Daily report for IODP Expedition 311, September 22, 2005
LOCATION: Site U1326 (CAS-3C)
SCIENCE UPDATE: Through the morning of September 22, 2005, the LWD/MWD tool string was re-initiated and deployed after completing Hole U1325A. Hole U1326A was spudded at 14:50 at a water depth of 1839 mbrf. Approval had been sought to deepen Hole U1326A to 350 mbsf (from an approved depth of 300 mbsf); however, the hole was completed (on the morning of September 22, 2005) before this request could be acted upon. LWD/MWD operations in Hole 1326A proceeded throughout the day without any significant problems. However, to improve drilling efficiencies, relative to our experience in Hole U1325A, the average ROP was increased to 35 m/hr. At a depth of 88 mbsf, an electrical resistivity log inferred gas-hydrate-bearing section was encountered, with measured resistivity values exceeding 10 ohm-m (over a background measurement of ~1.5 ohm-m). While drilling this inferred gas hydrate occurrence, the APWD measured annular pressures dropped slightly (only several psi) and ROP decreased to about 6 m/hr.
In preparation for coring, a science meeting was held to review PCS degassing experimental procedures and equipment setup. Other operational and technical meetings were conducted throughout the day. The gas hydrate core sampling plan was updated and modified according to suggestions from the science party. A H2S evacuation and fire drill was conducted at 13:00.