Research and application of key technologies for pre-construction of ICDP Nam Co Drilling Project， Tibet

Abstract:

The Nam Co Drilling Project in Tibet is a scientific drilling program implemented by the Institute of Tibetan Plateau Research， Chinese Academy of Sciences， in collaboration with the International Continental Scientific Drilling Program （ICDP）， which is a scientific drilling initiative aimed at retrieving lacustrine sediment cores from Nam Co to study and monitor climate change and global environmental dynamics. During this project， drilling operations were conducted at a water depth of approximately 100 meters， with the deepest borehole penetrating lakebed sediments to a depth of 700 meters. This paper investigates the primary technical challenges of lake drilling in Nam Co by examining the design and operational procedures for lake drilling platforms， including： platform design and modular assembly； anchor positioning； drilling equipment selection； polymer anti-collapse drilling fluids； P-diameter wireline coring tools； deepwater casing systems； and airbag-type casing centralizer designs. Centered on the demand for lake drilling capabilities with a maximum depth of 800 meters （including water depth of 100 meters）， this study develops relevant drilling technologies and equipment using a case example of a 250 meters borehole （including water depth of 100 meters）. The research provides critical technical support for the Institute of Tibetan Plateau Research， CAS in advancing studies on global climate change， biological evolution， tectonic evolution， paleomagnetic variations， and hydrological cycles.