The commingled exploitation of coal measure reservoirs has become the main trend in the development of coalbed methane (CBM) in the central and southern Qinshui Basin. In fact, the porosity and permeability (P&P) of coal measure reservoirs and the evolution of their stress sensitivity are a focus of the basic theory of commingling exploitation. In this study, the coal measure reservoirs in this area

In this study, the formation mechanism of authigenic chlorite in tight reservoirs and its influence on the adsorption capacity to tight oil have been analyzed. The occurrence states of chlorite and the formation mechanism have been analyzed by thin section (TS) and field emission scanning electron microscopy (FE-SEM) measurements. Due to the alteration of volcanic rock fragments, the mudstone pressurized

Multilayer drainage is one of the important technologies for coalbed methane (CBM) production in China. In this study, a multi-field fully coupled mathematical model for CBM production was established to analyze the multilayer drainage of CBM well group in southern Qinshui basin. Based on the numerical simulation results, the characteristics of CBM well production under different drainage rates and

This work deals with the development of Combined Energy Pattern & Power Density Method (CEPPDM) to evaluate the two parameters needed to define Weibull distribution. Five years (2015–2019) wind data recorded each 60-minutes interval at eleven representative sites in Pakistan was used and efficiency of CEPPDM was compared with Energy Pattern Factor Method (EPFM) and Power Density Method (PDM) with the

Supercritical carbon dioxide is known to change the pore structure of coals and thus affect their carbon dioxide sequestration capacity. In this study, supercritical carbon dioxide dependence of pore morphology of coals was reviewed. Results indicated that the micropore surface area and volume of dry coals varied between –20% and 20% after exposure to supercritical carbon dioxide. Changes in the micropore

In this work, a series of intensive laboratory tests are conducted to measure the material constituents, mechanical properties, and to examine macro-micro-failure modes of various types of rocks from tight gas reservoirs in the Da Qing oilfield in China. A set of key parameters are experimentally determined, including porosity, mineralogical compositions, microstructure, Young’s modulus, Poisson’s

The analysis and interpretation of the Dachaidan area, Qaidam Basin, is difficult, owing to the co-location of two groups of thrust faults (N–E faults and N–W faults) there and the area’s complicated structural deformation history. To address this problem, field geological investigation, seismic study, well logging, and drilling data were used to identify the key fault systems and their distribution

This paper explores the asymmetric relationship between renewable energy consumption, non-renewable energy, and terrorism on economic growth of Pakistan. We applied a novel econometric cointegration method known as a nonlinear autoregressive distributed lag modeling (NARDL). Our empirical findings indicate that positive and negative changes have a significant long-run asymmetric relationship between

The aim of this work is to determine the thermal storage temperature of a deep thermal reservoir, which has a great significance for the effective utilization of geothermal resources. The temperature of the reservoir was estimated by the cation ratio geothermometer and SiO2 geothermometer methods. The results indicate that the K–Mg geothermometer is the best method of the cation ratio methods, with

Underground coal gasification is a burgeoning coal exploitation technique that coal is directly converted into gaseous fuel by controlled combustion. In this paper, the gasification experiments of Inner Mongolia lignite, Xinjiang subbituminous coal, and Hancheng medium volatile bitumite were conducted respectively by using the tube furnace coal gasification experiment system. The gasification process

The replacement of gas hydrate in clayey sediment by a CO2/N2 (20:80) gas mixture injection was experimentally studied to explore the influence of clay on the gas exchange behaviours in the gas hydrate. Clay (montmorillonite) and silica sand were mixed in three different proportions (clay mass ratios of 10%, 30% and 50%) to simulate the host sediments of natural gas hydrate while pure silica sand sediment

By the year 2023, the Tunisian power transmission grid has been projected to include photovoltaic pool of power of 937 MW, scattered throughout the whole landscape of the nation. This paper investigates high photovoltaic energy penetration impacts voltage regulation and dynamic performance of the grid. Load flow analysis is implemented to investigate the power system capability for the case of incorporating

