Iraqi Journal of Chemical and Petroleum Engineering

Microwave power has a more significant effect on cracking with less energy consumption. The microwave power and the catalysis increase the racking rate and the conversion at lower temperatures. Accordingly, the generated hot spots in the catalyst offer a suitable condition for cracking (high rate and low temperature). The microwave technique was used to conduct the cracking of heavy naphtha. A set of experiments was done with microwave power (750–1250 W), preheating temperatures (150–250 ˚C), and space velocities (2–6 l/hr) with and without nitrogen injection. The nitrogen injection enhanced the conversion for all situations. The best result has a conversion of 47.37% with nitrogen injection at microwave power of 1250 W, a flow rate of 4 l/hr, and a preheating temperature of 250˚C. Generally, it was noted that the flow rate did not affect the conversion. Compared to conventional techniques, the microwave power increased both the reaction and conversion rates, allowing for work at lower temperatures that traditional methods cannot achieve. This study investigated how microwaves with catalysts affect residence time, energy savings, and conversion. The microwave technique experiment could be scaled up to become a mass production unit in any refinery.

The Jianbei gas reservoir, situated in the Altun Mountains of the Qaidam Basin, is a typical bedrock gas reservoir. Since its commissioning, the gas wells have generally encountered water breakthrough, leading to a significant drop in production. To address this issue, a pressurised gas lift process was implemented to drain water and boost production. While most wells exhibited positive production increases, some showed little to no change in productivity post-treatment. Therefore, it is imperative to investigate the reasons for these discrepancies and adjust/upgrade the original plan accordingly. Through comprehensive analysis from various perspectives, including fluid accumulation issues, the gas lift process itself, and wellbore structure, it was identified that the primary factors limiting the effectiveness of gas lift in the Jianbei gas reservoir are severe fluid accumulation in the wellbore, poor adaptability of the gas lift process in certain wells, inappropriate tubing size, and severe formation damage. To tackle these issues, the gas lift plan for the Jianbei gas reservoir was upgraded and optimised. Relevant parameters were redesigned based on tubing diameter optimization principles and gas lift characteristic curves, aiming to maximize the stimulation effect of gas lift. This approach effectively resolves the existing technical challenges and provides a solid scientific foundation and technical support for future gas reservoir management and development, ensuring optimal operation of the gas wells.

The Tigris River in Baghdad is increasingly polluted by industrial and agricultural activities and untreated sewage, posing serious risks to public health and the environment. This pollution degrades water quality through various physical, chemical, and biological contaminants. This research aims to use membrane filtration techniques to treat Tigris River water, improving water quality and ensuring a clean, safe water supply. The study assesses the efficiency of polypropylene (P.P) 1µm, ceramic 0.5µm microfiltration, and polyvinylidene fluoride (PVDF) 500KD ultrafiltration membranes in removing turbidity, total suspended solids (TSS), and E. coli, and their impact on permeate flux. Experiments were conducted at a temperature of 25°C and a flow rate of 20 L/h, with regular intervals and an initial turbidity of 65 NTU. The results indicated that after 1.25 hours of operations, the permeate flux decreased by 23.12% for polypropylene membranes, 32.63% for ceramic membranes, and 38.48% for PVDF membranes. The PVDF membrane demonstrated the best performance, removing 98.7% of turbidity, 88% of total suspended solids (TSS), and 100% of E. coli. This makes it the most efficient membrane among the tested options. Hermia’s model was used to study fouling in crossflow ultrafiltration (UF) and microfiltration (MF) membranes. Results showed that cake formation and standard pore-blocking models best predicted flux behavior for the ceramic membrane, while complete and intermediate pore-blocking models were more effective for the PVDF membrane. This study shows that membrane filtration improves Tigris River water quality by removing turbidity, suspended solids, and bacteria, ensuring a safe water supply.

