Energies | Free Full-Text | History, Geology, In Situ …
Coal seam gas (CSG), also known as coalbed methane (CBM), is an important source of gas supply to the liquefied natural gas (LNG) exporting facilities in eastern Australia and to the Australian …
A novel conceptual model of fracture evolution patterns in …
According to the theory of the trapezoidal broken model established by Xu et al. [15] and the V-shaped conceptual model of fracture evolution patterns in the overlying strata during horizontal ...
(PDF) Fracture Pattern of Overlying Strata in Multiple Coal …
Results of vertical measurement line No. 8 from the GR geological radar test with upper coal seam advancing. a No excavation. b 60-m face advance of the upper coal seam. c 120-m face advance of ...
geometry (using structure contours and structure | Chegg
Sociology questions and answers. geometry (using structure contours and structure section) 4. The attached figure shows the outcrop pattern of a fault plane (F) displacing a coal seam. Slickenlines on the fault indicate pure dip slip motion. - A) Construct a cross-section along line X-Y without vertical exaggeration (to do this successfully ...
FUNDAMENTALS OF COAL MINE ROOF …
horizontal stress than in entries driven parallel with it. During the past 15 years, horizontal stress has become central to an understanding of coal mine ground control. An …
Influences of Coal Seam Heterogeneity on Hydraulic …
Jiacheng Wang. 515 Accesses. 4 Citations. Explore all metrics. Article Highlights. The three-dimensional patterns of hydraulic fractures are presented with in situ underground …
Horizontal Coalbed Methane Wells Drilled from Surface
Surface drilled horizontal coalbed methane (CBM) wells have become the predominant method for degasification in advance of mining, and gas recovery in areas …
Crack propagation patterns and energy evolution rules of coal …
Lateral pressure coefficient is an important parameter in geological engineering, and it influences significantly the damage zone around boreholes. In accordance with the fundamental principles of the Particle Flow Code (PFC), various models were established to investigate the crack propagation patterns and energy evolution rules of coal in …
Numerical analysis of the influence of in-seam horizontal …
Among all horizontal borehole patterns simulated, pattern B (tri-lateral pattern), with the longest total borehole length, provided the maximum reduction of gas-in-place within the longwall panel. Its total methane productions were 1.7 × 10 6 m 3 and 4.0 × 10 6 m 3 of methane after 3 and 12 months of methane drainage, respectively.
Characterizing Coal Pillar Deformation and Air Leakage Pattern …
For dealing with the deformation of coal pillars, the horizontal strain (({varepsilon }_{x ... Study on the air leakage pattern of coal body in roadway. J Xi'an Jiaotong Univ 03:239–243. Google Scholar Zongxiang Li, Sun Guangyi Sun, Jibo Wang (2001) Numerical simulation of air leakage and oxygen consumption process in coal …
Geometry and Filling Features of Hydraulic Fractures in
All of the observed CBM wells exposed in the coal mine are vertical. According to the fracturing report handled by Shanxi Jincheng Anthracite Mining Group Co., LTD., water-carrying proppant is the main fracturing fluid type, and the volume of injected fluid varies from approximately 400 to 650 m 3.The volume of injected proppant changes …
Drilling Pattern, Blasting Design Types used In U/G mines …
Fan cut Drilling pattern. Burn cut. Coromant cut. Ring cut Drilling pattern. 1. Pyramid cut or Cone cut. इस पोस्ट में देखेंगे drilling pattern in underground coal mines और all 7 types of blasting design patterns जैसे wedge cut drilling pattern, pyramid cut drilling pattern, burn cut drilling pattern ...
Multi-branched horizontal wells for coalbed …
Horizontal wells, such as multi-lateral and multi-branched horizontal wells (MBHWs) have been effectively used in the development of coalbed methane (CBM) …
Coal Composition
Coal consists of a variety of substances with different chemical structures. The coal composition depends on the plant-based origin of the raw material and the coalification …
An integrated well-pattern optimization strategy to
For vertical well, the regular well pattern is usually adopted in conventional reservoir with relatively homogeneous formation, and the basic well pattern unit is a rectangle (square) or equilateral triangle. ... and fracturing operations on an assembly line. In addition, the coal/water/oil resources overlay requires a larger number of extended ...
