Drilling challenges and technological solutions in the development of oil deposits in fractured carbonate reservoirs

Introduction. Currently, carbonate reservoirs play an increasingly significant role in the global hydrocarbon balance. Most of the deposits discovered in recent years are fractured carbonate reservoirs. The potential for effective development of carbonate reservoirs lies in the development and application of new high-tech methods and advanced well drilling technologies. The article highlights the challenges of developing productive deposits in the Paleozoic basement of Tomsk region deposits represented by fractured carbonate reservoirs. The article considers the mining and geological conditions of carbonate reservoirs in the Paleozoic basement and the challenges that arise when using traditional drilling technologies. The article presents the results of an analytical review on the application of advanced technologies for drilling wells with horizontal completion. Some aspects of the application of nano drilling fluids for conditions of low-permeability carbonate reservoirs are highlighted. The content of the article is based on the author's research and analysis of publicly available literature. Methods and materials. The work is based on the generalization, systematization and analysis of factual material, scientific publications, and results of analytical studies. Results. Based on the generalization and analysis of geological and field data, the authors established that in the conditions of the identified group of fields, when developing fractured carbonate reservoirs, the productivity of a well depends on the number of natural cracks opened during drilling that penetrate carbonate rocks. Fault tectonics had a major impact on the development of highly fractured zones of carbonate reservoirs, which are the main reason for frequent absorption of drilling fluid when drilling wells with a horizontal end. Clustering of the well stock of the development object in carbonate reservoirs allowed to identify 3 groups of wells, opening up deposits with different filtration-capacity characteristics. It was established that the nature of the distribution of porosity and permeability depends on the development of reservoir fracturing associated with the position of tectonic faults. Analytical studies in the perimeter of Russian oil and gas companies have shown that the efficiency of well drilling technologies in fractured carbonate reservoirs is achieved through an integrated approach: detailing the geological structure of the target object, adapted drilling technology with the ability to regulate differential pressure in the well-formation system, as well as selecting optimal drilling fluids.