Iraqi Journal of Chemical and Petroleum Engineering

Membrane fouling is a major problem encountered in the use of microfiltration (MF) processes to separate the emulsified oil from water. This work involves assessing the efficacy of removing oil-in-water emulsion (O/W emulsion), and evaluating fouling resistance by studying the membrane morphology before and after fouling, and after washing with different cleaning solutions via field emission scanning electron microscopy (FESEM) analysis. Also, the fundamental mechanism involved in the flux drop during crossflow MF has been assessed using models such as the Hermia blocking models and the modified model by Field. The standard and intermediate pore blocking models provided the best prediction for experimental behavior when analyzing the decay in the flux with time for the bio silicon oxide/polyvinylchloride (B-SiO2/PVC) membrane and the stannic oxide/polyvinylchloride (SnO2/PVC) membrane. This research established regression equations of the flux for both membranes in which these equations are highly correlated with R2 of 98.33% for B-SiO2/PVC and R2 of 99.52% for SnO2/PVC using the surface response methodology (RSM). The high flux recovery ratio (FRR) is indicative of the improved antifouling feature of the manufactured membranes where it was 96.8% for B-SiO2/PVC and 94.6% for SnO2/PVC. The results obtained by Hermia and Field were in good agreement with RSM analysis supporting the standard pore-blocking mechanism.

This study aims to address the issue by providing valuable insights into the factors contributing to the wellbore instability and proposing effective measures to mitigate the problem in the southern part of the Rumaila oil field. A comprehensive one-dimensional mechanical earth model (1D MEM) was developed by utilizing various logs data from 4 wells across the south part of this field, including gamma ray, bit size, caliper, bulk density, and sonic compression and shear logs. The model was validated with laboratory tests, including Brazilin and Triaxial tests, as well as repeated formation tests. To analyze the wellbore stability, three different failure criteria, namely Mohr-Coulomb, Mogi-Coulomb, and Modified lade, were employed. The results indicated that the Mogi-Coulomb criterion was the most accurate failure criterion in predicting rock failure. Wellbore instability problems had been observed across the shale sections throughout the Rumaila oil field, particularly through Tanuma, Khasib, top and bottom of Ahmadi, Nahr Umr, and Upper Shale members and Middle Shale members of Zubair formations. The 1D MEM results indicated that Shaly formations exhibited low stiffness rocks (low Young\'s Modulus (YME)), low rock strength, and high Poisson\'s ratio (PR), suggesting potential challenges related to wellbore instability in the Tanuma, top and bottom of Ahmadi, Nahr-Umr, and Zubair formations. A sensitivity analysis was performed to determine the safest mud weight and the optimum well trajectory for future drilling operations. According to the updated mud window of this field in 2023, the pressure in the Mishrif and Zubair formations was reinforced by injection wells, as it was noted that the pressure behavior shifted from depletion (2000 Psi). Based on the findings of this study, the good inclination of (0-25°) can be drilled with the mud weight of 1.24-1.26 sg, while the good inclination of (25-40°) can be drilled with the mud weight of 1.28-1.30 sg in all directions (i.e., all azimuths). The stress regime in most of the formations was found to be a strike-slip to a normal fault regime. The findings of this study can significantly benefit the oil industry and enhance overall productivity.

The well-called KD-2 (for confidential reasons) is not producing because the bottom hole pressure of the well is greater than the reservoir pressure. The purpose of this paper is to activate the well KD-2 by the gas lift and electric submersible pump (ESP) with a rotating gas separator combination in order to increase its production. The completion and the pressure, volume, and temperature (PVT) data are processed under Pipesim and by integrating a certain number of calculations by the nodal analysis and the decline curve methods. The results obtained show that well KD-2 activated by the gas lift provides a flow rate of 3038.019 STB/day. In order to increase the flow rate of well KD-2 activated by the gas lift, the ESP with rotating gas separator is added and the flow rate becomes 4845.325 STB/day which represents a gain of 59.48% in flow rate. In addition, the gas lift and ESP with rotating gas separator combination guarantees an eight-year operating period for a probability of $ 3,601,197 with a return on investment of 2 months. The gas lift and ESP with rotating gas separator gas combination can be used to optimize the production of low-flow wells in the same geographical areas and to consider the reactivation of dead wells.

