Pyritization effect on well logging parameters in Jurassic reservoirs within S-E Western Siberian oil fields

A Janishevskii,T Ten,A Ezhova

doi:10.1088/1755-1315/43/1/012054

Abstract

Authigenic sulfide mineralization in hydrocarbon-saturated reservoirs distorts the electrical and density properties of rocks. The correlation between volumetric density, electro-conductive minerals and open porosity in 300 samples were determined. This fact made it possible to develop a nomograph in evaluating oil saturated reservoirs and could be applied in well geophysical survey data interpretation.

Highlights

Determining the reservoir fluid content during exploration and hydrocarbon, reserve estimation is based on the interpretation of production well logging data
Similar reservoirs were exposed in Shirotni Prioby(Tumen Oblast) oil fields within NezhneVartovsk, Surgut and Nojabrsko-Pursk oil-gas bearing areas. This fact was established in the 90s of the last century by engineers of the Petrophysics Laboratory, Siberian Research Institute of Petroleum Industry
These anomaly field geophysical characteristics of oilsaturated formations being determined as water-saturated due to low electric resistance values were the result of semi-conductor mineral occurrences in the rocks, such as sulphides, titanium and ferrum oxides

Summary

Introduction

Determining the reservoir fluid content (saturation) during exploration and hydrocarbon, reserve estimation is based on the interpretation of production well logging data. Ezhova and others) [3] These anomaly field geophysical characteristics of oilsaturated formations being determined as water-saturated due to low electric resistance values were the result of semi-conductor mineral occurrences in the rocks, such as sulphides, titanium and ferrum oxides. Pyrite and white iron pyrite have identical chemical composition (Fe – 46.6 %, S - 53.4 %), color (in reflected light-metallica, goldish), petrophysical properties (specific electric resistance – 10-5 10 Ohm.m·, density- 4.88 5.2 gr/cm3) [10]

Published under licence by IOP Publishing Ltd

Results and discussion

Conclusion