In a horizontal well drilling operation, a part of generated drill cuttings tends to settle down at a lower annular section. Formation of sand bed causes several operational issues such as low rate of penetration and stuck drill pipe. In this study, a lab-scale experimental work is carried out to investigate hole cleaning in the extended reach and horizontal drilling operation. This work focuses on

This review presents comprehensive waterless fracturing technologies and the latest advances in the field; summarizes and analyzes their technical principle, construction technology, performance characteristics, advantages and disadvantages, and field applications; and clarifies future research directions. The innovation of this paper is the proposal of a potential waterless fracturing technology.

In this article, we report the results of a 4-dimensional (3 spatial dimensions plus time) in-situ creep experiment on a milli-core shale plug from Barnett formation in Texas. An outstanding challenge in shale mechanics is connecting observable characteristics to predictable mechanical and hydraulic behavior. We employ novel imaging and analysis techniques to statistically link sample mineralogy and

Effective particle placement in complex fractures plays a crucial role in unconventional reservoirs. Non-planar fracture geometry poses a challenge to assess particle placement. Compared to the straight slot, particle-fluid flow in a curved fracture has not been fully understood. In this paper, particle-fluid flow in curved fractures is studied experimentally by laboratory size slots. The experimental

Fluid-driven granular transport is involved in many important geomorphological processes and industrial applications such as unconventional hydrocarbon recovery. Yet it remains challenging to fully understand the granular transport mechanisms in confined geometries. By performing simulations based on a coupled computational fluid dynamics and discrete element method (CFD-DEM) approach, we systematically

Production or injection of fluids from/in an underground storage site causes variations of pore pressure and stress states. These fluctuations significantly affect implications for hydraulic fracturing, wellbore integrity, top surface subsidence and heave, fault-reactivation, and stability of reservoir and caprock. Therefore, in order to keep optimal conditions during the process of gas injection and

The presence of fine particles has a significant impact on the mechanical behavior of hydrate-bearing sediments. In this study, a series of isotropic compression and triaxial tests were conducted using a customized testing system for hydrate-bearing sediment. Carbon dioxide hydrate was formed in the host sediments, which were mixtures of sands with silty-sized quartzitic or illite fine particles. The

As a clean gaseous fuel, methane (the main constituent of natural gas) has been widely used in the lives of residents and industrial processes. The oxy-fuel combustion technology for methane/carbon dioxide is an effective way to reduce the pollutant emissions of NOx, which is also beneficial to the capture of carbon dioxide. Herein, the stretch extinction characteristics of non-premixed flames induced

The paper examines the behaviour of buried continuous pipelines crossing strike-slip faults using experimental and numerical modelling. A newly developed experiment setup is presented along with the derivation of relevant scaling laws and non-dimensional terms governing global response of continuous pipelines to strike-slip faulting. Four model tests are carried out to understand the performance of

Mathematical models for characterizing hydrocarbon-water transport under flowback conditions have been intensively developed in past years. However, there have been few studies on salt transport. In this study, a mathematical model modelling the flowback behavior of salt in a multi-porous medium consisting of hydraulic fractures (HF), induced natural fractures (IF) and shale matrix (MP) under multi-phase

Strength and leak tests of newly constructed or modified pipeline sections or piping assemblies are required by code. This is often conducted by pressurizing incompressible medium, such as water, water-methanol or water-propylene glycol (PG) mixtures while the system is sealed. Major challenges are invariably encountered with leak tests, which rely on correlating changes in the test pressure to the

Geologic sequestration of carbon dioxide (CO2) captured from flue gas into deep unmineable coal seams is a promising option to mitigate greenhouse gas emissions. Also, the injection costs can be partially or entirely offset by the revenue generated through the additional methane recovered. Complex phenomena occur during primary coalbed methane (CBM) recovery and CO2 injection for enhanced methane production

Based on the requirements of low hydration heat and temperature rise of cement slurry used in deep-water gas hydrate formation, the thermal control effects of slag and fly ash on heat development of cement slurry were quantitatively and qualitatively investigated. The results show that the temperature rise, hydration heat and heat release rate of cement slurry were successfully reduced by slag and

The current study proposed an improved approach for application of Geomechanical Units (GMUs) classification in reducing the uncertainty of wellbore stability models. For this purpose, the optimal drilling direction and safe mud window were modeled in the Iranian Offshore oilfield, Persian Gulf basin. Two main normal faults created a graben with three geomechanical sectors in the study area including

