Geophysics
Mahammad Laribaghal; mehdi Torfi; Mehdi Khorasanian; Seyyed Reza Alavi Zaree
Abstract
Fin-pass rolls are the latest series of rolls in electric resistance welding (ERW) pipe production lines that form the sheets to tubular shape and adjust the edges of the sheet for welding. The rolls (made of AISI 8622 steel) lose their proper function after about 10 years of operation due to severe ...
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Fin-pass rolls are the latest series of rolls in electric resistance welding (ERW) pipe production lines that form the sheets to tubular shape and adjust the edges of the sheet for welding. The rolls (made of AISI 8622 steel) lose their proper function after about 10 years of operation due to severe wear and change of their original surface profile. The worn portions were removed by grinding and replaced by an AISI D2 high carbon steel ring to repair these rolls. After a short time of service (about one year), the edge of the repair ring was exposed to severe spalling and fracture. The present study investigated the causes of the rapid failure of the AISI D2 repair ring and proposed a solution to the problem. The surface morphology, hardness, and wear resistance were studied. Moreover, the stress analysis of fin-pass rolls was studied using ABAQUS 6.14 finite element software for the closer investigation of the failure mechanism. The leading cause of spalling was the inherent brittleness of the AISI D2 steel and the presence of a high-stress concentration at the edges of the repair ring. To overcome this problem, carburized AISI P20 steel, case hardened AISI 4140 steel, and hard chromium electroplated AISI 4140 steel were replaced, and the resulting properties were studied. The highest resistance to spalling and wear occurred with carburized AISI P20 steel because of the high surface hardness and the gradual increase of toughness from the surface to the depth in the carburizing process, increasing the wear resistance and retarding the growth of fatigue cracks.
Technical Inspection Engineering
Gholamreza Rashed; Maryam Salehi; Mohammadreza Shishesaz; Iman Danaee
Abstract
The effect of using Conocarpus extract as a green inhibitor on the corrosion behavior of mild steel in a 1M HCL environment was investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy ...
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The effect of using Conocarpus extract as a green inhibitor on the corrosion behavior of mild steel in a 1M HCL environment was investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The impedance test showed that the polarization resistance increased from 29 for the blank solution to 299 for the solution containing 2500 ppm of Conocarpus extract. The results of the polarization test showed that at room temperature, the corrosion current density for the blank solution decreased from 3.5E-4 to 2.6E-5for the solution containing 2500 ppm of Conocarpus extract, and the potential was shifted to negative values. The polarization test was performed at three temperatures of 25, 55, and 85. The results showed that the efficiency of 1925 ppm has decreased from 93% at room temperature to 86% at 85 ° C. Obviously, the high-temperature efficiency has not reduced significantly, which means the effectiveness of Conocarpus extract at high temperatures. FTIR test also proved that the corrosion inhibitory effect of Conocarpus extract is due to the presence of heteroatoms such as N, S, and O. The adsorption isotherm results showed that the adsorption of the extract as a single layer on the surface is consistent with the Langmuir isotherm.
Petroleum Engineering – Exploration
Bahram Alizadeh; Zollfaghar Eivazi Nezhad; Majid Alipour
Abstract
In this study, the hydrocarbon potential and depositional environments of the Coniacian Laffan formation were investigated in the Binak oilfield, SW Iran. With an average thickness of 80 m, the Laffan formation consists mainly of gray shales and thin argillaceous limestones in the study area. In order ...
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In this study, the hydrocarbon potential and depositional environments of the Coniacian Laffan formation were investigated in the Binak oilfield, SW Iran. With an average thickness of 80 m, the Laffan formation consists mainly of gray shales and thin argillaceous limestones in the study area. In order to investigate the hydrocarbon potential, 22 cutting samples from 5 wells of the Binak oilfield were analyzed by Rock-Eval 6 pyrolysis and organic petrographic techniques. The hydrogen index (HI) versus Tmax diagrams indicated mixed-type II/III kerogen with a maturity corresponding to the early stages of the oil window (Tmax ≈ 435 °C). In addition, plots of S1+ S2 versus TOC were consistent with a weak to excellent hydrocarbon potential for the Laffan formation. On the other hand, organic petrographic techniques indicated that the primary organic constituents of the Laffan formation are inertinite and bituminite with subordinate amounts of amorphous organic matter (AOM). In other words, the contained organic matter was mainly composed of inertinite and lacked significant hydrocarbon potential. An abundance of inertinite and the conspicuous absence of vitrinite macerals in the studied samples suggested that the Laffan formation was deposited under sub-oxic marine conditions. Furthermore, the presence of bituminite in the studied samples greatly influenced the Rock-Eval pyrolysis readings, so geochemical evaluation of the Laffan formation using only Rock-Eval pyrolysis data may lead to erroneous interpretations. Therefore, a combination of Rock-Eval and organic petrographic methods is necessary for reliable geochemical evaluation of the Laffan formation. The results of this study can be useful for a better understanding of the Cretaceous hydrocarbon system in the study area.
Petroleum Engineering – Reservoir
Temple N Chikwe; Mudiaga Onojake
Abstract
The geochemical investigation of trace metals in crude oils from some producing oil fields in the Niger Delta, Nigeria, was carried out to ascertain the petroleum source rocks and organic matter deposits. The concentrations of trace metals in crude oil samples obtained from eight producing fields from ...
