Petroleum Exploration and Development (Dec 2020)
Geological theory and exploration & development practice of hydrocarbon accumulation inside continental source kitchens
Abstract
Continental shale strata in China are rich in petroleum resources and are an important area to strengthen domestic oil exploration and development. Based on the latest progress in geological research and exploration and development of petroleum inside continental source kitchens of China National Petroleum Corporation exploration areas in recent two years, we have achieved the following results: (1) The geological connotations of continental hydrocarbon accumulation inside source kitchen and “sweet spot” have been proposed. The intra-source petroleum accumulation refers to the accumulation of liquid-rich hydrocarbons retained or captured in the continental organic-rich shale strata, and “sweet spot” refers to the favorable reservoir with higher oil content, better physical properties, easier to stimulate and higher in commercial development value in the overall oil-bearing continental source rock series, they can be divided into three types, interlayer, hybrid sediment and shale. (2) High-quality shale formations in both salt water and freshwater lacustrine basins can generate hydrocarbons on a large scale, shale strata have multiple types of favorable reservoirs with large-scale storage capacity, the intra-source shale strata are overall oil-bearing and large in resource scale, and there are multiple favorable shale series for development. The exploration and development practice is propelling the formation of a series of exploration and development key technologies with “sweet spot exploration” and “volume development” as the core. Some pilot tests of these technologies have provided an important scientific basis for the economic and effective development of hydrocarbon accumulation inside source kitchen, and popularization of these technologies have achieved encouraging results preliminarily. (3) Two types of continental intra-source petroleum resources in China have great potential, including medium-high maturity with liquid-rich hydrocarbons and medium-low maturity with organic-rich matter. The Ordos, Songliao, Bohai Bay and Junggar basins are the main areas of these resources. By addressing the theoretical and technical challenges in the exploration and development, the two types of resources inside continental source kitchens will become the realistic and major strategic replacement oil resources respectively in the future.
