Northeastern Egypt is one of the most important exposures in the Middle East and North Africa to study Jurassic facies. The present study analyzes 130 thin sections from a subsurface well (Well X) in the northern Gulf of Suez, and from two surface sections at Gebel Maghara (north Sinai) and Khashm Elgalala (North Eastern Desert), Egypt for petrographic and lithofacies analyses. In the present study

Physical simulation experiments of rock fracturing can effectively simulate the extension of artificial fractures within different lithology and interbedded rocks. Previous studies have focused on the conditions of artificial fracture initiation and propagation, while few studies have been conducted on the evolution and influencing factors of fractures in reservoir rocks. In this study, fracture evolution

Facies classification from well logs is an indispensable part of seismic interpretation and is important in the determination of sequence stratigraphy and ultimately reservoir characterization. Although there have been improvements in the tools used to perform this task, it remains laborious, subjective, and error-prone. Achieving a proper classification is complicated by increasing dataset sizes as

In order to understand the time-dependent characteristics of stimulation behaviors during hydraulic fracturing, the self-developed hydraulic fracturing monitoring system under triaxial loading was employed to investigate the cracks' propagation under shale-fluid coupling process. The results reveal that with different duration of fracturing fluid invasion, the pressurization rate of fluid pressure

Fractured porous media or double porosity media are common in nature. At the same time, accurate modeling remains a significant challenge due to bi-modal pore size distribution, anisotropy, multi-field coupling, and various flow patterns. This study aims to formulate a comprehensive coupled continuum framework that could adequately consider these critical characteristics. In our framework, fluid flow

One of the major challenges pertaining to a full hydrogen economy is hydrogen storage in the Earth's subsurface formations, such as deep saline aquifers and depleted oil and gas reservoirs. Generally, sedimentary basins are considered for this purpose due to their potential for large-scale storage. However, basaltic formations are also in comparable proportions having voluminous volcanic rocks, vast

The problem of lost circulation is a direct consequence of the presence of fractures or high permeability. Lost circulation material (LCM) is used to treat the loss that occurs or proactively strengthen the wellbore of the potential loss zones. The polyacrylamide (PAM)/Polyethylenimine (PEI) cross-linkable polymer gel is proven to work best in zone-sealing and plugging applications. In addition to

The mechanical behavior of the rock at the macro-scale depends significantly on its granular meso-scale structure as well as properties of each mineral component. Current methods only calibrate the mechanical properties from different macro-scale samples, which certainly introduces limitations to recognize the realistic physics behind rock failure. To address this problem, theoretical analyses of meso-scale

Wax deposition in oil wells seriously affects hydrocarbon production and causes inevitable economic losses. Especially in rodless pumping wells, due to the lack of the stirring effect of the sucker rod, the waxing of the tubing is more serious. According to the correlation law between flow velocity and wax deposition, a speed-increasing impeller wax prevention device was designed. Based on fluid dynamics

In the field construction of shale oil (gas) hydraulic fracturing, the veins present in the shale may deflect the propagation path of hydraulic fractures. The metal chalcopyrite veins are widely contained in Jimusar Shale, but the effect of the metal veins on the fracture propagation at different temperatures is still unclear. Based on the extended finite element simulation and semicircular bending

The Micangshan-Hannan Uplift area is proved a new shale gas exploration area with massive potential of Niutitang Formation in the past three years. Nevertheless, the organic matter enrichment mechanisms of this set of organic-rich shales lack discussion. Here, eighty-two samples of a drilling well from the Micangshan-Hannan Uplift, Upper Yangtze Block, South China were investigated for the organic

In this research, the effect of different clay minerals (bentonite, illite and kaolinite) on the combustion behavior and kinetics of crude oils from Kazan region (Russia) was studied using thermogravimetry (TGA) and differential scanning calorimeter (DSC). The ramped temperature experiments were performed at constant heating rates (10, 20 and 30 °C/min) under air atmosphere. In both TGA and DSC experiments

The production of gas and oil from the unconventional tight and shale reservoirs is the outcome through a series of cooperative efforts of drilling, completion, and production operations. This study aims to optimize these operations to enhance the well productivity and oil recovery, and ultimately to reduce the development footprint on the level of individual wells. More specifically, a comprehensive