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The geochemical investigation of trace metals in crude oils from some producing oil fields in the Niger Delta, Nigeria, was carried out to ascertain the petroleum source rocks and organic matter deposits. The concentrations of trace metals in crude oil samples obtained from eight producing fields from Niger Delta, Nigeria, were analyzed using a 700 model Perkin Elmer atomic absorption spectrophotometer. The results showed the following ranges for the trace metals: Cu (0.01–0.04 mg/kg), Fe (0.05–5.90 mg/kg), Ni (0.09–0.72 mg/kg); and V (0.008–1.05 mg/kg). Pb and Zn were lower than 0.01 mg/kg. Trace metal ratios such as V/Ni, V/Fe, and (V/V + Ni) were used to unravel the genetic correlation among the oils. All the crude samples except the sample from Nembe South-2 have a V/N ratio lower than 1.0, indicating that the organic materials produced the petroleum source rock. A cross plot of V/Ni revealed two genetic families for the crude oils, derived from a terrestrial and marine origin, which was confirmed by the ternary plot of V, Ni, and Fe, discriminating the crude oils from the producing fields into two distinct groups. The V/(Ni + V) of smaller than 0.5 showed that most crude oils were deposited in an oxic environment. A cross-plot of V/(Ni + V) and V/Fe showed a weak correlation, suggesting that it could not substitute for the V/Ni ratio in determining the origin and depositional environment of crude oil samples. Therefore, an in-depth knowledge of the concentration of trace metals, especially vanadium and nickel, within an environment during oil exploration is essential in developing new oil locations.
Petroleum Engineering
Mehdi Amiri; Jafar Qajar; Azim Kalantariasl
Abstract
Sarvestan and Saadatabad oilfields produce more than 140 bbl/day of wastewater due to oil processing. Due to environmental issues, the produced water is injected into a disposal well through a pipeline with a diameter of 8 inch and a length of 5 km. Formation of inorganic scale may accelerate the need ...
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Sarvestan and Saadatabad oilfields produce more than 140 bbl/day of wastewater due to oil processing. Due to environmental issues, the produced water is injected into a disposal well through a pipeline with a diameter of 8 inch and a length of 5 km. Formation of inorganic scale may accelerate the need for frequent reservoir acid stimulation, restrict flow path, and generally add unpredicted costs for water injection operations. This study predicts scaling tendency and examines scale precipitation at different pressures, temperature, and mixing ratios of injection wastewater with formation water in Sarvestan and Saadatabad oilfields. The experimentally measured chemical analysis of the injection water and formation water was used to estimate the amount, type, and composition of scale due to mixing and changes in thermodynamic conditions. Scaling tendency values for eight types of scale, namely CaCO3 (calcite), CaSO4 (anhydrite), CaSO4.2H2O (gypsum), FeCO3 (siderite), Fe(OH)2 (amorphous), NaCl (halite), Mg(OH)2 (pyrochroite), and KCl (sylvite), were investigated by commercial software packages OLI ScaleChem and StimCADE. The results show that the significant scales are CaCO3 and FeCO3 formed in Sarvestan and Saadatabad oilfields. The formation of these scales can lead to severe problems, such as disrupting equipment and decreasing production; thus, it is necessary to predict all types of scales before forming. It allows design and planning for chemical inhibitor treatment and prediction of injectivity problems and acid stimulation.
Technical Inspection Engineering
Mohsen Asadipoor; Ali Pourkamali Anaraki; Javad Kadkhodapour; Seyed Mohammad Hosein Sharifi; Afrooz Barnoush
Abstract
Abstract Although the hydrogen induced cracking (HIC) is recognized as one of the destructive modes for pipeline and component steels serving in sour environments, the behavior of the HIC is still not fully understood. On the other hand, although many efforts have been made to identify the effects of ...
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Abstract Although the hydrogen induced cracking (HIC) is recognized as one of the destructive modes for pipeline and component steels serving in sour environments, the behavior of the HIC is still not fully understood. On the other hand, although many efforts have been made to identify the effects of hydrogen on laboratory steel specimens, the study of actual industrial samples has received less attention. In this paper, we have studied the mechanism of the HIC in a damaged pipe of a real case study of the oil and gas industry (finger type slug catcher) using detection, characterization, and microstructural investigation methods. The detection of the HIC in the specimens by advanced ultrasonic techniques, failure analysis using tensile tests, chemical composition analysis, optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), and energy-dispersive spectroscopy (EDS) techniques and their correlation with the microstructure, type, and morphology of the inclusions were conducted. The results indicated that the value of elements, especially carbon (0.13 wt %) and manganese (1.44 wt %), satisfies the requirement of API 5L specification. Furthermore, the inclusions, such as elongated manganese sulfide and spherical aluminum oxide, and the pearlite grains or the interfaces of the ferrite–pearlite phases played an essential role in the HIC phenomenon as nucleation and propagation places of cracks. It was also observed that HIC cracks were mostly initiated and propagated through the center or near the center of a cross-section of specimens. This region was a segregated zone where the center segregation of elements has occurred. Finally, we recognized a linear correlation between the HIC susceptibility and hardness value in steel, where by moving away from the cracks (1800 µm) to the crack edges, the hardness value increased significantly (179–203 HV), confirming the diffusion of hydrogen into hydrogen traps.
