FIGURE 15 - uploaded by Sonja Richter
Content may be subject to copyright.
Contact angles of water droplets in model oil phase with either toluene or heptol as the solvent. The steel specimen is pre-wet with the asphaltenic oil phase and Arab Heavy crude oil. In all cases, the surface remains hydrophobic.
Source publication
Asphaltenes (heptane insolubles) from a variety of crude oils have been identified previously as contributors to inhibition of internal corrosion of mild steel pipelines. However, the mechanism of inhibition is unknown. To explore the mechanism, carbon dioxide (CO 2) corrosion rates and wettability (oil/water contact angles) have been measured usin...
Similar publications
The mechanisms by which hydrates deposit in a petroleum production-line are likely to be related to pipeline surface properties, e.g. pipeline material, surface energy and roughness. In this work, the wettability alteration of pipeline surfaces from contact with oil, as well as the adhesion energy between water and solid in the presence of oil is i...
Citations
... For instance, asphaltene can be used as an adsorbent to remove dyes from textile wastewater [40]. In addition, the internal corrosion of the stainless steel pipeline is controlled with adsorption asphaltene on it [11,274]. Asphaltene adsorption onto surface of nanoparticles is a practical way to inhibit precipitation of asphaltene in the system. ...
Adsorption of asphaltene onto mineral or metal surface is an undesirable process with several adverse effects such as wettability alteration, fouling pipelines/equipment, permeability reduction, and clogging of porous media. Adsorption science plays a pivotal role affecting almost every aspect of the oil industry. In this paper, we examined advantages and disadvantages of asphaltene adsorption investigation approaches from microscopic to macroscopic scale. There is a need for systematic investigation of asphaltene adsorption by considering all effective parameters and from different aspects at different scales. Although experimental methods, empirical correlations, theoretical modeling, intelligent approach (macroscopic scale) are considered as reliable methods for asphaltene adsorption process but cannot provide any information at atomic level. The focus of recent researches on asphaltene adsorption onto surface is on using molecular dynamics (MD) simulations to find the interaction force between asphaltene and surfaces under different conditions. We highlighted asphaltene adsorption process using experimental techniques, modeling, and MD simulations. Furthermore, consequence of asphaltene adsorption, theoretical and practical challenges in asphaltene adsorption research and recommendations are provided for future research. The outcome of this critical review can help to further current understanding of the asphaltene adsorption mechanisms to design more effective agents to reduce asphaltene precipitation in petroleum production and transportation related processes.
... The wettability analysis of liquid-solid-gas systems is crucial for several applications such as enhancement of oil recovery (Alnili et al., 2018;Suleymani et al., 2020aSuleymani et al., , 2020b, multiphase fluids flow through porous media (Al-Yaseri et al., 2017;Naik et al., 2015), protection of pipelines from corrosion (Azadi Tabar et al., 2020), CO2 capture and storage (Fauziah et al., 2018), oil-gas separation (Ajmera et al., 2011), and self-cleaning (Marmur, 2006;Azadi Tabar et al., 2019a). For instance, deposition of polar components of oil on the surface of pipe, which can change the wetting state of the pipe from water-wet to oil-wet, could hinder the transport of heavy oil with the help of water in pipelines. ...
... In such a condition, frictional losses will be increased due to direct interaction of the crude oil with the pipe (dos Santos et al., 2006). Also, when long-chain polar components like asphaltenes accumulate on the surface of plain carbon steel pipes (mild steel pipes), it has been found that they are able to invert wetting behavior of underwater systems and prevent the corrosion caused by CO 2 and NaCl (Ajmera et al., 2011;Ayello et al., 2011). Furthermore, several studies in chemical enhanced oil recovery have reported that chemical agents can alter the reservoir rock wettability by stimulating the rock surface. ...