For the obstruction and reinforcement of permeable rocks (pores and or fractures), materials to combat loss of circulation (LCMs) are commonly used in the drilling fluid. LCMs, when forming bridges, support and seal rocks, with the objective of preventing drilling fluid from reaching the reservoir. In this study, drilling fluid formulations were developed using full four-level factorial design (DOE)

Liquid nitrogen (LN) fracturing is an efficient technology for the development of unconventional gas resources. Due to continuous injection of cryogenic LN, the reservoir temperature decreases and then cooled rock regions are gradually generated during fracturing process. To investigate the breakdown behaviours of sandstone induced by LN fracturing, laboratory simulation experiments were performed

To verify the feasibility of applying ultrasonics to enhancing gas production from shale gas reservoirs, experimental study on the effects of ultrasonics on adsorption, desorption and seepage characteristics of shale gas using four samples from Sichuan Basin has been carried out. Adsorption and desorption of methane, were tested by volume method under different conditions, while the permeabilities

During the drilling in shale reservoirs using water-based drilling fluids, shale hydration leads to various risks such as wellbore collapse and stuck drills. However, the mechanism of shale hydration remains unclear. This work presents a comprehensive experimental investigation on the mechanisms of shale hydration using core samples of Sichuan shale (China), with a high content of illite. The impact

A high-strength pressure-resistant material and acid-resistant thickener are developed, and natural cores extracted from the Changqing Oilfield in China are wrapped in three dimensions to study the initiation, propagation, and characteristics of cracks. Conventional hydraulic fracturing, acid fluid fracturing, and thickener compound acid fluid fracturing were carried out through physical and numerical

Long-term storage of carbon dioxide (CO2) inside depleted reservoirs can help reduce the impact of greenhouse gas emissions. Portland cement has been shown to degrade significantly during long-term contact with CO2. This research aims to provide a new environmentally friendly, Class C fly ash-based cement as a potential alternative to Portland cement for CO2 storage wells. This was achieved by comparing

A sound understanding of the pore-fracture system across all scales provides an in-depth look at the intricate gas transport mechanisms in shale reservoirs. We performed a comprehensive multiscale characterization analysis on the Longmaxi shale samples using five complementary techniques: low-temperature gas (N2) adsorption (LTGA), mercury intrusion porosimetry (MIP), nuclear magnetic resonance (NMR)

High water production is a common problem in mature oil reservoirs. Gel-based treatments have been widely used as blocking agents to control water production in heterogeneous reservoirs. A comprehensive review of preformed particle gels (PPGs) status, properties, treatment methods, and mathematical modeling are being discussed in the present study. Different types of PPGs are categorized, and the main

The production of sand particles associated with the reservoir hydrocarbons becomes one of the most common problems a well of multi cycle steam stimulation may experience during reservoir lifetime. Therefore, it is essential to the investigation of sand particles migration and sand production mechanisms coupled with fluid flow for optimization design of injection and profile control parameters. This

In this paper, the genesis of dolomite in Longwangmiao Formation is analyzed through field investigation and geochemical methods, and dolomization model is established, which is very important for the next reservoir prediction in Longwangmiao Formation. According to the crystal size, the Longwangmiao Formation dolomite can be divided into two types: microcrystalline dolomite (MID) and macrocrystalline

Natural Gas (NG) compressibility factor as important property at any NG industrial applications determined by utilizing an intelligent approach precisely. Three thermodynamic properties include pressure, temperature and Joule-Thomson (JT) coefficient are selected as input parameters. These properties are chosen due to the measurement capabilities of available sensors. Unlike the traditional approaches

Hydraulic radial drilling is an effective technique to increase the production of low-yield oil and gas wells. To improve the operation effect of this technology, a new type of direct-rotating mixed-jet nozzle is proposed, and the drilling performance of the nozzle is studied by combining theoretical, experimental, and numerical simulations. Firstly, the theoretical and numerical simulation models

The Lishui Sag, situated at the East China Sea Shelf Basin, is regarded as one of the most prospecting oil exploration zones. Low exploration in this region requires detailed identification of source rocks to enhance further oil and gas exploration. Three potential source rocks, including the Paleocene Yueguifeng (E1y), Lingfeng (E1l) and Mingyuefeng (E1m) Formations, were investigated by integrating

