Key Technologies for Oil and Gas Development from Deep Carbonate Fractured-Vuggy Reservoirs

Abstract

China possesses abundant oil resources with a magnitude of 40.66×108 t of geological reserves contained in carbonate fractured-vuggy reservoirs. Fractured-vuggy reservoirs have become one of the most important fields in China’s oil and gas exploration and development, with the potential to markedly increase its explorable oil reserves and oil production. However, highly efficient development of this kind of reservoir can present a major challenge due to its large buried depth, i.e., larger than 6500 m, low accuracy in describing the carbonate fractured-vuggy body, and co-existence of diverse flow patterns. To address these issues, numerical models have been utilized to predict oil production and interporosity flow between water injection wells. After an approximately 20-year period of research and practice, key technologies for oilfield development have been proposed, including high-accuracy detection of multi-scale fractured-vuggy bodies, karst geological modeling, precise prediction of water flooding, and sour
gas injection. In addition, major advancements have been achieved in numerous aspects, such as implementing a 91.7% production rate in each new well of the Tahe Oilfield, maintaining high production of 5.5 million t per year over a long period of time, and discovery of one billion t of oil in the Shunbe Oilfield with consequent massive and rapid production.