Optimizing CAPEX and OPEX for High CO2 and H2S Field by Using Mechanistic Corrosion Modelling Approach

The gas contaminants especially CO2 and H2S from the well is a major threat to oil and gas production facilities and pipeline. Developing this type of reservoir cost enormous CAPEX and OPEX due the need for expensive materials or the need of continuous chemical injection. This paper outlines the opportunity of cost optimization for future field development and operational through mechanistic corrosion modelling approach. This method was embedded to an in-house corrosion prediction model that was first developed by collaboration with Ohio University in 2008 with capability to predict corrosion rate for partial pressure more than 20bar of CO2 and up to 1bar of H2S. The model validation was performed based on actual field production operated at 55°C and 22 bar of CO2 partial pressure followed the methodology as outlined in NACE paper C2012-0001449. Upon successful validation, the model has been deployed to assist an Operator of an offshore pipeline in Southeast Asia, operating at 97°C and 17 bar of CO2 partial pressure, to ascertain the risk due to CO2 corrosion and review the original pipeline design adequacy. Subsequently, the model has been utilized for an Operator of onshore facilities in Middle East to address specific issue encountered during the final stage of development for one of the wellpad in which the wells are expected to experience increase of H2S from 100ppm in original design to more than 1000ppm during actual production. This process changes raised a serious concern on the integrity of the materials as potential corrosion issue and the need for corrosion mitigation such as H2S Scavenger injection was not originally considered during early stage of engineering. The corrosion rate from the model has been validated against the intelligent pigging (IP) data and proven to be able to predict corrosion rate with +20% accuracy and more than 99% confidence level for CO2 partial pressure up to 25 bar with the presence of H2S. Based on deployment and utilization of the model, the high confidence in the model ability to accurately predict the corrosion rate will lead to potential CAPEX and OPEX optimization for the field development and during operational stage.

Mitigating CO2 Corrosion of Natural Gas Steel Pipelines by Thermal Spray Aluminum Coatings

Internal pipeline corrosion due to CO2 is a major challenge facing the oil and gas industry. To protect the pipelines and equipment from the ravages of CO2 corrosion, novel sacrificial coatings can be used. The objective of this study was to investigate the corrosion behavior of Al-based alloys as sacrificial coatings to protect pipelines in a CO2-saturated aqueous electrolyte (3.5 wt.% NaCl) at 4 bar CO2 partial pressure (3 barg) and 40 oC. The corrosion resistance of Al-based alloys and thermal spray coatings was evaluated in an electrochemical reaction autoclave using electrochemical methods (potentiodynamic polarization, linear polarization resistance, and electrochemical impedance spectroscopy). Post-corrosion surface characterization was performed by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy. The obtained data show Al-based alloys demonstrated promising protection against CO2 corrosion with no breakaway degradation issues.

Gasification Kinetics of Victorian Brown Coal-Derived Char in Fluidised Bed Reactor

In a chemical looping combustion (CLC) system, gasification kinetics of char holds immense importance being the rate-limiting reaction in the fuel reactor. This paper studied the gasification kinetics of char derived from Victorian Brown Coal (VBC) in a fluidised bed reactor which mimics the fuel reactor conditions of a CLC process. Mass of char, char particle size and gas flow conditions were optimised to ensure the gasification reaction free from mass transfer limitations. Effect of oxygen carrier, hematite, being the bed material was also studied. The experiments were conducted in the temperature range of 800C-950C, which is a typical range for fuel reactor. The experimental results were modelled with the help of grain model (GM) and random pore model (RPM) to analyse the kinetic parameters. Activation energy was found to be around 177 kJ/mol in sand bed and 175.5 kJ/mol in the hematite bed. Reaction in hematite bed was found to be 42% faster on average compared to the reaction in a sand bed. Fastest total conversion of char took as low as 4.1 minutes in hematite bed at 950C. While catalytic effect of hematite was ruled out due to insignificant change in activation energy, it was concluded that increase in CO2 partial pressure at the vicinity of char particle enhanced the reaction rate in the case of hematite bed. This study has generated relevant information for the CLC of Victorian Brown Coal with hematite as the oxygen carrier.