The lithofacies characteristics of fine sedimentary rocks affect the hydrocarbon generation capacity and reservoir performance of tight oil and are closely related to the sedimentary environment. On the basis of field outcrops and core observations, combined with logging data, thin section identification, grain size analysis, organic carbon analysis and physical property tests, the fine sedimentary

Performing drilling operations to explore and exploit oil and gas reservoirs by injection wells is one of the most essential pillars of the oil industry. Hence, the improvement of drilling mud properties has a particular role. In this research, a laboratory study was carried out on the effect of nano additive on rheological properties of drilling mud. The ZnTiO3 nanoparticles were synthesized and analyzed

Thief zone is a common reservoir unit with super permeability developed in giant carbonate reservoirs and readily leads to the breakthrough of fluids bring the challenge to water flooding development or tertiary oil recovery. To provide insight into the characteristics and origins of thief zones in Cretaceous carbonate reservoirs in Central and Southern Mesopotamian Basin, core analyses, well log,

An important requirement of reservoir management is to understand the properties of reservoir fluids and dependent phase behaviors. This makes it possible to determine the properties of reservoir fluids in laboratory pressure-volume-temperature (PVT) tests. Such laboratory tests are costly and time consuming, and reservoir data are sometimes not available. When estimating the in-place fluid volumes

This work addresses a field-scale model, in which the equations of multiphase/multicomponent fluid flow and geomechanics were fully coupled, to simulate natural gas successive storage/recovery processes in an Iranian sandstone depleted gas reservoir. First, a 1D mechanical earth model was developed for the reservoir wells and then converted to a geomechanical 3D model of the reservoir, through sequential

Spontaneous imbibition (SI) plays a key role in production mechanism of unconventional reservoirs. Trivially, with the goal of getting higher efficiency there always has been an incessantly research activities to develop the technology progressively. In this regard, thermodynamic variables (i.e. pressure and temperature) can directly influence the process performance of SI. Thus, numerous papers have

Although significant progress has been made in the tight gas exploration and development, there is still a limited understanding of the fluid charging and hydrocarbon accumulation in the sweet spot. In this study, a novel method is proposed to generate the stochastically constructed porous media which represents the transition region between tight surrounding sandstone and sweet spot. Based on the

In this paper, an adaptive timestep size selection algorithm applied in streamline-based simulation for highly heterogeneous and anisotropic reservoirs is presented. To handle an arbitrarily, anisotropic, and discontinuous permeability tensor, we use a non-orthodox Multipoint Flux Approximation Method with a Diamond stencil (MPFA-D) discretize the pressure equation. For the solution of the transport

During slide drilling with a bent motor assembly, accurate toolface setting and control are critical challenges, and the performance depends a lot on the directional drillers’ experience. An efficient and reliable controller is therefore needed to eliminate the variability in performance between drillers. However, low sampling frequency and large time delays make common feedback controllers often inoperative

Sandstone reservoirs with a depth of over 6000m of the Lower Cretaceous Bashijiqike Formation in the Kuqa foreland thrust belt, Tarim Basin in NW China provide a good example for studying multiple-stage diagenetic fluid activities and effects of fractures on reservoir quality in tight sandstone. Three types of fractures can be identified in the sandstone: fully sealed fractures, partly filled fractures

Mud pulse telemetry system plays a critical role in modern oil drilling engineering. However, the valid signal is complicated to be obtained because of the main disturbing of pump noises, especially in ultra-deep drilling operations. Therefore, four model-based noise suppression plans for the mud pulse signal pump are mainly proposed in this paper. First, three kinds of pump noise state-space models

The main risk during the construction of oil wells is the possibility of uncontrolled hydrocarbon flow occurring from the well to the environment, commonly known as a blowout. After the Macondo accident, in the Gulf of Mexico, in 2010, there has been, in recent years, a significant increase in researches related to both well integrity and operational safety. A possible approach is to seek tools that

Petroleum exploration in the Ordos Basin gradually expanded to the edge of the basin, but encountered difficulties on the southwestern edge. Compared with mature exploration areas inside the basin, the nature of reservoir fluids in the southwestern area is more complex. In order to better understand the oil / gas system in this area, this study conducted a detailed research on the geochemical characteristics

