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The primary purpose of acidizing operations in the oil and gas industry is to enhance hydrocarbon production. Acidizing has been a common and conventional method for years, especially when production engineers face issues like declining reservoir pressure leading to reduced production rates. Initially, the treatment solution is referred to as matrix acidizing. In acidizing operations, different additives are combined with the acid to control its behavior in the reservoir. These additives may include iron control agents, corrosion inhibitors, friction reducers, and more. Incompatibility among these additives, the acid, and reservoir fluids can lead to severe damage to the reservoir.... 

The process of injecting acid or acidizing, is one of the most common ways to stimulate oil and gas wells. The purpose of this process is to increase the productivity of the well by increasing the permeability of the reservoir rock around the well. This is especially important in carbonate reservoirs due to damage to the formation and low intrinsic permeability in some places. In order to minimize the effects of structural damage, conventional wormhole channels are created to pass through the injured area. One of the important factors in acid validation is achieving optimal injection rate, which means obtaining the highest permeability with the lowest amount of injected acid.Numerous... 

Downhole temperature measurement is one of the key tools for monitoring and analyzing the performance of production wells, evaluating water injection, and identifying multiphase flows within wells. The development of fiber optic technology and tools such as distributed temperature sensors has enabled the recording of high-resolution and detailed temperature profiles. These data, which measure temperature over a wide range along the wellbore, allow researchers to analyze complex downhole processes and identify fluid entry from various reservoir layers. However, accurately distinguishing the contribution of each layer to the total flow rate, especially under multiphase flow conditions and... 

Acidizing is a widely used well stimulation technique designed to mitigate formation damage and enhance oil and gas production. The effectiveness of acidizing operations relies on meticulous design. Consequently, before implementation, it is essential to create an optimal operational plan using suitable laboratory tools and numerical methods to maximize efficiency. Numerous studies have been conducted to investigate and model wormhole propagation in carbonate rocks, including commonly used two-scale continuum models. Although these models effectively predict physical behavior, the numerous parameters involved complicate history matching with laboratory results, potentially leading to... 

Simulation of logging tools can predict the tool's response under various conditions for petroleum engineers. One of the achievements of logging tool simulation is the prediction of tool behavior and the ability to interpret logs under different conditions. This is achieved by simulating the tool in various scenarios and collecting the log responses. Additionally, it can be utilized for validating the interpretations made. In this study, a dual lateral logging tool simulation has been conducted. This tool is applicable in wells containing drilling fluids with electrical conductivity. Given the impossibility of implementing the main focusing process of the tool, a novel method for numerically... 

Subtle faults refer to geological faults that are not easily identifiable using conventional seismic interpretation techniques. Identifying faults and fractures is of great importance in petroleum engineering, playing a vital role in reservoir management and the optimization of hydrocarbon extraction. Faults and fractures can act as fluid conduits, creating heterogeneity in fluid flow. Blocking faults or fractures can act as flow barriers and even lead to reservoir compartmentalization. Accurate fault identification aids in optimizing extraction methods, maximizing hydrocarbon recovery, and preventing issues such as induced seismicity caused by the reactivation of faults. For reservoir... 

Matrix acidizing is a method utilized for well stimulation, aimed at enhancing well productivity. The initial phase of this process is the pre-flush stage, designed to displace formation fluids from the treatment area. Direct contact between acid and crude oil in the formation can lead to formation damage due to the formation of precipitates and emulsions, thus reducing the efficiency of the well stimulation operation. In this study, the relative permeability data of the pre-flush fluid-oil measured in the laboratory are used to design the pre-flush stage  

Underground hydrogen storage is considered a strategic option for supporting the expansion of renewable energy systems and managing short-term and long-term supply–demand fluctuations. Despite its advantages, biological and geochemical reactions occurring in subsurface environments, particularly methanogenic reactions, can lead to hydrogen consumption, methane generation, and a reduction in storage efficiency. The primary objective of this study is to quantitatively and systematically evaluate the impact of methanogenic reactions on underground hydrogen storage performance in terms of produced gas purity, efficiency loss, and gas composition changes. In this work, a numerical model based on... 

Acidizing is one of the widely used practices of formation damage remediation. The success of this rather expensive job depends on the precise design and operation. Though, improper execution of an acid job, not only does not improve the formation damage but also can contribute to even more damage itself. For this purpose, it is critically important to thoroughly design an acidizing job conducting extensive lab experiments and utilizing numerical tools before operation in order for a successful acidizing. Unlike, carbonate acidizing, the chemistry of sandstone acidizing is very complex and challenging because of the wide variety of minerals and aqueous species present in the system. Hence, a... 

Lightweight drilling cement plays a crucial role when drilling in low-pressure formations. In such conditions, the reservoir pressure is lower than the hydrostatic pressure of the drilling fluids, increasing the likelihood of fluid infiltration into the formation. Drilling cement has multiple functions, including securing the casing pipes, preventing fluid migration into the formation or from the formation into the wellbore. In low-pressure formations, special attention must be paid to the cement weight to avoid increased pressure that could lead to formation invasion. Lightweight drilling cement is formulated using low-density materials and lighter properties to prevent excessive pressure... 

