scholarly journals Multi-functional oilfield production chemicals: maleic-based polymers for gas hydrate and corrosion inhibition

2021 ◽  
Vol 1201 (1) ◽  
pp. 012081
Author(s):  
M A Kelland ◽  
J Pomicpic ◽  
R Ghosh ◽  
C Undheim ◽  
T H Hemmingsen ◽  
...  
Keyword(s):  
Natural Gas ◽  
Corrosion Inhibition ◽  
Gas Hydrate ◽  
Open Circuit ◽  
Gas Production ◽  
Water Soluble ◽  
Test Method ◽  
Production Flow ◽  
Flow Lines ◽  
Better Than

Abstract Several chemical problems can occur during the production of oil and gas through flow lines. This includes corrosion, scale deposition and gas hydrate plugging. Three separate chemicals may be needed to treat these issues. Kinetic hydrate inhibitors (KHIs) are used in cold oil or natural gas production flow lines to prevent the formation and plugging of the line with gas hydrates. They are often injected concomitantly with other production chemicals such as corrosion and scale inhibitors. KHIs are specific low molecular weight water-soluble polymers with amphiphilic groups formulated with synergists and solvents. However, many corrosion inhibitors (CIs) are antagonistic to the KHI polymer, severely reducing the KHI performance. It would be preferable and economic if the KHI also could act as a CI. We have explored the use of maleic-based copolymers as KHIs as well as their use as film-forming CIs. KHIs were tested using a natural gas mixture in high pressure rocking cells using the slow constant cooling test method. A terpolymer from reaction of vinyl acetate:maleic anhydride copolymer with cyclohexy lamine and 3,3-di-n-butylaminopropylamine (VA:MA-60% cHex-40% DBAPA), gave excellent performance as a KHI, better than the commercially available poly(N-vinyl caprolactam) (PVCap). CO2 corrosion inhibition was measured by Linear Polarization Resistance (LPR) in a 1 litre CO2 bubble test equipment using C1018 steel coupons. The new terpolymer gave good CO2 corrosion inhibition in 3.6 wt% brine, significantly better than PVCap, but not as good as a commercial imidazoline-based surfactant corrosion inhibitor. The terpolymer also showed good corrosion inhibition efficiency at high salinity conditions, (density 1.12 g/cm3). VA:MA-60% cHex-40% DBAPA shifted the open-circuit potential to more positive values and significantly decreased the corrosion rate.

Importance of Gas Hydrates for India and Characterization of Methane Gas Dissociation in the Krishna-Godavari Basin Reservoir

2016 ◽  
Vol 50 (6) ◽  
pp. 58-68 ◽  
Author(s):  
Narayanaswamy Vedachalam ◽  
Sethuraman Ramesh ◽  
Arunachalam Umapathy ◽  
Gidugu Ananda Ramadass
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Gas Production ◽  
Hot Water ◽  
Economic Resource ◽  
Methane Gas ◽  
Hydrate Reservoir ◽  
Gas Hydrate Reservoir ◽  
Godavari Basin

AbstractNatural gas hydrates are considered to be a strategic unconventional hydrocarbon resource in the Indian energy sector, and thermal stimulation is considered as one of the methods for producing methane from gas hydrate-bearing sediments. This paper discusses the importance of this abundantly available blue economic resource and analyzes the efficiency of methane gas production by circulating hot water in a horizontal well in the fine-grained, clay-rich natural gas hydrate reservoir in the Krishna-Godavari basin of India. Analysis is done using the electrothermal finite element analysis software MagNet-ThermNet and gas hydrate reservoir modeling software TOUGH+HYDRATE with reservoir petrophysical properties as inputs. Energy balance studies indicate that, in the 90% hydrate-saturated reservoir, the theoretical energy conversion ratio is 1:4.9, and for saturations below 20%, the ratio is <1. It is identified that a water flow of 0.2 m3/h at 270°C is required for every 1 m2 of wellhead surface area to dissociate gas hydrates up to a distance of 2.6 m from the well bore within 36 h.

scholarly journals The Effects of the Length and Conductivity of Artificial Fracture on Gas Production from a Class 3 Hydrate Reservoir

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7513
Author(s):  
Shilong Shang ◽  
Lijuan Gu ◽  
Hailong Lu
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Energy Resource ◽  
Gas Production ◽  
Production Performance ◽  
Natural Gas Hydrate ◽  
Conductivity Method ◽  
Fracture Length ◽  
Hydrate Reservoir ◽  
Artificial Fracture

Natural gas hydrate is considered as a potential energy resource. To develop technologies for the exploitation of natural gas hydrate, several field gas production tests have been carried out in permafrost and continental slope sediments. However, the gas production rates in these tests were still limited, and the low permeability of the hydrate-bearing sediments is identified as one of the crucial factors. Artificial fracturing is proposed to promote gas production rate by improving reservoir permeability. In this research, numerical studies about the effect of fracture length and fluid conductivity on production performance were carried out on an artificially fractured Class 3 hydrate reservoir (where the single hydrate zone is surrounded by an overlaying and underlying hydrate-free zone), in which the equivalent conductivity method was applied to depict the artificial fracture. The results show that artificial fracture can enhance gas production by offering an extra fluid flow channel for the migration of gas released from hydrate dissociation. The effect of fracture length on production is closely related to the time frame of production, and gas production improvement by enlarging the fracture length is observed after a certain production duration. Through the production process, secondary hydrate formation is absent in the fracture, and the high conductivity in the fracture is maintained. The results indicate that the increase in fracture conductivity has a limited effect on enhancing gas production.

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