摘要
The term’ultra-deep layers’refers to those sedimentary formations which are currently,or have been,buried at depths exceeding 6000 m.China has continuously achieved major oil and gas breakthroughs in marine ultra-deep exploration,significantly promoting the strategic level of ultra-deep oil and gas resources over recent years.The ultra-deep formations of the cratonic basins in China are predominantly constrained to Precambrian to lower Paleozoic marine stratigraphy.
