus, in the system “inhibitor solution – gas hydrate – gas” in the process of gas hydrate recrystallization in the conditions close to equilibrium, microzones of supercooled water may occur, which in the absence of gas molecules access is crystallized into ice. The result of such solid phase structure formation is its increased stability in nonequilibrium conditions for a relatively long period of time.

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