This paper is the result of oil and gas survey engineering.
[Objective] Focusing on the scientific and technological task of shale gas investigation in the Yangtze River economic belt, China Geological Survey has deployed and implemented 173 shale gas exploration wells, completed more than 310000 m of drilling footage in recent years. Major breakthroughs in the shale gas investigation of Sinian system, Cambrian system, and Silurian system, and important discoveries in the shale gas investigation of Permian system has been achieved. It opened new areas, new strata, new types, and new insights of shale gas exploration. The basic geological survey wells are used to drill cores with low cost and short cycle. They are generally deployed in new blocks and new strata with insufficient data from adjacent wells. Aiming to provide technical support in drilling engineering for shale gas investigation.
[Methods] This article analyzes the related research progress of drilling projects deployed and implemented by China Geological Survey over the past decade, and a series of drilling technologies achieved have been classified and summarized.
[Results] The high-efficiency shale gas drilling equipment and technology system based on the innovative development of geological drilling equipment and technology are summarized:(1) Surface equipment for shale gas geological survey wells has been formed, including improved vertical shaft drilling rig suitable for well control safety of shale gas wells, drilling fluid solid control circulation system meeting the requirements of green exploration, etc.; (2) High-efficiency coring tools and drilling technology, focusing on the coring tools such as large-diameter wireline coring tools, KT series coring tools, inverted tower drilling tool assembly technology, air pipe following technology, etc.; (3) The research progress of high efficiency coring bits is described, including three types of bits, such as special-tooth PDC bits, impregnated block bits and impregnated diamond bits, and their application effects; (4) The progress of safe drilling technology and complex treatment is briefly discussed. The shale gas exploration drilling fluid technology, pressure control drilling technology, and drilling complex treatment such as lost return and sticking is introduced. In addition, the direction of shale gas drilling technology research is given.
[Conclusions] The review of above research progress can provide useful reference for shale gas exploration drilling engineering design and construction.