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

Author(s):  
V.A. Dokichev ◽  
◽  
A.I. Voloshin ◽  
N.E. Nifantiev ◽  
M.P. Egorov ◽  
...  

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».

Author(s):  
Akinsete O. Oluwatoyin ◽  
Oladipo O. Olatunji ◽  
Isehunwa O. Sunday

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.


2021 ◽  
Vol 230 ◽  
pp. 01014
Author(s):  
Nazar Pedchenko ◽  
Ivan Zezekalo ◽  
Larysa Pedchenko ◽  
Mykhailo Pedchenko

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.


2018 ◽  
Vol 40 (2) ◽  
pp. 69-74
Author(s):  
Yusep Kartiwa Caryana

Carbon Capture and Sequestration (0r Storage)known as CCS needs to be implemented in various development activities in Indonesia including downstream oil and gas industry because the government of Indonesia has adopted the Paris Agreement on Greenhouse Gas Emissions Reduction. Various capture techniques have been developed for capturing CO2 from post combustion emission. One of the new approaches considered for capturing CO2 and hence reducing to atmospheric emissions is based on gas hydrate (crystallization) technology. The basis of the technology is the selective partition of the target component between the hydrate phase and the gaseous phase. It is expected that CO2 is preferentially trapped and encaged into the hydrate crystal phase compared to the other components. Previous study found that the gas/hydrate equilibrium pressure and temperature for the fl ue gas mixture in the range of 7.6 MPa and 11.0 MPa at 274 K and 277 K respectively, are inappropriate to the downstream oil and gas industrial reality because the operating cost will be expensive to compress the gas to the hydrate formation pressure. Suitable hydrate promoters including Tetrahydrofuran (THF) and Sodium Dodecyl Sulfate (SDS) can be used to achieve moderate hydrate formation pressure and energy consumption appropriate to the industrial reality. In the presence of THF and SDS about 62.3 Nm3/m3 CO2 hydrate can be formed at 30 bar pressure and 274 to 277 K temperature within around 15 minutes reaction time.Many experiments result indicates that continuous hydrates formation will be feasible for scale-up to industrial settings including downstream oil and gas industry emission reduction if the technology assures an optimal contact between gas and liquid phases plus the proper hydrate promoter. However, compared to current international carbon credit, the feasibility of onshore CO2 abatement cost in downstream oil and gas industry sensitively depends on the distance of CO2 hydrate pipeline transportation.


Author(s):  
Catalin Teodoriu ◽  
Gioia Falcone ◽  
Amodu Afolabi

Gas hydrates are ice-like crystalline systems made of water and methane that are stable under high pressure and low temperature conditions. Gas hydrates have been identified as strategic resources and may surpass all known oil and gas reserves combined. However, these resources will become reserves only if the gas contained therein can be produced economically. In the oil and gas industry, gas hydrates may be encountered while drilling sediments of the subsea continental slopes and in the subsurface of permafrost regions. They also represent a flow assurance issue, as they may form in the well and in the flowlines, causing blockages. Deepwater drilling programmes have experienced problems when encountering gas hydrate formations. A major issue is that of phase transition, where gas hydrate goes from a solid state to dissociated gas and water, as there are rapid changes in fluid volumes and pressure. This can cause drilling equipment failure, borehole instability and formation collapse. After dissociation of water and gas, hydrates may be prevented from forming in the well by using appropriate inhibitors in the drilling mud. There is a need to develop fluids specifically for drilling through gas hydrate formations, either to unlock the unconventional reserves trapped in the crystalline gas hydrate structures or to safely reach underlying conventional reserves. To drill wells in a gas hydrate formation, a conductor casing is needed to allow close loop circulation of the mud, if different from seawater. The search for the ideal mud for drilling through gas hydrate formations must start with a review of past experiences worldwide and of the lessons learned. This paper presents a review of the problems encountered while drilling through gas hydrate formations. It identifies the key requirements for drilling fluids, based on the interaction between the drill bit, the drilling fluid and the formation. An evaluation of the environmental risk associated with drilling through gas hydrate formations is also presented.


2022 ◽  
pp. 95-115
Author(s):  
Anupama Kumari ◽  
Mukund Madhaw ◽  
C. B. Majumder ◽  
Amit Arora

The analysis and collection of data is an integral part of all research fields of the modern world. There is a need to perform forward mathematical modeling to improve the operations and calculations with modern technologies. Artificial neural network signifies the structure of the human brain. They can provide reasonable solutions quickly for the problems that classical programming cannot solve. An in-depth systematic study is presented in this chapter related to artificial neural network applications (ANN) for predicting the equilibrium conditions for gas hydrate formation, which can assist in designing future dissociation technology for gas hydrate so that this white gold can make world energy free for the future generation. This chapter can also help to develop a novel inhibitor for gas hydrate formation and save millions of dollars for the oil and gas industry.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5664
Author(s):  
Roman S. Pavelyev ◽  
Yulia F. Zaripova ◽  
Vladimir V. Yarkovoi ◽  
Svetlana S. Vinogradova ◽  
Sherzod Razhabov ◽  
...  

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.


2019 ◽  
Author(s):  
Christopher Ozigagu ◽  
Ting Zhou ◽  
Stephen Sanders ◽  
Teresa Golden

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.


Author(s):  
Weixin Pang ◽  
Qingping Li ◽  
Fujie Sun

The hydrate is an important issue that the flow assurance has to face in the oil and gas industry, especially in the deepwater area. With high pressure and low temperature, the hydrate formation is easily happened and leads to plug in the pipeline. In addition to the traditional thermodynamic inhibitor, the low dosage hydrate inhibitors (LDHI) has been increasing used as a costly effective technology for gas hydrate control. The LDHI include kinetic hydrate inhibitor (KHI) and anti-agglomerant (AA), the former can inhibit the hydrate formation in the pipeline, and the latter can prevent the agglomeration and plug of hydrate particles. According to the properties of oil and gas of South China Sea, a new KHI and AA were developed, a field test of the KHI has been undertaken and the results indicate that it can prevent the hydrate formation and plug in the pipeline well, the lab evaluation of the developed AA is in progress and the field test will be performed by the next year.


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