NMR study of bitumoids from oil-bearing formation rocks in the western Siberia

The work is devoted to the West Siberian sedimentary basin Bazhenov formation (or Bazhenov shale) – a unique oil-generating and oil-bearing geological formation. Bazhenov shale is an analog of the known shale oil deposits: Bakken, Eagle Ford and Monterrey (USA). Geological and geophysical exploration of bazhenites is an important problem today, which is connected with development of new methods and technologies of unconventional oil and gas reservoirs exploitation. The work is devoted to physical and chemical properties study of oil and bitumoids extracted from the Bazhenov rock samples using low-field Nuclear magnetic resonance (NMR) relaxometry method. NMR characteristics of oil and bitumoid samples from several deposits in the Western Siberia and their temperature dependence were studied. Rheological properties estimations and SARA (saturates, aromatics, resins and asphaltenes) analysis were carried out by means of NMR relaxometry data. The results of the work provide a new high-quality approach of NMR logging data interpretation in the sections of Bazhenov oil and gas wells completion.