Fractional order constitutive model of geomaterials under the condition of triaxial test     

Deshun Yin  Hao Wu  Chen Cheng  YangQuan Chen 《国际地质力学数值与分析法杂志》2013,37(8):961-972

Fractional calculus has been successfully applied to characterize the rheological property of viscoelastic materials; however, geomaterials were seldom involved in fractional order constitutive models (FOCM), and the topic of first loading and then unloading is rarely discussed through fractional calculus. In this paper, mechanical properties are considered as a ‘spectrum’, both ends of which are elasticity and viscosity, and the fractional order can be utilized to describe such properties quantitatively. In addition to conditions such as creep, stress‐relaxation, and constant‐strain‐rate loading, stress‐strain relationship under the condition of first loading and then unloading was also derived using FOCM. FOCM is then adopted to simulate triaxial tests of geomaterials under corresponding conditions. A comparison of test and numerical results demonstrates that FOCM can reasonably describe the mechanical characteristics of geomaterials.Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

塔里木盆地西部一间房露头区奥陶系台缘储层沉积体系分析   总被引：2，自引：0，他引：2  

焦养泉  荣辉  王瑞  吴立群  颜佳新  曾凡平  顾元  李荣 《岩石学报》2011,27(1):285-296

碳酸盐岩台地边缘优质储层相带预测一直是石油勘探家关注的焦点,露头沉积体系精细结构分析及其储集性能研究是总结预测模型的一把关键钥匙。在塔里木盆地西部一间房露头区,通过详细的野外地质调查、沉积体横向追踪与对比、典型沉积体系剖面写实、系统取样和室内测试分析等方法,对中奥陶统一间房组台缘生物礁-滩沉积体系、上奥陶统良里塔格组底部的台缘斜坡-斜坡扇沉积体系进行了系统的沉积体系内部成因相构成及其储集性能研究。研究认为台缘沉积体系具有复杂的内部构成,其成因相具有相对固定的空间配置格架和品质迥异的储集性能。在台缘靠近台地一侧往往发育生物礁-滩沉积体系,由生物礁、生物碎屑滩和台缘背景沉积等3种成因相组合构成。生物碎屑滩产出于生物礁周围,礁前则具有特征的砾质滩。由内侧滩向外侧滩沉积物颗粒变细、分选性变差、生屑含量和亮晶胶结物减少。而在台缘靠近盆地一侧,则往往台缘斜坡-斜坡扇沉积体系,主要由斜坡、斜坡扇、扇面水道和滑塌体等4种成因相组合构成。扇面水道通常切割斜坡扇,滑塌体周围往往伴生有小型斜坡扇体。由斜坡扇或者扇面水道的近端向远端,沉积物由砾质逐渐转变为砂质。在上述两种台缘沉积体系中,礁前内侧砂质滩和礁后内侧砂质滩、远端砂质斜坡扇具有良好的储层品质。比较而言,台缘生物礁-滩沉积体系的潜在储集性能总体上优于台缘斜坡-斜坡扇沉积体系。  相似文献   

Occurrence,thermal evolution and primary migration processes derived from studies of organic matter in the Lucaogou source rock at the southern margin of the Junggar Basin,NW China     

Jiao  YangQuan  Wu  LiQun  He  MouChun  Roger  Mason  Wang  MinFang  Xu  ZhiCheng 《中国科学:地球科学(英文版)》2007,50(2):114-123

The Lucaogou Formation carbonate-rich oil shale source rock is exposed at the southern margin of the Junggar Basin, Xinjiang, NW China. We have sampled it in detail and conducted microstructural, mineralogical and geochemical studies, including thin section petrography, UV fluorescence petrography, X-ray diffraction, vitrinite reflectance, bitumen reflectance, fluid inclusion analysis and Raman spectroscopy. Organic matter is disseminated through the carbonate-bearing siltstone source rocks and concentrated in numerous bedding parallel stylolites and in two sets of carbonate veins, one along bedding parallel fractures and the other cross-cutting stylolites and bedding. The research about maturity of organic matter finds vitrinite reflectance values increase from the dispersed kerogen (0.64%) to the stylolites (the one of oriented vitrinite is 0.72% and the one of migrated bitumen is 2.38%); Homogenization temperatures of fluid inclusions in veins containing hydrocarbon fluid inclusions show an increase from 178.5°C in the bedding parallel veins to 222°C in the cross-cutting veins, confirmed by Raman spectroscopy. These results support a model of progressive heating accompanied by fluid loss during later stages of thermal maturation of source rock and the onset of primary migration. Obviously, the occurrence of organic matter is the trace of hydrocarbon primary migration, and the bedding lamination surfaces and cross-cutting fissures are the principal pathways of hydrocarbon-bearing fluids migration. Bedding lamination surfaces evolved into stylolites along the earliest primary migration pathways, followed by bedding parallel and cross-cutting fissures.