Petroleum Engineering
Seyed Mohammadreza Mousavi; Saeed Jafari; Mahin Schaffie; Saeid Norouzi Apourvari
Abstract
Ultrasonic irradiation is a new, economic, and environmentally friendly technique for treating asphaltene aggregation in petroleum industry. In this study, the effect of ultrasonic radiation on asphaltene formation is investigated using conventional optical microscopy, viscosity measurement, and Fourier-transform ...
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Ultrasonic irradiation is a new, economic, and environmentally friendly technique for treating asphaltene aggregation in petroleum industry. In this study, the effect of ultrasonic radiation on asphaltene formation is investigated using conventional optical microscopy, viscosity measurement, and Fourier-transform infrared spectroscopy (FTIR). To this end, five crude oil samples, collected from different reservoirs, are used, and the effect of ultrasonic radiation on the structure of the crude oils is investigated at various exposure times. The results show that, at an optimum radiation time, the ultrasonic waves can break the asphaltene clusters and shift the size distribution of the asphaltene aggregate to a smaller size. In addition, the FTIR analysis reveals structural changes in the composition of the crude oil after the ultrasonic irradiation. By increasing the ultrasound exposure time, the viscosity of the asphaltenic oil first decreases to a minimum before rising again. Moreover, the measurement of asphaltene and resin content of the crude oils indicates that at exposure times longer than the one leading to the minimum viscosity, resin molecules are broken upon exposure to ultrasound. This can be the main reason for the existence of an optimum time in the application of ultrasonic radiation, after which the percentage of asphaltene particles and the viscosity of the crude oils increase.
Petroleum Engineering
Nima Hamidian Shoormasti; Seyyedalireza Tabatabaei-Nezhad
Abstract
Shale formations are essential for different disciplines, including wellbore stability studies in petroleum engineering. In shale stability studies, the prediction of transport parameters of water and ions is a significant issue (Farrokhrouz and Asef, 2013). A unique and novel method to address this ...
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Shale formations are essential for different disciplines, including wellbore stability studies in petroleum engineering. In shale stability studies, the prediction of transport parameters of water and ions is a significant issue (Farrokhrouz and Asef, 2013). A unique and novel method to address this subject is the Revil model (Revil et al., 2011), which, unlike previous models, considers physiochemical mechanisms in the pore space and needs a few easily measurable shale properties (Revil et al., 2004). In this paper, for the first time to our knowledge, the Revil model has been extended for salts of multivalent ions. The extended model for water and ion transport through shale has been evaluated against a range of experimental data sets in the literature. The extended Revil model only needs a few shale properties such as cation exchange capacity (CEC), porosity, and grain density, which can be readily measured in the laboratory. Further, in the present work, three parameters ( ) have been considered calibration parameters. In addition to extending the Revil model for multivalent salts, we derived a simplified equation to estimate ion selectivity (IS) and a proof for the conjecture that IS correlates with membrane efficiency (ME). Focusing on the data set of Albazali (2005), a complete matching could be obtained by adjusting calibration parameters for each test data. In the case of adjusting all experiments with only three standard calibration parameters, the prediction was not satisfactory. However, the “intact-anion method” results were more accurate than the “Donnan method”. When multiple sets of ME data in a broader concentration range, including low concentrations, were plotted along with high-concentration data, correlativity was significant (R2 > 0.9). Further, a sensitivity analysis of the model parameters was performed. Our findings pave the way for the appropriate mechanistic approach to investigating and handling practical engineering challenges associated with shale.
Chemical Engineering – Gas Processing and Transmission
Alireza Afsharpour
Abstract
In current work, perturbed chain-statistical associating fluid theory (PC-SAFT) equation of state (EoS) together with the reaction equilibrium thermodynamic model (RETM) was employed to correlate H2S solubility in three carboxylate ionic liquids including [emim][Ace], [bmim][Ace], and [hmim][Ace]. The ...
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In current work, perturbed chain-statistical associating fluid theory (PC-SAFT) equation of state (EoS) together with the reaction equilibrium thermodynamic model (RETM) was employed to correlate H2S solubility in three carboxylate ionic liquids including [emim][Ace], [bmim][Ace], and [hmim][Ace]. The RETM proposes a chemical reaction approach between ionic liquid (IL) (B) and H2S (A) in the liquid phase. Moreover, PC-SAFT EoS contributes to VLE calculations. All the H2S and the investigated ILs, as self-associating components, are assumed to follow the 2B association scheme. Five adjustable variables of PC-SAFT EoS for pure components were calculated using experimental data of liquid density and vapor pressure. Afterward, the binary systems were investigated by applying RETM. Indeed, two nested loops calculate the liquid phase, total pressure, and vapor phase concentrations, respectively. For these systems, an AAD% of 2.29%, 3.09%, and 7.65% was obtained for H2S–[emim][Ace], H2S–[bmim][Ace], and H2S–[hmim][Ace] systems, respectively.
Petroleum Engineering
Amin Poorzangheneh; Bijan Ghanavati; Borzu Asgari Pirbalouti
Abstract
Oil well cementing is a multi-purpose operation, in which cement slurries are prepared by mixing water, cement and various additives and is pumped into the well in order to isolate productive zones, protect the casing pipe, perform remedial operations, controlling drilling fluid lost or abandon the well. ...
