Iraqi Journal of Chemical and Petroleum Engineering

The solubility of asphaltenes in crude oils is predominantly influenced by variations in temperature, pressure, and oil composition. These alterations can precipitate asphaltene deposition, resulting in diminished permeability, obstruction of wells and auxiliary surface facilities, and ultimately, a reduction or cessation of production. Therefore, it is imperative for upstream and downstream processing engineers to comprehend and predict asphaltene phase behavior to implement effective preventative and remedial strategies and minimize costs. Asphaltene precipitation can be predicted through the application of solubility and colloidal theories. In this study, cubic equations of state and cubic-plus-association equations of state are utilized as solubility theory-based methodologies. The advanced versions of the Peng-Robinson (APR78) and Soave-Redlich-Kwong (ASRK) cubic equations of state are compared with cubic-plus-association (CPA) equations of state using Multiflash software to predict fluid and asphaltene phase behavior. The simulation results demonstrate a strong correlation between the ASRK model and the CPA model, with a minor deviation from the results of the APR78 model. This observation suggests that these models can effectively predict asphaltene behavior and yield acceptable results when compared to experimental data for fluid and asphaltene. Considering the likelihood of asphaltene deposition within wells, hence, it is recommended to develop a model to determine the locations and quantities of deposition.

As a result of the critical importance of crude oil in modern industrial society, oil spills, specifically those involving crude oil, generate substantial environmental and ecological difficulties. In contrast to conventional treatment approaches, nanotechnology has demonstrated its efficacy in remedying oil spills This type of pollution could occur during oil investigation, transit, or storage. This study adopted a straightforward and economical method utilizing iron oxide magnetic nanoparticles for oil spills cleanup. Magnetite Fe3O4 MNPs were synthesized using the co-precipitation technique, which involved combining ferric and ferrous ions in an alkaline solution at 80°C and a pH of 14. MNPs were characterized using X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometer (VSM). To improve their stability and efficacy, MNPs were coated with ethylenediaminetetraacetic acid (EDTA). Three samples of crude oil with different APIs (23, 28.4, and 40.3) were used to study the ability of coated MNPs for oil spill cleanup. Removal experiments were conducted at 25°C with a mass range of adsorbent (0.02-0.06 g). A neodymium magnet was utilized to extract the oil-contaminated magnetic nanoparticles from the water. The gravimetric oil removal (GOR) for APIs 23, 28.4, and 40.3 were 11.4 - 3.35, 7.19- 2.15, and 4.81 to 1.16 g/g, respectively. Experimental results demonstrated an inverse relationship between GOR and the API value, indicating that as the API value decreased, GOR increased, and vice versa. Furthermore, as the mass of the adsorbent material increased (0.02-0.06g), the GOR value decreased.

Aphron drilling fluids (ADFs) are finding increasing application in science engineering fields because of their distinctive characteristic. As the interest in the application of aprons-based fluids continues to grow, there is a decisive need to advance a deeper understanding of the factors affecting their behavior and properties, especially for successful petroleum industries, such as drilling depleted reservoirs and production. This study delves into investigating the density, rheological behavior and properties, filtration properties, bubble size, and their distribution of Aphrons-drilling fluids utilizing two ionic surfactants. Sodium Dodecyl Benzene Sulfate (SDBS) as an anionic surfactant, Cetyl Trimethyl Ammonium Bromide (CTAB) as a cationic surfactant, described as environmentally friendly, in Iraqi depleted reservoirs drilling. With an emphasis on the concentrations balance between Aphron generator (SDBS) and Aphron stabilizer (CTAB), the study analyzes the behavior and characteristics of Aphron drilling fluid. The investigation demonstrates that adding SDBS and CTAB reduces system density by 28%, owing to microbubbles production which is utilized with near-balance drilling. Rheological testing reveals that shear-thinning behavior in all Aphron samples improved, and the presence of SDBS affects the fluid's internal friction, gel strength, and short-term gel structure. Filtering control characteristic study demonstrates that the presence of microbubbles significantly minimizes fluid loss by 33% with 0.20% SDBS during filtering. Bubble size and dispersion studies demonstrate that 0.20% SDBS concentration, along with 0.30% CTAB, gives the best microbubble size and distribution. These findings suggest that Aphron fluids will be a promising innovation in petroleum industries, during actual drilling operations in Iraqi depleted oilfields.