. Double-tube heat exchangers are frequently utilized due to their low assemble and maintenance cost. In order to extract a large amount of thermal energy at minimum time and cost, an active method of air bubble injection was developed to increase the heat transfer rate through vertical double-tube heat. The current study explores the influence of air bubble injection on the thermal efficiency of vertical double tubes at counter flow. There were two main modes were adopted to conduct the experiments. The first mode was done without air injection (single phase). In the second mode, the air was injected into the heat exchanger\'s outer tube through a ring tube into the annular side of the heat exchanger. Cold water flow rate was ranged as (3, 3.5, 4, 4.5, 5 LPM) with 17°C temperature, while hot water was kept constant at (3LPM) with inlet temperature 70°C, and air was injected with (0.5, 1, 1.5, 2 LPM). Results found that overall heat transfer was enhanced by (41%), NTU (49%), effectiveness enhanced by (44%) and Nusselt number (45.2%).

One of the major elements faced in downhole drilling operations of oil and gas wells is the limited reach of coiled tubing (CT) in horizontal wellbores. To address this issue, this work creates an extended reach limit simulation of CT with starting bending curvature in a horizontal wellbore for an Iraqi well in the Ahdeb oil field. Using Drillbench software, a calculation approach is provided based on contact force and buckling models to determine the extended reach limit of CT. The findings of this study have significant implications for improving downhole drilling engineering design parameters and predicting the extended reach limit of CT. By considering factors such as friction resistance and contact force between the wellbore, a more accurate assessment of the CT’s abilities can be suggested based on well trajectory curvature and well devotion. To achieve this, a slim open hole with a diameter of 6 inches was drilled to a measured depth ranging from 3755 to 3986.5 m. The results showed that a consistent trend in azimuth and inclination in the completed section, with the hook load increasing by about 25 tons during pickup and decreasing by 11.4 tons during slack-off along the curved section due to friction effect. Additionally, elongation and relative stress showed slight increase during pickup in curved areas due to friction and temperature effect, while values decreased during slack-off due to drag action. Pressure loss in the curved section was found to be lower compared to the vertical section, primarily due to the bit nozzle discharge effect. Eventually, the friction coefficient values remained within acceptable industry limits. Ultimately, the study determined limited extended lengths for CT in this horizontal well.

This study aims to conduct a comprehensive formation evaluation of a pilot area within the Upper Shale Member of the Rumaila Oil Field. This evaluation is an essential step in the full development of the field. The application of well-log data and core analyses can help in obtaining the desired information about the geological characteristics of the formation. The process begins with measuring the formation temperature and water resistance utilizing Schlumberger’s charts and equations. The volume of shale was determined by two different methods, which were then used together to obtain the final shale volume. The porosity was determined using the conventional porosity equations from the porosity logs and the saturation was estimated based on Archie\'s equation. In core data analysis, an unconventional technique was utilized to determine rock type and permeability. The core porosity and the permeability were classified into four groups mainly using a self-organizing map and an unsupervised machine-learning method, and selected regression equations of each group were applied to estimate permeability in the core. The method depicted a good agreement between the core and estimated permeabilities, proving it as an effective tool. A complicated training data set was constructed based on the use of a multilayer perceptron neural network on coreless wells to identify rock types and permeability. Analyzing the petrophysical properties of the study area showed evidence that this area is characterized by heterogeneity. The heterogeneity of this formation is due to the presence of a considerable amount of shale, in addition to the significant characteristic differences in the layers and the same layer in different locations. The abundance of shale rock poses challenges during drilling operations, particularly due to shale washout which can lead to mechanical issues with the drilling string. Therefore, caution is advised when drilling new wells in the area to mitigate shale washout risks. Furthermore, the analysis identified layers with high hydrocarbon saturation that are viable for production. Conversely, some layers, characterized by shale presence and poor rock quality, are deemed unsuitable for production, and should not be considered as reservoir rock.