Reviews and syntheses: Heterotrophic fixation of inorganic carbon – significant but invisible flux in environmental carbon cycling

Heterotrophic CO2 fixation is a significant yet underappreciated CO2 flux in environmental carbon cycling. In contrast to photosynthesis and chemolithoautotrophy – the main recognized autotrophic CO2 fixation pathways – the importance of heterotrophic CO2 fixation remains enigmatic. All heterotrophs – from microorganisms to humans – take up CO2 and incorporate it into their biomass. Depending on the availability and quality of growth substrates, and drivers such as the CO2 partial pressure, heterotrophic CO2 fixation contributes at least 1 %–5 % and in the case of methanotrophs up to 50 % of the carbon biomass. Assuming a standing stock of global heterotrophic biomass of 47–85 Pg C, we roughly estimate that up to 5 Pg C might be derived from heterotrophic CO2 fixation, and up to 12 Pg C yr−1 originating from heterotrophic CO2 fixation is funneled into the global annual heterotrophic production of 34–245 Pg C yr−1. These first estimates on the importance of heterotrophic fixation of inorganic carbon indicate that this pathway should be incorporated in present and future carbon cycling budgets.

Experimental Study of O2-Enriched CO2 Production by BaCo0.8B0.2O3−δ (B=Ce, Al, Fe, Cu) Perovskites Sorbent for Marine Exhaust CO2 Capture Application

An effective approach for reducing CO2 emissions from marine exhaust is adopting oxyfuel combustion technology. A series of B-site doped BaCo0.8B0.2O3−δ (B=Ce, Al, Fe, Cu) perovskites as novel oxygen carrier applications were prepared by the sol-gel method. The oxygen desorption characteristics of the B-site doped BaCo0.8B0.2O3−δ perovskites and the effects of adsorption/desorption temperature, CO2 volume flow rate, CO2 partial pressures, and adsorption time were researched in the fixed bed reactor. The surface morphology and size of the oxygen carrier was observed by scanning electron microscope (SEM). Results showed that BaCo0.8Al0.2O3−δ and BaCo0.8Ce0.2O3−δ have comparable performance, considering the cost of the raw materials. BaCo0.8Al0.2O3−δ was selected as candidate for further study. The optimal adsorption/desorption temperature, CO2 volume flow rate, CO2 partial pressure and adsorption time for BaCo0.8Al0.2O3−δ were studied in detail. Results showed that the best operating parameters were determined to be 850 °C/850 °C for adsorption/desorption temperature, 200 mL/min for CO2 volume flow rate, 100% CO2 partial pressure, and 30 min for absorption time, respectively. Furthermore, multiple cycle results indicate that BaCo0.8Al0.2O3−δ sorbent has high reactivity and cyclic stability.

Mesoporous Organo-Silica Supported Chromium Oxide Catalyst for Oxidative Dehydrogenation of Ethane to Ethylene with CO2

Chromium oxide supported on mesoporous organo-silica (MOS) was synthesized with different Cr loading by an incipient method. The catalytic performance of a Cr(x)/MOS catalyst for CO2-based ethane dehydrogenation was investigated. The synthesized catalysts were characterized by XRD, BET, TEM, SEM, XPS, FTIR, and UV–Vis DR measurements. The textural properties of the prepared samples showed that the mesoporous nature of MOS sample was not disturbed by chromium impregnation. Among the prepared samples, Cr(8)/MOS catalyst exhibited good distribution of chromium species along with superior concentration of Cr6+ and the highest recorded Cr6+/Cr3+ ratio. The results revealed that the superior catalytic performance was reached at Cr(8)/MOS, with 50.4% and 90.1% of ethane conversion and ethylene selectivity, respectively. The catalytic activity decreased slowly over reaction time; it declined approximately 22% after 10 h of stream operation. The roles of CO2-based ethane dehydrogenation were also studied, where carbon dioxide can be a source of lattice oxygen and as a hydrogen consumer in reverse water–gas shift (RWGS) reaction. The effect of various catalytic factors, such as catalytic temperature, reaction time, space gas velocity, and CO2 partial pressure on the conversion of ethane, yield, and selectivity to ethylene, were investigated as well.

Preparation of Blackened Ca-based Composite Particles and Their Carbonation Kinetics Features

The calcium looping thermochemical thermal energy storage is one of the best high-temperature heat storage schemes for 3th concentrating solar power photothermal power, but its application is restricted by the inherent low solar absorptance and poor cyclic stability of CaCO3/CaO. Herein, the solar absorptance of CaCO3 particles is enhanced by doping Mn-Fe oxides, meanwhile, awns of setaria faberis and microcrystalline cellulose are used as bio-templates to generate pores inside the particles. The test results show that the prepared particles possess adequate anti-crushing strength, high cyclic stability, high solar absorption, and high carbonation rate. In addition, the carbonation kinetic equation of the composite porous particles is studied with the influence factors such as CO2 partial pressure, reaction temperature, and particle morphology taken into consideration. is of great significance for the design and regulation of the carbonator achieving highly stable heat output in the CaL thermochemical heat storage system.

