气候变化领域集成服务门户(CCPortal): Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea

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DOI	10.1029/2020JB020608
	Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea
	Amour F.; Christensen H.F.; Hajiabadi M.R.; Nick H.M.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	The locus and shape of the yield surface of chalk in the stress space represent key input parameters in geomechanical models, as it dictates the onset and amount of plastic deformation. The study aims at reconstructing for the first time the initial end cap and shear failure line of intact reservoir chalk in plots of mean-deviatoric stress versus porosity. One hundred and thirty-seven stress-strain measurements describe the effects of initial porosity between 30% and 45% and initial water saturation on the yield surface in order to cover a wide spectrum of reservoir rocks. The physico-chemical processes taking place at pore collapse under oil- and water-saturated conditions are discussed. The experimental data collected from previous works quantify the hardening and softening effects observed with decreasing porosity and increasing water saturation. The results also indicate that the stress interval characterizing the elastic to elasto-plastic transition zone and the curvature of the end cap are dependent on porosity and quartz content. These observed trends suggest changes in the sequence of local failures acting in the rock matrix at the onset of compaction. Comparisons with previous studies suggest that the water weakening effect differs between outcrop and reservoir chalk likely due to a change in mineralogy. A yield function is proposed to build the yield surface and to capture the porosity-dependent change in the shape of end cap and the water weakening effect. The outcomes provide key input data describing the mechanical behavior and properties of chalk under laboratory conditions required for compaction simulation studies. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	chalk; compaction; porosity; reservoir; water weakening effect; yield surface
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187285
作者单位	Danish Hydrocarbon Research and Technology Centre, Technical University of Denmark, Kgs. Lyngby, Denmark; Ramboll, Copenhagen, Denmark
推荐引用方式 GB/T 7714	Amour F.,Christensen H.F.,Hajiabadi M.R.,et al. Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea[J],2021,126(3).
APA	Amour F.,Christensen H.F.,Hajiabadi M.R.,&Nick H.M..(2021).Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Amour F.,et al."Effects of Porosity and Water Saturation on the Yield Surface of Upper Cretaceous Reservoir Chalks From the Danish North Sea".Journal of Geophysical Research: Solid Earth 126.3(2021).