scholarly journals Top-of-line corrosion in the presence of carbon dioxide for gas production facilities

2021 ◽  
Vol 225 ◽  
pp. 01002
Author(s):  
Ruslan Vagapov

Aspects of the development of corrosion processes under conditions of moisture condensation in the gas phase (top-of-line corrosion) in the presence of carbon dioxide, which lead to the formation of local damages, have been investigated. The influence of various factors on corrosion processes under conditions of moisture condensation (top-of-line corrosion) was studied: the acidity of the media (presence of acetic acid), the presence of alcohol (methanol is used in gas production as an inhibitor of hydrate formation), temperature, type of steel and the presence of a weld. In addition to the listed factors, the moisture content in the gas is the determining factor for the development of this type of corrosion under CO2 conditions. The rate of development of corrosion processes depends on the amount and composition of the liquid condensing on the metal surface. The rate of local carbon dioxide corrosion at top-of-line corrosion can reach several mm / year.

2019 ◽  
Vol 121 ◽  
pp. 02013 ◽  
Author(s):  
Dmitry Zapevalov ◽  
Ruslan Vagapov

The modern stage of development of many onshore and offshore gas and gas condensate fields is associated with objects in which carbon dioxide (CO2) gas is present in the production. The presence of CO2 in the produced gas in combination with other factors stimulates the intensive development of corrosion processes, which requires careful and reasonable attitude both to assess the degree of aggressiveness of the media and to choose technical solutions to ensure reliable and safe operation of hydrocarbon production facilities. The authors analyzed the existing approaches to the assessment of the danger of corrosion produced media, selection and implementation of protection against corrosion in the presence in them of aggressive CO2.


2018 ◽  
Vol 58 (9) ◽  
pp. 1751 ◽  
Author(s):  
Z. Amanzougarene ◽  
M. Fondevila

Two experiments were conducted to simulate in vitro the fermentation conditions under high-concentrate feeding. The concentration of bicarbonate ion in the buffer of the incubation solution was assayed in Experiment 1, by adjusting medium pH to 6.50, 6.25, 6.00, 5.75 and 5.50, in two incubation series of 12 h, using barley as the reference substrate. The pH diminished linearly (P < 0001) by lowering the buffer, and remained constant throughout 12 h, except for treatments 5.75 and 5.50, where pH dropped to 5.51 and 5.31 at 12 h. Gas production decreased linearly with a decreasing medium pH (P < 0.001), with the total volume of gas produced after 12 h being highly dependent (P < 0.01) on pH at 12 h (R2 = 0.629), thus demonstrating the importance of the incubation pH for estimation of fermentation of concentrate feeds. In Experiment 2, the effect of pH on direct and indirect proportion of gas was studied by adding 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 mmol of acetic acid, either with or without (water added instead) rumen inoculum, to the media. Linear multiple regressions established between the volume of gas produced and the addition of acetic acid, and the bicarbonate ion concentration showed high determination coefficients for water (R2 = 0.929) and rumen inoculum (R2 = 0.851). Without inoculum, indirect gas production ranged from 9.4 to 12.4 mL/mmol of acid for medium pH of 5.50–6.50. With rumen inoculum, indirect gas was 20.8 mL/mmol acid, although this may have been biased by the contribution of inoculum itself to direct fermentation.


2020 ◽  
Vol 86 (10) ◽  
pp. 23-30
Author(s):  
R. K. Vagapov ◽  
D. N. Zapevalov ◽  
K. A. Ibatullin

