Innovative asymmetric polyethersulfone (PES) membranes embedded with activated carbon (AC) were synthesized and then surface coated with thin PDMS layer. The membranes were then tested with advanced analytical techniques like FTIR, TGA, SEM and EDX analysis. Thereafter, the membranes were tested for gas permeation analysis with following five gases: carbon dioxide, hydrogen, nitrogen, helium and methane

Ultra-high-thickness (>15 m) is one of the unique features of coalbed methane (CBM) reservoirs in Junggar basin, Xinjiang, China. However, there are few studies on the vertical permeability and gas content heterogeneity of ultra-high-thickness reservoirs. We use the Fukang west block on the southern margin of the Junggar Basin as a characteristic-example. Logging data describe the vertical distributions

Hydraulic fracturing technology is the most effective stimulation method to develop hydrocarbons in tight reservoirs, but the invading of fracturing fluid into the reservoir matrix often causes permeability damage, resulting in reducing the effectiveness of the stimulation treatments. Therefore, in this paper, for tight cores with permeability of 0.10×10-3μm2, 0.05×10-3μm2 and 0.01×10-3μm2, the damage

Hole cleaning and cuttings transport play a vital role in the drilling operation. Various drilling problems such as a reduction in penetration rate, increase in the torque and drag, and an increase in the potential of differential sticking are often related to poor cuttings transport from a wellbore. Multiple parameters, including the fluid rheology, mud velocity, cuttings size, and drill pipe inclination

This work investigated buckling resistance of an X80 steel pipe containing a corrosion defect under axial compressive loading by finite element analysis. A 3-dimensional numerical model was developed to determine parametric effects on buckling behavior of the corroded pipeline. These included dimension of the corrosion defect (i.e., length, depth and width), pipeline geometry (i.e., outer diameter

Leak detection in pipelines has been a prevalent issue for several decades. Pipeline leaks from sources such as small cracks and pinholes are termed chronic leaks, as they have the potential of going unnoticed for long time periods, causing both economic losses and environmental damage. Literature lacks a comprehensive review of chronic leaks, especially under subsea or arctic conditions. Therefore

Hydrogen is considered as an alternative to fossil fuels that is practically unlimited, do not possess intermittency problems as wind/solar, and leads to zero carbon-emissions in its pure form and thus improving the air quality with respect to many other alternatives such as fossil fuels (i.e., natural gas streams). It is also an essential component in most CO2 to hydrocarbon conversion techniques

To improve the general understanding of diffusive processes in coal and investigate if representative reservoir properties can be estimated from measurements on crushed coal particles, adsorption and desorption experiments on crushed samples and large, intact core samples are carried out. Diffusion properties are analysed for methane, carbon dioxide and nitrogen up to a pressure of 10 MPa at a temperature

Thermal stimulation methods have been investigated to enhance gas extraction from the high maturity shale recently. In this paper, a Longmaxi shale core sample, with vitrinite reflectance=2.8%, was selected for canister tests to investigate the gas desorption process first at 55 oC and then switched to 110 oC. A mathematical model (self-similarity) was proposed to mimic the gas decaying process in

Temporary-plugging-and-diverting fracturing (TPD fracturing) is widely used to enhance hydrocarbon recovery from unconventional reservoirs. During TPD fracturing, diverters are injected to prevent the propagation of the previously formed fractures, then divert the fracturing fluid into the unstimulated zones. However, the influence of the fracture morphology on the diversion remains unknown. This study

Stress-sensitive permeability imposes a significant impact on production performance in a tight formation; however, the widely used models assume the constant permeability or same stress-sensitive level for different systems, resulting in incorrect prediction of production rate and reservoir properties. In this work, theoretical models have been formulated, validated, and used to characterize the transient

Although the exploration and development of tight gas have made great progress, the quantified study on gas migration and accumulation in sweet spots of tight gas reservoir is still limited. In this work, a computer program is developed to conveniently describe the different shape of sweet spots and the fractures in tight reservoir. Then, gas migration and accumulation processes are simulated, and

Visualizing and quantifying the pore structure at the nano-micro scale is critical for understanding the micro fluid transport and enrichment in coalbed methane (CBM) reservoirs. In this work, the detailed micro-nano scale pore parameters such as pore counts, pore area, pore volume and pore size distribution can be acquired by the focused ion beam-scanning electron microscopy (FIB-SEM) and X-ray computed

