Maraa western transect: Sites M0005-M0007
Maraa western transect: Sites M0005-M0007
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马拉西部横断面：地点 M0005-M0007
DOI：
10.2204/iodp.proc.310.105.2007
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发表时间：
2007
影响因子：
5
通讯作者：
D. McInroy
中科院分区：
文献类型：
--
作者：
G. Camoin;Y. Iryu;D. McInroy
在克服了导致月池门无法打开的液压油缸的问题后，Seacore的钻井和再入模板（DART）被部署在美国石油协会（API）的钻柱上（用作这次探险的导管），位于海床上方。从13时35分起，使用落水管水下摄像机对第一个地点周围的海底进行了调查。合适的位置位于距离计划位置约2 m处，DART放置在海床上，重量为8 T。拆除摄像机后，HQ（背负式）钻柱穿过API导管到达海底，并开始M0005 A孔的取芯作业。第一个堆芯于2000 h到达甲板。此后，取芯工作继续进行，筒体锁紧困难，在确定最佳取芯参数之前，使用短取芯行程以避免钻探而不是取芯。第一批岩心显示出较大的空洞，并且回收率很差。岩心筒堵塞和与钻头堵塞相关的误锁问题导致该井进展缓慢。当在一次特殊的钻柱起下钻后重新进入钻孔以从钻头上移除岩心堵塞物时，取心似乎在海底以下10.4米处重新开始。获得了良好的岩心，看来井眼已在一次偏斜中重新开始，或已避免了先前的偏斜。10月8日18时40分，M0005B孔作为新孔的起点。
After overcoming problems with a hydraulic ram that caused the moonpool doors to fail to open, Seacore’s drilling and reentry template (DART) was deployed on an American Petroleum Institute (API) drill string (used as conductor pipe for this expedition) to just above the seabed. From 1335 h, a seabed survey around the position of the first site was conducted using the downpipe underwater camera. A suitable site was located ~2 m from the planned position, and the DART was placed on the seabed with 8 T of weight. After removing the camera, the HQ (piggyback) drill string was run through the API conductor to the seabed and coring operations in Hole M0005A commenced. The first core arrived on deck at 2000 h. Thereafter, coring continued with difficult barrel latching, and short core runs were used to avoid drilling rather than coring until the best coring parameters were established. The first cores displayed large cavities, and recovery was poor. Core barrel jams and problems with blocked bit–related mislatching led to slow progress in this hole. When reentering the hole after one particular drill string trip to remove a core blockage from the bit, coring appeared to recommence at 10.4 meters below seafloor (mbsf). Good core was obtained, and it appeared that the borehole had been restarted in a deviation or had avoided a previous deviation. This was taken as the start of a new hole, Hole M0005B, at 1840 h on 8 October.