Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

• Main Authors: Casey Moore, Masataka Kinoshita, Yasuyuki Kano, Peter Flemings, Timothy Byrne, Eiichiro Araki, Demian Saffer, Lisa McNeill, David Boutt, Mai-Linh Doan, Weiren Lin, Chee Kin Khong, Takatoshi Ito, Yoshihisa Kawamura, Moe Kyaw Thu, Nobu Eguchi, and Ikuo Sawada, Harold Tobin
• Format: Article
• Language: English
• Published: Copernicus Publications 2012-04-01
• Series: Scientific Drilling
• Subjects: NanTroSEIZE
• Online Access: http://www.iodp.org/index.php?option=com_docman&task=doc_download&gid=3402
• ISSN: 1816-8957; 1816-3459

Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP) Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumberger)wireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity), and the least principal stress (S3) at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010). The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008), and leak-off test (Lin et al., 2008) and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009). In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future.