The development of shale oil/gas reservoirs has suffered constant changes, innovations and successive reactions, although it depends on the success of hydraulic fracturing, and mineralogy and morphology play a very important role in establishing brittleness and therefore controlling it. In this study, mineralogical and morphological characteristics of the Cretaceous Galembo Member Mudstones of the

The presence of natural fractures in the formation and its degree of heterogeneity condition the injection of CO2 into the aquifer as they affect the migration processes and its storage capacity. In ATAP experimental facility the petrophysical behavior of two carbonate formations was studied, with different proportions of limestone, dolomite, quartz and anhydrite and fissures sealed mainly by potassium

Natural gas hydrate is an attractive potential as alternative energy source. The initial studies of natural gas hydrate production test have shown that the hydrate productivity via conventional depressurization is still far to reach the commercial level, hence, hydraulic fracturing has been proposed to stimulate the hydrated formation to enhance production. However, the buried depth of hydrate-bearing

Understanding the differences among shale pore systems is crucial to exploring the enrichment mechanism of shale gas. In this study, we found that radiolarian micro-fossils are widely distributed in the overmature marine organic-rich Wufeng-Lungmachi formations surrounding the Sichuan Basin, South China. This enables an investigation on the full-scale pore structure characteristics of the two formations

When drilling through naturally fractured reservoirs, the remediation of drill-in fluid loss needs to be designed by taking both fracture plugging and formation damage into account. Lost circulation materials (LCMs) should be implemented efficiently to minimize the solid-laden fluid invasion into the fractures during the development of fracture plugs. This study investigated the effects of three LCM

Geomechanical analysis and integrity assessment of hydrocarbon reservoirs upon depletion and injection are crucial to ensure that CO2 storage projects can be safely implemented. The Bredasdorp basin in South Africa has a great potential for CO2 storage given its hugely available exploration data. However, there has not been any geomechanical characterization carried out on this basin to determine its

Nitrogen is a component that often needs to be removed from natural gas. A dual-reflux pressure swing adsorption (DR PSA) technology with activated carbon as the adsorbent was explored for N2 rejection from a binary mixture of 75 mol% CH4 and 25 mol% N2 via non-isothermal numerical modelling. The performance of the four DR PSA configurations (PL-A, PH-A, PL-B and PH-B) was studied by varying the following

This study investigates the micropore-mesopore spectrum in gas shales by augmenting two different pore size distribution calculation methods using two probe gases in low-pressure sorption analysis. The Barakar Formation shale samples collected from Wardha and Asansol belonging to two key potential basins in India, viz. Wardha and Raniganj, were studied to identify possible variations in pore attributes

One of the main purposes of hydraulic fracturing in unconventional resources such as shale is to improve the connectivity between existing natural fractures and the production well. Since the inherent permeability of shale is extremely low, this newly formed fracture connectivity provides faster paths for the hydrocarbon stored in preexisting natural fractures. We performed numerical simulations of

The pore structure and coal matrix compressibility evolution law and their influencing factors of middle-high rank coals was evaluated based on the combined application of high pressure mercury injection, low-temperature nitrogen gas adsorption and low-temperature carbon dioxide adsorption. The middle-high rank coals are dominated by macropores and micropores, along with lower developed mesopores.

A fracture acidizing treatment, as an effective way to enhance the well performance, is commonly used in fractured carbonate reservoirs operated with hydraulic fracturing stimulation. A fracture acidizing simulator is developed to model the fracture acidizing process in a fractured carbonate rock mass embedded with randomly distributed natural fractures. Mathematical models incorporating the hydro-chemical

The article presents the concept of construction of natural gas measuring systems with high variability of gas flow through a metering station. The considerations are based on the analysis of the flow rate range of gas meters available on the European market, performance analysis of real measuring systems located in gas stations as well as on laboratory tests of gas meters. Studies were carried out

In oil and gas production, natural fracture (NF) activation and the seismicities induced by hydraulic fracturing can cause unpredictable damage and even catastrophic consequences to reservoirs, which seriously threatens the safety of construction personnel and equipment. In this paper, the seismicities induced by hydraulic fracturing in naturally fractured reservoirs were investigated based on the