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Oil well cementing is a multi-purpose operation, in which cement slurries are prepared by mixing water, cement and various additives and is pumped into the well in order to isolate productive zones, protect the casing pipe, perform remedial operations, controlling drilling fluid lost or abandon the well. Various additives are used to improve the mechanical properties of the slurry, like cement retarders and accelerators which increase and decrease the thickening time of the cement slurry, respectively. Weight-enhancing additives are materials with specific gravity higher than cement, which can weight-up the slurry to overcome the hydrostatic pressure of mud and performing a good cementing job. Improving the mechanical properties of these type of cement slurries has always been an important issue in the discussion of oil wells cementing. In this study, the effects of nano zeolite on heavy-weight oil well cement slurry were investigated in laboratory to improve the rheological and mechanical properties of the cement. In the designed experiments, nano-zeolite was added to the slurry with the amount of 1, 2 and 3% BWOC (By Weight of Cement). The results showed that nano zeolite acts as an additive to reduce the thickening time, increase the plastic viscosity and reduces the yield point of the slurry. So, it should be noted to adjust the pumping time of the cement slurry by using other additives based on the required cementing job timing schedule. The experiments also showed that in general, the addition of nano-zeolite to the cement slurry from 1 to 3% BWOC led to an increase in the free fluid of the cement slurry, but did not show any effect on the control of the fluid loss. Finally, by adding 2% BWOC of nano zeolite, the compressive strength of the cement stone increased and the initial setting time of cement slurry decreased
Petroleum Engineering – Drilling
Mohamad Esmaiel Naderi; Maryam Khavarpour; Reza Fazaeli; Arezoo Ghadi
Abstract
A successful drilling operation requires an effective drilling fluid system. The aim of this work is to provide an effective solution for improving the rheological and filtration properties of water-based drilling fluid by using CuO nanofluid additive. CuO nanoparticles were synthesized by hydrothermal ...
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A successful drilling operation requires an effective drilling fluid system. The aim of this work is to provide an effective solution for improving the rheological and filtration properties of water-based drilling fluid by using CuO nanofluid additive. CuO nanoparticles were synthesized by hydrothermal method using autoclave, which can control the temperature as well as pressure. Then CuO nanofluid (eco-friendly ethylene glycol based) were produced to use as a drilling fluid additive. X-ray diffraction, Fourier-transformed infrared, scanning electron microscope were used to characterize nanoparticles. The results confirmed clearly the formation of high purity CuO nanoparticles forming a wire shape structure. The operating parameters were optimized by experimental design method and based on the optimal results, two long time stabilized nanofluids were prepared to improve the rheological properties and the fluid loss of a polymeric water-based drilling fluid. Xanthan, polyanionic cellulose and starch are commonly used in drilling fluids to improve rheological and fluid loss properties. Also, the effect of pH level of nanofluids on the improvement of water-based drilling fluid properties was investigated. The results showed that the nanofluid with pH=8 can be used as the best additive to improve the drilling fluid properties. The improvement of the yield point, apparent viscosity, 10-second and 10-minute gel strengths of the drilling fluid as well as the fluid loss were 45, 33, 200, 100 and 44 %, respectively.
Petroleum Engineering
Borzu Asgari pirbalouti
Abstract
This study investigated the application of iron oxide nanoparticles in the presence of an external magnetic field to control the rheology of drilling fluids. Drilling fluid rheology is one of the most critical factors in determining the optimal fluid. Drilling fluid must have good rheological properties ...
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This study investigated the application of iron oxide nanoparticles in the presence of an external magnetic field to control the rheology of drilling fluids. Drilling fluid rheology is one of the most critical factors in determining the optimal fluid. Drilling fluid must have good rheological properties to carry the drilled cuttings. On the other hand, polymers in the water-based drilling fluid control fluid loss. In low-density oil-based fluids, where the water content is low, rheological control is generally difficult since there is a limitation in selecting additives. In this study, the ferromagnetic fluid has been generated by adding nanoparticles of Fe3O4 to silicon oil. By adding ferromagnetic fluid to the oil-based mud under the influence of the external magnetic field, we examined the rheological behavior of the oil-based drilling mud. The external magnetic field can be applied in actual conditions in the middle of a magnetic drilling string. The results showed that the magnetic nanoparticles improved the drilling mud rheological properties. Moreover, the viscosity of the oil-based fluid without nanoparticles was measured 2 cP and increased to 33 cP by adding 4 wt % of iron oxide nanoparticles under an external magnetic field of 0.321 T. The magnetic field was also used for water-based mud (WBM), and the results showed that in water-based fluids containing polyanionic cellulose (PAC) polymer, the magnetic field did not have much effect on the rheological properties of the drilling mud compared to oil-based mud (OBM). Since water is the main component of the water-based fluid, increasing the magnetic field reduces the viscosity of the water-based fluid. The magnetic field increased fluid’s rheology by adding iron oxide nanoparticles to the polymer-based fluid. The viscosity of the water-based fluid containing nanoparticles increased to 850 cP under the magnetic field.
Oil and Gas Economics and Management
Ali Arabzadeh; Seyed Mostafa Mousavizade; Bahman Korojy; Seyed Alireza Hosseini
Abstract
A novel friction stir welding method called projection friction stir spot welding (PFSSW) was introduced to produce safe and reliable welds by using a pinless tool and a specially-designed projection on the surface of a backing anvil. This projection along with the tool rotation speed plays an important ...
