Research on the Controlling Factors and Grate Prediction of the Output of Pulverized Coal in Hancheng Block, Eastern Ordos Gas Field

2013 ◽  
Vol 734-737 ◽  
pp. 1460-1463 ◽  
Author(s):  
Xian Yue Xiong ◽  
Dai Yong Cao ◽  
Ming Xun Jie ◽  
Yong Bai ◽  
Xue Shen Zhu ◽  
...  
Keyword(s):  
Coal Seam ◽  
Mechanical Strength ◽  
Coalbed Methane ◽  
Controlling Factors ◽  
Pulverized Coal ◽  
Comprehensive Treatment ◽  
Root Mean Square Amplitude ◽  
Gas Field ◽  
Coalbed Methane Production ◽  
Coal Petrography

According to the 2012s workover treatment statistic in the Hancheng block, the eastern Ordos gas field, the workover caused by pulverized coal accounts for 41.8% of the total, which has seriously affected the continuous and stable drainage. This is one of the main factors which constraint coalbed methane production yield. In this paper, geological factors including the composition of coal petrography, the mechanical strength of coal petrography and coalbody structure destruction and engineering factors including drilling, fracturing and drainage were analyzed to study on the controlling factors on the output of pulverized coal. We conclude that the determinant on output of pulverized coal is the nature of coal seam, however engineering factors cause the output of pulverized coal directly. The root-mean-square amplitude attribute analysis was first used to display the mechanical strength of coal seam. Based on the result, we made the prediction about the possibility of the output of pulverized coal and divided the studying area into four grades. The research on the controlling factors and the prediction of the output of pulverized coal could provide the basis for the prevention and comprehensive treatment of pulverized coal.

Influence of Coal-Seam Water on Coalbed Methane Production: A Review

2015 ◽  
Vol 51 (2) ◽  
pp. 207-221 ◽  
Author(s):  
Jinxuan Han ◽  
Zhaozhong Yang ◽  
Xiaogang Li ◽  
Jian Zhang
Keyword(s):  
Coal Seam ◽  
Methane Production ◽  
Coalbed Methane ◽  
Coalbed Methane Production

CoalBed Methane Pad Wells Completion and Artificial Lift Optimizations: Case Study From Australia Surat Basin DS Gas Field

2021 ◽  
Author(s):  
Li Ming ◽  
Xia Zhaohui ◽  
Liu Lingli ◽  
Cui Zehong ◽  
Duan LiJiang ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Optimization Methods ◽  
Gas Production ◽  
Production Performance ◽  
Vertical Wells ◽  
Coal Seams ◽  
Gas Field ◽  
Well Completion ◽  
Artificial Lift ◽  
Coalbed Methane Production

Abstract The Coalbed Methane in Australia Surat Basin is main gas source for LNG project in east coast of Australia[1]. Traditionally, Coalbed Methane are drilled by vertical wells. But there are big intensively farmed land coverage in the Surat Basin, the multiple wells on single, larger pad from the surface, the bores slant away at around 70 degrees to intersect multiple, thin coal seams are applied to avoid the extra "footprint" and decrease the environment affect. Many pad wells production failure because of poor interburden isolation. Excessive solids production in pad wells resulted in new failures of holes in tubing due to accelerated erosion, which bring big challenges for the Coalbed methane production in deviated pad wells. The gas production in pad wells are analysised and the new pad wells optimization are proposed. First, the complete wire log (at least include GR and density log curves) need to acquire for correct thin coal seams correlation and locate the interburden sandstone position for future good sandstone isolation. Second the customized completion strategy and placement (swell packer) are applied in the pad wells and specialized tubing with enhanced erosion resistance to extend the run life. Thirdly ESP pumps and optimized tubing are installed in new deviated wells for good gas production. After the pad wells were put into production, the gas production was kept well for long time without pump problems. Swell able packer completion significantly eliminates sand problem by isolating in excess of or close to 80% of interburden sand. The above well completion and artificial lift optimization methods bring good production performance for the new pad wells and contribute much production for the producing gas field. The swellable packer completion also can be used in vertical wells and will be standard well completion methods for future gas development wells.