Wellbore stability constitutes a critical challenge that can precipitate an escalation in non-productive time (NPT) during drilling operations, subsequently resulting in an increase in well expenditures and consequent revenue deficits. Shale formations exhibit a greater propensity than many geological formations to induce complications during the drilling process. Consequently, advanced geomechanical analyses were executed on select wells within the Zubair oilfield to clarify the fundamental causes of instability predominant in the field. In this study, the model was applied to two specific wells (ZB-A and ZB-B) to perform a wellbore stability assessment utilizing available well log data, which includes parameters such as bit size (BS), caliber (CAL), shear sonic logs (DTS), compressional sonic logs (DTC), and gamma ray (GR) logs. Laboratory-derived data in addition to the minimum horizontal stress that were refined using the leak-off test (LOT) measurements. The predicted formation pore pressures were calibrated against the pore pressure readings obtained from a repeated formation tester (RFT). The Mogi-Coulomb failure criteria were employed to ascertain the safe operating mud window requisite for balanced drilling, owing to the criterion's capacity to accommodate the intermediate principal stress (σ2). The proposed mud weight values, derived from the model, range from 1.32 g/cc to 1.45 g/cc, whereas a mud weight of 1.19 g/cc was utilized during the drilling operations. The findings of this research can be used as a guide to choose the best mud weight to solve problems related to wellbore instabilities in this field.

This research investigated the two-phase flow behavior and mass transfer of CO2 bubbles in a water-sucrose solution in a horizontal pipe. The process used A Computational Fluid Dynamic (CFD) model that offers diverse applications in numerous industries. The simulation of two-phase flow with mass transfer is carried out using COMSOL® software version 5.6 and compared with experimental results. The model verified satisfactory concurrence with the experimental data. Multivariable such as concentration, velocity, and share rate were studied under different conditions (gas flow rate, liquid flow rate, bubble diameter, pipe diameter, and sucrose concentration). The gas flow rate was varied at the inlet, with values of (0.2, 0.45, and 0.7 L/min) for CO2 and (2, 4, and 6 L/min) for the sweeteners solution. The diameter of the bubbles ranged from (2 to 4 mm). The pipe diameter was (1.25 and 1.9 cm), and the sucrose concentration in the sweetener solution was (150 g/L). It was observed that the effect of bubble diameter was inversely to CO2 concentration, and the gas and liquid flow rates were directly proportional to concentration. The concentration of CO2 decreases as the concentration of sucrose increases. The relationship between bubble diameter and gas phase velocity was inverse, as well as studying the effect of variables on share rate.

Due to the research gap in the literature regarding the Nahr Umr formation within the Abu-Amood oil field, this study aims to develop a dynamic compositional reservoir model for this formation. Located in the Dhi Qar province of Iraq, the Nahr Umr Formation, primarily composed of sandstone, lies 3025 meters below sea level and holds significant hydrocarbon potential. This research focuses on building a compositional model to predict reservoir behavior under various production strategies, ultimately maximizing oil recovery. The model was constructed using geological report data and implemented with Petrel and CMG software. Utilizing pressure-volume-temperature (PVT) data and the Peng-Robinson equation of state (EOS), an accurate fluid properties model was developed. Through reservoir and well area calculations, this study demonstrates that the Nahr Umr reservoir can be effectively drained using only six producers. This comprehensive model is crucial for designing efficient production strategies and enhancing oil recovery in the Nahr Umr Formation.

Membrane fouling is the main problem that limits the use of membrane technology. This work focuses on using the Hermia models to determine the controlling fouling mechanisms, including intermediate pore blocking, complete pore blocking, standard pore blocking, and cake formation. Also, it investigates the estimation of the manufacturing costs, which included the costs of preparation materials and energy consumed during the preparation and casting processes of the polyvinylidene fluoride/polyethylene glycol (PVDF/PEG) and PVDF/PEG-tin oxide nanoparticles (PVDF/PEG-SnO2 NPs) membranes. The results of Hermia’s models were applied on the first, third, and fifth cycles of the rhodamine B dye solution filtration processes. Depending on linear fitting parameters, the membrane fouling occurred in all fouling mechanism types simultaneously. However, the predominating fouling mechanism was cake formation followed by intermediate pore blocking. Analysis of the parameters of the fouling models validated that the irreversible fouling exceeded the reversible fouling when the correlation factor (R2) value was higher than 0.95, which explains the continuous reduction of the permeate flux for both studied membranes. The estimated cost of the locally manufactured PVDF-based membranes did not surpass 80 $/m2 of the membrane. Also, the locally fabricated flat sheet ultrafiltration membranes are cheaper than other pristine PVDF membranes manufactured by Guochukeji Technology (Xiamen) Company.