Wettability alteration analysis form gas-repellent to gas-wet with the aid of chemical agents has been subjected of numerous studies. However, fundamental understanding of the effect of surface tension of liquid on repellency strength, the change in the intermolecular forces due to the adsorption of nanoparticles onto the rock surfaces, and exposure of treated rock in brine are not well discussed in the available literature. In this study, X-ray diffraction, Atomic Force Microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were applied to characterize the treated and fresh samples. Dynamic and static contact angle measurements were then combined with six methods of surface free energy analysis; Neumann, Zisman plot, geometric, harmonic, acid-base, and Chibowski, to model liquid intermolecular forces effect on contact angle and to calculate the surface forces. Surface characterization results showed that adsorbed fluorine and silicon elements onto the calcite surface due to treatment in the nanofluid resulted in an increment of surface roughness. The weight percent of 0.93 and 1.22 and surface fraction of 0.265 and 0.014 for adsorbed Fluorine and Silicon were observed, respectively. A reduction for surface free energy in the range of 20-35 mN/m was observed for different applied approaches. The results of geometric, harmonic, and acid-base models indicated that calcite intrinsically has a mildly polar surface with a negative surface charge. It was revealed that the magnitude of the dispersive component was nearly 1.6 times greater than the polar component. For the treated surfaces, the geometric, harmonic, and acid-base methods showed a high reduction in the polar force of surface (<4 mN/m), which implied that the dispersive forces of the surfaces were dominant (~13 mN/m). The acid-base model estimated a negative surface charge for calcite and treated calcite. Also, a reversible reduction in water repellency due to exposure of treated samples in brine was observed.
... The most common surface active organic compounds found in crude oil that have surfactant properties are those containing oxygen, sulfur, and nitrogen in their molecular structure. Furthermore, both asphaltenes and waxes have shown some beneficial inhibitive effects on corrosion [151]. Our present understanding of these phenomena is at best qualitative, making it virtually impossible to make any reliable predictions. ...
The current state of understanding of CO2 corrosion as related to internal corrosion of oil and gas pipelines made from mild steel is reviewed. The review covers the effects of basic physicochemical phenomena underlying CO2 corrosion, such as surface electrochemistry, homogenous aqueous chemistry, mass transfer, and formation of protective corrosion product layers. It then addresses some of the main “complicating factors,” such as multiphase flow, additional aqueous species, hydrocarbon composition, inhibition, and localized corrosion. Additional challenges seen in the field are presented at the end.
... Asphaltenes refer to large-molecule hydrocarbon compounds in the crude oil that are not soluble in heptane but can dissolve in toluene [35]. It is known that asphaltenes can affect corrosion of steel in the presence of liquid water in the transfer pipelines of crude oil at room temperature [36]. In our prior research, it was evidenced that asphaltenes did not affect the high-temperature corrosion by crude oil fractions [16]. ...
Naphthenic acids and sulfur compounds present in crude oils may cause corrosion in oil refineries. In some cases, corrosion product scale formed in these oils may provide corrosion protection, but in other cases this may not be true. Current research investigates the nature of protective scales formed on steel corroded by crude oil fractions using microscopic and analytical techniques. This research identifies a thin oxygen-containing layer in-between the steel and a thicker iron sulfide outer layer contributing to the protection against naphthenic acid corrosion. Formation of this oxygen-containing layer is likely due to naphthenic acids in the crude oil.
... n.a., not available in the referenced paper; OCP, open circuit potential. (Ajmera, Robbins, Richter, & Nesic, 2011), relating to its adsorption and persistence on the steel surface. On the basis of previous understandings, focused studies have been made regarding the influences of some subclass compounds on the corrosion inhibition and the wettability behavior of crude oil. ...
... If the contact angle is between 0° and 90°, the steel surface will be preferentially wetted by water, presenting a hydrophilic characteristic; if the contact angle is between 90° and 180°, displacement of water by crude oil should be expected, referring to a hydrophobic surface. Therefore, a number of studies have focused on the measurement of the contact angle and its relation to corrosion (Ajmera et al., 2011;Ayello, Robbins, Richter, & Nešić, 2013;Foss, 2009;Papavinasam et al., 2007). An alternative method to measure the wettability is a spreading test by examining the conductivity of a group of probes in oil-water mixtures. ...
