Dr. Mojtaba Rahimi | ISLAMIC AZAD UNIVERSITY KHOMEINISHAHR BRANCH (original) (raw)

Papers by Dr. Mojtaba Rahimi

Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 2025

Since the first well was drilled to discover underground formations, oil industry professionals h... more Since the first well was drilled to discover underground formations, oil industry professionals have explored many methods to increase the length and stability of the well and hence to achieve higher efficiency. The development of the drilling industry accelerated in the past decades to increase oil production and reduce related costs. The purpose of this study is to describe the existing drilling techniques and to deal with the optimization method for drilling a new well in the South Pars gas field. The South Pars gas field is a common offshore gas condensate field known as the largest gas field in the world, approximately 38% of which is located on the Iranian side. In this research, first a well plan was presented to start the optimization, and then, its final three holes (including 16, 12 ¼, and 8 ½inch holes) were modeled in Landmark software. During modeling in Landmark, the well profile, BHA (Bottom Hole Assembly), drilling fluid properties, drilling hydraulics, effective drag, and surface torque were simulated and then optimized based on operational constraints (such as pump capacity) and mechanical constraints. Furthermore, the mechanical energy characteristic method was used to study the correlations between the actual rate of penetration (ROP) obtained based on field data and theory, and the artificial neural network was used to optimize the drilling process. Landmark results indicated that the drilling of 16, 12 ¼, and 8 ½-inch holes was limited by the selection of mud characteristics, so the optimal values of plastic viscosity (PV), yield point (YP), revolutions per minute (RPM), and mud pumping volume per minute (GPM) were calculated. For each hole, the results from the modeling and optimization of the artificial neural network showed an excellent correlation between drilling parameters and ROP for the 12 ¼ and 8 ½-inch sections (R-Train, R-Test, R-Validation, and R-All were all larger than 0.99 for these sections), while the correlation was very good for the 16-inch section (the above parameters were all around 0.92 for this section). The results of this study can be applied to a real drilling process to maximize drilling efficiency.

Journal of Geomine, 2025

In this research, geomechanical modeling was used to determine the optimum inclination angle and ... more In this research, geomechanical modeling was used to determine the optimum inclination angle and route/trajectory of drilling and to maximize wellbore stability during a drilling operation. In this regard, different data, including wave transit time, rock mechanical parameters, and in-situ stresses, were utilized, and the optimal inclination angle and trajectory of drilling were investigated in different zones of a given oil field. The modeling results indicated that from low angles toward high angles, the maximum fracture pressure changes and this change is more noticeable with increasing depth. Moreover, the minimum collapse pressure does not change significantly with the depth, and this pressure usually occurs at low angles. Pressure changes in all zones of this oil field except for zones 14 and 15 have similar trends and their drilling inclination angle is smaller than 45 degrees, which is the optimum angle for safe drilling in these zones. In lower zones, a drilling inclination angle of less than 60 degrees covers the maximum collapse pressure and an angle of less than 45 degrees covers the minimum collapse pressure. Without taking into account the temperature, the range of optimum inclination angle and range of optimum azimuth were determined to be 10-15 degrees and 65-115 degrees, respectively, and collapse pressure and fracture pressure were estimated to be 6324 psi and 8085 psi, respectively. Increasing temperature increases the collapse pressure and decreases the fracture pressure and this, in turn, results in narrowing the safe drilling window. However, the temperature does not significantly affect the optimal drilling trajectory, and it mainly limits the safe drilling mud window in the formation.

