Computer interpretation of lateral resistivity logs

• Autorzy: Bała M. , Jarzyna J. , Cichy A.
• Języki publikacji: EN

Abstrakty

EN

Archive well logs are commonly used in prospecting for hydrocarbon deposits. Well logs are then reinterpreted with the use of new, sophisticated and more effective interpretation techniques that enable reservoir parameters of rock to be more accurately determined. Effective porosity and water, oil or gas saturation are usually calculated from resistivity logs. The measurement techniques previously used in Poland and East and Central European countries employed a set of lateral devices or a combination of normal and lateral devices with different investigation radii. A computer system for quantitative interpretation of a set of five lateral resistivity logs has been developed. It allows the following parameters to be calculated: resistivity and diameter of the flushed zone, resistivity and diameter of the invasion zone and true resistivity of the formation. To create a set of theoretical curves, analytic solutions and results of numerical modeling of the forward geophysical problem for different models of the rock medium with a borehole are used in the system. For all layers of a geological profile, changes in apparent resistivity as a function of tool length are analyzed and matched to theoretical curves by minimization of deviations between the selected co-ordinates of theoretical curves and the measurement points. To test the system, quantitative interpretation of lateral resistivity logs recorded in a few shaly-sandstone and carbonate formations was made. There was a good agreement between computed values of porosity and saturation and those obtained from borehole tests and core data.

Słowa kluczowe

EN

resistivity of rocks; resistivity logs

• Wydawca: Instytut Geofizyki PAN
• Czasopismo: Acta Geophysica Polonica
• Rocznik: 2001
• Tom: Vol. 49, nr 2
• Strony: 245--259
• Opis fizyczny: Bibliogr. 7 poz.

Twórcy

autor

Bała M.

autor

Jarzyna J.

autor

Cichy A.

• University of Mining and Metallurgy, Faculty of Geology, Geophysics and Environmental Protection, Kraków, Poland,