The National Methane Hydrates R&D Program
The DOE/JIP Gulf of Mexico Hydrate Research Cruise
During this expedition we will maintain a log of information relayed from the chief Scientist on the expedition. Whenever possible, images will be displayed along with the text.
May 13-15 - Days 27-29 - Status Report
May 13-15 - Keathley Canyon 151 - Logging and Coring
Location: Keathley Canyon 151
Science Update - May 13-15:
May 13: KC151#3 is currently drilling down in to a depth of 210 mbsf where coring will resume (sometime after 0100 hrs on 14 May).. The Fugro Corer (FC) tool will be used to recover 5.1-m cores in the more compacted muds expected at these depths. Six pressure cores will be attempted in five of the six high resistivity intervals logged between 220 and 300 mbsf. Imaging of core KC151-3-2H showed High-density layers/nodules just beneath the sulfate-methane interface. Samples will be analyzed post-cruise to determine if these layers are authigenic carbonates precipitated from the dissolved bicarbonate formed by anaerobic methane oxidation.
May 14: Four cores were successfully collected over the depth interval of 210-230 mbsf in KC151#3 between 07:30 and 21:00 hrs on Saturday. The last core (KC151#3-11P) was an Fugro Piston Corer core recovered with 145-150 bar pressure (just under hydrostatic for depth of 1562 mbsl). The pressure core was successfully transferred to an aluminum storage chamber and is currently undergoing a series of nondestructive tests. The core was from an interval previously shown by Logging While Drilling (LWD) data to have high resistivity, possibly caused by gas hydrate cementation. Cores collected earlier in this same interval (KC151#3-7C, -8C, -10C) were stiff gray muds with high salinity pore water (50 ppt) and low apparent gas content at the surface.
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Vertical Multi Sensor Core Logger
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May 15: The Fugro Pressure Core (11P) that was successfully brought up and transferred under pressure did not show any evidence for gas hydrate by core X-ray imaging or logging. Core 11P is undergoing a full range of experiments (Vp, Vs, resistivity, strength) with the MSCL-P (pressurized multi sensor core logger with central measurement chambers) to provide information on differences in physical properties between pressurized and nonpressurized cores. Seven more coring runs were made over the depth interval 230-265 mbsf in KC151#3 during the last 24 hrs. Cores 12C and 14C recovered the usual stiff gray mud with high salinity pore water (50 ppt) and low apparent gas content at the surface. The Hyacinth Rotary pressure core tool (HRC) recovered a partial core under pressure that was successfully transferred, imaged and logged. Core 15C contained the first distinct cold spot detected by the IR camera. The 10-cm whole round section with the cold spot was immediately cut out and placed in liquid nitrogen. The core material adjacent to the cold spot had the disturbed, mousse-like texture that is characteristic of sediment with decomposed gas hydrate. A pore water sample from immediately below the cold spot did not have lowered salinity, nor was the residual headspace gas content of the core above normal background levels. The IR-imaged cold spot and the mousse-like core texture are strong evidence for at least the former presence of gas hydrate. However, we have been unable to develop any additional confirming evidence for gas hydrates at the present time. Core 16C was an empty core barrel. An FHPC core (17H) recovered about 5 meters of sediment with several gas voids retained (core gas appears to be lost when using the FC coring tool).
Plans:
Take one pressure (FPC) core (18P) at 266 mbsf, then alternate coring and drilling with each pipe joint down to 380 mbsf. At 380 mbsf, start continuously coring through the depth corresponding to the seismic BSR (385 mbsf) to 405 mbsf, with pressure cores above and below the depth of the BSR.
Planning and Data Sheet for KC151 - #3 [PDF-10KB]
Special Report - Pressurized Coring and Analyses Equipment
Special Report - core handling
Special Report - Conventional Wireline Logging Operations in the Gulf of Mexico Gas Hydrate JIP Drilling Program - Timothy Collett, USGS
Maps of drill sites - Shows Keathley Canyon and Atwater Valley locations
Photos:
Coring Photo Gallery - Photos showing pressure coring and analyses equipment
Day 16 Photo Gallery - Photos by NETL scientist showing core analyses process and equipment
Day 13 Photo Gallery - Photos by NETL scientist showing drilling preparation
Day 12 Photo Gallery - Photos by NETL scientist showing core retrieval and processing
Day 10 Photo Gallery - Pressurized core prior to transfer to lab and seabed frame preparation
Day 6 Photo Gallery - Working with push cores and ROV photos of sample collection at AT 14
Day 4 Photo Gallery - Remotely Operated Vehicle (ROV), Sampling, Core Handling
Day 3 Photo Gallery - Preparation for Drilling
Day 2 Photo Gallery Loading the Uncle John [PowerPoint]
The drill ship out to sea - Setting up the lab [PowerPoint]
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