In recent years, the Eridu oil field has emerged as a key player in the petroleum industry in southern Iraq as it is the biggest Iraqi oil discovery in 20 years. Extending along a vast area of 5806 km2, the field has commercial oil reserves in formations such as Mishrif, Nahr Umr, Zubair, and Yamama. However, drilling operations in this field have faced significant challenges, including delays and suspensions caused by wellbore instability. One of the main obstacles encountered during drilling operations in the Eridu oil field is the occurrence of partial losses in weak vugs dolomite formations, as well as issues related to sever borehole instabilities such as drilling in tight holes, caving, and breakout due to shear failure in the borehole wall. To address these challenges, a 1 D Geomechanical model (1-D MEM) was constructed using data from vertical wells to better understand the underlying causes of drilling problems. The findings of the 1-D MEM, particularly in relation to mechanical rock properties, rock Elasticity factors, pore pressure, and fracture gradient complex formations like Tanuma and Mishrif, were instrumented in planning drilling operations for inclined and highly deviated wells. By utilizing open hole well logging data and calibrating the model with various resources of data including drilling observations, core mechanical analyses, and pore pressure measurements, a more accurate assessment of wellbore instabilities was achieved. The analysis revealed that many of the wellbore instabilities, such as pack-off, breakout, and stuck pipe, were attributed to the insufficient mud weight that failed to support the rock in the borehole wall. To avoid these issues, it was determined that a safe mud weight range of 11-12.5 ppg is necessary to prevent wellbore instability in shale formations. The study also highlighted the importance of using proper mud weight to prevent shear failure and other drilling complications. The findings of this study provide insights that can be utilized as a cost-effective tool for planning directional and horizontal drilling operations in the Eridu oil field. The accuracy of the failure criteria and geomechanical model is significantly superior and aligns with the analysis of breakouts observed in the caliper and image logs.

This paper deals with the development of a casing program on a well called A4-1 (for confidentiality reasons) for safe and cost-effective production. The data used are geological data and information on different depths. To achieve the paper\'s objective, first, the different casing installation depths are determined using Excel software, and the mud program required for drilling, as well as the different casing diameters, are found through analysis of the tool selection diagram. After calculating the various pressures and loads, the drilling handbook is used to select the different grades for each casing. The results show that, at a depth of 6480 feet, the surface casing has a diameter of 11\"3/4, weight of 65 ppf, and grade K55. At a depth of 9,200 ft, an 8\"5/8 diameter casing is used, with a weight of 44 ppf, and a grade C90. At depths of 10333.6 ft, the production casing is 6\'\'5/8 in diameter, weighs 32 ppf, and is grade C90. The investment for the casing is profitable for a casing installation time of one month.

Many researchers are currently investigating carbon dioxide capture and storage since it is suppressing the global warming phenomenon. Aqueous carbon dioxide chemical absorption is the most effective method. The present study incorporates the applicability and performance of blended alkanol amine solutions monoethanolamine (MEA) with diethylenetriamine (DETA) as a chemical blended absorbent investigated in a pilot scale column packed randomly with Rashing rings. The effect of operating conditions on absorption performance was examined. The performance investigation is given in terms of the overall mass transfer coefficient (KGa_v) and carbon dioxide capture efficiency (ƞ). Typically, DETA: MEA with a mass ratio of 1:1 and total mass concentration of 30 % wt. could provide the highest KGav with a value of 0.1572 (kmol/(m3*Kpa*hr)) and ƞ with a value of 98.79 %. While at the same condition in terms of liquid and gas rate, with DETA: MEA in the blending mass ratio 0.25:1, the KGav and ƞ values equal to: 0.1198 (kmol/(m3*Kpa*hr)) and 96.37%, respectively. Based on these findings, it is reasonable to assume that diethylenetriamine, a solution of alkanol amines, would serve as an efficient blending absorbent for carbon dioxide removal.

