Engineering Commons^™

Preliminarily Exploring The Theories And Technologies For Coalbed Methane Production Using Horizontal Wells: Comparison Of Conditions For Coalbed Methane And Shale Gas Exploitation, Wang Hongyan, Duan Yaoyao, Liu Honglin, Zhao Qun, Chen Shangbin, Lu Haibing, Shi Zhensheng, Sun Qinping, Chen Zhenhong, Zhou Shangwen, Yang Mingwei, Wang Cong

Coal Geology & Exploration

Through 30 years of unremitting explorations, coalbed methane (CBM) wells in China have gradually transitioned from vertical to horizontal wells. However, the lack of basic theories on CBM production using horizontal wells is the main challenge to current CBM development. Compared to shales, coal seams exhibit heterogeneity and a minor presence of foliations and brittle minerals, hindering the formation of volumetric fracture networks. Nevertheless, the roofs and floors of coal seams have high sealing capacities and mechanical strength, creating excellent conditions for hydraulic fracturing. Some fractures in coals are filled with calcite, rendering acidification conducive to the improvement of reservoir …

Geological Characteristics And Reservoir-Forming Potential Of Shale Gas Of Transitional Facies In Linxing Area, Eastern Margin Of Ordos Basin, Wu Peng, Cao Di, Zhu Guanghui, Liu Xueqing, Li Yong, Li Yangbing, Hu Weiqiang, Liu Zaizhen, Kong Wei, Fei Jingliang

Coal Geology & Exploration

Shale gas of transitional facies is the important replacing area for increase of shale gas reserves and production. On the basis of the experiment and research data of shale of transitional facies of Linxing area in the eastern margin of Ordos Basin, by selecting the strata series of Shanxi Formation, Taiyuan Formation and Benxi Formation as the research object, from the sedimentary environments, shale distribution, organic geochemical characteristics, mineralogy, physical characteristics and gas-bearing characteristics, etc., the geology characteristics of the shale gas transitional facies in the study area were summarized and dissected systematically to analyze its enrichment and reservoir-forming potential. …

Geochemical Characteristics Of Marine-Continental Transitional Facies Shale And Shale Gas In Linxing Area, Chen Xin, Wu Peng, Gao Jixian, Hu Weiqiang, Ding Wangui, Li Yangbing, Liu Xueqing, Ma Litao, Liu Cheng, Kong Wei, Cao Di, Chen Jianqi, Li Yong

Coal Geology & Exploration

In order to reveal the geochemical characteristics of shale and shale gas on the east edge of Ordos Basin, thin section identification, full rock and clay content, scanning electron microscope, organic carbon, rock pyrolysis, kerogen macerals, and kerogen carbon isotopes were tested, and the gas component and carbon isotopes composition of shale were analyzed. The results show that the mineral component of the transitional facies shale in Linxing area is mainly quartz and clay minerals, containing a small amount of calcite, plagioclase, potassium feldspar, dolomite and pyrite. Affected by the mineral genesis and deposition environment, different mineral components and organic …

Water Absorption Characteristics And Their Influence On The Mechanical Properties Of Longmaxi Formation Shale In Northeastern Chongqing, Liu Hong, Xu Fenglin, Chen Qiao, Zhu Honglin, Su Degui, Feng Kelai

Coal Geology & Exploration

A certain amount of casing deformation occurs during the shale reservoir fracturing. There is a certain amount of clay minerals in shale, and after contacting with water-based fracturing fluid, it will show the same expansion characteristics and strength weakening effect as mudstone, which will increase the casing external load. Aiming at the Longmaxi Formation shale in the northeast of Chongqing, the self-absorption and swelling characteristics of shale under different solution systems are studied by physical experiments to analyze the effect of shale hydration on its rock mechanical properties. The results show that the water absorption of shale has a logarithmic …

Effect Of Acidification On The Microstructure And Physical Properties Of Shale, Chen Liuyu, Li Xijian, Shen Zhonghui, Xu Shiqing, Ma Shengxiang, Yin Xin

Coal Geology & Exploration

As the main shale gas reservoir in Guizhou, it is proved that Longmaxi Formation has good shale gas accumulation conditions and resource development potential. In order to reveal the response law of acidification on the micropore structure and physical properties of Longmaxi Formation shale in Guizhou, the difference in physical properties of shale microstructures before and after acidification, such as pore volume, porosity, specific surface area and pore size distribution was quantitatively characterized by X-ray diffraction(XRD) analysis, mercury intrusion measurement, low-temperature nitrogen adsorption and nuclear magnetic resonance(NMR) experiment. The structural characteristics of the shale pores before and after acidification were …