The research aimed to create chitosan zinc oxide nanoparticles (Ch-ZnO NPs) for use as agents to combat biofilms produced by Acinetobacter baumannii. The Ch-ZnO NPs were produced using chitosan biomass as a cost-effective, eco-friendly material for synthesis purposes. The properties of the produced nanoparticles were analyzed through a range of methods. Fourier transform infrared spectroscopy (FTIR) carried out chemical structure identification and analysis. The maximum absorption peak, at 235 nm was confirmed through UV spectrophotometry. The X-ray diffraction (XRD) varied the hexagonal crystal structure with a particle size measurement of 34 nm. Surface morphology was probed using atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). Further details on the particle structure were obtained through high-resolution transmission electron microscopy (HR‐TEM). To assess how Ch-ZnO NPs perform in real-world scenarios when dealing with Acinetobacter baumannii bacterial infections and tackling biofilms effectively was the focus of the study, with exploration into its impact on cytotoxicity using the cell line model of A375 for potential medical applications. The research findings indicated that Ch-ZnO NPs exhibited capabilities in inhibiting biofilm growth from drug-resistant Acinetobacter baumannii bacteria strains with an IC50 concentration of 2.0 g/mL. The assessment of cell mortality rates highlighted a rise, in cell death among the treated cells from the application of Ch-ZnO NPs. The research revealed that Ch-ZnO NPs demonstrated ant-biofilm properties and cytotoxic effects, which suggest their potential for use is significant. This study emphasizes the promise of Ch-ZnO NPs as an efficient option for treating infections resistant to multiple antibiotics.

Adsorptive desulfurization is essential for supplying clean fuel, reducing environmental pollution, and obtaining strict regulatory standards. This study focused on the adsorptive desulfurization of benzothiophene from simulated fuel using Ni/ γ-Al₂O₃ as an adsorbent. The study investigated the effect of nickel ions loading percentage on the removal efficiency. Also, the most fitted kinetic and isotherm models for the process were indicated. The modified adsorbent was characterized by different techniques, including XRD, FESEM, and EDS. The measurements revealed a successful modification of Ni/ γ-Al₂O₃, achieving the required loading percentages (2-10%). The desulfurization investigation was carried out under varying conditions of adsorbent dose (0.2-1 g), Ni loading percentage (2-10%), initial sulfur level of 100-260 ppm, and contact time (15-600 min). The results showed that Ultra-deep desulfurization was accomplished, with 96% sulfur removed from the initial concentration of 100 ppm at 1 g of adsorbent under room temperature and atmospheric pressure, 10% Ni ions content, and 600 min of contact time, and the highest adsorption capacity was 57.2 mg S/ g adsorbent at 260 ppm. The Langmuir isotherm model best described the process with R² of 99.9%, while the pseudo-second-order kinetic model had R² of 99.99%.

Cabbage legs peroxidase was used in this study as an economical peroxidase enzyme. Inorganic low-cost supports surfaces such as black stone BS, sand S and quartz rock QR, were utilized to immobilize the catalyst enzyme. One of the chemical processes’ immobilization strategies used was the covalent binding technique. The resulting immobilized enzyme was characterized by SEM, EDS, BET analyses for identification of the main. All supports had their optimal Protein loading, pH, temperature, and reusability evaluated. The results showed that immobilization yield (IY%) was 85, 71, and 60 % for QR, S, BS respectively. The QR support showed an enzyme loading of 12 mg protein / g support, which was the highest capacity, while the S and BS support showed a protein loading of 8 mg protein / g support for each of them. The optimal range for all immobilized biocatalysts was found to be at pH of 6.0. Concerning biocatalyst optimum temperature, the outcome of increased temperature for biocatalyst with QR, S, and BS remains at the same value of 40 °C as the initial optimum temperature of the free enzyme. The biocatalyst enzyme's immobilization within QR showed great potential for chemical applications and problems associated with engineering.

