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Core Orientation and Susceptibility Logging |
1 Geomagnetism Laboratory, Department of Earth Sciences, University of Liverpool, PO Box 147, Oxford Street, Liverpool L69 3BX, UK
2 BP International Limited, Sunbury Research Centre, Chertsey Road, Sunbury-on-Thames, Middlesex TW167LN, UK
To interpret the directional physical properties of reservoirs it is necessary to obtain orientated specimens of well material. The standard technique in the petroleum industry has been the use of ‘down the hole’ tools, which leave a physical scribe on the core material during the drilling procedure. This method is expensive and is subject to a number of problems which can limit the accuracy of the results. A new orientation technique is presented in which a present day component of magnetization is isolated during the progressive thermal demagnetization of core material. This component is essentially a magnetic compass bearing for the core which can be used to rotate the core reference frame into the geographical system. Unlike the standard palaeomagnetic method it can be used both on undated core and core taken from complex tectonic areas.