There remains a good level of uncertainty in peak gas rate and the time to reach the peak for coalbed methane (CBM) wells owing to reservoir heterogeneity. The novelty of the present study lies in predicting the production behavior of wells in the emerging CBM block of Raniganj through extensive reservoir characterization coupled with reservoir simulation and validation. Ten regional (R-I to R-X) and

Liquid loading is a phenomenon in which liquid accumulates in the wellbore of mature gas wells, causing a significant reduction in production and sometimes permanent well abandonment. This paper introduces a new model for predicting liquid loading onset, based on the reversal of a non-uniform liquid film. The momentum balance equation for annular flow is, in the proposed model, expressed as a function

The deep coal-measure gas, including coalbed methane (CBM), tight gas (TG) and shale gas (SG), has attracted widely attention because of its great potential for natural gas development and multiple benefits. To determine the gas origin, migration and evolution in the west of Linxing block, 56 coal-measure gas samples from different horizons and depth were collected. The gas components and stable isotope

Difficulties encountered in describing fracture flow using classical fluid flow equations has led to extensive studies of the roughness effect on fracture flow over the past 70 years. Despite the significant progress made thus far, understanding the impact of roughness on fracture flow remains a complex challenge, as suggested by the discrepancies found among theoretical, numerical, and experimental

Preventing the secondary formation of natural gas hydrates is one of the key factors for the success of offshore natural gas hydrates production test. In this paper, according to the operational process of preventing the secondary formation of natural gas hydrates, the GO method model of the offshore natural gas hydrates depressurization production test process was established by using the DBN and

The distribution of pore-fracture structure in coal directly affects the storage and migration characteristics of fluids. Simultaneously, under the condition of high buried depth, the coal structure is further changed by the temperature-pressure coupling. To study the pore size distribution of coal and the deformation characteristics of different pore-fracture structures under temperature-pressure

Natural gas hydrate has become a hotspot for researchers because of its considerable economic benefits and potential strategic significance. In the hydrate exploitation process, the hydrate-bearing sediments get damaged, and the coupling effect of multi-physical fields is involved. In this study, a damage constitutive model of hydrate-bearing sediments is established by considering decomposition damage

Machine learning algorithms are extensively used to reduce the complexity of applied problems in various fields, including energy. Accurate prediction of the performance of water alternating gas (WAG) as an enhanced oil recovery (EOR) process is of great importance in the optimal management of the hydrocarbon resources. In the current work, a hybrid mathematical model is proposed for the near-immiscible

The prediction of rock permeability is important in the extraction of oil/gas from tight reservoirs. Permeability is determined by connected pores and their distribution in rocks. The existence of pore can induce stress concentration around pore surface which affects pore strains. In common permeability models, volumetric pore strains are used to quantify the permeability evolution during gas production

Polymeric membranes, especially polyimide membranes, are widely preferred in gas separation processes due to their superior properties such as inherently high permeability, selectivity, and easy processing. Zeolitic imidazolate frames (ZIFs) are crystalline porous materials exhibiting some unique properties, such as tunable pore sizes, thermal and chemical stability. In this study, a series of polyimide/ZIF-95

Coal structure is highly related to paleo-stress variation and the pore structure of coals can be modified through tectonic activities. This study characterizes the pore structure variations for various coal samples with different tectonic deformation intensities. The low temperature N2 and pressure CO2 adsorption analyses were conducted to quantify the pore structures, and high pressure CH4 adsorption

One of the principal factors in Shale instability is the stress variation due to water invasion into Shale in water-based drilling fluids, consequently causes in wellbore instability. This comprehensive study aims to improve the rheological properties and plug the nanometers Shale pore throat with biogenic silica oxide Nanoparticles. To do this, a new procedure of waste product from an agricultural

Using nitrogen as the blanket for the construction of a gas storage salt cavern by the solution mining under gas (SMUG) method has many advantages, such as improved safety, enhanced environmental protection and better economy. A critical issue for its field application is how to accurately predict and optimize the cavern leaching parameters when using SMUG. We propose a mathematical model for predicting

In order to reveal the influence of gas pressure on the gas adsorption law of middle-rank coals, four groups of typical middle-rank coals in China were used as the research objects, using saturated, centrifugal, drying equipment and Low-field Nuclear Magnetic Resonance (LNMR) system to carry out coal samples. The pore structure characterization test and the isotherm adsorption test under different

Rock fractures are crucial conduits for fluid flow in fractured rock masses. Three-dimensional (3D) discrete fracture network (DFN) modeling approach, which can explicitly characterize the fracture and its network arrangement, has been increasingly utilized in various engineering applications. This paper presents a review of the development and application of 3D DFNs for modeling naturally fractured