... Results from Arba heavy crude-oils tests revealed that asphaltenes have little partitioning in the aqueous phase and thereby have no influence on the corrosiveness of the brine solution. In contrast, they play a strong role in modifying the wettability of the steel surfaces and the persistency of the adsorbed oil layers (Ajmera et al., 2011). ...
The control of multiphase flow corrosion during oil production is a challenging task. In this review, the impact of crude oil on pipeline corrosion is broadly discussed, with the notion to reduce corrosion risks of pipelines in aggressive field conditions. First, the properties, emulsion stability, and multiphase flow patterns of crude oil fluids are concisely summarized and correlated to the corrosion behavior. Second, for proper evaluation of the corrosiveness of the oil-brine mixtures, related corrosion test methods and experimental techniques are critically evaluated. Third, the effects of crude oil on corrosion inhibition are conceivably attributed to four aspects, i.e. the entrainment of water, the wetting by crude oil, the partitioning effect, and the modification of the corrosion product layers. Fourth, the presence of crude oil may consume more corrosion inhibitors; however, the inhibitors can produce additional benefits on corrosion mitigation in oil-brine mixed conditions, such as altering the surface wettability to hydrophobic and enhancing the entrainment of water. Finally, some ideas to reduce pipeline corrosion are proposed and future research viewpoints are discussed.
... Corrosion testing of Crude 1 showing corrosion inhibition occurring in the direct inhibition step, but it is not persistent. For Crude 1, the partitioning step was not included.7 ©2014 by NACE International. ...
Field experience in oil and gas transportation shows that, in certain cases, the presence of crude oils can be beneficial in minimizing corrosion despite relatively high water cuts. In other cases, corrosion may occur at low water cuts. Limited research has been conducted to study what in the crude oil chemistry can explain this phenomenon. In the present work, fifteen different crude oils were tested for corrosion inhibition and wettability alteration (change from water wet to oil wet surface). The corrosion inhibition was measured in 4 steps: precorrosion, partitioning, direct inhibition, and persistency. The wettability of the surface was assessed by measuring the water-in-oil contact angle on a crude oil pre-wet steel surface. The results showed that some crude oils were capable of inhibiting corrosion, while others were not, and some were able to change the steel surface wettability from water wet to oil wet, while others could not. Interestingly, not all crude oils that could inhibit corrosion would alter the wettability and vice versa. Four different categories of crude oils were identified with respect to their ability to inhibit corrosion and alter steel wettability and mechanisms were suggested to explain this behavior.
... Carbon dioxide corrosion in the multiphase environments can become a function of water content and/or dispersion in relation to the oil phase and, depending on the transportation velocity, corrosion rates can be effectively suppressed. Ajmera et al. [7] reported significant reductions in the corrosion rates in the CO 2 -saturated solutions with respect to the effective chemical constituents in the crude oils correlating that to the wettability and hydrophilic and/or hydrophobic properties of the emulsified interfaces. Paraffin-based crude oils were indicated as effective natural inhibitors decreasing the corrosion rates by as much as 50–70% at 42 °C during flow conditions attributing that to the polar nature of the adsorbed layers [8]. ...
The purpose of this experimental work was to investigate selected electrochemical aspects of the corro-sion behavior of API-X100 in CO 2 -saturated, multivari-able-controlled corrosion media. Utilizing potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), the corrosion rates, anodic dissolution, cathodic regimes, and free interfacial interactions were discussed. The tests were performed with respect to the environmental factors of 10, 20, 30, 40, 50, and 60 g L -1 chloride and of 10, 20, 30, 40, 50, and 60 mL L -1 acetic acid at 20 and 90 °C in the absence and presence of 10 vol% crude oil. The corrosion rates exhibited a peak value with respect to the chloride content while they increased continuously with the acetic acid content irrespectively from temperature. The corrosion behavior was nearly independent from chloride in the presence of acetic acid and oil demonstrated an effective inhibition in all conditions. EIS results showed an agreement with the polarization findings and indicated adsorption-controlled mechanisms.