Multi-branched horizontal wells for coalbed methane …
If coal bed thicknesses are the same and L = r, then a horizontal wellbore will be in contact with 64% more rock volume.If L = 2r, then it will be in contact with 128% more volume. π is a mathematical constant and refers to the ratio of a circle's circumference to its diameter, equal to 3.14159.. Multi-branched horizontal coal bed wells (MBHW) …
Productivity characteristics and controlling factors of …
The No. 3 coal seam, predominantly extracted from a coal block within the Qinshui Basin, boasts high gas content and vast geological resources, rendering it an area of great potential for CBM development (Chen et al., 2020; Yang et al., 2023).However, the study area is characterized by intricate fault structures, substantial variations in coal …
Fracture Development Patterns and Micro–Macrostructural …
The floor elevation of the coal seam varied between 931.6 and 944.0 m. It extends in the 65° direction, dips at 255°, and has an inclination of 1–3°, classifying it as a nearly horizontal coal seam. The main roof predominantly consists of sandy mudstone and medium-grained sandstone, with thicknesses ranging from 9.15 to 24.85 m.
Fracture Pattern of Overlying Strata in Multiple Coal …
tribution pattern and continued to expand forward in the horizontal direction, which formed a"wave"-type periodic motion. Then, a new"three-in-one" gas control mode was proposed with the evolution anddistribution law of mining fractures. Zhou et al. [45, 46] obtained the deformation law of the coal seam by combining physical simulation and
Drilling and completion technologies of coalbed methane
The aerated UBD pattern of CBM horizontal well is shown in Fig. 24, after the gas is injected into the cave through the tubing in vertical well, it is mixed with the drilling fluid to form a gas–liquid two-phase flow, which is then circulated in annulus and finally returned to surface from the horizontal well, thereby reducing the pressure of ...
Study on Effects of Thermal Resistance and Thermal …
As the degree of technology has rapidly increased throughout the 21st century, modern UCG technology (based on horizontal wells of coal seams) and mobile gas injection equipment has become increasingly mature. 10,11 By having a retractable injection of oxygen, cavities can be continuously formed in the coal seam, thus allowing …
Abutment pressure distribution pattern and size optimization of coal
The Longde Coal Mine of Huadian Corporation mainly mines a 2 −2 coal seam, which is a near-horizontal coal seam with an average thickness of 3.5 m, an average depth of 200 m, and an inclination of 1~2°. The coal seam has a simple structure and contains parting bands in local areas. It is a stable recoverable coal seam.
Flow patterns of pulverized coal pneumatic conveying and …
Pneumatic conveying experiments of pulverized coal were carried out in three experimental systems which were vertical conveying of 20 mm pipe diameter, horizontal conveying of 20 mm and 50 mm pipe diameter. The ECT was employed to research flow patterns in vertical and horizontal pipes and the empirical formulas were …
Characteristics of Mining-Induced Fractures Under Inclined Coal …
The accurate identification of gas migration channels and enrichment regions is essential for the utilization of gas resources and safe coal mine production, which are closely related to the evolution of mining-induced fractures. Therefore, we conducted a similarity simulation study of inclined coal seam group multiple mining, adopting the 1930 …
horizontal coal pattern
RU2293833C1 - Method for making horizontal draining system ... FIELD: technology for extraction of mineral resources from underground formations, in particular, method and system for providing access to underground formations from earth surface, and method for producing gas from coal bed, which substantially reduce or abolish disadvantages and …
(PDF) Simulation Study of the Roof Fracture Pattern of a Horizontal
Application of a horizontal section top-coal caving in a steeply inclined thick coal seam not only effectively resolves the problem of the large dip angle of the coal seam and slipping and dumping of mining equipment but also significantly reduces
Flow patterns classification of dense-phase pneumatic …
For dense-phase pneumatic conveying of pulverized coal, the superficial gas velocity has a linear relationship with vertical pressure drop and transport capacity. Fig. 6 shows the relationship between superficial gas velocity and particle. Conclusions. In this paper, the flow patterns of dense-phase pneumatic conveying of pulverized coal …
Characteristics and formation mechanism of plug flow in the …
The pulverized coal was discharged from the feeding tank (7) and conveyed by the dry air to pass through the vertical pipe that has an installed pressure sensor (9), ECT (10), solid mass flowmeter (11) (Thermo Ramsey 2109) and differential pressure sensor (12) for which the measuring point distance is 4.2 m. The high precision diaphragm …
Research on reasonable layout parameters of working faces …
The subsidence pattern of the coal seam within a range of approximately 146 m above the remaining coal pillar is convex and in a non-sufficient subsidence state, which is close to the ...
Numerical Simulation Research on Well Pattern …
dip coal seams, meaning currently unable to learn particular reservoir characteristics. There have been some studies on the optimization of well patterns for high–dip angle coal seams. Mu et al ...