Journal of Molecular Liquids, 2024

Asphaltene is a complex blend of high-molecular-weight hydrocarbons present in crude oil. It is a... more Asphaltene is a complex blend of high-molecular-weight hydrocarbons present in crude oil. It is a solid, insoluble component that precipitates from oil under certain circumstances, such as temperature (Temp), pressure, or composition changes. Despite its problems, asphaltene has potential uses in a variety of sectors, including the manufacture of carbon materials, asphalt, and pharmaceuticals. Specifically, this study investigated the changes in the asphaltene compaction process under carbon dioxide (CO2) injection by examining changes in initial temperature and analyzing influencing parameters such as radial distribution function, radius of gyration, and density changes. In this study, thermodynamic equilibrium in simulated asphaltene samples was achieved within 10 ns, with temperature and kinetic energy stabilizing at 310 K and 0.86 kcal/mol, respectively. The subsequent analysis focused on the agglomeration of asphaltene molecules under varying temperatures. The agglomeration process was completed within 10 ns, with the gyration radius stabilizing at 30.5 Å, providing insights into asphaltene behavior and its impact on petroleum fluid properties. At 300 K, asphaltene agglomeration increased viscosity to 23.3 Pa.s by reducing molecular movement, illustrating the complex relationship between aggregation and fluid viscosity. The study also observed that asphaltene agglomeration increased viscosity to approximately 23.3 Pa.s at 300 K due to reduced molecular movement. As the temperature was raised from 300 to 400 K, the maximum density profile decreased from 0.0225 to 0.0207 atom/Å³, while the gyration radius of asphaltene molecules decreased from 30.54 to 28.51 Å and viscosity increased from 23.3 to 23.92 Pa.s. These results highlight the intricate effects of temperature on asphaltene dynamics and petroleum fluid properties.

Journal of Solid Mechanics, 2024

Mohr-Coulomb and Mogi-Coulomb failure criteria and caliper logs were utilized to determine the sa... more Mohr-Coulomb and Mogi-Coulomb failure criteria and caliper logs were utilized to determine the safe mud window. The results demonstrated that the formations located at the north wing of the studied oil field are more stable than the other zones. Among the investigated zones, Zone 5 is the most stable and Zone 6 is the least stable zone in terms of shear stability. Zones 1 and 2 in the south wing and Zones 3 and 4 in the middle wing of the oil field are also highly unstable. The Mohr-Coulomb failure criterion is more competent in predicting the stability of the wells compared to the Mogi-Coulomb failure criterion. The main reason for instability in the wells of this oil field is the selection of non-proper mud weight (usually far smaller than optimal mud weight) while drilling. The least mud window is in the middle zone in Well 3, and the safe mud window is about 15 Mpa in other parts of the field. In Zones 6 and 7 of the field, the safe mud window is 22.95 and 32.92 MPa, respectively. A 40-degree azimuth is the safe drilling route to decrease the instability of wells during drilling operations in this field.

Journal of Chemical and Petroleum Engineering, 2024

Condensate and liquid blockage is a serious problem in gas condensate reservoirs as it reduces ga... more Condensate and liquid blockage is a serious problem in gas condensate reservoirs as it reduces gas production. There are many methods to solve this problem, however, most of them are temporary or expensive. Wettability alteration of reservoir rocks from a liquid-wet state to a gas-wet state via nanoparticles is a long-lasting, cheap, and environmentally friendly solution to condensate blockage. With the aim of promoting this treatment in field scales, this review article presents a report of almost all the research carried out in this area. The results of different research teams are compared and the advantages and disadvantages of each research are detailed. Furthermore, the mechanisms and effects of gas-wetting alteration are fully explained, and the existence of an optimum wettability state is discussed. We found that silica nanoparticles are the most commonly used type of nanoparticles in wettability alteration towards a gas wet state due to their effectiveness and endurance. Most importantly, we present two new theories about the application of nanoparticles in the wettability alteration process of condensate reservoirs. First, it may be possible to inject nanoparticles into reservoirs via foam which not only stabilizes foam but also increases the effectiveness of wettability alteration treatment. Second, nanoparticles can be used to alter the wettability and prevent fines migration and sand production simultaneously. This review can be utilized as a reference in expanding the use of nanoparticles in gas-wetting alteration in field scales.