Promising domestic gas and gas condensate fields are characterized by the presence of CO2 in the composition of the extracted raw materials which (in combination with moisture condensation and a number of other factors) stimulates the intensive development of local corrosion processes). The paper presents the results of studying corrosion of gas production objects using methods of analytical control (gas chromatography with mass spectrometry, X-ray fluorescence spectrometry, X-ray diffraction). It is shown that key parameters (CO2 partial pressure, mineralization, pH factor, total pressure, etc.) should be considered with allowance for their expected changes during the life cycle of the field and production facilities. To determine the ultimate local corrosion rates, corrosion tests were carried out under conditions of moisture condensation. The corrosion development under CO2 conditions is shown to depend on the amount of moisture formed during condensation on metal surfaces, composition and content of the condensate in the vapor phase. Monoethylene (MEG) glycol which is used in gas production as a hydrate formation inhibitor can be also present in the condensed medium. MEG concentration also significantly contributes to the rate of corrosion processes Local carbon dioxide corrosion rate can attain several millimeters per year. Analytical methods can be successfully used in combination with other control methods to predict and monitor a corrosion situation (content of a corrosion inhibitor, presence of the corrosion products or deposits, etc.) at gas production facilities.


1962 ◽  
Vol 40 (6) ◽  
pp. 991-1011 ◽  
Author(s):  
R. P. Harpur

The anaerobic carbon dioxide production of minced ascaris muscle decreases markedly when worms are kept in vitro for 3 days. Using this gas production as an index, and a factorial design, the effects of nitrogen, oxygen, carbon dioxide, antibiotics, vitamins, amino acids, glucose, potassium, and ammonium ions were investigated. For this study the worms were kept in media which were changed every 3 hours and the gaseous phases were maintained by bubbling gas continuously through the media. Under these conditions 20% oxygen was extremely toxic but carbon dioxide (5%) provided some relief from this effect. Even 5% oxygen caused more decrease in the index than did nitrogen alone, but this was not true when a mixture of amino acids and glucose was present. Ammonium ions had a beneficial effect in nitrogen but a detrimental effect in the presence of 20% oxygen. A high potassium ion concentration (24 mM) was detrimental in the absence of carbon dioxide but appeared to enhance the beneficial effects of carbon dioxide.


Author(s):  
R. K. Vagapov ◽  
D. N. Zapevalov ◽  
K. A. Batullin

The paper investigates aspects of the development of corrosion processes under conditions of moisture condensation in the gas phase in the presence of carbon dioxide, which lead to the formation of local damage. The authors developed and tested a methodology for conducting steels corrosion testing The causes of the formation and the corrosive effect of moisture condensation on steel under conditions of carbon dioxide corrosion at gas production facilities are analyzed. It was found that at elevated temperatures, when the temperature difference is higher, more moisture condenses on the surface of the steel, which leads to an increase in the rate of both general and local corrosion by 2–3 times, compared to room temperature. The increased localization of corrosion processes under conditions of moisture condensation and the presence of CO2 makes the depth index of steel corrosion much higher than the general corrosion rate. When assessing the corrosiveness of environments with condensation of the aqueous phase, the rate of corrosion associated with the depth of the observed corrosion damage should be taken into account. According to the test results, it was determined that samples from the weld compared with the sample from the main body of the pipe differ in the degree of localization of corrosion in conditions of moisture condensation.


2020 ◽  
Vol 5 (4) ◽  
pp. 527-530
Author(s):  
Azubuike Hope Amadi ◽  
Chukwuebuka E. Okafor

Flow assurance has been a topic of concern since the start of crude oil and gas production and transportation. The formation of Hydrates is an important issue likely to cause clogs in pipelines during production and transportation of oil and gas. Therefore, production and transportation of such fluids are simulated using software’s like Unism to know the possibility of hydrate occurrence so they can be avoided. This work is based on the simulation of processed well effluents from Rose Field to analyze the hydrate formation temperature and water dew point at different points of the process facility. At the crude oil line the hydrate formation temperature was -69.9565 C, while the water dew point was not defined because it’s a liquid phase. At the gas line the hydrate formation temperature was 4 C at 1803psia and water dew point was -42.7 C. These values are parameters necessary for hydrate formation prediction, hence, they were analyzed and recommendations made to manage effective flow assurance.


