Thermal properties of bazhen formation rocks of surgut and nizhnevartovsk arches of western-siberian plate from continuous core profiling

Abstract

Results of thermal property investigations of Bazhen formation rocks are described. Povkhovskoye, Yuzhno-Yagunskoye and Novoort’yagunskoye oil fields located in northern descent of Nizhnevartovsk arch and northeastern part of Surgut arch of Western-Siberian plate were studied. Continuous non-contact high resolution thermal profiling core samples was used that allows to record profiles of volumetric heat capacity and a thermal conductivity principal component along bedding, to determine a thermal conductivity principal component perpendicularly to bedding, thermal anisotropy and heterogeneity coefficients. It was established that the rocks are characterized by essential multi-scale thermal heterogeneity (from 1 mm) and significant thermal anisotropy. The thermal properties vary within wide ranges established for rocks studied previously with the same technique for other areas of the Western-Siberian plate. Rock samples of Povkhovskoye and Novoort’yagunskoye oil fields are essentially more homogeneous. Obtained detailed data on the rock thermal properties allow to form representative databases for basin and hydrodynamic modeling, they allow also to record continuous profiles of total organic carbon, to determine elastic-strength properties and acoustic anisotropy, to improve spatial resolution of geophysical well logging methods using their combination with continuous high-resolution thermal properties profiling on full-size core samples.