Journal of Modern Processes in Manufacturing and Production, 2023

This study aimed to scrutinize the impact of the electrical discharge machining (EDM) parameters ... more This study aimed to scrutinize the impact of the electrical discharge machining (EDM) parameters of A413 alloy for two cases of dielectric, one with alumina powder and one without, using Taguchi's experiment design method. The completed studies regarding the EDM of the metal-base composites reveal that insufficient research work has been carried out on this composite material. In this research, by using Taguchi's experiment design and through the simultaneous analysis of Total Normalized Quality Loss (TNQL) and Signal-to-Noise ratio (S/N) of the outputs, the impacts of the current intensity, voltage, pulse on-time, and pulse off-time on the material removal rate (MRR), surface roughness (SR), and tool wear rate (TWR) were investigated. The results showed that the use of 3g/L of alumina powder in kerosene dielectric averagely led to a 6.47%, 9.14%, and 19.40% reduction in MRR, SR, and TWR, respectively. Also, the results acquired using TNQL and S/N analyses demonstrated that the optimum experiment was composed of the third level of voltage (A3), the first level of current (B1), the first level of pulse on-time (C1), and the third level of pulse-off time (D3). It was concluded that the current intensity had the greatest impact on the MRR and SR. However, the pulse-on time had the greatest influence on the TWR. It was also observed that the MRR declined by adding 3g/L aluminum oxide powder in the kerosene dielectric which in turn caused a reduction in the SR and the TWR compared to the case of the kerosene dielectric without powder.

Journal of Oil & Gas Exploration and Production, 2022

Journal of Advanced Processes in Material Engineering, 2022

In this research, the effect of input parameters of Electrical Discharge Machining (EDM) on A356 ... more In this research, the effect of input parameters of Electrical Discharge Machining (EDM) on A356 nano-composite reinforced by 3.5% alumina (Al2O3) was examined and optimized by the Taguchi technique based on the L9 orthogonal array and duplicated levels technique. The input parameters of these experiments consisted of voltage (two-level), current intensity (three-level), pulse on-time (three-level), and pulse off-time (three-level). Moreover, the output parameters were comprised of the material removal rate of the workpiece, the tool wear rate of the machining, and the surface roughness of the workpiece. The analysis of the results and investigation of the signal-to-noise graphs (S/N) and variance analysis (ANOVA) were carried out by using software. Also, with the determination of the loss function of total normalized values of the output parameters based on appropriate weight coefficients, the optimum level of each input parameter was identified. Besides, with performing the variance analysis, the magnitude of contribution percentage of each of the input parameters in the total variance was calculated. Based on the obtained results, it was concluded that the most influential parameter on the material removal rate was the pulse off-time, on tool wear rate was the current intensity, and on the surface roughness was the pulse on-time. Furthermore, the first level of the voltage (80 V), the first level of the current intensity (10 A), the first level of the pulse on-time (35 µs), and the second level of the pulse off-time (70 µs) were determined as the optimum input parameters. The contribution percentage of the input parameters in the total variance for voltage, current intensity, pulse on-time, and pulse off-time was found to be 12.98, 20.96, 5.47, and 60.60, respectively.

Journal of Oil & Gas Exploration and Production, 2022

Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 2022

In this study, the impact of input parameters of Electrical Discharge Machining (EDM) on A356 nan... more In this study, the impact of input parameters of Electrical Discharge Machining (EDM) on A356 nanocomposite reinforced by 6% SiC was investigated and optimized using Taguchi's method based on the L9 orthogonal array and dummy level approach. We considered voltage, current intensity, pulse ontime, and pulse off-time as the input parameters. Furthermore, material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) were taken into account as the output parameters. The analysis of results and examination of the signal-to-noise graphs (S/N) and analysis of variance (ANOVA) were performed using Minitab@16 software. Moreover, with the determination of the loss function of total normalized values of the output parameters based on assumed weight coefficients, the optimal level of each input parameter was established. Besides, the magnitude of contribution percentage of each of the input parameters in the total variance was computed through the variance analysis. According to the achieved results, the second level of the voltage (250 V), the first level of the current intensity (10 A), the third level of the pulse on-time (100 µs), and the first level of the pulse off-time (30 µs) were determined as the optimal input parameters. The contribution percentage of the input parameters for voltage, current intensity, pulse on-time, and pulse off-time was determined respectively to be 20, 62.06, 9.19, and 8.05.