... When surface active compounds found in crude oils were studied separately, it was found that some of the sulfur and nitrogen containing compounds provided excellent corrosion protection, while others provided only moderate or negligible protection. 8 Ajmera et al. 9 found that asphaltenes have a direct effect on corrosion inhibition as well as wettability of steel surfaces. In addition, dos Santos, et al. 10 investigated the roles of crude oil polar components, including asphaltenes and naphthenic acids, on steel surface wetting by contact angle measurements and concluded that their removal transitioned the behavior of the surface from being oil wetted to water wetted. ...
Crude oil composition is highly variable and complex. Its components can be broken down into four different classes by solubility characteristics such as: saturates, aromatics, resins, and asphaltenes. Within each class are myriad of chemical compounds, and many have the potential to interact with the pipeline wall to confer protection from corrosion. In this work the focus is on saturates, with the the n-paraffins chosen as being most relevant for the purposes of the present study. A representative pure model compound for the n-paraffins used in the experiments is eicosane (C 20H 42). A mixture of eicosane and a clear, inert model oil was prepared with a range of paraffin concentrations (0-50% eicosane). The chemical properties of the mixture were measured, including the Wax Appearance Temperature (WAT), density, viscosity and interfacial tension. The CO 2 corrosion rate for carbon steel was measured both below and above the WAT, using the linear polarization resistance (LPR) technique. The protectiveness of the long-chain paraffin layer was challenged by inducing flow (hydrodynamic shear stress) and by increasing temperature. The eicosane successfully conferred corrosion retardation at temperatures below the WAT; however, this protection did not withstand the effect of shear stress or increased temperature. Further analysis by using sessile drop contact angle measurements using a goniometer revealed that the protectiveness by the eicosane is related to changes in the wettability of the surface. The hydrophobicity of the steel surface increased as the concentration of the paraffins in the synthetic paraffin-oil mixture was increased.
In Petapahan, Kotabatak, and Suram West Area Gathering Station, Hot water shipping system is used as oil shipping system for production. This fluid is highly corrosive and there is no corrosion protection by corrosion inhibition available for this pipeline until now, hence multiple leaks occurred massively since several years ago. This thesis focused in analysis of amine-based corrosion inhibitor with several concentration variations against API 5 L Grade-B corrosion rate in waxy oil fluid inside Petapahan - Kotabatak and Suram West Area – Petapahan Pipeline. Concentration variation that used are 0, 20, 40, 60, 80 and 100 ppm while pipe has outside diameter of 4.5 in (114.3 mm) and thickness of 0.237 in (6.02 mm). Corrosion rate analysis conducted using potentiodynamic polarization (Tafel plot). For Petapahan – Kotabatak fluid, corrosion rates are 10.51, 15.85 and 46.60 mpy at temperature of 30, 40 and 50 C. 20 ppm amine-based inhibitor injection at 50 C showed lowest corrosion rate at 46.10 mpy. While for Suram West Area fluid, corrosion rates are 12.19, 12.41 and 29.85 mpy at temperature of 30, 40 and 50 C. 60 ppm amine-based inhibitor injection at 50 C showed lowest corrosion rate at 26.92 mpy. Hardness test conducted also showed a drop in HVN no from 48.39 to 13.74
The presence of carbon dioxide (CO2) in oilfield produced water, which could be natural or intentionally injected component in oil and gas production, is extremely corrosive to pipelines and tubings. Oilfield produced water is mainly brine solution comprising organic acids, purely condensed water as well as aggressive ions like SO42−, Cl− and dissolved acid gases (like CO2). CO2 induced corrosion in this media is more detrimental than corrosion induced by HCl. This study critically unveiled the CO2 corrosion behavior of steel in oilfield produced water. The subjects covered include the chemistry of CO2 in water, supercritical CO2 condition, computational fluid dynamics (CFD), and corrosion control. Corrosion resistant alloy has been proved to exhibit remarkable corrosion resistance due to formation of strong protective film that can prevent localized corrosion. Moreover, the use of viable surface-active compounds, which are constituents of crude oil is a promising strategy for pipeline steel corrosion mitigation.