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A novel friction stir welding method called projection friction stir spot welding (PFSSW) was introduced to produce safe and reliable welds by using a pinless tool and a specially-designed projection on the surface of a backing anvil. This projection along with the tool rotation speed plays an important role in having a reliable joint with excellent mechanical properties and good surface appearance. This welding technique can be widely developed in oil and gas, as well as in automotive, aerospace, and transportation, industry. The effect of tool rotation speed (1000, 1600, 2000 rpm) on the hardness, microstructure, and mechanical properties of 2024 aluminum alloy sheets was investigated. The surface appearance of the welding zone showed that the keyhole was not formed, and the appearance of the weld was almost smooth. Fracture surfaces of the failed specimens present the interfacial fracture at the tool rotation speed of 1000 rpm and circumferential fracture at tool rotation speed of 1600 and 2000 rpm.
Petroleum Engineering
Mohsen Mansouri; Mehdi Parhiz; Behrouz Bayati; Yaser Ahmadi
Abstract
One of the critical issues in the oil industry is related to asphaltene precipitation during different stages, and using nanoparticles is known as a standard method for solving this problem. Although nickel oxide and zeolite have been addressed in previous research to solve the asphaltene precipitation ...
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One of the critical issues in the oil industry is related to asphaltene precipitation during different stages, and using nanoparticles is known as a standard method for solving this problem. Although nickel oxide and zeolite have been addressed in previous research to solve the asphaltene precipitation problem, using NiO/Na-ZSm-5 (the primary goal of this study) has not been developed to solve relevant asphaltene precipitation problems. The crystalline structure and morphology of the synthesized nanoparticles were analyzed with the help of X-ray diffraction spectrometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDXS). The results show that the nanoparticles were well synthesized and preserved their crystalline structure with a diameter of 13.6 nm after synthesis. The EDXS analyses also proved that the sorbent adsorbed an amount of asphaltene. In the next step, asphaltene adsorption experiments were carried out at various concentrations of asphaltene and temperatures, and the effect of different variables, including the initial concentration of asphaltene, temperature, and the ratio of heptane to toluene, on the asphaltene adsorption rate was evaluated. The results indicate that with an increase in the initial asphaltene concentration from 25 to 2000 ppm, the asphaltene adsorption rate in zeolite increases. At concentrations less than 500 ppm, a rise in the temperature reduces the asphaltene adsorption, while at concentrations higher than 500 ppm, raising the temperature from 25 to 55 °C increases asphaltene adsorption capacity on zeolite. Further, more significant adsorption is observed at a heptane-to-toluene ratio of 0.4 with q = 25.17 mg/g. Evaluating the effects of kinetic adsorption molecules of asphaltene on these nanoparticles shows that the adsorption process reaches equilibrium in less than 2 h. The experimental data were adapted according to Lagrangian pseudo-first-order and pseudo-second-order models to determine the kinetic mechanism of this process. The Langmuir and Freundlich adsorption isotherms were evaluated, and the isotherms resulting from the Langmuir isotherm model were of good conformity, indicating that adsorption at the homogenous level occurred with a single-layered coating. In the final step, after evaluating the thermodynamic conditions, the spontaneity of the asphaltene adsorption process was proved.
Petroleum Engineering
JOSHUA LELESI KONNE; Ogochukwu Vivian Udeh; Grace Agbizu Cookey; GODWIN CHUKWUMA JACOB NMEGBU
Abstract
Increasing demand of hydrocarbons has prompted new strategies of recovery by application of nanoparticle- surfactant flooding in Chemical Enhanced Oil Recovery (CEOR). Some mechanisms involved in improving oil mobility are alteration of rock wettability and reduction in interfacial tension between the ...
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Increasing demand of hydrocarbons has prompted new strategies of recovery by application of nanoparticle- surfactant flooding in Chemical Enhanced Oil Recovery (CEOR). Some mechanisms involved in improving oil mobility are alteration of rock wettability and reduction in interfacial tension between the oil and water. In this work, silica (SiO2) nanoparticles (NPs) were synthesized, characterized and their effect on wettability alteration and interfacial tension (IFT) between the oil and SiO2 NPs dispersed in Sodium dodecyl sulphate (SDS) solutions was determined. Experiments on displacement of oil by flooding with brine and NPs dispersed in SDS solution were investigated in a micro glass model. X-ray Diffraction (XRD) pattern and Scanning Electron Microscopy (SEM) confirmed the mineral structure and platy polycrystallite morphologies that gave an estimated particle size of 88 nm using Scherrer’s formula. Fourier Transform Infrared Spectroscopy (FTIR) showed characteristic symmetric and asymmetric stretching vibrations. The wettability alteration and IFT measured showed changes in wettability from water-wet towards a more water-wet condition and a decrease in IFT respectively as the SDS concentration increased. The optimium oil recovery of 67.45% was obtained at 2.08 mM SDS when SDS concentrations were varied (2.08, 6.25, 8.33, 10.42 and 14.58 mM) at constant SiO2 NPs (0.1% wt.). Having obtained the optimum oil volume from OOIP at 2.08 mM SDS, SiO2 NPs concentration was varied (0.05, 0.1, 0.15, 0.2 and 0.25% wt.) at constant SDS concentration (2.08 mM). This optimized approach gave an excellent total oil recovery of 78.36% at 0.2% wt. SiO2NPs. It is therefore recommended that 0.2% wt. SiO2NPs with 2.08 mM SDS be applied in oil recovery.