In this work, a 3-dimensional finite element (FE) model was developed to investigate the effect of cyclic loading, which is induced by vibration during operation of in-line inspection (ILI) tools, on local stress and strain distributions and failure pressure of an X80 steel natural gas pipeline containing a corrosion defect. Modelling was also conducted on a low-grade X60 steel pipe for comparison

The anisotropic characteristics is obviously performed for the marine shale in Northwestern Hunan, China, it's closely related to the developed bedding existing in shale formation layers. While the investigations of the shales' anisotropic behaviors under the different bedding angles are still lacking on comprehensive understanding in this region. In order to understand shales' anisotropic behaviors

Estimation of gas solubility in a brine solution is essential for many chemical/petroleum industrial applications including EOR with gas injection, geological storage of CO2 in deep saline aquifers, mitigation of corrosion related issues for sour gas fields and many more. Since the type of salt can significantly alter the gas-solubility in formation brine, we develop a robust methodology to predict

Sembar Formation of Cretaceous encountered in Khajari-01 and Miran-01 wells, which are located in the Southern Indus Basin (SIB), Pakistan. Total organic carbon (TOC) content is generally measured by traditional methods such as the evaluation of side wall cores and formation cuttings in a geochemical lab. Data obtained from these experimental techniques are not continuous and also a time-consuming

Lattice Boltzmann method (LBM) is an efficient tool to perform direct numerical simulation of gas flow in micro-size pores. Despite great advances in LBM and its use in describing gas flow in micro-size channels in slip and transitional flow regimes, exploring formulations that are able to capture flow behavior in domains with complex boundary geometries remains a challenging task. As a result, the

This paper comprehensively reviews CO2 sequestration process in saline aquifers. The storage mechanisms including structural, residual, solubility, and mineral trappings are assessed along with a discussion of their relative contributions, and their key parameters and optimisations. In view of storage security and capacity, effects of rock and fluid properties and reservoir conditions together with

The aim of the study was to analyse the effect of temperature on the sorption and diffusion of CO2 and CH4 on hard coal. Four coal samples, characterized by various degrees of coalification, were used in the research. The sorption measurements were carried out in three temperature values: 278 K, 313 K and 353 K and for the consecutive pressure values of 1 bar, 5 bar and 15 bar. Langmuir's sorption

Unconventional methane resources are usually diluted in air, which prevents their use as feedstock in chemical or thermal processes. Some of them (e.g. coal mine ventilation air or diluted landfill biogas) are emitted directly to the atmosphere without harnessing, increasing the contribution of methane to global warming. Gas permeation membranes offer an alternative for the concentration of these methane

Initial water content and subsequent fracturing fluid injection lead to gas-water flow in shale nanopores, especially the water-wet pores. But there is few research and experiment to introduce relative permeability curves governing multiphase transport behaviors in shale nanopores. With the consideration of water true slippage and gas slippage, an analytical model illustrating gas-water relative permeability

High pressure rheological properties of methane hydrate slurries entail the high-pressure rheometer that can deliver a suitable mixing to form in situ methane hydrate from the multiphase system. However, the hydrate formation was extremely challenging in conventional cup and bob geometry due to its plane surface. In this work, modified Couette geometry has been used in a high pressure rheometer to

Pipelines are efficient in transporting natural gas over large distances. Wet carbon dioxide present in pipelines can create an environment that is corrosive to steel. Polymer liners made from either polyethylene or polyamide (nylon) are presently used to mitigate internal corrosion in natural gas pipelines. Gas diffuses through all polymers over time, and polymer-only liners lower the steel corrosion

High performance water removal plays a significant role in restoring the gas production when water invasion happens to tight gas reservoirs. In this paper, core samples with the air permeability in range of 0.01 - 1 mD were selected to investigate water removal behavior in tight gas reservoirs. Meanwhile, the gas flow capability during the process of water removal was discussed. The water desaturation

Recently, flowback data analysis enabled us to evaluate important fracture parameters including fracture conductivity and volume in unconventional reservoirs. To perform the analysis, diagnostic plots, straight-line techniques, and history-matching techniques have been used. Immediate water and gas production usually occurs on flowback in shale gas wells. In this paper, a novel workflow is developed