Wind resource assessments are carried out for two sites in Tuvalu: Funafuti and Nukufetau. The wind speeds at 34 and 20 m above ground level were recorded for approximately 12 months and analyzed. The averages of each site are computed as the overall, daily, monthly, annual, and seasonal averages. The overall average wind speeds for Funafuti and Nukufetau at 34 m above ground level were estimated to

Accurate wake model in wind farm layout optimization can help extracting maximum power generation, minimizing cost of energy and prolonging wind turbines’ lifetime as well. With the development of different wake models, the wind farm layout optimization results based on the models should be updated. This paper investigates the performances of four wake models in wind farm layout optimization using

Scientific and industrial development has given rise to a rapidly increasing energy demand. Alternative and augmented energy resources are expected everywhere due to scarcity and depletion of other non-renewable resources. During recent years wind and solar had emerged as a promising cleaner energy source to offer a favourable solution with better efficiency. Hence, the attention has now diverted towards

Shale gas production after drill-in, completion, and hydraulic fracturing is strongly affected by formation damage. In order to determine the damage mechanisms for nonmarine shale reservoir, a series of assessments of sensitivity damage, water block damage, water-based drill-in fluids damage, and water damage to gas diffusion on 20 shale samples obtained from Chang 7 Formation were conducted and analyzed

Rule-based reservoir modeling methods integrate geological depositional process concepts to generate reservoir models that capture realistic geologic features for improved subsurface predictions and uncertainty models to support development decision making. However, the robust and direct conditioning of these models to subsurface data, such as well logs, core descriptions, and seismic inversions and

Zeolites are important diagenetic minerals in petroleum reservoirs and have complex impacts on reservoir quality. To highlight this critical and challenging issue, we conduct a case study in the Middle Permian Lower-Wuerhe Formation in the Mahu Sag, Junggar Basin, China. Formation mechanism of zeolites and their impacts on the reservoir quality. Our results show that there are five types of zeolite

Application of Weibull distribution in a generalized way to estimate wind potential cannot always be advisable. The novelty of this work is to estimate wind potential using Normal probability density function. A comparison of five probability distributions namely Normal, Gamma, Chi-Squared, Weibull, and Rayleigh was done using three performance evaluation criteria. Four years (2015–2018) hourly wind

This study examines the impact of financial development on carbon dioxide emissions in Nigeria over the period 1971–2014. Income per capita, energy consumption, exchange rate and urbanization are incorporated in the analysis. The empirical analysis based on linear and nonlinear autoregressive distributed lag techniques provides evidence of long-run relationship among the variables in Nigeria. The results

The real exchange rate is a key indicator of a country’s trade competitiveness in the world. This paper investigates the interaction between oil price and real exchange rates in Saudi Arabia during the period January 1986 -March 2019, using monthly data. This study uses the autoregressive distributed lag model and the error correction model in order to investigate the existence of a long-run equilibrium

Coal fines produced during drainage of coalbed methane reservoirs can affect the permeability of the coal reservoir and damage production facilities such as downhole pumps, shafts, and valves. Thus, to clarify the mechanism of coal fines output is very important to high production of coalbed methane. The characteristics of coal fines can be used to identify the sources of the coal fines and to develop

Coalbed methane as one type of clean energy has become an important gas resource recently. High-pressure water injection in coal seams is an effective approach for improving gas extraction efficiency, which is determined by the gas displacement characteristic and pore structure of coal. To investigate the gas displacement characteristics in coal and its pore response and influential factors, gas adsorption

This study employed the bottom-up life cycle assessment method, examining the life cycle carbon emissions of three dwellings constructed at different times with different techniques in Yinchuan City, China, i.e. traditional earth brick dwelling (Case 1), brick–straw bale dwelling (Case 2), wood–straw solar energy dwelling (Case 3). The study aimed to find the methods of reducing carbon emissions, so