Petroleum Engineering
Bardiya Yazdani; Amir Hossein Saeedi Dehaghani
Abstract
This research aims to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture are investigated by microwave radiation. ...
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This research aims to investigate the effect of microwaves on the physical and chemical properties of heavy crude oil in the presence of different minerals. In this regard, the physical and chemical changes of the oil and rock powder (sand and carbonate) mixture are investigated by microwave radiation. Viscosity and temperature changes of two samples are measured. IP143 and elemental analysis (carbon, hydrogen, nitrogen, and sulfur) are used to extract and identify the composition changes of asphaltene. The viscosity and temperature changes show that for both samples at the beginning of microwave radiation, there is a decrease in viscosity due to heavy hydrocarbon particle cracking, such as asphaltene, and converting them into lighter ones. Light compounds evaporate by continuing the radiation and temperature increase; finally, the viscosity increases. The evaporation process in the carbonate powder sample starts earlier than in the sand powder. From elemental analysis, it is concluded that the sulfur and nitrogen in asphaltene decrease almost the same for both samples, and this decrease is more evident for sulfur; thus, the rock powder combined with oil does not have a significant effect on the reduction of these elements. The increase in IFT is also observed due to the evaporation of light oil compounds, and IFT increases further due to the higher temperature of the sample containing carbonate rock powder.
Petroleum Engineering
Mehdi Bahari Moghaddam; Mostafa Fathalizade
Abstract
Enhanced oil recovery (EOR) is a vital part of the process of oil production from sandstone and carbonate reservoirs. Maintaining and increasing oil production from many fields require proper selection, design, and implementation of EOR methods. The selection of EOR methods for specific reservoir conditions ...
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Enhanced oil recovery (EOR) is a vital part of the process of oil production from sandstone and carbonate reservoirs. Maintaining and increasing oil production from many fields require proper selection, design, and implementation of EOR methods. The selection of EOR methods for specific reservoir conditions is one of the most difficult tasks for oil and gas companies. Screening of different EOR techniques considering previous experiences from the methods applied in other fields is a first step in the recommendation of any costly EOR operations. In this paper, EORgui software was utilized to screen eight enhanced oil recovery methods in one of Iran’s offshore sandstone oil fields. The reservoir is composed of two sections with different fluid properties, namely API, viscosity, and oil composition, but relatively homogeneous rock properties and high permeability (1500 mD). The results show that polymer flooding is technically the most suitable enhanced oil recovery method in the upper zone of the reservoir with a high percentage matching score of 90%, and immiscible gas injection with a matching score of 83% is ranked second. For the lower part of the reservoir containing a fluid with much higher viscosity, immiscible gas injection (83% matching) can be recommended. Furthermore, polymer flooding predictive module (PFPM) was utilized to investigate the impact of polymer concentration on oil recovery performance of the upper part with an ultimate recovery of about 40% at the optimum concentration.
Petroleum Engineering – Exploration
Bahram Habibnia; Omid Vallipour; Majid Alipour
Abstract
The Qale-Nar oilfield is an asymmetric two-humped anticline located in the northernmost part of the Dezful embayment, in which the fractured Asmari carbonates are the primary reservoir rock. In this study, for the first time, the organic geochemistry of oils produced from the Asmari reservoir is used ...
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The Qale-Nar oilfield is an asymmetric two-humped anticline located in the northernmost part of the Dezful embayment, in which the fractured Asmari carbonates are the primary reservoir rock. In this study, for the first time, the organic geochemistry of oils produced from the Asmari reservoir is used to investigate the reservoir continuity and possible compartmentalization. To this end, geological information from the studied oilfield was combined with bulk geochemistry (e.g., °API gravity) and molecular characteristics (e.g., gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) data) of the produced oils. Two oil samples obtained from wells 6 and 10 of the studied oilfields indicate significant differences in their bulk and molecular geochemical properties. Accordingly, a scenario was presented to better explain the reservoir charging and compartmentalization in the Qale-Nar oilfield. In this scenario, low-maturity hydrocarbon pulses first charge the eastern culmination of the Qale-Nar oilfield. The activity of a fault plane located between wells 6 and 10 could induce a barrier between the two wells. Consequently, the late hydrocarbon charges with higher maturity could only charge the compartment belonging to well 6. Therefore, well 10 could not receive these high-maturity hydrocarbon pulses due to the lack of lateral connectivity. The information obtained from this study can be of great help in future reservoir studies with important implications for field development projects and enhanced-recovery plans.
Petroleum Engineering
Yaser Ahmadi
Abstract
Using nanoparticles for adsorbing asphaltene is an efficient method for upgrading actual oil samples compared to other expensive mechanical treatments or even solvents, such as n-pentane and n-heptane, and surfactants. This study uses nickel–zeolite oxide nanoparticles for asphaltene adsorption ...
