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The AAPG/Datapages Combined Publications Database

CSPG Bulletin

Abstract


Bulletin of Canadian Petroleum Geology
Vol. 39 (1991), No. 2. (June), Pages 221-221

"Interbedded Sand Analysis Using a Pulsed Power Deep Induction Tool: A Turbidite Example [Abstract]"

Patterson, D.1, Harkins, J.1, Volk, W.1

ABSTRACT

Interbedded Sand Analysis (XISA) is a bimodal model that computes a resistivity profile which makes use of a new, extended range, high resolution induction tool (XHR*) along with existing high resolution shale indicators such as a shallow dielectric log.

The XHR is used to provide an accurate resistivity profile in thinly bedded turbidites where the conventional devices show low contrast in these hydrocarbon-bearing intervals. This unique device uses a pulse source and two simultaneously sampled receiver arrays that are offset. Each array provides a digitally sampled log representing the average resistivity over a 12-inch interval. Since the two assemblies are offset, they do not measure the same 12-inch interval and therefore overlap to provide greater coverage and information. The logs from the two assemblies combine to form a composite curve that can be correlated with other high resolution devices.

In this turbidite example, the XISA analysis uses the XHR and EPT** logs to generate a resistivity profile for thin beds. XISA uses the EPT as a shale indicator and reconstructs the resistivity based on the assumption of a constant shale resistivity, Rshale, and computes Rsand. From this information, XISA computes high resolution resistivity with the combination of the maximum value of the two XHR curves. This new deep resistivity (XISA=Rt) can then be used in a straightforward water saturation evaluation based on as assumed constant porosity in the clean layers as defined by the shale indicator.

* Mark of MPI

** Mark of Schlumberger

End_of_Record - Last_Page 221-------

ACKNOWLEDGMENTS AND ASSOCIATED FOOTNOTES

1 Magnetic Pulse Incorporated, Fremont, California 94538

Copyright © 2003 by The Society of Canadian Petroleum Geologists. All Rights Reserved.