Journal of Oil & Gas Exploration and Production, 2021

Journal of Mineral Resources Engineering, 2020

In recent years, the use of micro X-Ray images with very high resolution (as low as 100 nm) in di... more In recent years, the use of micro X-Ray images with very high resolution (as low as 100 nm) in different scientific fields has led to the development of modern methods for performing various calculations
and measurements. The use of these images has become quite popular among petroleum engineers. This is because the reservoir rock-related properties like petrophysical properties and the properties that are
simultaneously related to reservoir rock and fluid such as drainage and imbibition phenomena can be estimated using micro X-Ray images. To estimate these properties, some geometrical properties of grains
of two different cores are calculated and compared to each other through micro X-Ray images and some software. Then, with the help of the micro X-Ray images, the necessary information for simulation of the
pore network of the rock is gathered. Afterward, with the use of this information and some other software, the pore network of each of these rocks is simulated and consequently, the porosity and permeability of
each of these rocks are estimated. In the simulation process, some assumptions are made to prevent the complexity of the calculations. These assumptions result in a deviation of the calculated values from
real (laboratory) values. Therefore, using the calculated geometrical values obtained in the first step, a relationship is achieved by which the calculated values of the simulation are brought closer to those of the
laboratory. In this research, based on the aforementioned steps and by using the sphericity, convexity, and aspect ratio of grains obtained from 2D images, a correlation is developed. Ultimately, the estimated rock
properties procured by simulation are related to measured laboratory data through this correlation.

Oil Exploration and Production Journal, 2020

‫مقدمه‬ ‫چکیده‬ )rahimi@iaukhsh.ac.ir( ‫مکاتبات‬ ‫ار‬ ‫د‬ ‫ه‬ ‫عهد‬ ‫ه‬ ‫نویسند‬ * ‫ ی:‬ ‫واژگان ... more ‫مقدمه‬ ‫چکیده‬ )rahimi@iaukhsh.ac.ir( ‫مکاتبات‬ ‫ار‬ ‫د‬ ‫ه‬ ‫عهد‬ ‫ه‬ ‫نویسند‬ * ‫ ی:‬ ‫واژگان کلید‬ ‫گل،‬ ‫ایم��ن‬ ‫پنج��ره‬ ‫ژئومکانیک��ی،‬ ‫م��دل‬ ‫تنش.‬ ‫توزیع‬ ‫چاه،‬ ‫دیواره‬ ‫پایداری‬ 98/12/21 ‫ه:‬ ‫نویسند‬ ‫ارسال‬ ‫تاریخ‬ 98/12/23 ‫اور:‬ ‫د‬ ‫به‬ ‫ارسال‬ ‫تاریخ‬ 99/02/27 ‫اور:‬ ‫د‬ ‫پذیرش‬ ‫تاریخ‬ ‫مقاله‬ ‫اطالعات‬

Journal of Geological Research, 2019

Stress-dilatancy relationship or plastic potential function are crucial components of every elast... more Stress-dilatancy relationship or plastic potential function are crucial components of every elastoplastic constitutive model developed for sand or cemented sand. This is because the associated flow rule usually does not produce acceptable outcomes for sand or cemented sand. Many formulas have been introduced based on the experimental observations in conventional and advanced plasticity models in order to capture ratio of plastic volumetric strain increment to plastic deviatoric strain increment (i.e. dilatancy rate). Lack of an article that gathers these formulas is clear in the literature. Thus, this paper is an attempt to summarize plastic potentials and specially stress-dilatancy relations so far proposed for constitutive modelling of cohesionless and cemented sands. Stress-dilatancy relation is usually not the same under compression and extension conditions. Furthermore, it may also be different under loading and unloading conditions. Therefore, the focus in this paper mainly places on the proposed stress-dilatancy relations for compressive monotonic loading. Moreover because plastic potential function can be calculated by integration of stress-dilatancy relationship, more weight is allocated to stress-dilatancy relationship in this research.

Journal of Oil & Gas Exploration and Production, 2019

Journal of oil & gas Exploration and Production, 2018

Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 2025

Journal of Geomine, 2025

Journal of Molecular Liquids, 2024

Journal of Solid Mechanics, 2024

Journal of Chemical and Petroleum Engineering, 2024

Journal of Modern Processes in Manufacturing and Production, 2023

Journal of Oil & Gas Exploration and Production, 2022

Journal of Advanced Processes in Material Engineering, 2022

Journal of Oil & Gas Exploration and Production, 2022

Journal of Simulation and Analysis of Novel Technologies in Mechanical Engineering, 2022

