Mapping fractures using 1D anisotropic modelling of magnetotelluric data: a case study from the Otway Basin, Victoria, Australia

被引:17
作者
Kirkby, A. [1 ,2 ]
Heinson, G. [1 ]
Holford, S. [3 ]
Thiel, S. [1 ,4 ]
机构
[1] Univ Adelaide, Sch Phys Sci, Elect Earth Imaging Grp, Adelaide, SA 5000, Australia
[2] Geosci Australia, Canberra, ACT 2601, Australia
[3] Univ Adelaide, Australian Sch Petr, Adelaide, SA 5000, Australia
[4] Geol Survey South Australia, Adelaide, SA 5001, Australia
关键词
Electrical properties; Magnetotellurics; Permeability and porosity; Fracture and flow; Fractures and faults; ELECTROMAGNETIC METHODS; GEOTHERMAL RESOURCES; EXPLORATION; 90-DEGREES; INVERSION; EXAMPLE; PHASES; TENSOR; STATE; LOG;
D O I
10.1093/gji/ggv116
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
We present 1D anisotropic inversion of magnetotelluric (MT) data as a potential tool for mapping structural permeability in sedimentary basins. Using 1D inversions of a 171 site, broadband MT data set from the Koroit region of the Otway Basin, Victoria, Australia, we have delineated an electrically anisotropic layer at approximately 2.5 to 3.5 km depth. The anisotropy strike is consistent between stations at approximately 160A degrees east of north. The depth of anisotropy corresponds to the top depth of the Lower Cretaceous Crayfish Group, and the anisotropy factor increases from west to east. We interpret the anisotropy as resulting from north-northwest oriented, fluid-filled fractures resulting in enhanced electrical and hydraulic conductivity. This interpretation is consistent with permeability data from well formation tests. It is also consistent with the orientation of mapped faults in the area, which are optimally oriented for reactivation in the current stress field.
引用
收藏
页码:1961 / 1976
页数:16
相关论文
共 50 条
  • [1] 3D-Geo, 2009, HOT ROCK LTD OTW BAS
  • [2] Alexander E, 1992, 9270 DEP MIN EN S AU
  • [3] [Anonymous], 1997, LEAD EDGE, DOI DOI 10.1190/1.1437486
  • [4] [Anonymous], 1950, Dokl Acad Nauk SSR
  • [5] [Anonymous], 2006, APPEA J, DOI DOI 10.1071/AJ05016
  • [6] The electrical resistivity log as an aid in determining some reservoir characteristics
    Archie, GE
    [J]. TRANSACTIONS OF THE AMERICAN INSTITUTE OF MINING AND METALLURGICAL ENGINEERS, 1942, 146 : 54 - 61
  • [7] A review of permeability-prediction methods for carbonate reservoirs using well-log data
    Babadagli, T
    Al-Salmi, S
    [J]. SPE RESERVOIR EVALUATION & ENGINEERING, 2004, 7 (02) : 75 - 88
  • [8] Electrical anisotropy and conductivity distribution functions of fractal random networks and of the crust: The scale effect of connectivity
    Bahr, K
    [J]. GEOPHYSICAL JOURNAL INTERNATIONAL, 1997, 130 (03) : 649 - 660
  • [9] Remote sensing of subsurface fractures in the Otway Basin, South Australia
    Bailey, Adam
    King, Rosalind
    Holford, Simon
    Sage, Joshua
    Backe, Guillaume
    Hand, Martin
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 2014, 119 (08) : 6591 - 6612
  • [10] Bain JS, 1962, Report No.: 7200-G-94