A large portion of slickwater is trapped in gas shale formations after the hydraulic fracking process. To address the effect of slickwater retention on methane desorption, the adsorption and desorption isotherms for methane before and after slickwater treatment were measured based on the volumetric method using shale samples from the Longmaxi formation, China. We found the adsorption and desorption

Sweetening of natural gas is a necessary process step to meet transportation and commercial standards. Amine-based solvents have been conventionally used for absorption-based removal of contaminants, like acid gas from natural gas. The process has inherent high energy penalty issues during solvent recovery and large fugitive emissions due to the solvent's low vapor pressure. Contrarily, ionic liquids

Fusain samples from lignite and high-volatile bituminous coal were obtained by stripping. The morphological characteristics of the fusain samples and raw coal samples were observed under an optical microscope and scanning electron microscope. The pore structure characteristics of the samples were quantitatively characterized through high-pressure mercury injection and low-temperature liquid N2 adsorption

Previous natural gas explorations in Ordos Basin were conducted in areas with thick coal deposited. Recently, natural gas flow were discovered in southern basin where very thin coal seams were developed, implying the contribution from other source rocks, e.g. the coal measure mudstones. In order to thoroughly assess the quality and gas potential of coal measure mudstones, 58 mudstones from borehole

Protective seam mining is one of the most commonly used technique to realize stress relief and permeability enhancement of reservoirs, so as to improve gas drainage efficiency. However, for coal reservoir with a hard roof, such as the tight sandstone, magmatic rocks, the distribution and evolution of destressed zone and gas field have not been fully understood, which leads to an inefficient gas control

This paper investigates the influence of failure of transmission network key elements on security of natural gas delivery. The proposed framework combines the probabilistic structure integrity study and the hydraulic analysis. A factor called a volumetric loss was introduced to quantify the effect of network failure. Based on the magnetic flux leakage diagnostics, the rupture probability of steel tube

Polymeric membranes performance in gas separation can be improved by using zeolites as the filler in the polymer matrix to form mixed matrix membranes (MMMs). Pure-silica Si-CHA zeolite and Pebax-1657 copolymer are individually capable of separating acid gases from natural gas. However, the corresponding MMM has not been investigated in the literature. Therefore, in this work, Si-CHA zeolite was incorporated

Natural gas consumption forecasting technology has been researched for 70 years. This paper reviews the history of natural gas consumption forecasting, and discusses the changes in forecasting horizons, influencing factors, and forecasting performance. According to the characteristics of forecasting models used in different periods, the history of natural gas consumption forecasting can be categorized

The current study presents a novel and high-sensitivity in-line inspection (ILI) method for gas pipelines. The proposed method is based on integrated ILI methods, optical sensor and bimorph sensor. The uniqueness of the proposed method lies in; (1) combining two advanced methods for more accurate and sensitive outcome, (2) real-time inspection of target pipeline, (3) specifically designed sensor array

This study integrates results from petrographic investigations, spot permeability measurements, computed tomography (CT) scans, and core water flooding experiments to investigate the potential correlation between the spot permeability and the bulk permeability of burrow-related reservoirs. These results are obtained from samples collected from Thalassinoides-bearing strata of the upper Jurassic Hanifa

Natural gas hydrate (NGH) has been regarded as a fossil fuel reserve for the future on account of its tremendous potential. The numerical modeling on NGH formation/dissociation mechanism contributes to better understanding its accumulation and distribution feature, and optimizing the development program. This paper aims to develop a new simulator for the NGH formation in the core-scale sandy sediments

Acoustic emission (AE) and electromagnetic radiation (EMR) monitoring technology have been widely used in coal and rock dynamic disaster monitoring. However, the prediction of coal and gas outburst using original signal directly may cause the false and missing alarms due to the failure to identify valuable potential information, which may lead to the decrease of prediction accuracy. This paper presents

A series of core flooding tests were conducted using a specially-designed matrix–fracture model to assess the performance of CO2 huff and puff (‘huff-n-puff’) injection with respect to the enhanced oil recovery (EOR) of tight oil. Four key influencing factors were taken into consideration: number of huff-n-puff cycles, matrix permeability, matrix size, and gas type. The results imply that CO2 huff-n-puff

Non-ideal gas flow behaviors are investigated by an Enskog-Vlasov type kinetic model considering the simultaneous effects of gas molecule size (volume exclusion) and long-range intermolecular attractions at the molecular level, which corresponds to the real gas equation of state at the macroscopic level. The Knudsen minimum is captured and a local Knudsen maximum may appear if gas molecule sizes or