The rapid expansion of the Internet of Things (IoT) and cloud computing has opened new horizons in the field of "Cloud-Based Control". However, outsourcing control computations to third-party cloud servers raises serious concerns regarding the privacy of sensor data and the system model. Homomorphic Encryption (HE), as a key solution, enables direct processing on encrypted data, but its application in real-time control loops introduces challenges such as computational overhead, encryption noise, and system dynamics impacts. This research aims to develop a comprehensive framework for the secure control of linear and nonlinear dynamic systems, with a focus on the CKKS encryption scheme. In the... 

Carbonate matrix acidizing is a widely applied stimulation technique for enhancing oil and gas wells productivity through the formation of highly conductive channels known as wormholes. Uniform acid distribution within the target formations is a key factor governing the success of this stimulation method. However, in carbonate reservoirs, strong heterogeneity among productive layers and the presence of preferential flow paths such as fractures and wormholes hinder effective stimulation of less permeable intervals, thereby reducing acidizing efficiency. To address this challenge, diversion methods are employed during acidizing operations to temporarily block highly permeable pathways and... 

Carbonate matrix acidizing using hydrochloric acid which causes CO2 generation is one of the most popular well stimulation techniques in recent decades. Lots of the wormhole propagation models developed for laboratory scale, assumes that the cores are fully saturated with aqueous solution and no CO2 gas is produced. Final purpose of this research is to develop a geochemical model describing equilibrium composition of a 3 phase system of acidic solution-gas-rock accurately in common pressure and temperature conditions of carbonate matrix acidizing to obtain main inputs of acid reactive flow in porous media from it. In this regard, concept of the “extent of the reaction” is defined and after... 

One of the best stimulation methods for oil and gas wells is matrix acidizing in order to increase the near wellbore permeability. in acidizing, good acid coverage in different layers is one the main goals. so, various methods have been presented. important part in using these methods is to not damage formation and economic matters. modern methods utilize VES acids for this purpose. viscoelastic characteristics of these materials by formation of miscellaneous, increases the apparent viscosity by a large degree. for this reason, VES fluids can be used to improve acid divergence in acid injection operation. acid system based on viscoelastic surfactants that is changed to gel instantly, can be... 

Formation acidizing is one of the best well stimulation methods to remove reservoir damage and improve recovery of oil and gas well. The proper design of acidizing operations can significantly improve the production of a formation. In the meantime, causing formation damage and precipitation in oil flowlines, which may be caused by the incompatibility of the stimulation fluid with the reservoir fluid and rocks, is one of the most serious problems in the operation, which reduces permeability and oil/gas production. As a result, the success of the acidizing operation requires to study the interaction of components of operation (acid, reservoir water, formation rock, and acid additive)... 

An important step in the early stages of an oilfield development is the accurate identification of the location of production and injection wells which has a significant impact on productivity and profitability of the reservoir. Recently, operation companies in petroleum industry focus on production optimization, recovery enhancement and cost reduction; as a result, application of non-conventional wells (NCW) or non-vertical wells have dramatically increased. Well placement optimization is a complicated task as it is a function of several contributing factors including reservoir heterogeneities and economic constraints. The complexity of this task increases when it is considered as a... 

Acidizing operation is performed in oil and gas reservoirs with the aim of overcoming formation damages, increasing permeability and reducing skin factor. In carbonate reservoir, the hydrochloric acid increases the permeability of the areas around the well to a more than its initial value by dissolving part of the formation minerals. Considering that most of Iran's oil and gas reservoirs are in the category of carbonate reservoirs, it is important to study the reaction kinetics of carbonate minerals and acids used in acidizing operation. The complex and multifactorial nature of the acidizing operation in the reservoirs has made it very difficult to design a successful and optimal operation.... 

Injection of acid into the carbonate rock dissolves the rock, and the porous medium is constantly changing. As a result, the boundaries between the acid and the porous medium, which are in fact the interface between the solid phase and the liquid phase, are constantly changing. Therefore, on the issue of acid injection into carbonate rock, we are facing dynamic boundary conditions. Also, due to the simultaneous solution of transfer and reaction phenomena, modeling acid injection into carbonate rock faces many challenges.In such problems, the ALE method, which is a combination of the best features of the Lagrangian method and the Eulerian method, offers a very precise solution and is used as... 

Many of gas condensate reservoirs, including rich gas and lean gas, face with fast well productivity decline. The origin of this problem is condense accumulation around the well bore which known as condensate blockage. There are different condensate blockage mitigation methods, one of which is acid fracturing that is suitable for tight carbonate reservoirs with low KH. Acid fracturing simulation is high difficult and have not been undertaken a study that can adopt with experimental and field test results, so researchers usually use practical method and many developed software in this area use correlation form laboratory data. However, the literature show that experimental results can just... 

In this work, a basic model for numerically simulating matrix acidizing in carbonate formations is developed. This model employs laboratory linear acid core-flooding data and avoids any fitting parameters. Wellbore-scale numerical simulation is based on finite-volume method with Cartesian coordination and cubic meshing. Mass transfer equations are based on fluid front tracking and the momentum transfer equation is the Navier-Stokes equation for flow in porous media. The effect of fine-scale dissolution phenomena of carbonate rocks are translated into the coarse-scale by homogenization. In this work, it is tried to achieve a simple but logical approach towards a correct simulation, avoiding...