Отправлено: 02.11.16 07:25. Заголовок: New Relations of Water Saturation’s Calculus from Well Logs

Acta Geophysica
DOI: 10.1515/acgeo-2016-0063
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Ownership: Institute of Geophysics, Polish Academy of Sciences;
© 2016 Malureanu et al.
New Relations of Water Saturation’s Calculus from Well Logs
Ion MALUREANU1
, Tudor BOACA2
, and Daniela-Doina NEAGU1
1
Petroleum-Gas University of Ploiesti, Faculty of Petroleum and Gas Engineering,
Department of Petroleum Geology and Reservoir Engineering, Ploiesti, Romania
e-mails: imaluraenu@upg-ploiesti.ro, daniela.neagu@upg-ploiesti.ro
2
Petroleum-Gas University of Ploiesti, Faculty of Letters and Science, Department
of Information Technology, Mathematics and Physics, Ploiesti, Romania
e-mail: tboaca@upg-ploiesti.ro
Abstract
The saturation in water or hydrocarbon is an important petrophysical
parameter used for the evaluation of oil and gas reservoirs. It represents
the amount of hydrocarbons in a reservoir. There are many
relations to determine the water saturation from well logs by using the
physical properties of rocks. The accurate determination of the hydrocarbon
formation or the water saturation is given by the accuracy of the parameters
used for calculating and by the relations used.
This paper makes an analysis of the relations for water saturation
calculation using the Walter H. Fertl classification. The four types of relations
were modified using the MacLaurin series of the exponential
function. It also analyses the cases when the water saturation is not to be
found in the variation range [0,1]. The new relations giver values that are
always greater than 0 and we have established the conditions for the water
saturation to be less than 1.
In the final part of the paper we make an application which confirms
the theoretical aspects presented in the first part of the paper.

Key words: water saturation, well log, true resistivity, MacLaurin series.