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Using nanoparticles for adsorbing asphaltene is an efficient method for upgrading actual oil samples compared to other expensive mechanical treatments or even solvents, such as n-pentane and n-heptane, and surfactants. This study uses nickel–zeolite oxide nanoparticles for asphaltene adsorption and solving asphaltene precipitation problems. Although nickel–zeolite oxide nanoparticles have been used in previous studies as an asphaltene adsorbent, observing the relationship between asphaltene adsorption on their surface and asphaltene precipitation in the presence of nanoparticles during the actual process is not covered. For addressing this relation, we performed a series of experiments included Fourier-transform infrared spectroscopy (FTIR), CO2–oil interfacial tension tests, Langmuir and Freundlich isotherm models, and natural depletion tests in the presence of nickel–zeolite oxide nanoparticles. The Langmuir model better fitted the adsorption data than the Freundlich model, which shows that the adsorption occurs on a homogeneous surface with monolayer coverage. Based on the CO2–oil interfacial tension results, there are two different slope forms in interfacial tension readings as pressure increases from 150 to 1650 psi. Due to asphaltene aggregation, the second slope (900–1650 psi) is slower than the first one (150–900 psi). Three pressures of 1350, 1500, and 1650 psi and nickel–zeolite oxide nanoparticles at a concentration of 30 ppm were selected for the natural depletion tests, and the basis of selection was high-efficiency adsorption at these points. As pressure decreased from 1650 to 1350 psi, asphaltene precipitation changed from 8.25 to 10.52 wt % in the base case, and it varied from 5.17 to 7.54 wt % in the presence of nickel–zeolite oxide at a concentration of 30 ppm. Accordingly, nickel–zeolite oxide nanoparticles adsorbed asphaltene on their surface correctly, and the amount of asphaltene precipitation decreased in the presence of nickel–zeolite oxide nanoparticles.
Petroleum Engineering
Fahimeh Mirzaei; Ahad Ghaemi
Abstract
In this research, the rate of CO2 absorption into methyl diethanolamine–piperazine (MDEA–PZ) solution was investigated. To model the mass transfer flux in the reactive absorption processes, the dimensionless parameters of the process were obtained using the Buckingham Pi theorem and considering ...
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In this research, the rate of CO2 absorption into methyl diethanolamine–piperazine (MDEA–PZ) solution was investigated. To model the mass transfer flux in the reactive absorption processes, the dimensionless parameters of the process were obtained using the Buckingham Pi theorem and considering the effective parameters in mass transfer. The CO2 mass transfer flux in the reactive absorption process depends on the mass transfer parameters of both the liquid and gas phases. Based on the dimensionless parameters obtained, a correlation is proposed to calculate the mass transfer flux of acidic gases in MDEA–PZ solutions. The mass transfer flux in the reactive absorption process is modeled based on the four laws of chemical equilibrium, phase equilibrium, mass balance, and charge balance. Experimental data from the literature were used to determine the constants of the derived correlation as a function of dimensionless parameters. In the provided correlation, the effects of dimensionless parameters including film parameter, CO2 loading, ratio of diffusion coefficients in the gas–liquid phase, CO2 partial to total pressure, and film thickness ratio as well as factors such as temperature, the number of free amines in the solution, the partial pressure of CO2, on the CO2 mass transfer flux were investigated. According to the results, the absorption rate decreases with increasing CO2 loading and film parameter, and the mean absolute deviation is about 3.6%, which indicates the high accuracy of the correlation.
Chemical Engineering – Transport phenomena
Maedeh Mahmoudi; Nima Esmaeilian; Farzin Zokaee Ashtiyani; Bahram Dabir
Abstract
Asphaltene-induced formation damage is one of the complicated processes of permeability damage in porous media, particularly in the near-wellbore area. Asphaltene particles precipitate out of the bulk fluid phase during production as a consequence of pressure drop, which may reduce permeability owing ...
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Asphaltene-induced formation damage is one of the complicated processes of permeability damage in porous media, particularly in the near-wellbore area. Asphaltene particles precipitate out of the bulk fluid phase during production as a consequence of pressure drop, which may reduce permeability owing to both deposition of asphaltene nanoparticles on porous media surfaces and plugging of pore throats by larger asphaltene agglomerates. Asphaltene precipitation and deposition in production tubes and surface facilities are well-documented concerns, and many solutions for managing them are available. However, the effects of asphaltene in the reservoir, particularly in the near-wellbore zone, are little known. In this study, using an artificial porous medium, experimental data on pressure drop due to changes in parameters such as flow rate, type of precipitant n-alkane solvent (N-heptane alkane solvent and n-decane are used), and percentage of precipitant were obtained. Next, the amount of permeability reduction due to asphaltene deposition in a porous medium has been calculated. To identify the dominant mechanism in reducing clogging, experimental data was fitted with the proposed quasi-experimental models at different time intervals. One of the study's accomplishments was determining the major mechanism of permeability reduction (in vitro) using a reasonably basic model with the least dependent parameters and a decent approximation. According to the findings, pore throat plugging becomes the dominant mechanism of permeability reduction, although filtration cake formation and surface deposition may exist during the tests.
Petroleum Engineering – Drilling
Aref Khazaei; Reza Radfar; Abbas Toloie Eshlaghy
Abstract
Iran is one of the largest oil and gas producers in the world. Intelligent manufacturing approaches can lead to better performance and lower costs of the well drilling process. One of the most critical issues during the drilling operation is the wellbore stability. Instability of wellbore can occur at ...
