The ultrasonic response of numerical simulation and analysis of scattering characteristics in digital core for shale reservoir

doi:10.6038/cjg2018K0563

	The ultrasonic response of numerical simulation and analysis of scattering characteristics in digital core for shale reservoir
	Wang Zhiwei 1,2; Fu Liyun 1; Zhang Yan 1; Wei Wei 1
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2018-03-01
卷号	61 期号:3 页码:1069-1082
关键词	Longmaxi Formation digital shale core Heterogeneous two-phase media modeling Pore elasticity two-phase media ultrasonic numerical simulation Coda wave scatter analysis and heterogeneity assessment
ISSN号	0001-5733
DOI	10.6038/cjg2018K0563
文献子类	Article
英文摘要	The precision and stability of the numerical algorithm is seriously challenged when applied to the modeling of strong heterogeneity on scales from micrometer to nanometer in the digital core of Longmaxi Formation shale at ultrahigh frequency. In this paper, we divide the major compositions in the digital core of Longmaxi Formation shale into four types, namely quartz, clay, pyrite and porosity. The liquid phase (oil) is assumed to be uniformly distributed throughout the medium. Based on the measured porosity and permeability of the digital core and the prior petrophysical parameters of minerals, a heterogeneous two-phase model is elaborately established. Then, the scattering attenuation of the ultrasonic wave propagating in the shale core is simulated by using the high-precision finite difference (FD) method with rotating staggered grid and non-split convolution perfect matching layer (CMPL) based on Biot's two-phase media equation. The boundary-reflection energy and its effects on coda waves can be numerically modeled by precisely controlling the number of matching layers. By comparing with the coda Q values measured in the ultrasonic experiment, we quantify the boundary-reflection energy and its effects on coda waves in the experiment. The results of ultrasonic numerical tests at various central frequencies show that the scattering attenuation comes to maximum at frequency of 600 MHz. According to the scattering pattern analysis in the L/a-ka diagram, we infer that the heterogeneity length of the shale digital core is equivalent to the order of ultrasonic wavelength at 600 MHz. Based on the numerical simulation of the ultrasonic scattering in the shale digital core, the heterogeneity length of the core can be quantitatively evaluated, providing the basis for the prediction of acoustic heterogeneity in the shale reservoir.
WOS关键词	SEISMIC-WAVE PROPAGATION ; CODA WAVES ; CONVOLUTIONAL PML ; GRAZING-INCIDENCE ; POROUS-MEDIA ; ATTENUATION ; STRESS ; LAYER
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000428609900022
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/83164]
专题	中国科学院地质与地球物理研究所
通讯作者	Wang Zhiwei
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resource Res, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Wang Zhiwei,Fu Liyun,Zhang Yan,et al. The ultrasonic response of numerical simulation and analysis of scattering characteristics in digital core for shale reservoir[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2018,61(3):1069-1082.
APA	Wang Zhiwei,Fu Liyun,Zhang Yan,&Wei Wei.(2018).The ultrasonic response of numerical simulation and analysis of scattering characteristics in digital core for shale reservoir.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,61(3),1069-1082.
MLA	Wang Zhiwei,et al."The ultrasonic response of numerical simulation and analysis of scattering characteristics in digital core for shale reservoir".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 61.3(2018):1069-1082.