Research Progresses of Micro-Nano Pore Networks in Shale Oil Reservoirs in China

Abstract

For the past decades shale formations have become major reservoirs, after sandstones and carbonates, for hydrocarbon (oil and gas) exploration and development. According to the China national petroleum assessment 2007, China is rich in oil shale reservoir. In China, the total oil shale resources and shale oil resources are estimated at 7199×108 tons and 476×108 tons, respectively. Although the shale reservoirs contain a great resource potential, progresses in shale (tight) oil development have been very slow for the complexity and heterogeneity of the pore systems. The pore structures and networks are key factors affecting the development of shale oil. SFor the past decades shale formations have become major reservoirs, after sandstones and carbonates, for hydrocarbon (oil and gas) exploration and development. According to the China national petroleum assessment 2007, China is rich in oil shale reservoir. In China, the total oil shale resources and shale oil resources are estimated at 7199×108 tons and 476×108 tons, respectively. Although the shale reservoirs contain a great resource potential, progresses in shale (tight) oil development have been very slow for the complexity and heterogeneity of the pore systems. The pore structures and networks are key factors affecting the development of shale oil. Shale reservoirs contain different storage space and transport channels, including nanopores in clay mineral matrix, inter-granular micro-nano pores, microfractures, artificial fractures. The multi-scale pore structure gives oil and gas molecules a variety of flow forms such as Brownian motion, adsorption and desorption, diffusion, slippage, and Darcy flow. Different size pore flow excitations are different, and the pore networks have important influence on the coupling of multi-scale and multi-mechanical flow. Thus, revealing the pore structures especially the micro-nano pore networks of unconventional reservoirs as shale can assist in estimating their elastic transport and storage properties, thus enhancing the hydrocarbon productivity and recovery. In this work, the differences of different methods for research of micro-nano pore networks in shale oil reservoir in China were compared, the applicability and progresses of different methods were also discussed.

AAPG Datapages/Search and Discovery Article #90332 © 2018 AAPG International Conference and Exhibition, Cape Town, South Africa, November 4-11, 2018