doi:10.2204/iodp.proc.324.106.2010
Operations
Times in this chapter are given in local ship time. During transit to Site U1346, shipboard clocks were advanced 1 h, resetting local ship time to Sydney Standard Time (Universal Time Coordinated + 10 h). No further adjustments to the clock were made during the expedition.
The 112 nmi transit from Site U1348 to Site U1349 required 12.2 h at an average speed of 9.2 kt. By 1245 h on 7 October 2009, the vessel was positioned on the new drill site.
The drill string was routinely deployed, and after the driller tagged seafloor at 3138.0 m drilling depth below rig floor (DRF) (3127.0 meters below sea level [mbsl]) (Table T1) or ~5 m deeper than the corrected precision depth recorder depth, Hole U1349A was spudded with the rotary core barrel (RCB) system at 0600 h on 8 October. The hole was drilled with a wash barrel to 116 m drilling depth below seafloor (DSF), where coring was initiated. The sediment portion of the hole was cored with the usual low average recovery (23%) because of the prevalence of soft sediments and chert to 165.1 m DSF, where basement was encountered. Coring in the hole continued into basement without incident to 250.4 m DSF (85.3 m into basement) by 1430 h on 11 October, when coring in the hole was terminated early (see Fig. F4 for an overview). The decision to cut short coring at this site was made during a science meeting held earlier in the day. Hole U1349A was cored with an overall average recovery of 49.0%. The basement portion of the hole was cored at an average rate of penetration of 1.8 m/h and with an average recovery of 67.4%.
The hole was prepared for logging with a 50 bbl mud flush followed by a round trip of the drill string from 250 to 86 m DSF. After an additional 50 bbl mud treatment, the bit was released at the bottom of the hole with the rotary shifting tool on the coring line. Prior to tripping the drill string to the logging depth of 119.3 m DSF, the hole was displaced with 56 bbl of 10.5 ppg heavy mud. The first log of Hole U1349A was made with the triple combination (triple combo) tool string, which was deployed at 2140 h on 11 October and retrieved at 0240 h the next morning. The second log was conducted with the Formation MicroScanner (FMS) tool string, which was deployed at 0355 h and recovered at 0930 h. The hole was found to be good condition except for one tight spot just below the end of the pipe, and both the triple combo and FMS runs retrieved excellent data.
After the logging equipment was secured, the drill string was pulled out of the hole to 2880 m DRF, where the pipe trip was suspended for 1.5 h to conduct a routine slip and cut of 115 ft of drilling line. Once the drill string and beacon were recovered and the drilling equipment secured, the vessel departed for the next site at 1930 h on 12 October.