Leg 124E

Philippine Sea - Engineering Tests

Leg 124E gave ODP engineers the opportunity to evaluate new and modified drilling systems and techniques in adverse operational conditions of high winds and seas, specifically to determine the capabilities of the diamond coring system (DCS), the modified navidrill core barrel (NCB) system, a prototype of the pressure core sampler (PCS), the redesigned extended core barrel (XCB), as well as performance evaluations of ODPÍs coring techniques in deep-water chert sequences, logging technology developed at Lamont-Doherty Geological Observatory, and the deep-water dynamic-positioning capabilities of JOIDES Resolution. Six sites were investiagted during Leg 124E (Site 772 to Site 777).

These sea-trials of the DCS firmly established the feasibility of handling and deploying a slim-hole diamond coring system through ODP 51/2-in. drill pipe suspended from a floating vessel and cutting core in 1600 m of water under severe operating conditions. The trials identified areas that require further development, such as the need for more rugged core barrel systems and resolution of hole instability problems.

Tests of the XCB, the latching system for the "ONDO" temperature-measurement system, the PCS, and the pore water sampler "colleted" delivery system were all successful and proved the NCB system to be superior to the XCB system in coring chert sequences.