The combined system of electrocoagulation (EC) and electro-oxidation (EO) is one of the most promising methods in dye removal. In this work, a solution of 200 mg/l of Congo red was used to examine the removal of anionic dye using an EC-EO system with three stainless steel electrodes as the auxiliary electrodes and an aluminum electrode as anode for the EC process, Cu-Mn-Ni Nanocomposite as anode for the EO process. This composite oxide was simultaneously synthesized by anodic and cathodic deposition of Cu (NO3)2, MnCl2, and Ni (NO3)2 salts with 0.075 M as concentrations of each salt with a fixed molar ratio (1:1:1) at a constant current density of 25 mA/cm2. The characteristics structure and surface morphology of the deposited nano oxides onto the graphite substrates were determined by (XRD), (FE-SEM), (AFM), and (EDX). The results shown that nano Cu-Mn-Ni oxides were successfully deposited onto the anode and cathode. The crystal size and root mean square for the cathode were 30.79 nm and 79.36 nm, respectively, while for the anode, they were 24.19 nm and 41.88 nm, respectively. Furthermore, the combined system was examined for C.D, NaCl concentration, and time. In the EC-EO combined system, the cathode and anode were efficient when used as anodes for the EO process, besides aluminum. The cathode was more effective in the removal process than the anode due to its larger crystal size and the rough, granular shape of its surface. When current density (C.D) increased from 3 to 6 mA/cm², the removal efficiency shifted from 95% to 98%. However, excellent removal of 98% and 96.5% was attained with 1.665 and 2.0859 kWh/kg of dye as energy consumption in the presence and absence of NaCl salt, respectively by applying 6 mA/cm2 within 20 min of electrolysis.

Predicting permeability is a cornerstone of petroleum reservoir engineering, playing a vital role in optimizing hydrocarbon recovery strategies. This paper explores the application of neural networks to predict permeability in oil reservoirs, underscoring their growing importance in addressing traditional prediction challenges. Conventional techniques often struggle with the complexities of subsurface conditions, making innovative approaches essential. Neural networks, with their ability to uncover complicated patterns within large datasets, emerge as a powerful alternative. The Quanti-Elan model was used in this study to combine several well logs for mineral volumes, porosity and water saturation estimation. This model goes beyond simply predicting lithology to provide a detailed quantification of primary minerals (e.g., calcite and dolomite) as well as secondary ones (e.g., shale and anhydrite). The results show important lithological contrast with the high-porosity layers correlating to possible reservoir areas. The richness of Quanti-Elan's interpretations goes beyond what log analysis alone can reveal. The methodology is described in-depth, discussing the approaches used to train neural networks (e.g., data processing, network architecture). A case study where output of neural network predictions of permeability in a particular oil well are compared with core measurements. The results indicate an exceptional closeness between predicted and actual values, further emphasizing the power of this approach. An extrapolated neural network model using lithology (dolomite and limestone) and porosity as input emphasizes the close match between predicted vs. observed carbonate reservoir permeability. This case study demonstrated the ability of neural networks to accurately characterize and predict permeability in complex carbonate systems. Therefore, the results confirmed that neural networks are a reliable and transformative technology tool for oil reservoirs management, which can help to make future predictive methodologies more efficient hydrocarbon recovery operations.

The current study examines the combined impacts of ultrasonic waves and nano silica (NS) on reducing the viscosity Sharqy Baghdad heavy crude oil with an API gravity of 20.32. NS of an average particle size of 59.93 nm and 563.23 m²/g surface area were produced utilizing the sol-gel technique from Iraqi sand. The XRD analysis indicates the existence of an amorphous silica, the SEM analysis showed that NS tends to agglomerate, and the FTIR spectra exhibited the presence of siloxane and silanol groups. In addition, the TGA analysis demonstrated a total weight loss of 15.62%, validating the thermal stability of the NS. The experiments included a study of the impact of ultrasonic power, exposure time, duty cycle, temperature, and the combined effects of the ultrasonic waves and silica nanoparticles on the degree of viscosity reduction percentage (DVR%). The results demonstrated that the viscosity of the heavy crude oil decreased by 27.83% at an irradiation time of 2 min, power of 360 W, 0.8 duty cycle, a temperature of 35 ⁰C, assisted by nano silica at a concentration of 1500 mg/L.

