Inversion for microseismic focal mechanisms in attenuated strata and its resolution

doi:10.6038/cjg20160825

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院页岩气与地质工程重点实验室

	Inversion for microseismic focal mechanisms in attenuated strata and its resolution
	Zhai Hong-Yu 1,2; Chang Xu 1; Wang Yi-Bo 1; Yao Zhen-Xing 1
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2016-08-01
卷号	59 期号:8 页码:3025-3036
关键词	Stratum attenuation Microseismicity Focal mechanism inversion Inversion resolution
DOI	10.6038/cjg20160825
文献子类	Article
英文摘要	Microseismic focal mechanism inversion is significant for the unconventional oil and gas development. Microseismic signal is characterized by high frequency and small energy, so it is easy to be influenced by formation attenuation effect, and to cause serious waveform distortion and unreliable inversion results. After analyzing the previous microseismic moment tensor inversion methods and some of their deficiency, this paper proposes a new method for microseismic focal mechanism inversion considering the stratum attenuation effect. On the other hand, the Q factor of actual strata is hard to estimate precisely and the microseismic events are very complex. So we design a simple observation model with three vertical wells and four basic moment tensors which are added 30% random perturbation to simulate the actual field situation. In the process of numerical computation, we assume the sediments' Q factor has different levels of error. Based on this assumption, we can calculate the inversion error of the new moment tensor inversion method and analyze the inversion resolution by using the SVD of Frechet derivative matrix due to Q factor error. According to the theoretical calculation, the application conditions of the various focal mechanism inversions can be summarized for different types of microseismic data. Furthermore, the theoretical calculation proves that only using direct P waves can obtain a better inversion result than using direct P and S waves simultaneously. After analyzing the inversion error and the inversion resolution, we conclude that the joint inversion by using direct P and S wave data can estimate a better T value and a better k value can be inversed by using direct P wave separately. Moreover the direct P wave has a less sensitivity about the sediment Q factor. Based on this conclusion we can effectively reduce the negative influence on the focal mechanism inversion result by utilizing different types of wave data to determine the different parts of microseismic focal mechanisms.
WOS关键词	MOMENT-TENSOR INVERSION ; PHENOMENOLOGICAL DESCRIPTIONS ; SEISMIC SOURCES ; DISPLACEMENTS ; EARTHQUAKES ; EVENTS ; MEDIA ; SHALE
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000381166400025
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/53373]
专题	地质与地球物理研究所_中国科学院页岩气与地质工程重点实验室
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Shale Gas & Geoengn, Beijing 100029, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhai Hong-Yu,Chang Xu,Wang Yi-Bo,et al. Inversion for microseismic focal mechanisms in attenuated strata and its resolution[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2016,59(8):3025-3036.
APA	Zhai Hong-Yu,Chang Xu,Wang Yi-Bo,&Yao Zhen-Xing.(2016).Inversion for microseismic focal mechanisms in attenuated strata and its resolution.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,59(8),3025-3036.
MLA	Zhai Hong-Yu,et al."Inversion for microseismic focal mechanisms in attenuated strata and its resolution".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 59.8(2016):3025-3036.