LITHOLOGY AND RESERVOIR PROPERTIES OF PRECEMBRIAN DEPOSITS OF THE LENA-ANABAR OIL-AND-GAS REGION

Abstract

The relevance. Nowadays, one of the priority directions in expanding the hydrocarbon base of Russia has become the research and development of its northern regions. The Lena-Anabar oil-and-gas region is located in the North part of the Siberian platform and is characterized by a very irregular geological and geophysical exploration. Precambrian deposits are the most poorly studied, despite their quite high reservoir potential, as well as direct and indirect signs of oil and gas potential. For more effective further geological exploration work in this region, a detailed study of previously drilled well sections is necessary, with the identification of lithological features of reservoir rocks, conditions for their formation and distribution. The object: Precambrian deposits discovered by deep drilling on the territory of the Lena-Anabar oil-and-gas region. The aim of the research is to identify perspective hydrocarbon reservoirs based on the analysis of the composition, structure, sedimentary environments and reservoir properties of Precambrian sediments of the Lena-Anabar oil-and-gas region. Methods: creating sections of Precambrian deposits based on detailed macro- and microscopic analysis of core material and well logs data; correlation of sections in view of lithological, paleontological and geophysical data; genetic analysis of the main lithological types of rocks and clarification of their sedimentation conditions; estimation of the influence of sedimentation and post-sedimentation factors on formation of reservoir properties; identification of levels of potential reservoirs Results. It was established that the Precambrian section is represented by the alternation of packs of carbonate and terrigenous rocks and its accumulation took place in a large range of environments: from delta to sublittoral, with a significant prevalence of shallow-water sedimentation. It was discovered that there are potential reservoir rocks in Precambrian sediments, and the most perspective levels are related to the Vendian part of the section.

Keywords

• lena-anabar oil-and-gas region
• lithology
• reservoirs
• upper riphean
• vendian