Journal of Oil & Gas Exploration and Production, 2021

Journal of Mineral Resources Engineering, 2020

Oil Exploration and Production Journal, 2020

Journal of Geological Research, 2019

Journal of Oil & Gas Exploration and Production, 2019

Journal of oil & gas Exploration and Production, 2018

University of Alberta (Canada), 2014

The near wellbore region is subjected to cyclic loads due to repeated changes of the mean effecti... more The near wellbore region is subjected to cyclic loads due to repeated changes of the mean effective stress. These repeated loads result in plastic deformation and sanding problems which can occur in injection or production wells. The difficulty is more pronounced in weakly consolidated reservoirs since they are more prone to sanding. Therefore it is required to investigate the material response to cyclic loading.
In this research, the mechanical behaviour of uncemented and cemented sands under monotonic and cyclic loading are studied. Emphasis is placed on the constitutive modeling. A critical state constitutive model which was developed at the University of Alberta for monotonic behavior of cohesionless sands was chosen as the base model.
First with modification of the hardening law, plastic volumetric strain increment and unloading plastic modulus, the original model was modified to describe sand behavior under cyclic loading. The modified model was calibrated and validated against triaxial cyclic loading tests for Fuji River sand, Toyoura sand and Niigata sand. Comparison between the measured and predicted results suggests that the model can capture the main features of sands under cyclic loading. Second the original model was modified for cemented sands. Formulation of the yield function, elastic moduli, plastic modulus, flow rule and other components of the original model were modified. Having incorporated these changes, the radial mapping formulation of bounding surface plasticity was incorporated in the model. The modified model was assessed against monotonic triaxial tests. Third to simulate the mechanical behaviour of cemented sand/soft sandstone under cyclic loading, some further modifications were incorporated into the model. Destruction of the cementation bonds by plastic deformation was considered as the reason for the mechanical degradation of cemented sands. To model cyclic response, the unloading plastic and elastic moduli were formulated based on those of loading. The proposed model was evaluated against laboratory triaxial tests, and the model agreed with experimental observations. Fourth the application of the proposed constitutive model was ultimately extended to cases that are not under conventional triaxial conditions. This was performed by incorporating the inherent anisotropy and -parameter into formulation of the proposed model.

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Sand production cannot take place from intact sandstone regardless of the intensity of the bond b... more Sand production cannot take place from intact sandstone regardless of the intensity of the bond between sand grains since the fluid flow cannot provide enough force to detach sand particles from the rock structure. This means the cementation between sand grains in the neighborhood of the producing tunnels (cased hole completion) or around wellbore walls (open hole completion) must first disappear. Moreover, operational conditions of the well also have to provide sufficient seepage force for displacing sand particles. The destruction of the cementation is caused by the effective stresses around the perforations or wellbore walls depending on field in-situ stresses, reservoir pore pressure, and geometry of the producing cavities. Completion strategy and production development plan for wells of a given reservoir can be optimized by predicting the locations and conditions that lead to the onset of sand production. Sand production (sanding) materializes in three stages: a) failure or full degradation of the rocks around the cavity, b) separation of the sand particles from the failed rock structure, and c) transport of the detached particles into the wellbore by drag forces. Shear failure, tensile failure, critical pressure drawdown, and erosion-based criteria are the most famous sanding criteria in numerical models of sand production. These sanding criteria along with conditions leading to failure of sandstone around petroleum wells due to applied cyclic loads are reviewed in detail, and the research findings are concluded in the end.

3rd National Conference on Efficiency and Intelligentization of Energy Systems, 2024

In this study, we investigate the effect of adding rice husk on the filtrate volume of water-base... more In this study, we investigate the effect of adding rice husk on the filtrate volume of water-based drilling mud (a mixture of water and bentonite). The laboratory results obtained from the filtration have shown that the volume of the filtrate decreases with the increase in the mass of the additive studied in this research. Furthermore, a two-layer feedforward artificial neural network was designed to predict the filtrate volume of studied drilling muds for arbitrary mass values of the additive and filtration times of the mud sample. Then it was trained for each group of data. The regression diagrams corresponding to each set of training, validation, and test data indicate the accurate and optimal performance of the network, so that the percentages of the average error obtained for the test data of the network is equal to 0.5884 .