The lower olefins (Ethylene, propylene, and butylene) are considered the key to the polymeric and petrochemical industries. Dehydration of alcohols to produce light olefins (Methanol-to-olefins reaction) over SAPO-34 molecular sieve has attractedintoigh attention. Modified SAPO-34 zeolite catalyst with Zr metal was successfully prepared under microwave irradiation using morpholine as a structure direct agent. The microwave energy power used was 800 w and the crystallization time was 200 min. The catalyst sample was characterized by XRD, SEM, EDX, BET, FTIR, and TGA analysis. XRD analysis exhibited a typical chabazite structure with high crystallinity. The analysis showed macrocrystalline particles with moderate distribution of silica in the framework structure and a low surface area of 77 m2/g. The vibration peaks of the prepared catalyst showed agreement with the SAPO-34 CHA structure. Catalyst performance towards methanol-to-olefins conversion was performed in a trickle bed reactor with temperatures of 350, 400, 450, and 500 oC at a weight hourly space velocity of 7.7 h-1. The results also reveal at a temperature of 400 oC , that the best olefins selectivity was obtained, reaching 70%, with a longer lifetime of 500 min. methanol conversion was almost 100% at all reaction temperatures. In addition, the effect of methanol concentration was investigated and the results showed that increasing of water content plays a role in increasing catalyst lifetime and preventing coke depositions in pores.

In the current study, a novel date pit activated carbon, an environmentally friendly adsorbent, was, chemically activated by phosphoric acid, and employed as a bio-sorbent for Cd2+ adsorption from a simulated polluted solution. Utilizing a variety of characterization techniques, the surface morphology and functional groups of manufactured activated carbon and raw date pits are identified. The prepared activated carbon had an adsorption surface area and pore diameter values of 1700 m2/g and 3.78 nm, and this indicated the greatest increase in surface area. The effect of pH, initial Cd2+ concentration, contact time, and operating temperature on Cd2+ removal by date pit activated carbon was studied. A higher Cd2+ adsorption capacity of 48.34 mg/g was attained for a contact time of 240 min, initial concentration of 100 mg/L, and pH of 6 at 30 °C. The efficacy of Cd2+ adsorption on date pit activated carbon improved as the initial pH of the adsorbate increased to 6 and Cd2+ concentration decreased. At a given temperature of 30 °C, the Freundlich isotherm demonstrated to be the most adaptable one, indicating multilayer coverage with a 41.15 mg/g maximum adsorption capacity. For sorption favorability, the separation factor has been within the range of 0.001 to 0.003. Subsequently, the results demonstrated that the removal efficiency was adversely impacted by the rise in treatment temperature from 30 to 40 °C.

This work presents an investigation into the ultra-desulfurization of heavy naphtha fuel (model using BT and DBT) using oxidation and solvent extraction techniques. Ozone produced by the DBD (Dielectric barrier discharge) plasma generator was employed in the oxidation process as an oxidant, and acetonitrile was used as a solvent extraction. Box-Behnken experimental design was adopted in the current study to examine oxidation desulfurization by non-thermal plasma for the various operation conditions including time, flow rate, and temperature on sulfur removal efficiency. Acetonitrile with an oxidized oil/solvent ratio of 1:1(v/v ratio) was utilized as the extraction solvent. The results showed that the maximum sulfur removal of about 91% was obtained with a temperature of 50°C, flow rate of 75 ml/min, and time of 4 hours.

Adsorbents based on agricultural biomass have been subjected to several investigations in recent years owing to their low cost and promising adsorption capabilities. This paper aimed to demonstrate the efficiency of utilizing date pits modified with hydrogen peroxide as agricultural biomass in extracting heavy metals from polluted water in a column continuous flow system. The resulting modified adsorbent (MDP) has a surface area of 278.18 m2/g. The derived adsorbent was investigated under changed operating parameters including the flow rate (4-12) ml/min, pH (4-10), initial metal ion concentration (30-60) mg/L, and temperature (20-50) °C to determine their effect on heavy metals adsorption efficiency. The response surface methodology (RSM) experimental design was utilized to study the primary and combined influence of four key parameters, including (A) initial metal ion concentration, (B) pH solution, (C) solution temperature, and (D) flow rates of the influent, on the metal removing efficiency (Re%). optimization in fact, an analysis of variance (ANOVA) revealed a high coefficient of regression, or R2 > 0.90. Furthermore, the removal efficiency was positively influenced by reducing the initial ion concentration, flow rate, and temperature. in addition, the pH shows maximum effectiveness at a neutral state. In general, Cu (II) adsorption shows a higher affinity to adsorb over the MDP surface compared to Zn (II). The MDP adsorbents exhibited a promising removal efficiency for metal ions and further investigations are needed.

