Exploration Prospect of Low Rank Coalbed Methane Coal in Huhehu Depression Hailar Basin

2013 ◽  
Vol 734-737 ◽  
pp. 1196-1199 ◽  
Author(s):  
Cheng Wu Xu
Keyword(s):  
Experimental Data ◽  
Coal Seam ◽  
Coalbed Methane ◽  
Mineral Content ◽  
Low Rank ◽  
Control Factors ◽  
Hailar Basin ◽  
Target Layer ◽  
Coal Seam Thickness ◽  
Favorable Area

CBM resource in Huhehu depression Hailar Basin is large. Damoguai formaiton is the most favorable exploration coalbed methane target layer for top depth of 500-1200m, big coal seam thickness, low seam mineral content and high vitrinite by drilling, seismic and experimental data. Then cover character is evaluated and distribution is predicted. By analogy other low-level the CBM reservoir control factors, the south of depression is the most favorable area of CBM exploration for bigger coal thickness and better sealing conditions.

Mineral Characteristics of Low-Rank Coal and the Effects on the Micro- and Nanoscale Pore-Fractures: A Case Study from the Zhundong Coalfield, Northwest China

2021 ◽  
Vol 21 (1) ◽  
pp. 460-471 ◽  
Author(s):  
Sandong Zhou ◽  
Dameng Liu ◽  
Yidong Cai ◽  
Yingjin Wang ◽  
Detian Yan
Keyword(s):  
Adsorption Capacity ◽  
Coalbed Methane ◽  
Mineral Content ◽  
Northwest China ◽  
Low Rank ◽  
Low Rank Coal ◽  
Mineral Characteristics ◽  
Type D ◽  
Coal Reservoir ◽  
Nuclear Magnetic

The mineral characteristics (occurrence, type, and content) of low-rank coal and their influence on coalbed methane (CBM) reservoirs are investigated at the micro- and nanoscales. Six coal samples of three representative coalmines were used to demonstrate the uniform tectonization from the Zhundong coalfield, NW China. Based on optical microscopy and scanning electron microscopyenergy dispersive spectrum (SEM-EDS) analysis, the mineral composition and occurrence characteristics were discussed. The micro- and nanoscale reservoir characteristics in low-rank coal (pore size distribution and adsorption capability) were studied by diverse methods, including lowtemperature N2 adsorption/desorption, mercury intrusion porosimetry and CH4 isotherm adsorption analysis. The coal reservoir nuclear magnetic T2 spectra of porosity and movable fluid were obtained by combining low-field nuclear magnetic resonance (NMR) analysis, which has an advantage of determining pore fluid technology. The mineral content is highly variable (4˜16 vol.%) in the Xi Heishan prospecting area of the Qitai region. Kaolinite, goyazite, ankerite and anorthosite were microscopically observed to be filling in coal pores and microfractures, and the minerals are given priority to silicate minerals. There is a greater content of mesopores (100–1000 nm) and transition pores (10–100 nm), and they are well connected. The micropores (0–10 nm) are dominated by parallel plate, closed or wedge-shaped pores. Furthermore, the microfractures are mainly observed for types B (width ≥ 5 μm and length≤ 10 mm) and D (width<5 μm and length<300 μm). The results show that microfractures B and C (width< 5 μm and length ≥ 300 μm) are better connected, but the orientation and connectivity of type D are worse. The Langmuir volume and mesopore content decreased with increasing mineral content, which shows that the low-rank coal minerals filled some adsorption space; the reduced CBM adsorption capacity and cellular pore and intergranular pore filled with minerals affect the mesopore content. Therefore, mineral characterization significantly influences methane adsorption capacity and pore structure.

Low Rank Coalbed Gas Preservation Conditions of Inversion Study

2013 ◽  
Vol 448-453 ◽  
pp. 3747-3750
Author(s):  
Feng Long Huo ◽  
Cheng Wu Xu
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Prediction Method ◽  
Low Rank ◽  
Coal Bed ◽  
Accumulation Factor ◽  
Affecting Factors ◽  
Coalbed Gas ◽  
Lithology Prediction ◽  
Preservation Conditions

The preservation conditions of coalbed gas reservoir are one of the most important affecting factors. Coal seam roof and floor of coalbed methane is the most direct emission barrier. That is the direct control of coal seam gas accumulation factor. A coal seam roof lithology prediction method at present more popular is the wave impedance inversion. But the results have multiple solutions. While the technology of stratmagic seismic can be a very good solution to the traditional seismic attributes application problems. It can provide precise results for coal seam roof lithology prediction, providing geological basis for evaluation and development of coal bed gas.