The ventilator of the heating tower and the circulating pump of the anti-freeze solution are the main electrical equipment of a heating tower heat pump system, besides the compressor. By controlling the working frequencies of the ventilator of the heating tower and circulating pump of the anti-freeze solution, the effects of the operation parameters of a closed-type heating tower on its heat absorption

The development of coalbed methane not only ensures the supply of natural gas but also reduces the risks of coal mine accidents. The micropore structure of coalbed methane reservoir affects the seepage of coalbed methane; improvement of pore structure is one of the effective methods to enhance the efficiency of coalbed methane exploitation. In this study, low-pressure nitrogen gas adsorption, specific

Human beings face unprecedented Covid-19 pandemic outbreak since the beginning of 2020. This disease started to change economic, social, and individual conventional behaviors. Several economic activities have sharply declined, and demand for commodities is decreasing, such as oil. This commodity has also suffered from disagreement among Organization of Petroleum Exporting Countries (OPEC)+ members

Conventional cooling systems consume a high percentage of the world’s total electricity generation. Because absorption cooling systems can be mainly operated with thermal energy, they can be used to reduce such percentage. In the present paper, an analysis is carried out to determine the cooling potential that can be obtained from a geothermal well in a location of Mexico by using a single-stage absorption

The aim of this study was to determine the coal characteristics in the Chico-Lomã coalfield, Brazil and to evaluate the potential of natural gas associated with the coal seams (CBM), by carrying out a test well (CBM001-CL-RS) for collecting coal samples, followed by gas desorption measurements, and petrographical and chemical analyses of the coals and their methane adsorption capacities. The gas collected

In this present study, a twice-peeling model was established to analyze the hyperbolic coal pillars stability in underground coal gasification and then propose the concept of stripping degree to show model details for numerical simulation. The data shows that hyperbolic coal pillars stability can be analyzed through the twice-peeling model. Considering the coal pillars peeling and high temperature

Continuous probability distributions have long been used to model the wind data. No single distribution can be declared accurate for all locations. Therefore, a comparison of different distributions before actual wind resource assessment should be carried out. Current work focuses on the application of three probability distributions, i.e. Weibull, Rayleigh, and lognormal for wind resource estimation

Ten-year hourly recorded wind meteorological data at six sites along the coastline of Pakistan at two heights (10 and 50 m) were extrapolated to two higher heights (80 and 100 m). Monthly and seasonal analysis of variation in air density (ρ), wind speed, Weibull parameters (K and C), wind power density, and wind energy density with height was investigated. Analysis shows that wind shear coefficient

Hydraulic fracturing has been proven to be an effective technique for stimulating petroleum reservoirs. During the hydraulic fracturing process, the effects of the natural fracture, perforation orientation, stress reorientation, etc. lead to the production of a non-planar, mixed-mode I/II hydraulic fracture. In this paper, a criterion for a mixed-mode I/II hydraulic fracture crossing a natural fracture

This study proposes economic evaluation of CO2 geological storage with enhanced oil recovery. The procedures consider capital expenditures and operating costs of infrastructures and revenues from oil recovery and carbon tax credits. Extensive CO2 geological storage with enhanced oil recovery simulations was conducted to determine the most promising scenario among cases, where miscibility was controlled

CO2 flooding recovery strongly depends on the minimum miscibility pressure (MMP). Conventional tests to determine gas–oil MMP such as rising bubble apparatus and slim tube displacement are either costly or time consuming. In order to propose a quick and accurate model to determine MMP, a back-propagation neural network is presented for MMP prediction during pure and impure CO2 injections. Five new

Hydraulic fracture initiation and propagation are extremely important on deciding the production capacity and are crucial for oil and gas exploration and development. Based on a self-designed system, multi-perforation cluster-staged fracturing in thick tight sandstone reservoir was simulated in the laboratory. Moreover, the technology of staged fracturing during casing completion was achieved by using