Analysis Of Reservoir Conditions Of Shale Gas In Middle Permian Wenbishan Formation In Fujian Province, Chen Quanlin

Coal Geology & Exploration

This study is performed on the geological conditions of shale gas in Middle Permian Wenbishan Formation in Fujian Province. It is based on organic geochemistry, rock minerals and reservoir physical property after geology survey and drilling. The results indicate that kerogen is Ⅲ-type, organic carbon is usually between 1% to 2%, R_ran is between 3.76% to 4.91% in the shale of Wenbishan Formation, and the shale is in the mature stage. The content of brittle minerals is generally low. The shale has medium porosity and extremely low permeability, the micro and meso-pores constitute the major space for gas adsorption. …

Shale Gas Potential Of Yanguanjie Formation And Longtan Formation In Central And Southeastern Hunan Province, Cao Taotao, Deng Mo, Liu Hu, Huang Yanran, Stefan Andrew Hurssthouse

Coal Geology & Exploration

In order to reveal the shale gas potential and exploration direction of the marine-continental transitional shale in central and southeastern Hunan, samples were collected from the Lower Carboniferous Yanguanjie Formation and Upper Permian Longtan Formation, measurements were conducted on TOC, R_ran, kerogen carbon isotope, maceral composition, X-ray diffraction, scanning electron microscopy, porosity, permeability and methane sorption capacity. The results indicate that Yanguanjie Formation and Longtan Formation shale are at the mature stage, and mainly dominated by type Ⅲ kerogen. The Longtan shale generally has higher TOC content, while Yanguanjie shale has usually low TOC content. The minerals are …

Properties Of Mud Cake Associated With Silica Shale Powder Intrusion Into Drilling Fluid, Mo Dingqiang, Sun Pinghe, Zhao Binkui, Wang Jingyuan, Zhang Shaohe, Cao Han

Coal Geology & Exploration

Drilling fluid is very important for maintaining the stability of the hole wall in shale drilling. The mud cake formed by the fluid loss also plays a decisive role in protecting the reservoir. In order to study the influence of shale rock powder intrusion into low-solid-phase drilling fluids on the basic properties of mud cakes, the paper selects the siliceous shale powders in northwestern Hunan as the research object, and designs orthogonal experiments. In addition, the test results are analyzed using variance and range, which show that the content of rock powder is the main factor affecting the thickness of …

Adsorbability Of Shale In Coal Measures And Its Influencing Factors, Zhang Baoxin, Fu Xuehai, Zhang Qinghui, Zhou Baoyan, Liu Zheng

Coal Geology & Exploration

In order to reveal the adsorption and gas-bearing characteristics of shale in coal measures, this study was based on the gas content, isotherm adsorption, high-pressure mercury injection, and liquid nitrogen adsorption of more than 200 coal shale in six major coal fields in Shanxi Province and Junggar basin. XRD diffraction and other measured data, the adsorption and gas characteristics of shale were analyzed, and the influencing factors were discussed. The results show that the measured gas content of shale is between 0-5.87 cm³/g, concentrated at 0.90-2.00 cm³/g; V_L is between 0.11-6.3 cm³/g with …

Application Of Fuzzy Mathematics In Selecting The Favorable Location Of Shale Gas Survey Well: Taking Northwest Guizhou As An Example, Lin Lamei, Zhang Jinchuan

Coal Geology & Exploration

Exploration and development of shale gas in China is now in the early-middle stage. Drilling geological survey well is an important mean to obtain data and discover shale gas in the blank area of Lower Paleozoic shale data in south China. However, due to the extremely complex structure and geomorphic conditions in these areas, it is very difficult to optimize the location of wells. Taking northwest Guizhou as an example, based on a large number of field geological survey work, the evaluation criteria of geological and engineering geological conditions for shale gas survey well location are put forward. In the …

Slides: Environmentally Friendly Drilling Systems Program (Efd), Rich Haut

Best Practices for Community and Environmental Protection (October 14)

Presenter: Rich Haut, Houston Advanced Research Center

23 slides