Study on Coalbed Methane well Type Optimization of Badaowan Formation in Junggar Basin

2014 ◽  
Vol 535 ◽  
pp. 622-625
Author(s):  
Cheng Long Liu ◽  
Hui Guo ◽  
Xiang Hao Wang ◽  
Jin Wang
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Evaluation System ◽  
Horizontal Well ◽  
Evaluation Method ◽  
Junggar Basin ◽  
Fuzzy Evaluation ◽  
Ahp Method ◽  
Well Drilling ◽  
Coal Seam Thickness

This paper applies AHP method and fuzzy evaluation method to establish evaluation system of CBM well type in Junggar Basin. Conclusions are drawn as follows: weight of each factor which determines well type optimization is very different, coal seam depth is 0.402, coal seam thickness is 0.295, coal permeability is 0.163, coal seam dip is 0.14. Sikeshu area and center of the basin is not suitable for CBM ground drilling. Changji to Fukang area and Muleihasakexian to Wucaiwan area and East Wuerhe area are favorable for vertical well drilling. Jimusaer area is favorable for horizontal well drilling. Other areas in Junggar Basin need vertical and horizontal well joint drilling.

scholarly journals Numerical Simulation Research on Well Pattern Optimization in High–Dip Angle Coal Seams: A Case of Baiyanghe Block

2021 ◽  
Vol 9 ◽  
Author(s):  
Hongli Wang ◽  
Xiao Zhang ◽  
Suian Zhang ◽  
Hongxing Huang ◽  
Jun Wang
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Horizontal Well ◽  
Gas Production ◽  
Low Rank ◽  
Water Migration ◽  
Coal Seams ◽  
Well Pattern ◽  
Dip Angle ◽  
Desorption Model

The Baiyanghe block in Fukang, Xinjiang, China, is rich in coalbed methane (CBM) resources, and several pilot experimental wells have yielded high production. Due to the high dip angle (35–55°) of the coal seam in this area, the lack of understanding of the geological characteristics, the physical properties of coal, and gas–water migration law lead to immature development techniques and poor overall development benefits. We first conducted desorption and adsorption tests on low-rank coal of this area and found residual gas in the coal. We established a coalbed methane desorption model suitable for this area by modifying the isotherm adsorption model. Next, by analyzing the influence of the gas–water gravity differentiation in the high–dip angle coal seam and the shallow fired coalbed methane characteristics in this area, we discovered the leakage of CBM from the shallow exposed area of the coal seam. Given the particular physical property of coal and gas–water migration characteristics in this area, we optimized the well pattern: (i) the U-shaped along-dip horizontal well group in coal seams is the main production well for gas production with a spacing distance of 312 m; (ii) a multistage fracturing well drilled in the floor of coal is for water production; and (iii) vertical wells with a spacing distance of 156 m in the shallow area is to capture CBM leakage. Using numerical simulation and net present value (NPV) economics models, we optimized the well pattern details. Applying our CBM desorption model, the numerical simulator can improve the accuracy of the low-rank coalbed methane productivity forecast. The optimization results demonstrated the following: 1) the cumulative gas production of single U-shaped well increased by 89% with the optimal well spacing, 2) the cumulative gas production of the well group increased by 87.54% after adding the floor staged horizontal well, and 3) the amount of CBM leakage decrease by 67.59%.

Evaluation of Favorable Area in the Weibei Coalbed Methane Field: a Study by Using Grey Correlation Analysis

2013 ◽  
Vol 295-298 ◽  
pp. 3342-3345 ◽  
Author(s):  
Ying Li ◽  
Da Meng Liu ◽  
Yan Bin Yao ◽  
Xiao Hong Wang ◽  
Zhao Wei Yin
Keyword(s):  
Correlation Analysis ◽  
Coal Seam ◽  
Coalbed Methane ◽  
Methane Concentration ◽  
Gas Content ◽  
Reservoir Pressure ◽  
Grey Correlation ◽  
Gas Saturation ◽  
Grey Correlation Analysis ◽  
Favorable Area

Based on the gas analysis results of coalbed methane (CBM) wells in the Weibei CBM field, two main recoverable target seams (Nos. 5 and 11) were evaluated for the potential of exploration and exploitation by using the grey correlation analysis method. The main influnce factors on the CBM potential by increasing importance are gas content, gas saturation, buried depth, methane concentration, critical desorption pressure,reservoir pressure and coal thickness for the No.5 coal seam; while they are gas saturation, gas content, critical desorption pressure, methane concentration, buried depth, reservoir pressure and coal thickness for the No.11 coal seam. The exploration potential of No.5 coal seam is better than that of No.11. The favorable area for CBM exploration are the areas including Well block W2, W3, W4 and W8 in the middle of Weibei CBM field.

