Deep continental scientific drilling engineering in Songliao Basin: Progress in earth science research

The eastern borehole of Well SK-2, among the "two wells and four boreholes" of the deep continental scientific drilling engineering in Songliao Basin, is situated in Anda of Heilongjiang Province and was finished officially on May 26^th, 2018. Well SK-2 mainly focused on four scientific objections, i.e., paleoclimate research, resource and energy exploration, basic geological research and development of deep exploration technology. During the process if drilling which began in 2014, drilling, coring, logging, analysis of chemical element and structural exploration of surrounding areas were carried out during the SK-2 drilling engineering, and some preliminary progresses were made in scientific research:4134.8 m-long in-situ core data were acquired, and the most complete and continuous continental strata of the cretaceous were described with high resolution of centimeter-level, thus building the standard continental stratigraphic profile. Besides, evolution history of the continental facies in the Cretaceous period from scale of one million to one hundred thousand years was reconstructed for the first time, and an important climatic event of the Cretaceous was found. Apart from these achievements, evidence of Paleo-Pacific plate subduction and convergence in the deep was found, which contributes to genetic re-recognition and deep hydrocarbon exploration in Songliao basin. The implementation of deep continental scientific drilling engineering in Songliao Basin is of great significance in exploring the earth's mystery, seeking for deep energy and solving environmental problems. It is considered to be a solid step in the way of heading deep of the earth.