The Finite Element Analysis of Magnetic Field Characteristics of the Cased Hole with Pulse Source
详细信息
- 责任者：Yu Bing (Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education ; Yangtze University ; Jingzhou 434023 ; China) ; Liu Diren
- 刊名：Geophysical and Geochemical Exploration
- 出版年：2011
- 卷期：35(5)
- 关键词：套管内测井 ; logging through casing ; 电磁场 ; electromagnetic field
- 页码：p.689-691
- 图表：4 illus., 11 refs.
- 分类号：1600
- 出版序号：1008
- issnNo：ISSN1000-8918
- isbnNo：CN11-1906/P
摘要
The magnetic field of pulse source in the cased hole was analyzed by the finite element method.The effect of relative magnetic permeability of casing,casing thickness and the pulse width on the magnetic field distribution was discussed.The magnetic field in pulsed cased hole is considered as two parts in time domain: early signal and late signal.The early signal decreases obviously and includes mainly the useless signals and high frequency part of useful signal.The late signal is the low frequency part of useful signal and decreases slowly,thus containing the information of strata.The magnetic intensity is small when relative magnetic permeability of casing is very large.When the relative magnetic permeability of casing is small,the magnetic intensity is large but decreases drastically.The measurement is more favorable for the moderate relative magnetic permeability of casing.