The Influences of the Rank of Coal on Methane Sorption Capacity in Coals/Wpływ Rzędu Węgla Na Pojemność Sorpcyjną Metanu W Węglach

2014 ◽  
Vol 59 (2) ◽  
pp. 509-516
Author(s):  
Andrzej Olajossy
Keyword(s):  
Sorption Capacity ◽  
Coalbed Methane ◽  
Vitrinite Reflectance ◽  
Sorption Isotherms ◽  
Volatile Matter ◽  
Low Rank ◽  
Hard Coal ◽  
Petrographic Composition ◽  
Methane Sorption ◽  
Indian Coals

Abstract Methane sorption capacity is of significance in the issues of coalbed methane (CBM) and depends on various parameters, including mainly, on rank of coal and the maceral content in coals. However, in some of the World coals basins the influences of those parameters on methane sorption capacity is various and sometimes complicated. Usually the rank of coal is expressed by its vitrinite reflectance Ro. Moreover, in coals for which there is a high correlation between vitrinite reflectance and volatile matter Vdaf the rank of coal may also be represented by Vdaf. The influence of the rank of coal on methane sorption capacity for Polish coals is not well understood, hence the examination in the presented paper was undertaken. For the purpose of analysis there were chosen fourteen samples of hard coal originating from the Upper Silesian Basin and Lower Silesian Basin. The scope of the sorption capacity is: 15-42 cm3/g and the scope of vitrinite reflectance: 0,6-2,2%. Majority of those coals were of low rank, high volatile matter (HV), some were of middle rank, middle volatile matter (MV) and among them there was a small number of high rank, low volatile matter (LV) coals. The analysis was conducted on the basis of available from the literature results of research of petrographic composition and methane sorption isotherms. Some of those samples were in the form (shape) of grains and others - as cut out plates of coal. The high pressure isotherms previously obtained in the cited studies were analyzed here for the purpose of establishing their sorption capacity on the basis of Langmuire equation. As a result of this paper, it turned out that for low rank, HV coals the Langmuire volume VL slightly decreases with the increase of rank, reaching its minimum for the middle rank (MV) coal and then increases with the rise of the rank (LV). From the graphic illustrations presented with respect to this relation follows the similarity to the Indian coals and partially to the Australian coals.

scholarly journals Quantify Coal Macrolithotypes of a Whole Coal Seam: A Method Combing Multiple Geophysical Logging and Principal Component Analysis

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 213
Author(s):  
Chao Cui ◽  
Suoliang Chang ◽  
Yanbin Yao ◽  
Lutong Cao
Keyword(s):  
Principal Component Analysis ◽  
Coal Seam ◽  
Coalbed Methane ◽  
Principal Component ◽  
Component Analysis ◽  
Gas Production ◽  
Index Model ◽  
Geophysical Logging ◽  
The Relationship ◽  
Observation Results

Coal macrolithotypes control the reservoir heterogeneity, which plays a significant role in the exploration and development of coalbed methane. Traditional methods for coal macrolithotype evaluation often rely on core observation, but these techniques are non-economical and insufficient. The geophysical logging data are easily available for coalbed methane exploration; thus, it is necessary to find a relationship between core observation results and wireline logging data, and then to provide a new method to quantify coal macrolithotypes of a whole coal seam. In this study, we propose a L-Index model by combing the multiple geophysical logging data with principal component analysis, and we use the L-Index model to quantitatively evaluate the vertical and regional distributions of the macrolithotypes of No. 3 coal seam in Zhengzhuang field, southern Qinshui basin. Moreover, we also proposed a S-Index model to quantitatively evaluate the general brightness of a whole coal seam: the increase of the S-Index from 1 to 3.7, indicates decreasing brightness, i.e., from bright coal to dull coal. Finally, we discussed the relationship between S-Index and the hydro-fracturing effect. It was found that the coal seam with low S-Index values can easily form long extending fractures during hydraulic fracturing. Therefore, the lower S-Index values indicate much more favorable gas production potential in the Zhengzhuang field. This study provides a new methodology to evaluate coal macrolithotypes by using geophysical logging data.

The Capture, Utilization, Storage of CO2 in Methane Recovery

2015 ◽  
Vol 1092-1093 ◽  
pp. 1620-1624
Author(s):  
Zhi Hao Yang ◽  
Zhi Ping Li ◽  
Feng Peng Lai ◽  
Jun Jie Yi
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Deep Layer ◽  
Coal Rank ◽  
Recovery Ratio ◽  
Methane Recovery ◽  
Storage Technology ◽  
And Storage ◽  
Rational Evaluation ◽  
Important Significance

According to the problems that the coalbed methane resource was rich in deep seam in China, but the economic and technology conditions were limited, it would be hard to mine with a conventional method. The CO2 capture, utilization and storage technology was provided (CO2-ECBM). The application of the technology would not only improve the methane recovery ratio from deep and unminable layer, but also put CO2 effectively in the deep layer for storage to reach a target of reducing emission. The study showed that a coal rank, coal seam pressure, coal seam permeability, injection time, injected gas types and others would affect to the recovery ratio of methane in a production mine. Therefore, before we use this technology, a rational evaluation should be conducted on the place location. So the capture and storage technology of CO2 has an important significance in protecting the natural environment.

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