The elastic properties of reservoir formation are usually measured through laboratory triaxial tests or are estimated from empirical correlations obtained from well logs. Both approaches have similar limitation of the estimated value being representative of near-wellbore region. The former, however, has the further limitations of being costly and the unavailability of core samples for having a reliable

Conventional hydraulic fracturing often causes problems such as reservoir damage, water consumption, and pollution. Recently, liquid nitrogen (LN2) fracturing, an environmentally friendly fracturing technology, has attracted more attention. In this paper, the mechanism of surface crack propagation in coal and sandstone induced by LN2 is explored through laboratory tests and numerical simulations. An

Shale generally contains water that has a significant effect on the adsorption of methane in shale. Since methane in shale is mostly stored in an adsorbed state, understanding the effect of moisture on shale adsorption behavior will play a vital role in shale gas development. In this paper, an adsorption model has been proposed to consider the effects of moisture to describe the methane adsorption

The extraction of coalbed methane can supply clean energy to society and improve the safety of subsurface coal mining. The low and ultra-low permeability of coal seams has resulted in the significantly low efficiency of methane production in surface and subsurface extraction systems. Fluid stimulation has been extensively applied for the enhancement of formation permeability. However, the response

The water-gas relative permeability of tight sandstones governs the gas production performance and recovery efficiency in a gas reservoir. Reservoir heterogeneity cannot be neglected when we extrapolate water-gas relative permeability curves. However, efforts to determine the variation with rock types and controls of the gas and water permeability have proven insufficient. Rock composition and pore

Strong heterogeneity and anisotropy result in complex flow and relatively low oil recovery in fractured-vuggy reservoirs. In this work, we assess the Cahn-Hilliard phase field method (PFM) and the pairwise force smoothed particle hydrodynamics (PF-SPH) method in modeling 2D multiphase flow through fracture-vug medium, in terms of different capillary numbers, mobility ratios, gravity, and wettability

Organic-matter (OM) pores play a significant role in the pore systems of shale formations. Numerous studies have analyzed the characteristics of OM pores. However, fewer studies reported the effects of OM pores on shale properties. In this study, a comprehensive pore-scale investigation of the impacts of OM pores on various physical properties of shale samples based on multicomponent and multiscale

Shale reservoirs can be stimulated by injecting cryogenic fluids such as liquid nitrogen (LN2) to initiate and propagate fractures and to connect existing natural fracture networks. This research aims to investigate the efficacy of the cryogenic treatments on the porosity, permeability, and mechanical properties (Young's modulus, Poisson's ratio, brittleness, bulk compressibility, and unconfined compressive

This paper introduces an analytical approach for the performance of the fractured reservoir considering the impact of the matrix block size, shape, and distribution. The objective is better understanding the roles of the variable interporosity flow systems, fracture flowing systems, and reservoir matrix heterogeneity in the responses of the wellbore pressure drop, flow rate, cumulative production,

The volcanogenic tuff layers are widely developed in the organic-rich shale systems of unconventional oil and gas resources. The tuffaceous shale composed of terrigenous detrital components and water-laid tuff is characterized by the complex porous structure related to tuff and organic matter (OM), which hampers the prediction of surface wettability and in-situ oil movability for the tight reservoir

Dry coal samples and coal samples with different water invasion times (DWITs) were prepared, and X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and low-pressure nitrogen adsorption (LPNA) experiments were carried out to analyze the pore fracture volume and distribution. The fractal dimension of the aperture surface was calculated with the MIP and LPNA data of these coal samples. We found

The growing research on the features of shale pore structures has deepened the understanding of shale oil and gas storage capacity. Nevertheless, few studies have focused on the differences of the specific parameters that are characteristic of the nanopore structure in shales with different lithofacies. Such parameters include the full-scale ranges of the pore specific surface area and pore volume

Breakthrough pressure is a key parameter of the caprock sealing ability for gas reservoirs. It has also become an important parameter for gas production from tight reservoirs, such as shale gas reservoirs, as water in these tight formations may require gas to overcome the breakthrough pressure before being produced. Laboratory measurement is essential to obtain the breakthrough pressure because no

To Predict the driving force of a cup pig has significant meaning in ensuring the success of its pigging operation. The pigging process of the cup pig with a specific structure under different conditions (with different friction coefficients and interferences) was simulated based on the 3D finite element method (FEM), and the equations of contact stress on cups were studied with the method of nonlinear