Journal of Petroleum Research & Studies

The Mu Formation is considered one of the most widespread Cretaceous periods in Iraq and its typical section is located in the province of Sulaimani in the Qamchuqa region. The study area is located in the X oil field, which is located to the southwest of the dome of Baba and southwest of the city of Kirkuk about 12 km and represents an asymmetrical subsurface fold whose axis extends in a Northwest-Southeast direction and the field is located in the unstable platform zone in the Foothill zone. The Formation consists of limestone and dolomitic limestone, organodetrital and argillaceous, the upper contact of the Formation is unconformable with the Dokan Formation, while the lower contact is graded with the Upper Sarmord Formation. The current study showed that most of the parts of the Formation contain a shale rate of less than 35%, and it was found through the logs (density, neutron and gamma rays) that the effective porosity rate is determined between (4-15) %, the rate of shale content is between (21-34) % and the permeability rate is between (0.66-13.8) mD in a well XA, while in the XB well, the shale content rate ranges between (21-38)%, the effective porosity rate is between (8-18) %, and the permeability rate is between (1.6-18.8) mD. The Formation was divided into six reservoir units depending on the variation of shale content, porosity rate and permeability. The reservoir unit (MUE, MUC) is considered the best reservoir unit in the XA well, while the MUF unit has bad reservoir qualities in the same well. In the XB well, MUC & MUE are considered to be the best reservoir units, while MUF & MUB have less reservoir specifications compared to the previous two units. The water and hydrocarbon saturations were calculated with the movable and residual fractions of the invaded and uninvaded zones, as well as the total volume of water and oil within the Formation. After calculating the reservoir properties, the three-dimensional reservoir model was drawn by Petrel software to clarification the distribution of hydrocarbon saturation of the formation units; the net pay thickness of the Formation was calculated.

The issue of water inflows is one of the major concerns in the oil industry. This paper presents studies conducted in 2020 on the X field\'s well M.01, which, over the years, encountered challenges related to water inflows, though its initial production had no such issues. The primary objective of this paper is to propose a viable solution to reduce water inflows, thereby maximizing surface oil production in a cost-effective manner. To achieve this, a nodal analysis was conducted to evaluate the well\'s performance in terms of liquid flow (water and oil). Production logs were used to identify the new oil saturation zone, where new perforations were made. Finally, an economic assessment was performed using the production decline prediction curve. Confidential data, including completion, reservoir, log, and economic data, were processed using PIPESIM and EXCEL software. According to the results, water inflows in well M.01 were caused by the displacement of the water-oil contact, due to partial penetrations via the water cone phenomenon, which reduced oil flow from 3005.585 STB/d to 241.9834 STB/d. To address this issue, a perforation was made using coiled tubing at the 100% oil saturation zone, and the two levels were isolated using a plug via a slickline. This intervention resulted in an oil flow of 2931.087 STB/d, with a water flow of 325.6764 STB/d. After production optimization using wellhead pressure sensitivity curves and flowline diameter adjustments, oil flow increased to 3872.435 STB/d, and water inflow decreased by 90%. The critical flow rate calculation indicated that production must not exceed 5150 STB/d to avoid a rapid water breakthrough. The project to perforate only in the oil saturation zone for optimal production is projected to remain profitable for 11 years, with a return on investment in 1 year, 7 months, and 8 days.

Permeability is a crucial petrophysical attribute to be accurately estimated due to its direct influence on reservoir characterization, heterogeneity assessment, reservoir simulation, and the level of uncertainty in decision-making during field development planning. However, measuring permeability often involves expensive core analysis or well test analysis. It is typically not feasible to conduct such analysis across an entire reservoir involving cores from all wells. Therefore, there is a need to accurately model and predict permeability as a function of routinely obtained, lower cost, well logging data. Machine learning algorithms (ML) have been recently developed to reliably predict permeability by leveraging well logs data. In this research, an efficient tree-based (TB-ML) algorithm incorporating extreme gradient boosting (XGBoost) is employed to predict permeability in the Mishrif carbonate reservoir (Iraq) based on facies and well logging data. The recorded and interpreted well log variables used as input variables include gamma ray, caliper, density, neutron porosity, shallow and deep resistivity, total porosity, spontaneous potential, photoelectric factor, and water saturation. Additionally, core-derived permeability and porosity data is used to calibrate the ML predictions. The discrete reservoir facies are distinguished by applying a k-means clustering algorithm. Subsequently, the TB-ML algorithm is developed using the default and fine-tuned hyperparameters with the aid of two search algorithms: random search and Bayesian optimization. The permeability predictions are evaluated using cross-validation and error quantification metrics, which include the adjusted coefficient of determination (R2) and root mean squared error (RMSE). A comparison of adjusted-R2 and RMSE for the various TB-ML model configurations developed is compared for training and testing subsets to illustrate their permeability prediction performance. These results suggest that the method is sufficiently reliable to be generalized for application in both carbonate and clastic reservoirs in other oil and gas fields.