Using biodegradable chemicals such as potassium sorbate, potassium citrate, and potassium bicarbonate in drilling mud is pivotal for enhancing the rheological mud properties while addressing environmental concerns. Despite their proven success in various industries, their potential in drilling operations remains largely untapped. The presence of potassium ions in these chemicals can consider them as promising alternatives to the traditional shale inhibitors including KCl. In this study, different concentrations (1%-7%) of the selected chemicals were incorporated into the drilling mud, with varying weights (3.5g to 24.5g). These drilling muds were then subjected to different tests encompassing mud density, rheology, filtration volume, and pH. The results indicated that potassium sorbate at 7% concentration notably an increase in mud viscosity with a shear stress reading of 150 at 600 RPM. Conversely, potassium citrate exhibited similar rheological properties to KCl, with a shear stress reading of 50 at the same concentration. The results of Potassium bicarbonate are comparable to the results of KCl. Potassium sorbate significantly enhanced the mud filtration properties at 7% concentration, yielding approximately 5 ml filtrate in 7.5 minutes, while the other chemicals showed minimal impact on filtration volume even at higher concentrations. All materials maintained a pH of around 8 at elevated concentrations. This study underscores the potential of biodegradable materials in optimizing rheological mud properties for efficient and environmentally friendly drilling operations.

Carbon dioxide (CO2) is the primary factor considered to be responsible for global warming. CO2 capture technology has been considered an important issue to decrease greenhouse gas emissions. The current research investigates the functionalization of Multi-Wall Carbon nanotubes (MWCNTs) by Ethylenediamine (EDA) solution which is used for CO2 capture at various operating conditions. Surface functionality groups and morphology of MWCNTs and physical properties were analyzed by X-ray diffraction (XRD), Fourier Transforms Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), surface area Brunauer Emmett and Teller (BET). The physical and chemical properties of CNTs have changed after the functionalization process, which enhances MWCNTs adsorption for CO2 gas. According to the study's results, during the functionalization process, amine groups bound to carbonaceous surfaces created CO2 adsorption sites on multi-walled CNTs, increasing the adsorption capacity of MWCNTs. The CO2 adsorption capacity was determined by volumetric technique at temperatures from 309 to 333 °K and a pressure of 1 to 7 bar. The exothermic nature of the adsorption process was indicated by the decreasing of CO2 adsorption capabilities via MWCNTs and MWCNTs-EDA with temperature rising. The results showed that the MWCNTs-EDA are a potential low-temperature adsorbent for CO2 capture. In addition, 0.6968 mmol g−1 of CO2 was adsorbed by MWCNT-EDA at 309 °K, while raw MWCNT adsorbed only 0.3428 mmol g−1 at the same condition. Both the Freundlich and Langmuir adsorption isotherms were used to model the experimental data, with the conclusion being that the Freundlich model fits the data well.

Sand production is one of the major challenges in the oil and gas industry. This problem exists when sand is produced along with oil and gas causing relevant damage to production equipment, thus decreasing in the productivity of wells. Therefore, a comprehensive geomechanical analysis is necessary to mitigate sand production. This study aims to assess the potential of sand production across the Nahr Umr Formation using the 1-D Mechanical Earth Model (MEM). Tech-log software coupled with well log and core data have been employed to accurately determine the possible rock geomechanical parameters, in-situ stresses and pore pressure at which rock failure might occur. Once MEM is complete, the Poro-elastic method is used to figure out the critical drawdown pressure (CDDP) and accurately predict the sand production onset. Additionally, the effect of different well completion types on the value of the CDDP was examined, and thus it was concluded that cased hole completion is the first line of defense against sand production, and can also be considered as a strategy of sand control because it reduces the sand production potential and increases the operation drawdown. Furthermore, to demonstrate the effectiveness and applicability of our method and technique, a case study was conducted to illustrate the reliability of our method in predicting sand-producing intervals under different depletion rates and completion scenarios. The finding showed that the depth 2527.7 m is a potential location for sand production as the CDDP reads a positive value revealing a high potential for rock failure. Moreover, sensitivity analysis has been performed by considering different ranges of Unconfined Compressive Strength (USC), Poisson ratio, minimum horizontal stress (Shmin), maximum horizontal stress (SHmax), vertical stress, sand grain size, perforation diameter, perforation orientations, stress ratio, and hole deviation. These factors play an essential role in optimal decisions related to real-time sand control techniques. Through the results, it is clear that as the UCS, Shmin, and SHmax increase, the sand-free drawdown and depletion also increase, and vice versa. Also, results show that as the depletion rate increases, the CDDP decreases in both cased and open hole conditions, revealing that the onset sanding likely occurs as the depletion rate is elevated. Based on these findings, a necessary modification to the completion design has been made, ensuring sand-free production from a clastic reservoir located in the southern area of Iraq.