Secondary recovery methods such as waterflooding are often applied to depleted reservoirs for enhancing oil and gas production. Given that a large number of discretized elements are required in the numerical simulations of heterogeneous reservoirs, it is not feasible to run multiple full-physics simulations. In this regard, we propose a data-driven modeling approach to efficiently predict the hydrocarbon

Reservoir rock contains many multi-scale, unevenly distributed pores, and the pore structures of shale in different reservoirs and geological environments vary greatly. Because the seepage velocity and pressure field are related to the pore spatial variations, the inhomogeneity of the seepage is superimposed on the anisotropy of the rock’s physical properties, which will affect the distribution of

The pore-throat size determines the oil and gas occurrence and storage properties of sandstones and is a vital parameter to evaluate reservoir quality. Casting thin sections, field emission scanning electron microscopy, high-pressure mercury injection and rate-controlled mercury injection are used to qualitatively and quantitatively investigate the pore-throat structure characteristics of tight sandstone

Coalbed methane wells in the Shizhuangnan Block exhibit significant productivity differences. The reasons were determined based on the impact analysis of geological factors and drainage strategies on production capacity at 82 wells. Grey relational analysis was further utilized to quantitatively analyze the correlation degree of geological parameters to production characteristics. It is found that

The pore structure is an essential factor that influences the isothermal characteristics of methane adsorption of coal, and the pore structure is altered after methane adsorption. In this study, a high-rank coal sample was investigated via methane adsorption isothermal measurement, and changes in the pore structure were studied using low-pressure N2 adsorption and low-pressure CO2 adsorption before

Central air conditioning is the main energy-consuming equipment in modern large-scale commercial buildings. Its energy consumption generally accounts for more than 60% of the electricity load of an entire building, and there is a rising trend. Focusing on reducing central air conditioning energy consumption is a first priority to achieve energy savings in modern large-scale commercial buildings. To

Lithium battery is a new energy equipment. Because of its long service life and high energy density, it is widely used in various industries. However, as the number of uses increases, the life of the energy battery gradually decreases. Aging of battery will bring security risks to energy storage system. Through the life prediction of energy lithium battery, the health status of energy battery is assessed

Current work focusses on the wind potential assessment in South Punjab. Eleven locations from South Punjab have been analyzed using two-parameter Weibull model (with Energy Pattern Factor Method to estimate Weibull parameters) and five years (2014–2018) hourly wind data measured at 50 m height and collected from Pakistan Meteorological Department. Techno-economic analysis of energy production using

The adjustment and control of the water injection rate is a commonly used method for increasing the cumulative oil production of waterflooded reservoirs. This article studies the production optimization problem under the condition of a fixed total water injection rate. The production process is divided into several segments. Considering the correlation between the segment’s time intervals and the well’s

The geochemical feature and evolutionary history of hydrocarbons from the deep Cretaceous Bashijiqike (K1bs) Formation tight sandstone reservoir in the Dabei Gas Field, Kuqa Depression were investigated using gas chromatography, gas chromatography–mass spectrometry, inclusions petrography and micro-thermometry, laser Raman spectroscopy, and quantitative grain fluorescence. The result indicates that

In order to study the distributions of the biomarker of the continental source rocks in the Sichuan Basin, 71 source rock samples were collected from the Upper Triassic-Lower Jurassic strata in different regions. The n-alkanes, isoprenoids, terpane, sterane, sesquiterpenes, caranes and aromatics in the extracts were analyzed in detail. GC-MS analysis has been conducted to analyze the biomarker of the

To achieve zero-energy building target, both China and the US have planned pathway by formulating guidelines and standards. China has published National China technical standard for nearly zero energy building (CTS-NZEB), which defines detailed principles of zero-energy building. The US LEED zero energy evaluation system has been released based on LEED rating system. Defined target and scope have been