This study aimed to evaluate the reservoir petrophysical properties (porosity, water saturation, and permeability) for optimal flow unit assessment within the Sadi Formation. Utilizing open hole logging data from five wells, the Sadi formation was divided into two rock units. The upper unit (A) is 45-50 meters thick, mainly consisting of limestone, mainly consisting of shaly limestone at the lower part. The lower unit (B) has a thickness of approximately 75-80 meters and is primarily composed of limestone, further subdivided into three subunits (B1, B2, B3). The average water resistivity is 0.04 ohm-m, and the average mud filtrate resistivity is 0.06 ohm-m. The Pickett plot was utilized to determine Archie parameters (tortuosity factor=1, cementation factor= 2, saturation exponent = 1.94). Petrophysical properties were determined through a sequence of operations involving lithology identification, shale volume estimation, porosity calculation, water saturation calculation, and permeability estimation. Lithology was identified using neutron, density and sonic logs with (N-D, M-N) cross plots, which show that the Sadi Formation is mainly limestone. The Gamma ray log was employed to estimate the shale volume of the Sadi Formation using the Larionov equation of old rock, resulting in a shale volume of 7%-58%. After calculating porosity using neutron-density logs, the resulting porosity matched the core porosity. Archie equation was used to calculate the formation’s water saturation, with water saturation less than 0.48 (cut-off) obtained in B1, B2 and B3 units. Finally, the formation permeability was estimated using the Flow Zone Indicator method, which provided a good match with core permeability. Porosity and water saturation were estimated with depth using Techlog software. The best hydrocarbon-holding unit is B2, which has the highest porosity, lowest water saturation, and the best permeability, with a thickness of 20.1 meters. As a result of this study, core plug analysis and well logging data identified eight distinct units in the Sadi Formation. There are three flow sub-units in upper Sadi (B1), three flow sub-units in Sadi (B2) and two sub-units in Sadi (B3). Additionally, it has been found that the marl rock unit (A2) separates the water-bearing zone (A1) from the oil-bearing zone (B).

This study aimed to explain the biosynthesis process of Zinc and Iron oxide nanoparticles (Zn- O+ Fe- ONPs) using an extracellular enzyme, which in turn produced from particular environmental bacteria isolates Escherichia coli a stabilizing and reducing agent. Biosynthesized (ZnO+FeO) nanoparticles have presented many applications such as catalysis, biosensing, anticancer, and biomedical, etc. The optimum condition for Zn-O and Fe-O biosynthesis was characterized through several techniques such as UV-Vis, AFM, XRD, FT-IR, and FE-SEM. In particular, a cut-off phenomenon of the biological synthesized Zn-O and Fe-O was found at around 287 nm using UV-Vis, while spherical shape particles were noticed using FE-SEM techniques. Also, the AFM analysis revealed that Zn-O and Fe-O NPs have an average diameter size of 75.03 nm. Determine the FTIR spectrum of the biosynthesized Zn-O and Fe-O nanoparticles showing Zn-O at the broad peak at 509.17-426.24 cm. Where the study shows the best removal of organic pollutants after using the nano-mix oxides of the following organic pollutants (Henecosaine, Eicosane, Tridecane, Docosane, Tetradecane) The removal percentage was straight (6.13-2,34-0,49-1.87-0,84%). After measuring the drinking water sample before and after using the nanoparticles with the GC-Mass device. The best percentage for removing inorganic pollutants of (Pb, Cr, Cu) after treatment mixture nanoparticles, and the removal percentages were respectively (12.24-1.37-0.44%). As for (Cd, Al) the percentage was respectively (8.11-3.94) after using the nanoparticles with the ICP-EOS device.

Lithology identification plays a crucial role in reservoir characteristics, as it directly influences petrophysical evaluations and informs decisions on permeable zone detection, hydrocarbon reserve estimation, and production optimization. This paper aims to identify lithology and minerals composition within the Mishrif Formation of the Ratawi Oilfield using well log data from five open hole logs of wells RT-2, RT-4, RT-5, RT-6, and RT-42. At this step, the logging lithology identification tasks often involve constructing a lithology identification model based on the assumption that the log data are interconnected. Lithology and minerals were identified using three empirical methods: Neutron-Density cross plots for lithology identification, M-N cross plots (also known as Litho-porosity cross plots) for mineral identification, and Matrix identification (MID) plots. Neutron-density cross plots show that the Mishrif formation consists of limestone with some data points tending to the dolomite line east of the field and to the sandstone line west of the field. The M-N and MID plots indicate that calcite is the major mineral for the Mishrif formation; however, quartz grows to the west of the area while dolomite increases to the east. These findings underscore the importance of integrating multiple well-log interpretation techniques to capture lithologic and mineralogical complexity, providing critical insights for reservoir management and targeted exploitation strategies in heterogeneous carbonate systems.