This study focuses on preparing and evaluating AgY zeolite as an adsorbent for the desulfurization (ADS) of dibenzothiophene (DBT) using a model fuel. Kinetic models and adsorption isotherms were investigated for this process. The AgY zeolite characterization was studied using XRD, BET, and XRF. XRD and XRF techniques revealed that AgY zeolite was successfully prepared with 21.42% wt. Ag. The BET results showed that the pore volume of AgY zeolite was 0.3596 cm³/g and the surface area was 531 m²/g. The desulfurization study was done with an initial sulfur content of 100–460 ppm. With 93% sulfur removal from the initial concentration of 100 ppm, ultra-deep desulfurization was achieved. The effect of contact time on the adsorption efficiency was investigated within a range of 10-120 min, and the results showed that most sulfur removal (52%) occurred after 10 minutes, while it reached 75% after 120 min with a sulfur capacity of 57.5 mg S/g. The results indicated that the Langmuir isotherm model was the most suitable to describe the process with R² of 99.29%, while the pseudo-second-order was the most fitted kinetic model to the data with R² of 98.57%.

Drilling operations in Basra's oil fields, particularly targeting the Dammam, Hartha, and Shuaiba formations, are facing significant challenges related to lost circulation. This study investigates the effects of incorporating lost circulation materials (LCMs) into bentonite-based and polymer-based drilling muds. Experiments were carried out using a high-pressure high-temperature filter press to evaluate the rheological properties and filtration performance of the different mud systems prepared using bentonite and polymer mixed with various compositions of additives. The results showed that the incorporation of LCMs increased the plastic viscosity and yield point of the polymer mud by 25-30%, while the impact on the bentonite mud was less significant. Notably, the using of fine-sized LCMs influenced the rheological characteristics of the polymer mud system, resulting in a 35-40% increase in parameters as the LCM concentration was raised. In terms of filtration performance, the bentonite mud exhibited the highest total fluid loss, whereas the polymer mud showed the lowest. The adding of LCMs led to a 20-25% reduction in fluid loss for both mud systems, with fine-sized LCMs at higher concentrations proving most effective in the polymer mud. In conclusion, this study demonstrates the substantial influence that the type, size, and concentration of LCMs can have on the rheological and filtration properties of drilling muds. It is confirmed that the polymer mud system is particularly sensitive to these LCM parameters. Desalination elimination of 80.95% associated with a maximum power output of 420 mW/m3 in the system.

This paper examines the performance of a Direct Contact Membrane Distillation (DCMD) system experimentally and theoretically. The system uses a super hydrophobic electrospun nanofiber membrane to desalinate water. Investigations were carried out into how the feed concentration, feed flow rate, and feed temperature affected permeate flux. as system operating parameters to aid in comprehending the factors impacting the DCMD process. The application of DOE and Taguchi methods achieved statistical optimization of the DCMD process's performance. In addition, the study of mass and heat transport in DCMD was described by a theoretical model. While the feed concentration (0- 210 g/L) significantly affected flux, the feed's temperature (35-55 °C) and flow rate (0.2-0.6 L/min) mostly dominated the impact on system performance. The created model numerically solved the DCMD process using MATLAB software, describing it as a system of nonlinear equations. Various operating conditions were used to investigate the efficiency of the superhydrophobic electrospun nanofiber membrane in treating 210 g/L NaCl salt water. Changing the feed temperature and concentration affected the hypothetically suggested path across the membrane, according to the simulation results presented in this paper. Excellent agreement was observed between the experiment results and the constructed model's predicted results. Every instance maintained a high salt rejection rate (over 99.9%). The DCMD produced a gain output ratio (GOR) of 0.87 and a temperature polarization coefficient of 0.78 to 0.91. The system achieved a maximum thermal efficiency of 73.5%. The optimal parameters, which are 70 g/L, 0.6 L/min, and 55°C.

Typically, sandstone oil reserves comprise various clay minerals, such as illite, chlorite, and kaolinite. The existence of these clay minerals drastically affected the quality of these reservoirs. This paper attempts to detect clay minerals and environmental deposition of the upper shaly-sand unit (USSU) of the Nahr Umar formation, as it is the main reservoir. It is a portion of an anticline composed of a lower Cretaceous clastic sandstone formation. The kind of environment, clay minerals, and depositional correlation between total organic matter and uranium content were determined using a spectral log of gamma-ray (SGR). According to the SGR log, the primary constituents of USSU are mixed-layer clays, which are illite, kaolinite, and chlorite. The investigated wells in the field's western north have Th/U (thorium/ uranium) ratios ranging from 0.465 to 18.4. Based on the Th/U ratio, the USSU had a mostly shallow marine with continental and marine environment traces. Additionally, a Th/K (thorium /potassium) cross-plot revealed that as kaolinite decreased, illite increased in the formation's southern region.

