The Motion Decoupled Delivery System: A New Deployment System for Downhole Tools
Friday, 19 December 2014: 12:01 PM
The Motion Decoupled Hydraulic Delivery System (MDHDS) is a new downhole tool delivery system that is deployed by wireline and uses drill string pressure to advance a penetrometer (or other downhole tool) into the formation at the bottom of the borehole. After hydraulic deployment of the penetrometer, the bottom-hole assembly (BHA) is completely decoupled from the penetrometer; this eliminates the adverse effects of ship heave. We tested the MDHDS at Site U1402 (the location of Site 1073, ODP Leg 174A), offshore New Jersey, during two days of ship time during Integrated Ocean Drilling Program (IODP) Expedition 342. We emplaced a penetrometer successfully and documented that the penetrometer was decoupled from drill string movement. The pore pressure (7.5 MPa) was slightly overpressured. Based on this successful field test, the MDHDS has been certified by the USIO for shipboard use. The MDHDS is an IODP-funded engineering development led by The University of Texas at Austin, in conjunction with the USIO and Stress Engineering Services. This sea trial was the culmination of a 7 year development effort that included extensive engineering design, fabrication, and field testing.