Real-time identification of fluid characterization is important to execute and/or modify the proposed well program and provide a better understanding of the application of gas ratio analysis. In this study, reservoir fluids were characterized during drilling by analyzing light gases released as a result of formation rocks being penetrated. Drilling mud is used to carry reservoir gas during this process. The required data included the values of liberated gas molecules from the main reservoir section extracted by gas chromatograph (GC) during drilling, that data was collected from five wells (A, B, C, D, and E) in the X oilfield. The gas measurements included the gases from Methane (C1) to Pentane (C5) measured in real-time by the gas chromatograph in the mudlogging units. The ratios of C1-C5 gases were used to determine the values of wetness ratio (Wh), and hydrocarbon balance (Bh) in the 3rd and 4th pay reservoirs. Results showed good indications of fluid type compared to the actual well test and were capable of distinguishing between heavy and light hydrocarbons in the reservoir section. A joint interpretation of electric logs and mudlogging gas data leads to an enhanced understanding of well results, which in turn can be used to optimize future logging and well testing.

Sand production is one of the major challenges in the oil and gas industry, so comprehensive geomechanical analysis is necessary to mitigate sand production in mature fields. The absence of crucial well logs is an essential challenge in the oil and gas industry, necessitating geologists and engineers to rely on empirical equations to predict the absence of log intervals.
A comprehensive study was carried out on geomechanical modeling using data logs from two wells located in the Nahr Umr formation in Southern Iraq. Furthermore, the geomechanical parameters used by the predictive model were verified through caliper measurements. A machine learning technique was employed to predict the absence of acoustic log in Well-5 instead of using empirical equations. Additionally, two sand management models were developed and compared - one using the empirical Gardner equation and the other employing machine learning techniques.
The sand management model based on the Gardner equation predicted the production of sand from the beginning. However, it did not match the actual production data observed in real life. On the other hand, the machine learning-based model indicated no probability of sand generation, which aligned with the observed production data. The findings of this study demonstrate the advantages of using machine learning over traditional empirical equations for geomechanical studies in the particular area under study. Also, these findings suggest that machine-learning techniques might be applied to more basins in southern Iraq. The current research improves our understanding of the impact of machine learning on sand management as well as geomechanical characterization. This study has the potential to enhance procedures for making decisions in the petroleum and natural gas industries and contribute valuable knowledge to improved ways of handling sand production problems.

The study area is located in an unstable region within the Mesopotamian basin of the Arabian plate. It is surrounded by several oil fields that produce hydrocarbons from NW-SE-trending anticline formations, which are compatible with the direction of the Zagros folded axis. The study area is characterized by the presence of bubble point pressure discrepancy at the same productive reservoir unit, which raised several doubts about the faults or reefs that led to this phenomenon and the future impact on the development strategy of the study area. The study aimed to assess how faults and reef affect the development plan for carbonate oil reservoir. The process involves three steps tailored to fit the specific characteristics of the research area before the development strategy of oil production. The first step was creating a seismic model to identify any irregular amplitudes of reflected events and abrupt discontinuities, which could indicate either a reef or a fault. This was followed by creating a geological model based on faults and reef, developing a reservoir model, and conducting historical matching. The study proved the presence of a fault and excluded the presence of a reef. Four development plan scenarios were created for a 20-year period based on the probabilities of the fault and reef. The study found that case four had the most favorable results among all the cases. This case showed a production plateau that lasted for seven years with slight fluctuations

Ecological materials are those that are used in projects and reduce the environmental impact of the project, help improve the quality of life for people who live and work in the facility, and reduce environmental pollutio+
n. Oil is of great importance on the economic level, as it is one of the basic resources in the economic wheel among the countries of the world. However, the use of this resource faces many challenges, as it is one of the depleted resources threatened with annihilation, not to mention the environmental problems resulting from the oil industry in its various stages. This research aims to diagnose the problem of Iraqi cement, where the problem of Iraqi cement lies in the fact that its silica content is low, about 18%, its strength is low, and its thickening time is short, in addition to its high softness, and it hardens quickly. The novelty in this research is the use of sider leaves, ground walnut shells, and silica dust as environmentally friendly additives, and demonstrating their effect on the properties of Iraqi cement. The tests were carried out on the aforementioned materials in their normal size and with a nanoparticle, as the results showed that each of the crushed walnut shells, silica dust and ground nut shells contributed to increasing the compressive strength of Iraqi cement, and the materials in their Nano size 100 nm were better than what they are in the normal size. The results showed that Nano-sized Sider paper reduced the density of the mortar because it contained saponin when 1.5% BWOC was added. One of the most important conclusions of the research is that adding Nano-silica dust at a rate of 1.5% BWOC increased the resistance strength of cement by about 3 times what it was without addition at a temperature of 38 degrees Celsius.