Chronic wound infections are a major cause of chronic wound development. This study aimed to investigate the role of Fe2O3 nanoparticles (Fe2O3 NPs) in the growth inhibition of multidrug resistant bacteria (MDR) and enhancement of human foreskin cell line migration and proliferation. For this aim, Fe2O3 NPs were synthesized from the bacterial extract and characterized it with UV-Vis, EDS, FTIR, AFM and FESEM assays. In addition, investigate the antibacterial effect using the well diffusion method. as well as study the cytotoxicity effect via MTT assay and the migration of cells through the scratch wound assay for human foreskin (HFF) cell line. The results confirmed the synthesis of Fe2O3 as the UV-Vis, which showed a peak at 288 nm; EDS showed peaks that corresponded to that of Fe2O3 NPs; FTIR showed absorption of functional groups belonging to bacterial extract, while FESEM revealed the irregular agglomerated shape, and AFM showed a mean diameter of 84.45 nm for Fe2O3 NPs. The green synthesized Fe2O3 revealed an antibacterial activity on MDR bacteria (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). Moreover, a significant increase in the viability of HFF cell line in dose dependent manner leading to the enhancement of these cells to migrate and proliferate to close the scratched line in 12h of incubation under the effect of these NPs. In conclusion, the findings of the current study exhibited a successful synthesized nanoparticles Fe2O3 from bacterial extract. These NPs presented a significant antibacterial impact against MDR bacteria. Most importantly, they showed a significant biocompatibility and promoted cell viability, migration and proliferation in HFF cells. These findings point up the capability of Fe2O3 as a promising treatment for wound healing applications.

Geomechanics plays a significant role in all phases of an oil and gas field’s life cycle, from exploration to production and even beyond field abandonment. It has various applications in the petroleum industry, such as predicting safe mud window and determining the magnitude and direction of in-situ stresses. The objective of this study is to determine the magnitude and orientation of far-field stresses, identify fault types, estimate pore pressure, and evaluate mechanical properties for different formations by constructing a one-dimensional geomechanical model (1D-MEM) for a deep well in the Halfaya oilfield. This study utilizes open-hole log measurements, including density, sonic compression and shear wave velocities, gamma-ray, caliper, and bit size. The results from the model indicate that the Mishrif A, Mishrif B1, Mishrif B2, Mishrif C1, Mishrif C2, Mishrif C3, Mauddud, Nahr Umr B, Ahmadi, and Zubair formations exhibit normal faulting. On the other hand, the Nahr Umr A, Shuaiba, Ratawi, and Yamama formations show strike-slip faulting. The Rumaila formation, based on the magnitudes of the far-field stresses (????????, ????????, and ????ℎ), appears to exhibit reverse faulting. Furthermore, the Yamama formation demonstrates abnormally high pore pressure, while other formations are considered natural pressure formations. In terms of rock properties, shale and sand formations have lower Young's modulus, Poisson's ratio, and UCS, whereas limestone formations have higher values. Moreover, limestone formations exhibit higher friction angles compared to sandstone and shale formations.

Formation evaluation is a critical process in the petroleum industry that involves assessing the petrophysical properties and hydrocarbon potential of subsurface rock formations. This study focuses on evaluating the Mauddad Formation in the Bai Hassan oil field by analyzing data obtained from well logs and core samples. Four wells were specifically chosen for this study (BH-102, BH-16, BH-86, and BH-93). The main objectives of this study were to identify the lithology of the Mauddud Formation and estimate key petrophysical properties such as shale volume, porosity, water saturation, and permeability. The Mauddud Formation primarily consists of limestone and dolomite, with some anhydrites present. It is classified as a clean formation due to its low shale volume of approximately 17%. The results of the study show a low water saturation of around 30% and an effective porosity reaching up to 32% (with an average of 11%). The Mauddud Formation was further analyzed using the cluster analysis method, which identified four distinct hydraulic flow units (HFUs). The permeability of the Mauddud Formation was predicted using the flow zone indicator method, revealing a range from moderate to sound quality, averaging approximately 22 md.