The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
H U Shengbiao - One of the best experts on this subject based on the ideXlab platform.
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evaluation of gas resource kitchen for the upper paleozoic Coal Measure ordos basin
Natural Gas Geoscience, 2007Co-Authors: H U ShengbiaoAbstract:The Ordos basin is located on a stable platform of monoclinal structure,and tectonic movements were mainly elevation and subsidence since the Paleozoic.The Yulin,Wushenqi,Sugeli gas fields are found in the Upper Paleozoic Coal Measure.The gas resource rock is mainly the Upper Paleozoic Coal seams,then dark mudstone.The source rocks were buried and matured quickly since the Triassic,and ceased at the end of the early Cretaceous because of the late Yanshan movement.The Ordos Basin was uplifted and eroded at that time.The Paleotemperature of the resource rocks decreased rapidly,and the amplitude of the temperature falling was so large that the temperature was too low to generate hydrocarbon again.At the end of the early Cretaceous,the vitrinite reflectivity was above 1.3% in the most part of the basin,being overmature in the south and decreased northward.Although the abundance of organic matters is high,but the mature rate of the resource rock is less than 0.03%/Ma,the gas generation rate is mainly from 0.2×108 m3/(km2·Ma) to 0.4×108 m3/(km2·Ma),the averaged hydrocarbon generation interval is up to 104.7 Ma,and the percentage of gas generation in the main hydrocarbon generation interval is 55.9%.
Yanjie Gong - One of the best experts on this subject based on the ideXlab platform.
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the experimental modeling of gas percolation mechanisms in a Coal Measure tight sandstone reservoir a case study on the Coal Measure tight sandstone gas in the upper triassic xujiahe formation sichuan basin china
Natural Gas Geoscience, 2016Co-Authors: Shizhen Tao, Xiaohui Gao, Jianhui Zeng, Xiangxiang Zhang, Chun Yang, Jingya Zhang, Yanjie GongAbstract:Abstract Tight sandstone gas from Coal-Measure source rock is widespread in China, and it is represented by the Xujiahe Formation of the Sichuan Basin and the Upper Paleozoic of the Ordos Basin. It is affected by planar evaporative hydrocarbon expulsion of Coal-Measure source rock and the gentle structural background; hydrodynamics and buoyancy play a limited role in the gas migration-accumulation in tight sandstone. Under the conditions of low permeability and speed, non-Darcy flow is quite apparent, it gives rise to gas-water mixed gas zone. In the gas displacing water experiment, the shape of percolation flow curve is mainly influenced by core permeability. The lower the permeability, the higher the starting pressure gradient as well as the more evident the non-Darcy phenomenon will be. In the gas displacing water experiment of tight sandstone, the maximum gas saturation of the core is generally less than 50% (ranging from 30% to 40% and averaging at 38%); it is similar to the actual gas saturation of the gas zone in the subsurface core. The gas saturation and permeability of the core have a logarithm correlation with a correlation coefficient of 0.8915. In the single-phase flow of tight sandstone gas, low-velocity non-Darcy percolation is apparent; the initial flow velocity (Vd) exists due to the slippage effect of gas flow. The shape of percolation flow curve of a single-phase gas is primarily controlled by core permeability and confining pressure; the lower the permeability or the higher the confining pressure, the higher the starting pressure (0.02–0.08 MPa/cm), whereas, the higher the quasi-initial flow speed, the longer the nonlinear section and the more obvious the non-Darcy flow will be. The tight sandstone gas seepage mechanism study shows that the lower the reservoir permeability, the higher the starting pressure and the slower the flow velocity will be, this results in the low efficiency of natural gas migration and accumulation as well as low gas saturation. The laboratory modeling on gas migration accumulation mechanism in Coal-Measure tight sandstone can provide a theoretic foundation to reveal the tight sandstone gas enrichment regularity, evaluation of prospecting area, and the study of development mechanism.
Yong Kong - One of the best experts on this subject based on the ideXlab platform.
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laboratory testing of silica sol grout in Coal Measure mudstones
Materials, 2016Co-Authors: Dongjiang Pan, Nong Zhang, Zhengzheng Xie, Xiaowei Feng, Yong KongAbstract:The effectiveness of silica sol grout on mudstones is reported in this paper. Using X-ray diffraction (XRD), the study investigates how the silica sol grout modifies mudstone mineralogy. Micropore sizes and mechanical properties of the mudstone before and after grouting with four different materials were determined with a surface area/porosity analyser and by uniaxial compression. Tests show that, after grouting, up to 50% of the mesopore volumes can be filled with grout, the dominant pore diameter decreases from 100 nm to 10 nm, and the sealing capacity is increased. Uniaxial compression tests of silica sol grouted samples shows that their elastic modulus is 21%–38% and their uniaxial compressive strength is 16%–54% of the non-grouted samples. Peak strain, however, is greater by 150%–270%. After grouting, the sample failure mode changes from brittle to ductile. This paper provides an experimental test of anti-seepage and strengthening properties of silica sol.
Dongjiang Pan - One of the best experts on this subject based on the ideXlab platform.