The effectiveness of dynamic models in field development and predicting future reservoir performance depends on the accuracy and reliability of geological models. These models are constructed based on an accurate categorization of reservoir rock types and the identification of flow units. understanding the geological structure, lithological characteristics, and depositional processes is crucial in differentiating rock types and determining flow units within strata. This study focuses on identifying rock types and flow units within the upper Cretaceous reservoir/Qamchuqa formation of the Jambur oilfield. By employing four petrophysical techniques across six wells, it was determined that the Rock Fabric Number technique and the Winland porosity-permeability relation were insufficient for accurately estimating permeability, primarily due to constraints in regression analysis. The classification of flow zone indicators resulted in the identification of five distinct rock classes that offer a more reliable means of assessing permeability in intervals lacking core data. Subsequently, the cluster analysis process sorted the reservoir rock into cohesive groups based on the raw log data and calibrated it with the Flow Zone Indicator (FZI) method. In conclusion, permeability can be determined through equations derived from the FZI method, and the establishment of petrophysical characteristics within a geological model can be achieved by utilizing rock facies derived from cluster analysis.

The gas-lift method is crucial for maintaining oil production, particularly from an established field when the natural energy of the reservoirs is depleted. To maximize oil production, a major field\'s gas injection rate must be distributed as efficiently as possible across its gas-lift network system. Common gas-lift optimization techniques may lose their effectiveness and become unable to replicate the gas-lift optimum in a large network system due to problems with multi-objective, multi-constrained & restricted gas injection rate distribution. The main objective of the research is to determine the possibility of using the genetic algorithm (GA) technique to achieve the optimum distribution for the continuous gas-lift injection flows in the structure of the network of Zubair, oil field with 10 gas-lift injected wells. This will be done through numerical simulation and modeling studies. The overall enhancement of the filed production rate is found to have increased from 15767 STB/day to 19847 STB/day. The well\'s reservoir pressure and water cut sensitivity studies are carried out to study the possible impacts of these elements upon the well and its efficiency through the course of the field. Our understanding of the potential benefits of utilizing gas lift techniques in a field from a technical and economical point of view is deepened by the use of examples from economic analysis. Furthermore, even though the idea of employing GA in this manner is not new, this work discusses GA-based optimization methodologies for increasing the oil production rate by using gas lifting in a Zubair oilfield. In order to assign gas injection rates to specific wells in a network throughout the field using limited gas injection rates, the model for optimization will be laid out step-by-step making it simple to understand and employ as a guide, especially for the front-line production technicians involved in the development and design of gas-lift systems.

Catalytic microwave-assisted pyrolysis of biomass is gaining popularity as an alternative to fossil fuels due to health, environmental, climate, and economic issues. This study conducted a catalytic pyrolysis process of the Albizia plant\'s branches using an Iraqi clay catalyst (bentonite) focusing on the variables including the biomass-particle size, experimental time, microwave power level, and the catalyst-to-biomass ratio. The physical and chemical properties of the resulting biofuel were analyzed presented by HHV, acidity, density, viscosity, GC-MS, FTIR for bio-oil and SEM, EDX, BET, HHV, FTIR for biochar. The study revealed that addition of bentonite as a catalyst led to enhanced production of biogas produced from 5% to 45% and decreased the power level used from 700 W to 450 W. Also, it raised the production of bio-oil generated with less power level and duration time. The addition of catalyst also affected the characteristics of bio-oil produced such as reducing the acidity by increasing its pH from 5 to 5.7, lowering the viscosity from 4.8 to 3.3 cSt, and the density from 1045 to 1039.2 kg/m3. Adding catalyst increased the percentage of aromatic and alcoholic substances in the bio-oil which led to improve the calorific value from 19.5 to 23 MJ/kg. Additionally, the biochar properties also improved, where the surface area and pore volume increased from 0.5512 to 40.384 m2/g and 0.00011 to 0.0361cm3/g respectively. The higher heating value was raised from 23.5 to 25 MJ/kg also. CH4 is also increased from 3.6 to 8.6% which is one of the essential fuel gasses.