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Surface forces are quite influential at the commencement of the formation of a new phase. They pl... more Surface forces are quite influential at the commencement of the formation of a new phase. They play an important role in multi-phase flow inside oil reservoirs and piping lines as well. A quantitative index in this regard is molecular tension at the boundary of two fluids, the so-called interfacial or surface tension. Interfacial or surface tension are usually considered as indicator of intermolecular forces at separating surface between two fluids. Applied force on the boundary layer between the liquid phase and gas phase and between two liquids are called surface and interfacial tension, respectively. Surface tension between oil and injected gas has an enormous impact on miscible injection and hence, this profound effect has motivated researchers to measure and investigate this parameter experimentally using various approaches. In this research, the magnitude of surface tension between oil and gas under different temperatures, pressures, and compositions of injected gas is accurately measured by the pendant drop method for gas injection studies performed for two Iranian oil reservoirs named reservoir (a) and (b). Miscibility conditions under various temperatures, pressures, and fluid compositions are determined through outcomes of this study and if the miscible injection is being of importance, conditions coming from the results of this study shall be taken into account.

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Determining the contact surface of fluids is one of the challenges of field development planning ... more Determining the contact surface of fluids is one of the challenges of field development planning and reservoir management. From a thermodynamic point of view, the gas-oil contact is the deepest place where the most fluid composition changes occur so that the depth of a discontinuity takes place there because of the instantaneous phase change at the contact surface. This instantaneous phase change can originate from gravitational, chemical, and thermal forces. In this study, simulation was performed using Eclipse and Petrol software. To perform this simulation, first the initial contact surfaces as well as the changes in the contact surface during the production history determined from pressure test experiments and production logs were used. Then changes in water-oil and gas-oil contact levels were predicted for future years of production. Considering the surface distribution of water-oil contact, it can be understood how deep the water-oil contact surface has expanded in each area of the reservoir. By studying this water-oil contact surface, it is possible to increase the prediction accuracy of the drilling location of the new wells and the potential dangers (water conning).

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Formation damage implies a reduction in the absolute permeability of the reservoir rock or a redu... more Formation damage implies a reduction in the absolute permeability of the reservoir rock or a reduction in the relative permeability of the producing fluid. One of the prevalent problems during production from oil and gas reservoirs is the migration of the fines for which a solution shall be found. These fines will displace towards the producing well and larger particles will form as well due to interaction among the fines which ultimately gives rise to the formation damage and production reduction. Also, one of the most crucial reasons for the formation damage may stem from drilling fluid and completion fluid. Invasion of dissolved solids or fluid present in the drilling mud and or well completion fluid towards pores of the rock, the so-called mud loss, can cause substantial damage to the producing formation. In this paper, nanotechnology and nanoparticles performance are investigated to figure out how they can stabilize the in-situ fines in their place and how they can diminish the drilling fluid loss.

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Enhanced oil recovery is one of the most crucial steps in production from hydrocarbon reservoirs,... more Enhanced oil recovery is one of the most crucial steps in production from hydrocarbon reservoirs, and shale reservoirs are one of the most important unconventional hydrocarbon reservoirs. Shale gas resources are formed in shale rocks, and source rock, reservoir rock, and cap rock are the same in these reservoirs. To expand shale gas reservoirs, techniques for creating artificial fractures around the wellbore are applied. Production from oil and gas reservoirs will be followed by a pressure drop in them. By production in condensate reservoirs, the pressure can be reduced to below the dew point. As a result, condensate will be produced in the reservoir, especially in the area around the wellbore. This considerably reduces gas production. There are several ways to alleviate this problem and enhance recovery from shale gas reservoirs including thermal and chemical methods, gas injection, water injection, drilling horizontal wells, hydraulic fracturing, CO2 injection, and nitrogen injection. Some of these techniques are investigated and analyzed in this research.