Study on Influencing Factors of Coal Fines Produced by CBM Wells in Hancheng Block, Shaanxi Province, China

2013 ◽  
Vol 295-298 ◽  
pp. 3228-3231
Author(s):  
Xue Shen Zhu ◽  
Dai Yong Cao ◽  
Ying Chun Wei ◽  
Yuan Yuan ◽  
Zheng Yao ◽  
...  
Keyword(s):  
Coal Seam ◽  
Influencing Factors ◽  
Coalbed Methane ◽  
Control Measures ◽  
Shaanxi Province ◽  
Output Factors ◽  
Seepage Channel ◽  
Coal Petrography ◽  
Coal Fines ◽  
Precipitating Factor

To ensure the continuous and stable exhaust process of coalbed methane wells, prevent coal fines from lowering the guidance ability of seepage channel, and solve the problem of stuck pump and submerged pump caused by gathering of coal fines, taking Hancheng block as the experimental area, this paper analyses on the source of the coal fines, and divides it into two categories of original coal fines and secondary coal fines. Based on the characteristics of coal petrography, coal structure, coal seam and engineering factors, we make analysis of their factor on the output of coal fines, and we conclude that the characteristics of coal petrography are the foundation, and the engineering is the precipitating factor, but the development of deformed coal is the primary factor. The study on the division of types of coal fines and output factors can provide a guidance for reasonable coal-fines-control measures.

Analysis of Distribution of Coalbed Methane and Geological Controlling Factors in Huanghebei Mining Area

2013 ◽  
Vol 448-453 ◽  
pp. 3757-3761
Author(s):  
Yan Ru Meng ◽  
Zeng Xue Li ◽  
Hai Yan Liu ◽  
Nan Jiang ◽  
Juan Liu
Keyword(s):  
Coal Seam ◽  
Coalbed Methane ◽  
Mining Area ◽  
Controlling Factors ◽  
Methane Content ◽  
Burial Depth ◽  
Distribution Characteristics ◽  
Deep Well ◽  
Hydrogeological Conditions ◽  
Geological Factors

Distribution characteristics of coalbed methane in Huanghebei mining area were studied and influence of geological factors such as faults, lithology of coal seam roof and floor, magmatic activities, burial depth and upper bedrock thickness of coal seam and hydrogeological conditions on occurrence of coalbed methane were deeply discussed in this paper. Coalbed methane content of mining area increased gradually from southeast to northwest. Coalbed methane in deep well points of mining area is dominated by methane and that in shallow parts contained higher content of nitrogen.

scholarly journals Dual diagnostic method for fracture morphology of thermal coalbed methane reservoir

2019 ◽  
Vol 23 (5 Part A) ◽  
pp. 2741-2748
Author(s):  
Xiao Pu ◽  
Dali Guo ◽  
Yunxiang Zhao
Keyword(s):  
Coal Seam ◽  
Dual Diagnosis ◽  
Coalbed Methane ◽  
Fracture Morphology ◽  
Calculation Model ◽  
Critical Depth ◽  
Well Production ◽  
Single Well ◽  
Coalbed Methane Reservoir ◽  
Coalbed Methane Production

In most thermal coalbed methane production practices, the average single well production is low and the economic benefit is low. In order to improve the production of thermal coalbed methane, this paper presents a dual diagnosis method for fracture morphology of thermal coalbed methane reservoir to improve hydraulic fracturing effect. The study is carried out as follows: firstly, improved log-log curve method to adapt to coal seam fracturing construction, secondly, establish the inclined stress calculation model of coal seam to obtain the critical depth value, and finally, combine the improved log-log method and critical depth method to form a dual diagnosis approach. Take Baiyang River in Xinjiang as an example, obtain the traffic, rock mechanics and other parameters suitable for the Baiyang River block, the fracture morphology is verified by fracturing data. The experimental results show that the approach can diagnose fracture morphology accurately. <br><br><font color="red"><b> This article has been retracted. Link to the retraction <u><a href="http://dx.doi.org/10.2298/TSCI191209454E">10.2298/TSCI191209454E</a><u></b></font>

scholarly journals Production analysis for fractured vertical well in rectangular coal reservoirs

2018 ◽  
Vol 73 ◽  
pp. 62
Author(s):  
Chen Li ◽  
Zhenzhen Dong ◽  
Xiang Li
Keyword(s):  
Coal Seam ◽  
Analytical Solutions ◽  
Methane Production ◽  
Coalbed Methane ◽  
Finite Conductivity ◽  
Storage Coefficient ◽  
Vertical Well ◽  
Production Analysis ◽  
Coalbed Methane Production ◽  
And Diffusion

