Chinese Continental Scientific Drilling Project is one of China's Key Scientific Engineering  Projects. It's also one of the ICDP (International Continental Scientific Drilling Program) Projects. By employing modern deep drilling high techniques, this project is to drill a 5000 meter deep hole at the eastern part of Dabie-Sulu ultra-high pressure metamorphic belt with global geoscientific significance, to study the forming and exhumation mechanisms of the ultra-high pressure metamorphic belt by adopting the analyzed data from the core, liquid and gas samples taken from the hole, the in-situ logging data and the information; to reveal the deep materials constitution of the plate margins and mineralization and the fluid action; and to establish a deep crustal laboratory for long term observation and a base for research on deep crust materials. In addition a complete new system and technique for deep and hard rock drilling will be developed through the implementation of the project, thus the drilling technique in China will be improved to a new level. This project, organized by the Ministry of Land and Resources, the People's Republic of China, is implemented by the Chinese Continental Scientific Drilling Engineering Center of China Geological Survey. It was implemented between 2001 and 2005.
The project's deep well CCSD-1 was spudded in on June 25, 2001, The drilling operation of the project was successfully completed on March 8, 2005, with the final depth reached 5158m.
Such kind of drilling project, the drilling of a 5000m deep continuously cored borehole in extremely hard crystalline rock, has never been conducted in China before. With its high risk and high difficulty, the drilling project belongs to the toughest drilling task even in the world. Only few countries in the world had finished such kind of drilling project. The drilling technical personnel of CCSD Engineering Center had overcome many difficulties and resolved different kinds of drilling technical problems encountered in the drilling process of CCSD-1, and reached the drilling target with high degree of difficulty by using drilling technologies developed by themselves.
The implementation of the CCSD Project has gained important achievements both in geo-scientific research and in drilling engineering.
The main preliminary geo-scientific research achievements are as follows:
1. Coesite, as a typical ultrahigh pressure mineral, has been discovered through the CCSD cores, as well as widely observed in various rock types in the Donghai region, an about 3800 km2 area. This indicates that a huge amount of crustal materials, including eclogites and their country rocks as a whole，had deeply subducted.
2. Many special minerals have been discovered in the garnet peridotite from the depth of 600-680 m of the CCSD borehole. They are unusual minerals in nature, e.g., the barringerite (Fe2P) is the first time reported on the Earth, which probably originated from deep mantle.
3. Different bacteria species with special characteristics were discovered in the cores of CCSD borehole, and some of them are alive. This important discovery is a challenge to the origin of life. Also, since the new discovered microbes contain special components, e.g., high-temperature resistant bio-enzyme and proteins, they are of potential value in using of their properties.
The main drilling and logging engineering achievements are:
1. The PDM/hydro-hammer/diamond coring system developed by CCSD Engineering Center for using in hard rock and deep hole coring project, is an innovated coring system which has many advantages, such as high rate of penetration, long core run length, good core recovery and quality, less wear of drill string, power consumption and disturbance to the borehole wall and so on. That is to say that this technology is characterized by its high performance, good quality and safety and low cost and is a leading technology in the field of hard rock and deep hole core drilling.
2. The hydro-hammer drilling technology has been improved obviously which has stabilized the leading position of China in this field.
3. The development of diamond coring system, hole opening system and directional drilling system suitable for hard rock and deep hole drilling have raised the level of China's drilling technique to a new high.
4. The complete logging in and systematical reaserch on crystalline metamorphic rock has filled the blank in this field in China. It's the first time in China that the continuous core orientation of nearly 5000m long borehole section has been realized by using dada of image logging and core scanning.
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