Catalytic cracking is fundamental in oil refineries for producing valuable fuels and chemicals. Conventional catalysts lack optimal selectivity resulting in inferior fuel quality. This work develops an innovative cobalt-hafnium oxide nanocomposite catalyst supported on mesoporous silica. The tailored nanostructure displays remarkable activity, selectivity and stability for upgrading hydrocarbon fractions. Composite synthesis first prepares cobalt nanoparticles, hafnium oxide and mesoporous silica separately then assembles these via impregnation. Catalyst characterization analyzes morphology, crystallinity and porosity. A fixed-bed reactor evaluates performance cracking model feed at 500 °C and 2 bar. Products undergo chromatographic quantification revealing 94% heavy oil conversion and 67% gasoline selectivity at 8 h-1 space velocity. Analysis shows obtained high purity, high-octane fuels match industry benchmarks. The stable selective nanocomposite catalyst successfully upgrades petroleum streams under mild conditions to improve refinery economics.

This study optimized the condition of a model fuel containing organo-sulfur compounds (benzothiophene and dibenzothiophene) that were oxidized by non-thermal plasma. The process involved ozone generation through dielectric barrier discharge, followed by extraction using acetonitrile. The results demonstrated the efficient oxidation and removal of dibenzothiophene and benzothiophene by non-thermal plasma. The desulfurization efficiency reached 93.78% under the optimum conditions, that involving a voltage of 11Kv, temperature of 50ºC, duration of 4 hours, and a flow rate of 75 ml/min. When heavy naphtha was oxidized under optimal conditions, it was found that sulfur removal was 91. 082%. Furthermore, the kinetics of oxidation for this system were investigated, it Supposed mechanism and kinetics studies on ozone revealed that the oxidative desulfurization of organosulfur compounds could present a pseudo-first-order kinetic. The reaction rate constant for heavy naphtha was d 0.4759 h-1.

The research aims to solve the problem of corrosion in oil pipes buried in the soil by studying the addition of tobacco extract on the rates of corrosion of low carbon steel in a solution that simulates the soil conditions. The corrosion solution used is an aqueous solution that simulates soil conditions and pH of the solution was pH = 6.8 at 30◦C samples of low carbon steels were used, which are used in the petroleum industries. In this research, the Tafel polarization method was carried out in Tobacco extract solution using Potentiostat device was used to measure corrosion parameters: corrosion potential, corrosion current, Tafel slopes and corrosion rates of all samples for the purpose of knowing the inhibition efficiency and completing the corrosion cell calculations. It was found that the samples coated with tobacco dust have lower corrosion currents than that of uncoated base (blank sample) at all month starting from June to November, but the coated samples have the lowest corrosion rate on June month (after 60 days’ immersion in soil), the corrosion rate was 0.02237 mpy as comparison to as received blank 5.6168 mpy with inhibition efficiency 99.6%. But it becomes 3.2083 mpy on November month with inhibition efficiency 42.88% on November month because formation of a protective layer on the steel surface, it reduces the corrosion rate due to the absorption of water and the chloride ions.

The composite Bi(1-x) SrxFeO3 (x = 0.0, 0.2, 0.4, 0.6, 0.8) was produced via solid-state reaction technique at 850 °C, in order to evaluate how strontium affects the structure. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive ‎X-ray spectroscopy (EDX), magnetic analysis (VSM), and band gap energy measurements ‎were performed by UV- visible spectroscopy. ‏The results obtained are the formation of ‎crystalline materials of rhombohedral surfaces and change to the pseudocubic phase ‎at x = 0.4. The particle size declines ‎from 36.5 nm up to 17 nm for the pure sample in BSFO. The strontium Sr+2 caused an increase in ‎Remnant magnetization (Mr) and coercive field (Hc), which lead to the magnetization ‎development of BiFeO3, UV- visible spectroscopy used to‏ ‏calculate the direct optical ‎band gap of all samples had its value on the order of 2.4 to 2.9 eV.

The Yamama Formation consists of two types of sediments (granular units) consisting of Oolitic and Peloidal grainstone in addition to benthic Foraminifera (reservoir units), which grow towards the center basin during Highstand conditions within the environment confined between (Inner-Mid Ramp), and that they represent a shallowing upward cycle.
Granular sediments formed on top of a base consisting of mud-supported limestone (impermeable rocks) to create the second type of sediments that formed during transgressive conditions, which extend over most of the ramp platform and increase the mud support towards the outer ramp. Yamama Formation consists of multiple reservoir units separated by impermeable rock units. Reservoir units with high hydrocarbon potential are considered because petroleum systems are available. In southern Iraq, they are considered an exploratory target within the deposits of the early Cretaceous period. The study area contains (SS-3, SS-2, SS-1, and LL-1) wells. Yamama Formation is divided into four sub-cycles (YA, YB, YC, and YD). The structural maps represent the stratigraphic units of the Yamama Formation by interpreting the data of the seismic cube, which indicated that (the SS and LL) fields represent a structural axial, whose axis extends north-south. SS field consists of two domes and three wells in the southern dome penetrated Yamama Formation, but the northern dome is the most closed, with dimensions (14 x 10) km with closure of about (60) meters, no borehole has been drilled in it, which makes it an exploration target. Yamama Formation in the LL field penetrated by the LL-1 well only and shows the existence of a structural closure with dimensions (4 x 2.5) km and a closure of (30) m. The seismic stratigraphic interpretations explained the development of the Yamama Formation platform, which contributed to the formation of three stratigraphic traps.