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Iran is one of the largest oil and gas producers in the world. Intelligent manufacturing approaches can lead to better performance and lower costs of the well drilling process. One of the most critical issues during the drilling operation is the wellbore stability. Instability of wellbore can occur at different stages of a well life and inflict heavy financial and time damage on companies. A controllable factor can prevent these damages by selecting a proper drilling mud weight. This research presents a drilling mud weight estimator for Iranian wells using deep-learning techniques. Our Iranian data set only contains 900 samples, but efficient deep-learning models usually need large amounts of data to obtain acceptable performance. Therefore, the samples of two data sets related to the United Kingdom and Norway fields are also used to extend our data set. Our final data set has contained more than half-million samples that have been compiled from 132 wells of three fields. Our presented mud weight estimator is an artificial neural network with 5 hidden layers and 256 nodes in each layer that can estimate the mud weight for new wells and depths with the mean absolute error (MAE) of smaller than ±0.039 pound per gallon (ppg). In this research, the presented model is challenged in real-world conditions, and the results show that our model can be reliable and efficient in the real world.
Geophysics
Afshin Amiri; Majid Bagheri; Mohammad Ali Riahi
Abstract
Seismic well tying is a crucial part of the interpretation phase in exploration seismology. Tying wells usually involves forward modeling a synthetic seismogram from sonic and density logs and then matching the obtained synthetic seismogram to the seismic reflection data. A huge amount of time is required ...
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Seismic well tying is a crucial part of the interpretation phase in exploration seismology. Tying wells usually involves forward modeling a synthetic seismogram from sonic and density logs and then matching the obtained synthetic seismogram to the seismic reflection data. A huge amount of time is required to deal with it, yet the outcome signal may not be satisfying and may be suffering a low cross correlation between the seismic signal and the synthetic one; it also requires a high quality synthetic trace. Another problem with the so-called manual tying is that the tying process is not repeatable, indicating that one can rarely obtain the same stretched and squeezed signal if the tying procedure is repeated. In recent years, some researchers have used the dynamic time warping (DTW) method to address well tying problems. They have obtained good results according to the correlation between the seismic signal and the warped synthetic signal. This research demonstrates that the result will be better if filtering is applied before tying, and then the warped signal is smoothed. We also propose a simpler algorithm for extracting a warped signal from the warping curve and the original synthetic trace, which gives rise to better performance for well tying.
Petroleum Engineering – Production
Abdorrahman Mehri Ghahfarrokhi; Hassan Shokrollahzadeh Behbahani; Ezzatollah Kazemzadeh; Gholam Abbas Safian
Abstract
Nowadays, use of visco-elastic surfactants as the main component of gel diverters is becoming more and more common among well completion engineers, as well as stimulation service companies. Gel diverter, as other kinds of diverters, is used in multi-layered carbonated reservoirs to diver acid into less ...
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Nowadays, use of visco-elastic surfactants as the main component of gel diverters is becoming more and more common among well completion engineers, as well as stimulation service companies. Gel diverter, as other kinds of diverters, is used in multi-layered carbonated reservoirs to diver acid into less permeable sublayer. As use of these materials becomes more common, modeling and simulating the gel-acid injection process becomes more required. In this study, a mathematical model is generated to simulate gel-acid injection process, and experimental data is compared with data predicted by the model. The purpose of this study is to investigate the field possibility of injection gel-acid and to generate a model for simulating this process, in order to smart permeability enhancement in Ahwaz oilfield, one of Iranian Southwest oilfields. The solutions predicted by model are in an acceptable correlation with experimental data. The generated model can be used for other multi-layered carbonated oilfields.
Petroleum Engineering
Mehdi Rezaei Abiz; Saeid Norouzi Apourvari; Saeed Jafari; Mahin Schaffie
Abstract
Although experimental studies confirmed the effectiveness of nanoparticles in enhanced oil recovery applications, no comprehensive investigation has been carried out to reveal the effect of different subsurface factors on this improvement. Proper application of nanoparticles mainly depends on their ability ...
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Although experimental studies confirmed the effectiveness of nanoparticles in enhanced oil recovery applications, no comprehensive investigation has been carried out to reveal the effect of different subsurface factors on this improvement. Proper application of nanoparticles mainly depends on their ability to travel long distances within a reservoir without agglomeration, retention, and blocking the pore throats. This study strengthens our understanding of the effect of the main subsurface factors on the nanofluid-assisted enhanced oil recovery. To this end, a transport approach utilizing the kinetic Langmuir model is developed and validated using experimental data. After that, the effects of reservoir rock type and its properties (clay content and grain size), the salinity of injected fluid, and the reservoir temperature on the transport and retention of nanoparticles in porous media concerning enhanced oil recovery methods are investigated. Since the concentration of nanoparticles in the injected fluid and on the rock surface (as deposited) control the mobility and wettability alteration, the effect of subsurface factors and salinity of injected fluid on this deposition is also analyzed. The results showed that the rock type and its properties significantly affect the transport and retention of nanoparticles in porous media. Brine salinity also has the most significant impact on the amount of nanoparticles deposited on the rock surface. The surface covered by nanoparticles increased from 10% to 82% after changing salinity from 3 wt % NaCl to the API brine.