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experimental study of imbibition characteristics of silica sol in Coal Measure mudstone matrix
Applied Sciences, 2017Co-Authors: Dongjiang Pan, Nong Zhang, Changliang Han, Sen Yang, Chenghao Zhang, Zhengzheng XieAbstract:Coal-Measure mudstone is a typical dual-porosity media, and grouting in a matrix system is dominantly controlled by the imbibition effect for silica sol. This paper studies the imbibition effect using mudstone in the Huaibei mining area and silica sol as grouting material as an example. Groutability, driving force, and diffusion difficulty affecting the imbibition effect were tested by a mercury porosimeter, nanoparticle size analyzer, optical contact-angle measuring device, surface tension meter, and rotary viscosity meter. After finely grinding a mudstone sample, a pressureless imbibition process was conducted through nuclear magnetic resonance equipment for 216 h to study colloid spontaneous migration and phase characteristics. Results show that silica sol absorption rate follows a power function and that the spectrograms of T2 are distributed in a triple peak pattern, with a tendency to move to the right of vertex time. The paper lays a theoretical and experimental foundation for field grouting in the Coal mine.
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laboratory testing of silica sol grout in Coal Measure mudstones
Materials, 2016Co-Authors: Dongjiang Pan, Nong Zhang, Zhengzheng Xie, Xiaowei Feng, Yong KongAbstract:The effectiveness of silica sol grout on mudstones is reported in this paper. Using X-ray diffraction (XRD), the study investigates how the silica sol grout modifies mudstone mineralogy. Micropore sizes and mechanical properties of the mudstone before and after grouting with four different materials were determined with a surface area/porosity analyser and by uniaxial compression. Tests show that, after grouting, up to 50% of the mesopore volumes can be filled with grout, the dominant pore diameter decreases from 100 nm to 10 nm, and the sealing capacity is increased. Uniaxial compression tests of silica sol grouted samples shows that their elastic modulus is 21%–38% and their uniaxial compressive strength is 16%–54% of the non-grouted samples. Peak strain, however, is greater by 150%–270%. After grouting, the sample failure mode changes from brittle to ductile. This paper provides an experimental test of anti-seepage and strengthening properties of silica sol.
Shuai Yin - One of the best experts on this subject based on the ideXlab platform.
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S-wave velocity prediction of marine-continental transitional Coal Measure rocks using multipole array sonic logs and the rock-matrix modulus extraction method
Interpretation, 2019Co-Authors: Siqi Wang, Jianguo Zhang, Shuai Yin, Chao HanAbstract:Accurate prediction of the S-wave velocity of highly heterogeneous Coal Measure strata using high-resolution logging can effectively identify high-quality reservoirs. We have used multipole array sonic logs to predict the S-wave velocity of Coal Measure strata based on the conventional empirical method (CEM), multiple regression method (MRM), and rock-matrix modulus extraction (MME) method. Moreover, we used a complex multiple parameter iterative computational method of forward calculation and inversion in the MME method. Our results indicate that the MME method can effectively extract several rock modulus parameters. There are good binomial relationships between the extracted rock modulus parameters ([Formula: see text]) and between the extracted modulus parameters and the P-wave impedance ([Formula: see text]). The average relative errors of the S-wave velocities predicted by the CEM, MRM, and MME methods are 7.58%, 5.64%, and 2.31%, respectively. The MME method can effectively extract and couple effective information from different types of conventional well logs and perform high-precision S-wave time difference prediction.
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logging assessment of tight clastic rock reservoir fractures via the extraction of effective pore aspect ratios a case study of lower permian strata in the southern qinshui basin of eastern china
Journal of Natural Gas Science and Engineering, 2016Co-Authors: Shuai Yin, Wenlong Ding, Wen Zhou, Yuming Shan, Ruyue Wang, Jianjun LiuAbstract:Abstract Research on tight gas enrichment in Coal Measure strata is contentious worldwide. Gas logging anomalies are very common in the upper Paleozoic Coal-bearing strata in the Southern Qinshui Basin of eastern China. The distribution characteristics of these free gases are closely related to the degree of fracture development. The rock pore aspect ratio (α) can reflect the morphology of rock pores and fractures. In this paper, we use full wave logging data to propose a new logging assessment method for tight clastic rock reservoir fractures via the extraction of effective pore aspect ratios. The basic concept is as follows: (1) we extract the rock matrix mineral modulus and dry rock modulus of the rocks using an optimized algorithm, and (2) we invert the effective pore aspect ratio of Coal Measure strata using the theoretical model of a differential equivalent medium. The research results show that the studied clastic rocks in Coal Measure strata are very tight, with porosity levels that are generally less than 5%, and sections in which fractures have formed often correspond to relatively low α values of less than 0.1. The microfracture-bearing sections identified based on α inversions correspond well to the sections with fractures at the core scale. Thus, this method can be used to identify fractured sections at the core scale. For sandy mudstone, microfractures mainly exist in sandy intervals, and α is negatively related to rock porosity and positively related to shale content. Regardless of lithology, i.e., sandstone, mudstone or Coal, the communication and transport capacity of fracture systems are greater than those of the pore system, and Coal-derived gas reservoirs form when there are good gas sources, transportation systems, fracture systems and preservation conditions. Similar to the formation mechanism of fractures in rocks, α is also derived from mechanical mechanisms, and this study shows that the inversion process is effective in characterizing the degree of fracture development in tight clastic rocks in Coal Measure strata based on elastic rock properties.