Methods and Technology of Prediction, Exploration and Development of Oil Fields in the Palaeozoic Carbonate Formations of the West Siberian Basin

N. P. Zapivalov, G. V. Vedernikov, A. A. Trofimuk

Within the past few years twenty five oil fields have been discovered in Paleozoic carbonate rocks of Western Siberian Basin. The best known of these are Maloicha, Urman, Archin and Tabogan. The complexity of the reservoir rocks and variety in the types of traps are the distinguishing feature of the Paleozoic deposits. It is very difficult to define the types of traps since the pools are not controlled by structures. The reservoir properties of the carbonate rocks have been improved by the leaching effect of CO₂ that migrated along fractured zones. Gas-hydrothermal solutions also play a role in porosity enhancement.

Organic build-ups in Devonian carbonates have proved to be the most promising targets in the search for oil accumulations. Oil flows up to 1200 barrels/day have been obtained from the metasomatic dolomites of the front slope facies of the Maloicha reef. It is now possible to predict these zones using 3D seismic, high precision gravity and remote sensing data. Exploration requires the drilling of deep wells (up to 9000 feet) with open hole testing. Development of the fields (for example, Maloicha) has shown that production can be sustained with natural lift without water flooding or other secondary methods.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995