As one kind of unconventional natural gas, coalbed methane is an important energy resource that is subject to active research. Gas exists in coalbed methane reservoirs in two forms: free gas and adsorbed gas. In the course of coalbed methane production, the reservoir experiences pressure decrease, desorption, diffusion, and seepage. Previous models of coalbed methane production were mainly concerned with circular boundaries. However, field tests revealed that some fractured wells possess the characteristics of rectangular boundaries. For fractured rectangular coalbed methane reservoirs, it is necessary to deal with the four boundaries with mirror image theory, which complicates calculations. In addition, the desorption and adsorption process of coalbed methane exerts a strong effect on the seepage process. Furthermore, the complexity of the rectangular coal seam embedded with the finite-conductivity fracture results in a significant computational challenge. For the first time, this paper presented a fast analytical solution for a finite-conductivity fractured vertical well model with either rectangular closed or constant-pressure boundaries in the coal seam. On the basis of the Fick diffusion law and the Darcy seepage law, a mathematical model that considers diffusion in matrix and seepage within natural fractures was established. Then, we integrated the fracture conductivity function method with the hydraulic fracture model to greatly increase computational efficiency. The analytical solutions were validated against a numerical simulation. Parameter sensitivity analysis reveals that interporosity coefficient and storage coefficient, respectively, affect the appearance time and degree of desorption and diffusion. Desorption coefficient mainly describes the capacity of desorption and diffusion. Well storage coefficient, conductivity factor, and skin factor mainly affect the early stage of production. Finally, the proposed solutions were applied to field history match. The model developed is applicable to production analysis and well testing for coalbed methane reservoirs. The new proposed model extended flow mechanism of coalbed methane, and provided a better production and pressure forecast for coalbed methane reservoirs. In addition, the analytical solutions can be used to generate type curves for fractured vertical wells with finite conductivity and in the rectangular boundary, and provide a sound theoretical basis for well tests in the coal seam. The model is also applicable to other types of unconventional gas reservoirs, such as gas shales, in which the same processes are present.

scholarly journals Assessing the impact made by the geological features of a coalfield on producing well’s operation

2020 ◽  
Vol 7 (7) ◽  
pp. 41-48
Author(s):  
Galina I. Matniiazova ◽  
◽  
Mariia P. Khaidina ◽  
Keyword(s):  
Coal Seam ◽  
Hydraulic Fracturing ◽  
Coal Mining ◽  
Methane Production ◽  
Coalbed Methane ◽  
Gas Production ◽  
Surrounding Rock ◽  
Gas Migration ◽  
Coalbed Methane Production ◽  
The Impact

Introduction. Coalbed methane extraction increases the economic efficiency of coal mining being a main measure mitigating coal mining risks. Research aim was to assess the impact made by host rocks with different reservoir properties on coalbed methane production dynamics before and after hydraulic fracturing. Methodology. A coal seam model has been constructed using software systems; the coal seam has been represented as an integrated deposit of two minerals, coal and gas. Gas production scenarios with and without impact on the seam have been calculated as well. A model of a coal bed with a hydraulic fracture was constructed in application program package Petrel (Shlumberger). Results. The calculation results showed the development of gas migration from the coal matrix to the surrounding rock through the fracture system during gas production. The use of hydraulic fracturing has positive impact on the dynamics of gas production from coal seams. Hydraulic fracturing revealed the growth of desorbed gas migration into the host interlayers. Analysis of coal methane migration to the surrounding rock has shown that the host rock can be considered as a transportation route for coalbed methane production.

scholarly journals Prediction of high-quality coalbed methane reservoirs based on the fuzzy gray model: An investigation into coal seam No. 8 in Gujiao, Xishan, North China

2020 ◽  
Vol 38 (4) ◽  
pp. 1054-1081
Author(s):  
Huang Bo ◽  
Qin Yong ◽  
Wanhong Zhang ◽  
Qiming Zheng ◽  
Songlin Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coal Seam ◽  
Coalbed Methane ◽  
Low Permeability ◽  
Gray Model ◽  
High Quality ◽  
The North ◽  
Reservoir Permeability ◽  
Geological Factors ◽  
Coalbed Methane Production

Coalbed methane (CBM) resources are abundant in the Gujiao block, Xishan coalfield, China. However, few studies have been conducted on the coalbed methane geology of the Gujiao block. In the present study, based on logging responses and numerical simulations, the coal structures of coal seam No. 8 of this block were identified, and the mechanical properties of the coal and its roof/floor were calculated. The geological factors influencing the coalbed methane reservoir were quantitatively characterized according to the fuzzy gray model. High-quality coalbed methane reservoirs in the No. 8 coal were predicted and classified using the model, and some suggestions on rational exploitation were determined. Reservoirs of the No. 8 coal are dominated by the III-type, followed by the II- and IV-types. The III-type reservoirs are the most common, and primarily developed at the Xiqu, Zhenchengdi, Malan, and Tunlan coal mines in the north of the studied area. The III-type reservoirs represent low coalbed methane contents, high thickness proportions of granulated-mylonitized coal, and low burial depths. The II-type reservoirs are primarily developed close to the axis of the Malan syncline and in the south and northwest of the studied area, and have low permeability, less significant differences between the mechanical properties of coals and their roofs and floors, and low reservoir pressure gradients. The IV-type reservoirs have a scattered development, dominance of granulated-mylonitized coal, and low permeability, indicating low potential to improve reservoir permeability. Targeted exploitation technology and drainage systems corresponding to the different types of coal reservoirs should be proposed to improve coalbed methane production.

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