Differential pipe sticking (DSP) is a main challenge when using water-based drilling fluids developed with bentonite clay. This study employed a Fann VG meter, a self-fabricated tester, and a stickance tester to examine the effect of oil on water-based drilling mud (WBM) and to control this issue. The study found that oil is more suitable than WBM for the composition of drilling fluids. Empirical investigations showed that adding oil to the drilling fluid maintained its rheological characteristics, reduced filtration loss from 19 to 8 cc, and decreased the friction coefficient from 0.32 to 0.05. The tendency of the drilling fluid to stick was also significantly diminished, indicating its effectiveness in preventing differential stuck pipe issues associated with water-based drilling mud. Additionally, it was observed that oil should be used in high-permeable zones rather than WBM. The Nahr Umr oil field was selected to study the problem of differential stuck using a simple well site test for monitoring and optimizing drilling fluid properties. The study concluded that using emulsion mud as a drilling fluid can prevent and treat differential stuck pipe without any torque, due to its ability to reduce the friction coefficient to less than 0.05. However, it is essential to ensure that the oil percentage does not exceed 3% to avoid any change in the rheological properties.

An effective drilling operation relies substantially on a reliable drilling fluid system, significantly impacting its success. Drilling fluids, particularly reservoir drill-in fluids (RDF), are crucial for minimizing formation damage and maximizing output. As soon as the reservoir is drilled, formation deterioration starts; thus, an optimized RDF with minimal harm is essential considering geology, reservoir fluids, and other factors. This study aims to improve reservoir drilling fluid to minimize skin damage by comparing nanoparticle-based RDFs with conventional drilling fluids used in the Mishrif formation, drilled horizontally 3000 meters. Employing nanoparticles in drilling fluids can improve performance and thermal resistance up to 300°F. Laboratory tests and field data were compared in this study. Nanoparticles in both freshwater and saltwater drilling fluids showed significant enhancements in filtration parameters and rheological qualities. Results indicated that the RDF with Fe2O3 nanoparticles enhanced filtration properties and stability. Optimal Fe2O3 concentrations were 1g at 300°F and 1.5g at 400°F. Adding Fe2O3 nanoparticles to reservoir drilling fluid resulted in a 40% reduction in fluid loss rate and decreased mud cake thickness. Additionally, nanoparticles improved the flow properties of the drilling fluid at high temperatures up to 200°F, ensuring a controlled and more consistent decrease in parameters such as plastic viscosity (PV), yield point (YP), and gel strength without any indication of thermal deterioration.

In recent years, energy demand has constantly grown worldwide, promoting the oil and gas sector to develop innovative solutions for improving productivity from unconventional reservoirs such as tight oil reservoirs. One of the significant issues in this area is determining the optimal well locations to maximize net present value (NPV). This procedure involves analysing several factors such as reservoir geometry, permeability, porosity distribution or fluids contact, and other factors that affect locations and number of infill wells. The difficulty of these considerations, combined with economic concerns and reservoir related risks, makes it even more challenging to identify the optimum development program for a given field. In this context, this study provides a useful optimization approach for identifying the optimal well location in the Halfaya oil field, a southern Iraqi tight oil field. This approach aims to overcome the issues related to optimizing reservoir development. This study employed the Genetic Algorithm as the main optimization engine due to its effectiveness in solving multidimensional and nonlinear problems. Multiple scenarios were developed with specified well configurations to identify the best scenario for maximizing NPV. This involves conducting multiple optimization runs using the Petrel/Eclipse software to develop a reliable field plan. Consequently, cumulative production for this oilfield has been comprehensively defined and reviewed. The results showed that the genetic algorithm gives acceptable values in optimization problems with relatively few decision variables. This led to an increase in NPV by 5.63%, 19.63 % and 29.30% for scenarios of one, three and five infill wells, respectively.