With the continuous production of oil wells, the reservoir properties, such as permeability and porosity, are changing accordingly, and the reservoir heterogeneity is also enhanced. This development is vulnerable to the problem of the one-way advance of injected water and low efficiency of water flooding. The interwell connectivity between injection and production wells controls the flow capacity of

The stability of underground water-sealed oil storage caverns is of great importance for safe excavation and operation. To analyze the scope of the failure zone and underground cavern stability accurately, a new method was developed that integrates the rock tunneling quality index Q-system and stability graph method with 3D laser scanning and numerical simulation. The point cloud data were obtained

Coalbed methane (CBM) is a kind of high-quality and large reserves unconventional gas resource, development of which can not only reduce methane emission from coal mining and alleviate the greenhouse effect, but also effectively reduce coal mining accidents and obtain economic energy (Karacan et al., 2011). The total CBM reserve in China is estimated to be 30.05 trillion cubic meters (Tcm), and the

Of the many available sources of renewable energy, solar thermal energy is the most abundant, the efficient use of which could have a broad impact on human life (Farjana et al., 2018). While the low-temperature solar thermal technology is relatively well developed and has been commercialized (Evangelisti et al., 2019), there is an urgent demand to develop technologies for medium-temperature solar steam

Global coal consumption grew by 1.4% in 2018, which was twice the average growth rate in the previous 10 years. Consumption growth was led by India and China (BP, 2019). Furthermore, coal utilization will continue to play a leading role in energy consumption in the next decades (Qin et al., 2015). Along with the massive consumption of coal, the processes such as storage, transportation, combustion

The development of renewable energy to reduce reliance on traditional thermal, coal, or nuclear power generation methods has been the goal of governments in recent years (Johansson, 1975). China as the world’s most important country for wind power and solar power, had the world’s largest wind (169 GW) and solar (77.7 GW) capacities along with highly competitive wind and solar photovoltaic (PV) manufacturing

Currently, tight oil is a relatively realistic substitute for the conventional hydrocarbon resources in the future. However, tight reservoirs are usually characterized by small pore throats, low permeability, large seepage resistance, and low single well production, and the effective development rates of the tight oil reservoirs are low (Lin et al., 2018, 2019; Shanley and Cluff, 2015; Wang et al.

A, Augusteen

After decades of development, China has become both the largest producer and the consumer of coal in the world. As of the end of 2018, the proven reserves of China’s coal resources are 138,819 million tons, of which more than 60% are distributed in the north-west (Dudley, 2019; Jinhua et al., 2018; Wang and Zhang, 2018); however, most of these areas have extremely fragile ecosystems, especially with

The exploration and development of shale gas in China have reached breakthroughs in recent years, and the marine shale gas in southern China has gained industrial production capacity (Jiang et al., 2016a; Zhang et al., 2004; Zou et al., 2010). Marine shales in southern China have favorable conditions such as high TOC, high Ro and overpressure. In addition to marine shale gas, marine-continental transitional

The Pearl River Mouth Basin is a Cenozoic hydrocarbon-rich basin in the northern part of South China Sea (Gong and Li, 1997; You et al., 2018). In this basin, the Wenchang Depression is an important part of the Zhu III Superdepression. In total, 1 × 108 m3 of crude oil and more than 300 × 108 m3 of natural gas have been found in the depression and its surrounding areas, demonstrating that the depression

Termit Basin is a typical Mesozoic-Cenozoic extensional rift basin located in the southeast of Niger (Figure 1(a)) (Fairhead, 1986; Genik, 1992, 1993; Liu et al., 2012a, 2012b). It is the second largest hydrocarbon prolific basin following the Muglad Basin in the West and Central African Rift System (WCARS) (Genik, 1992, 1993; Liu et al., 2012a, 2017; Wan et al., 2014; Xiao et al., 2019; Xue et al