The increase in the pressure bearing capacity is critical for mitigation of lost circulation, and to do so the strength of the plugging zone should be increased via picking an effective evaluation method and choosing the proper particle size distribution (PSD). Therefore, in order to successfully investigate this process, the traditional evaluation device of lost circulation should be improved for

Fault acts as an important vertical migration conduit for hydrocarbons in rift basins and can transport hydrocarbons from deep-buried organic-rich sediments to shallow-buried coarse-grained sequences. Such migration process is expected, but generally needs to pass through thick mudstone intervals and its controlling factors are not well understood. The low-relief regions of the south Bohai Sea in the

A spatial model of the 3D formation drillability field is crucial for drilling optimization in the petroleum area. In this paper, a new spatial modeling method is proposed for the 3D formation drillability field, which has two stages. In the first stage, the number of formation modes is determined according to the formation characteristics and these modes are identified by the fuzzy c-means clustering

Major corrosion influence factors in the production well of CO2 flooding in Xinjiang oilfield were investigated, and corresponding anticorrosion measures (relating to corrosion inhibitors and corrosion-resistant alloys) had been contrasted in order to select a most suitable scheme to solve the tubing corrosion issue. The results showed that the corrosion of N80 steel in liquid phase was mainly affected

Correlation is widely used and its importance has become even more pronounced in big data. Generally, scientists and engineers look for highly correlated variables and ignore weakly correlated variables. We use a more holistic view of correlations in evaluating unconventional resources by integrating correlation with causal inference. In formation evalutions, many variables are involved and they generally

Heat injection is considered to be an effective technique to increase Coalbed methane (CBM) production, which indicates the important role of temperature in gas flow. In this paper, two different experimental schemes have been designed, and the seepage tests concerning variable effective stress and variable pore pressure have been carried out respectively under different temperature conditions. A permeability

This paper develops a rigorous and advanced data-driven model to describe, analyze, and forecast the global crude oil demand. The study deploys a hybrid approach of artificial intelligence techniques, namely, the genetic-algorithm, neural-network, and data-mining approach for time-series models (GANNATS). The GANNATS was developed and applied to two country cases, including one for a high oil producer

The excessive reach of new fractures during hydraulic fracturing can interact with the pre-existing fracture system during reservoir stimulation. This phenomenon is known as Frac Driven Interaction (FDI), which can greatly compromise the production performance of the wells. The key to minimizing the impact of FDI is to effectively control the length of fractures through a proper fracturing design.

In the daily practice of Formation Evaluation for porosity calculation considering the shale volume is common the adoption of simple hypotheses about the physical properties of the reservoir rock constituents. In this paper, it is argued that an accurate estimate of clay mineral physical properties in the reservoir rock are essential for a realistic porosity calculation, once it may be different from

Water saturation in porous media plays a significant role in static, dynamic reservoir modeling and petroleum reserves calculations. In this paper, a Pliocene conglomerate type of sandstone Caspian reservoir was studied. The objective of this paper is to apply water saturation calculation method using fractional flow and PLT (Production Logging Tool) and to compare the results with other methods. In

To evaluate the effectiveness of the acidic and oxidation reactions of stimulating organic-rich shale during fracturing, we conducted imbibition experiments using the oxidant (Na2S2O8), under no confining pressure conditions. The chemical-induced fracturing process of Na2S2O8 with Marcellus shale samples was tested and evaluated by these methods: the mass changes before and after imbibition tests were

Nowadays, unloading gas wells with coiled tubing is a common application to the field. However, it still lacks of adequate understanding of dynamic behavior of the unloading process. This paper investigates the process of liquid unloading by gas lift with coiled tubing under transient conditions. This unloading process can be divided into three stages: liquid rising in tubing, liquid slug production

Geothermal energy is a sustainable and renewable source that can be extracted by circulating a single- or two-phase fluid through a geothermal well system. Two-phase flow and heat transfer models are required for predicting pressure and temperature profiles in oil, gas, and geothermal wells. We model fluid flow, thermodynamics and heat transfer in an idealised vertical well for single-(i.e., water)

Initial fracture morphology and variation of acid-rock reaction temperature caused by alternate stages were ignored in the traditional alternate multistage acid-fracturing experiments, so a new design method of experiment simulation was proposed with these considerations in this paper. Alternate multistage acid-fracturing experiments were carried out based on this new method through using self-generating