Chemical geodynamics of continental subduction-zone metamorphism: Insights from studies of the Chinese Continental Scientific Drilling (CCSD) core samples

2009 ◽  
Vol 475 (2) ◽  
pp. 327-358 ◽  
Author(s):  
Yong-Fei Zheng ◽  
Ren-Xu Chen ◽  
Zi-Fu Zhao
Keyword(s):  
Subduction Zone ◽  
Scientific Drilling ◽  
Core Samples ◽  
Continental Subduction

Effect of Drill-Ship Motions on Core Sample Conditions During the Nankai Trough Seismogenic Zone Experiment

2009 ◽  
Author(s):  
Yuichi Shinmoto ◽  
Kazuyasu Wada
Keyword(s):  
Deep Sea ◽  
Nankai Trough ◽  
Drill String ◽  
Seismogenic Zone ◽  
Ship Motions ◽  
Scientific Drilling ◽  
Core Samples ◽  
Core Recovery ◽  
Drilling Parameters ◽  
Core Conditions

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Stage 1A, which is a part of the Integrated Ocean Drilling Program (IODP), is a series of expeditions in scientific drilling and coring operations aboard the first riser-equipped deep sea drilling vessel, Chikyu. The objectives are to recover good quality core samples and collect data on undersea properties and drilling conditions, which will also provide valuable information for future expeditions. The coring operations were carried out under harsh drilling and ocean conditions so that core recovery was inconsistent and fluctuated from high to low. Moreover, differences in independent lithology, depth, and the type of coring tools from previous expeditions made it necessary to analyze and optimize drilling parameters with new data. A serious concern in retrieving core samples was the vertical heave motions caused by the drill-ship since the active heave compensator system could not be activated before operations due to the extreme deep sea conditions and only the passive heave compensator was used. The drill string and coring tools are particularly vulnerable to the high heaving movements of the vessel so that the core recovery rate and quality are also adversely affected. The present work presents an analysis of geotechnical information, drilling parameters and the drill-ship motions the NanTroSEIZE expedition in order to optimize core conditions and maintain high core recovery.

Drilling‐induced isothermal remanent magnetization

Geophysics ◽  
1990 ◽  
Vol 55 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Michael J. Pinto ◽  
Michael McWilliams
Keyword(s):  
Remanent Magnetization ◽  
Mineral Exploration ◽  
Petroleum Exploration ◽  
Isothermal Remanent Magnetization ◽  
Scientific Drilling ◽  
Core Samples ◽  
Considerable Success

The recovery of core samples is important in petroleum exploration, mineral exploration, and scientific drilling projects; and often complete orientation of the samples (azimuth and plunge) is desirable. Recovered cores are usually not azimuthally oriented because of the costs associated with deployment and operation of downhole orientation tools. Inexpensive paleomagnetic orientation methods have been used with considerable success in the borehole environment (Van der Voo and Watts, 1978; Kodama, 1984; Bleakly et al., 1985a, b; Evans and Mailol, 1986; Layer et al., 1988; McWilliams and Pinto, 1988). In some cases, the technique has been hampered by secondary magnetizations associated with the drillstring and/or coring tool, magnetizations which have partially or completely overprinted the primary and secondary magnetizations used for orientation.

scholarly journals A new hybrid pressure-coring system for the drilling vessel <i>Chikyu</i>

2014 ◽  
Vol 17 ◽  
pp. 37-43 ◽  
Author(s):  
Y. Kubo ◽  
Y. Mizuguchi ◽  
F. Inagaki ◽  
K. Yamamoto
Keyword(s):  
Hydrostatic Pressure ◽  
Nankai Trough ◽  
Geochemical Characteristics ◽  
Methane Hydrates ◽  
Scientific Drilling ◽  
Core Samples ◽  
Core Recovery ◽  
The Many ◽  
Gas Tight

Abstract. Retrieving core samples without releasing the in situ hydrostatic pressure during core recovery is one of the many technical challenges in scientific drilling. We report here a newly developed hybrid pressure-coring system for the use on the drilling vessel Chikyu and its successful use during expeditions 906 and 802 in the Nankai Trough of Japan. The system is gas-tight and hence enables researchers to study in situ geophysical and geochemical characteristics of sediments containing gaseous components, such as methane hydrates that cannot be reliably recovered with nonpressure coring systems. In addition, pressure coring is a powerful tool, not only for scientific but also for hydrocarbon resources research.

Sign in / Sign up

Export Citation Format

Share Document