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Occurrence, thermal evolution and primary migration processes derived from studies of organic matter in the Lucaogou source rock at the southern margin of the Junggar Basin, NW China     

JIAO YangQuan  WU LiQun  HE MouChun  ROGER Mason  WANG MinFang  XU ZhiCheng 《中国科学D辑(英文版)》2007,50(Z2):114-123

The Lucaogou Formation carbonate-rich oil shale source rock is exposed at the southern margin of the Junggar Basin, Xinjiang, NW China. We have sampled it in detail and conducted microstructural, mineralogical and geochemical studies, including thin section petrography, UV fluorescence petrography, X-ray diffraction, vitrinite reflectance, bitumen reflectance, fluid inclusion analysis and Raman spectroscopy. Organic matter is disseminated through the carbonate-bearing siltstone source rocks and concentrated in numerous bedding parallel stylolites and in two sets of carbonate veins, one along bedding parallel fractures and the other cross-cutting stylolites and bedding. The research about maturity of organic matter finds vitrinite reflectance values increase from the dispersed kerogen (0.64%) to the stylolites (the one of oriented vitrinite is 0.72% and the one of migrated bitumen is 2.38%); Homogenization temperatures of fluid inclusions in veins containing hydrocarbon fluid inclusions show an increase from 178.5℃ in the bedding parallel veins to 222℃ in the cross-cutting veins, confirmed by Raman spectroscopy. These results support a model of progressive heating accompanied by fluid loss during later stages of thermal maturation of source rock and the onset of primary migration. Obviously, the occurrence of organic matter is the trace of hydrocarbon primary migration, and the bedding lamination surfaces and cross-cutting fissures are the principal pathways of hydrocarbon-bearing fluids migration. Bedding lamination surfaces evolved into stylolites along the earliest primary migration pathways, followed by bedding parallel and cross-cutting fissures.  相似文献   

Occurrence,thermal evolution and primary migration processes derived from studies of organic matter in the Lucaogou source rock at the southern margin of the Junggar Basin,NW China     

Jiao YangQuan  Wu LiQun  He MouChun  Roger Mason  Wang MinFang  Xu ZhiCheng 《中国科学D辑(英文版)》2007,50(2):114-123

The Lucaogou Formation carbonate-rich oil shale source rock is exposed at the southern margin of the Junggar Basin, Xinjiang, NW China. We have sampled it in detail and conducted microstructural, mineralogical and geochemical studies, including thin section petrography, UV fluorescence petrography, X-ray diffraction, vitrinite reflectance, bitumen reflectance, fluid inclusion analysis and Raman spectroscopy. Organic matter is disseminated through the carbonate-bearing siltstone source rocks and concentrated in numerous bedding parallel stylolites and in two sets of carbonate veins, one along bedding parallel fractures and the other cross-cutting stylolites and bedding. The research about maturity of organic matter finds vitrinite reflectance values increase from the dispersed kerogen (0.64%) to the stylolites (the one of oriented vitrinite is 0.72% and the one of migrated bitumen is 2.38%); Homogenization temperatures of fluid inclusions in veins containing hydrocarbon fluid inclusions show an increase from 178.5°C in the bedding parallel veins to 222°C in the cross-cutting veins, confirmed by Raman spectroscopy. These results support a model of progressive heating accompanied by fluid loss during later stages of thermal maturation of source rock and the onset of primary migration. Obviously, the occurrence of organic matter is the trace of hydrocarbon primary migration, and the bedding lamination surfaces and cross-cutting fissures are the principal pathways of hydrocarbon-bearing fluids migration. Bedding lamination surfaces evolved into stylolites along the earliest primary migration pathways, followed by bedding parallel and cross-cutting fissures.  相似文献