2020 ◽  
Vol 25 (4) ◽  

The current stage in the development of promising gas and gas condensate fields in the Russian Federation is associated with facilities whose production includes carbon dioxide. Such objects include the Urengoyskoye oil and gas condensate field (Achimov deposits), the Bovanenkovskoye oil and gas condensate field, and the Kirinskoye gas and condensate field. The presence of CO2 in the produced gas, in combination with moisture condensation and a number of other factors, stimulates the intensive development of local corrosion processes. The main factors that influence the development of corrosion at infrastructure facilities and its localization in the presence of CO2 are considered. It is noted that when assessing the degree of aggressiveness of the environment, it is necessary to consider not only the CO2 content, but also other basic operating parameters that can affect corrosion. During the exploitation of gas fields, the conditions of moisture condensation that contribute to corrosion arise, which occurs when a temperature gradient arises and the produced gas is rapidly cooled. Higher temperatures increase both the amount of precipitated moisture and, accordingly, the rate of local corrosion. Simulation tests have shown that the development of local forms of corrosion (pitting, ulcers) are possible even at low CO2 partial pressures (from 0,025 MPa and above) in the presence of condensed moisture.


1980 ◽  
Vol 20 (05) ◽  
pp. 377-384 ◽  
Author(s):  
E. Brunner ◽  
W. Woll

Description of Problem In recent years the search for natural gas has yielded many reserves that contain high concentrations of hydrogen sulfide. Production of sour gas initially was on a limited scale but since has increased considerably as a result of price increases for fossil fuels. Substantial quantities of sulfur now are produced from the hydrogen sulfide in these natural gas sources. In several of these natural gas fieldse.g., in Canada and north Germany-gas production is hampered severely due to the presence of elemental sulfur dissolved in the gas. The gas-bearing deposits are interspersed with elemental sulfur, which is dissolved to a greater or lesser extent in the sour gas, the solubility being strongly dependent on the pressure, temperature, and composition of the gas. It is well-known that the solubility of sulfur increases with increasing pressure, temperature, and hydrogen sulfide content. As a result of the geothermal temperature profile, the gas stream cools as it rises up the production tubing and there is a drop in pressure due to frictional effects. Consequently, the solubility drops and sulfur is deposited when the solubility limit is exceeded. The gases desolved in the liquid sulfur- principally hydrogen sulfide and carbon dioxide- lead to a lowering of the freezing point. At temperatures between 393.15 and 373.15 K, the sulfur begins to solidify in the line, blocking the tubing and bringing gas production to a standstill. To prevent such blockages, suitable solvents are pumped into the well via an annular space surrounding the production tubing to dissolve the sulfur, which then is carried to the surface with the gas stream. A discussion of the technological problems involved in this process is beyond the scope of this paper. It would be of great value and solving the problem associated with the production of sour natural gas to have more data on, among other things, the solubility of sulfur in compressed sour gases of various compositions over a range of temperatures and pressures. There is little literature on the solubility of sulfur in different natural gases. Kennedy and Wieland reported the results of measurements on the methane/carbon-dioxide/hydrogen-sulfide/sulfur system at pressures up to 40 MPa and temperatures up to 394.15 K Roof examined the solubility of sulfur in hydrogen sulfide up to 30 MPa and 383.15 K, but his results differ considerably from those of Kennedy and Wieland. Swift has published data on the solubility of sulfur in hydrogen sulfide at pressures between 35 and 140 MPa and temperatures between 394.15 and 450.15 K. Using a gas saturation method, we now have measured the solubility of sulfur in pure hydrogen sulfide and in four synthetic sour gas mixtures composed of H2S, CO2, CH4, and N2 in the temperature range of 373.15 to 433.15 K and at pressures up to 60 MPa. Solubility of Solids and Liquids in Compressed Gases It is particularly important that gas-phase fugacity coefficients be employed when calculating the solubility of a solid or a high-boiling liquid in a compressed gas. In general, these fugacity coefficients must be determined experimentally. Corrections for the nonideality of the gas phase, as are employed at lower pressures, can lead to completely erroneous results here. A consideration of both systems-solid/liquid and liquid/liquid is presented in the following. P. 377^


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