Theories and practices of carbonate reservoirs development in China

Carbonate reservoirs in China have the characteristics of diversified accumulation pattern, complex structure and varying reservoir conditions. Concerning these characteristics, this article tracks the technical breakthroughs and related practices since the 1950s, summarizes the developed theory and technologies of carbonate reservoir development, analyzes their adaptability and problems, and proposes their development trend. The following theory and technologies have come into being: (1) carbonate reservoir formation mechanisms and compound flow mechanisms in complex medium; (2) reservoir identification and description technologies based on geophysics and discrete fracture-vuggy modeling method; (3) well testing analysis technology and numerical simulation method of coupling free flow and porous media flow; (4) enhanced oil recovery techniques for nitrogen single well huff and puff, and water flooding development techniques with well pattern design in spatial structure, changed intensity water injection, water plugging and channel blocking as the core; (5) drilling and completion techniques, acid fracturing techniques and its production increasing techniques. To realize the efficient development of carbonate oil and gas reservoirs, researches in four aspects need to be done: (1) complex reservoir description technology with higher accuracy; (2) various enhanced oil recovery techniques; (3) improving the drilling method and acid fracturing method for ultra-deep carbonate reservoir and significantly cutting engineering cost; (4) strengthening the technological integration of information, big data, cloud computation, and artificial intelligence in oilfield development to realize the smart development of oilfield.