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

To explore carbonate reservoirs on a reservoir scale, we should investigate them on the micro-por... more To explore carbonate reservoirs on a reservoir scale, we should investigate them on the micro-pore scale first. Carbonate reservoirs possess permeable and porous rocks containing hydrocarbon. The porosity of carbonate rocks consists of three extreme genetic groups, namely purely sedimentary pores, purely diagenetic pores, and fracture-induced pores. Although there is a broad range of intermediary pores, the three aforementioned genetic groups of porosity are indicative of three different geological processes. The keyword here is rocks. Carbonate rocks are composed of rock grains and may contain mud and cement. Skeleton and non-skeleton-based components along with mud and cement present substantial information regarding diagenetic and sedimentary media in which these rocks have been formed. Hydrocarbon reservoirs contain fluids, hence, concepts such as porosity, permeability, saturation, wettability, and capillary pressure are discussed to characterize them. After these preliminary studies/discussions, diagenetic processes and media are discussed to find out how the porosity of carbonate reservoirs is decreased, increased, or generated due to mechanical and chemical processes of different diagenetic media. In this paper, these challenges are investigated, and potential opportunities for exploration and exploitation of these valuable reservoirs are examined.

1st National Conference on Stone Industry: Exploitation, Processing, and Marketing, 2024

Well completion engineering is one of the most important and effective branches in petroleum engi... more Well completion engineering is one of the most important and effective branches in petroleum engineering and also one of the most challenging tasks after the completion of a well drilling operation. There are various methods to complete the well, but the oil engineering team must choose the most effective way to complete the well according to the characteristics of the reservoir, operating conditions of the well, and technical and economic issues. In this study, it has been tried to introduce the types of well completion methods, the types of completion string and the arrangement of these parts in the well, to implement a completion program in such a way as to enable maximum production for a long time with minimum cost.

5th national Conference and 1st International Conference on Cement Industry and Oncoming Horizon, 2019

National conference of chemical engineering students, Kermanshah, Iran., 2010

Water-flooding is the most common secondary oil recovery method that successfully has been used f... more Water-flooding is the most common secondary oil recovery method that successfully has been used from 1896 to now. Presently this method be considered as a cheap secondary oil recovery method, too. Water availability, water injection convenience, high capability of water distribution in oil region and high efficiency of water in displacing oil in oil region are the most reasons of Popularity of this method in comparison with other methods. In contrast, low volumetric sweep efficiency of water particularly in seriously heterogeneous reservoirs is one of the most important disadvantages of water-flooding. The first efforts for improving water-flooding sweep efficiency were done by Delting in 1944. He tested and patented a number of additives, including water-soluble polymers. Improving sweep efficiency of waterflooding process by additives, including water-soluble polymers for increasing water viscosity is the Purpose of Polymer flooding process. In this research, polymer flooding history, process mechanism, utilized polymers, process concepts, required elements for field design of polymer flooding and new approaches in polymer flooding have been investigated.

National conference of chemical engineering, Tabriz, Iran, 2008

The laws of conservation of mass, momentum and energy form basis of the field of transport phenom... more The laws of conservation of mass, momentum and energy form basis of the field of transport phenomena. These laws applied to the flow of fluids results in the equation change of velocity, Temperature and concentration with respect to the time and position in the system. The dynamics of such systems, which have more than one independent variable, are modeled by partial differential equations. The most commonly encountered partial differential equations in chemical and petroleum engineering are of first and second order. In this work simulation of a system containing water and vapor, in a rectangular cell, initially at saturation condition in their own temperatures, (20 and 80°C respectively) up to steady state condition has been done. This paper summarizes our solution approach to the solution of 8 nonlinear coupled unsteady states PDE {in two phases} in original problem.

Sharif University of Technology, 2008

The Caspian Sea is a landlocked lake and has not outlets, meaning that it is a closed sea and pol... more The Caspian Sea is a landlocked lake and has not outlets, meaning that it is a closed sea and pollutions can remain in the area for decades. Water pollution in this Sea has been measured to be dramatic. Beaches and coastlines are so polluted that swimming in most areas of the sea is hazardous, and toxic waste threatens to contaminate drinking water supplies for people living in the region. The impact of the environmental degradation on human health has been measurable with higher rates of cancer recorded in the area.
In this research, different environmental issues of Caspian Sea and effect of oil and gas activities on pollution of Caspian Sea have been investigated. Finally, several recommendations for decreasing of Caspian Sea pollutions, especially pollutions due to oil and Gas activities, have been given.

Journal of Chemical and Petroleum Engineering, 2024