Lipopolysaccharide endotoxin injections elevated salivary TNFα and corneal temperatures and induced dynamic changes in circulating leukocytes, inflammatory cytokines, and metabolic indicators in wether lambs

Pathogenic infections increase morbidity and reduce performance in livestock, and thus understanding the comprehensive physiological changes associated with infections can benefit production sustainability. In this study, we sought to investigate such physiological responses to an acute immune challenge in lambs. Polypay wethers received single IV injections of 1.5 µg/kg lipopolysaccharide endotoxin (LPS-injected; n = 6) or saline (controls; n = 6). Corneal temperatures (via infrared thermography), rectal temperatures, blood, plasma, and saliva were assessed every 2 h for 10 h after injections. Blood was also assessed at 24 h. LPS-injected lambs exhibited elevated (P < 0.05) corneal and rectal temperatures that peaked at 4 h but were still slightly greater (P < 0.05) than controls at 10 h. Circulating total white blood cells, monocytes, and granulocytes were reduced (P < 0.05) in LPS-injected lambs within the first 4 h but were subsequently greater (P < 0.05) than in controls. Lymphocytes were reduced (P < 0.05) in LPS-injected lambs over the first 8 h and did not differ from controls thereafter. Red blood cells, hematocrit, and hemoglobin were increased (P < 0.05) in LPS-injected lambs over the first 6 h, indicating mild dehydration. Blood glucose briefly increased (P < 0.05) in LPS-injected lambs at 2 h but was less (P < 0.05) than in controls thereafter. Blood lactate was greater (P < 0.05) in LPS-injected lambs between 6 and 10 h after injections, which together with reduced (P < 0.05) CO2 partial pressure indicated a metabolic shift toward glycolysis. LPS-injected lambs exhibited a transient increase (P < 0.05) in plasma TNFα at 2 and 4 h only and sustained increases (P < 0.05) in CXCL9 and CXCL10 beginning at 6 and 4 h, respectively. They also exhibited a mild, paradoxical increase (P < 0.05) in the anti-inflammatory sFRP3. Salivary TNFα was increased (P < 0.05) in LPS-injected lambs at 2 h only. Regression analyses indicated that rectal temperatures were a generally poor predictor of the other inflammatory components in this study, with the exception of circulating leukocyte populations. Likewise, correlations among the 10 cytokines measured in this study were generally weak, with notable exceptions between CXCL9 and CXCL10 and between IL-21 and IFNγ. These findings demonstrate that physiological changes to even short-lived immune challenges are dynamic in nature and persist beyond the time frame of febrile responses and other common assessments.

SARS-CoV-2 Renal Impairment in Critical Care: An Observational Study of 42 Cases (Kidney COVID)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leads to 5% to 16% hospitalization in intensive care units (ICU) and is associated with 23% to 75% of kidney impairments, including acute kidney injury (AKI). The current work aims to precisely characterize the renal impairment associated to SARS-CoV-2 in ICU patients. Forty-two patients consecutively admitted to the ICU of a French university hospital who tested positive for SARS-CoV-2 between 25 March 2020, and 29 April 2020, were included and classified in categories according to their renal function. Complete renal profiles and evolution during ICU stay were fully characterized in 34 patients. Univariate analyses were performed to determine risk factors associated with AKI. In a second step, we conducted a logistic regression model with inverse probability of treatment weighting (IPTW) analyses to assess major comorbidities as predictors of AKI. Thirty-two patients (94.1%) met diagnostic criteria for intrinsic renal injury with a mixed pattern of tubular and glomerular injuries within the first week of ICU admission, which lasted upon discharge. During their ICU stay, 24 patients (57.1%) presented AKI which was associated with increased mortality (p = 0.007), hemodynamic failure (p = 0.022), and more altered clearance at hospital discharge (p = 0.001). AKI occurrence was associated with lower pH (p = 0.024), higher PaCO2 (CO2 partial pressure in the arterial blood) (p = 0.027), PEEP (positive end-expiratory pressure) (p = 0.027), procalcitonin (p = 0.015), and CRP (C-reactive protein) (p = 0.045) on ICU admission. AKI was found to be independently associated with chronic kidney disease (adjusted OR (odd ratio) 5.97 (2.1–19.69), p = 0.00149). Critical SARS-CoV-2 infection is associated with persistent intrinsic renal injury and AKI, which is a risk factor of mortality. Mechanical ventilation settings seem to be a critical factor of kidney impairment.