Advanced CORKs for ODP Drilling in the Nankai Trough: Sustained Observations of Subsurface Pressures in an Accretionary Prism

Becker 00-83156建议项目是为将安装在大洋钻探计划(ODP196)第196段上的两个先进环流阻挡改装套件(A-CORKS)的采购和仪器成本。这些仪器将用于对南开海槽俯冲带三个地层区的地下流体压力进行持续观测-俯冲板块的洋底、增生楔与俯冲地壳之间的滑脱以及增生楔内的主要断层。先进的软木塞使用多个封隔器串来独立地封闭井眼的几个区域，这与最初的软木塞设计形成了鲜明对比，该设计将整个井眼长度的流体压力测量整合在一起。A型软木塞还将允许对现场流体进行最终采样。这项提议是一个更大的跨国努力的一部分，包括加拿大和澳大利亚的资源，用于设计和制造A型软木塞，安装A型软木塞和相关的由日本资助的仪器串，由ODPJOIDES决议钻井船进行，以及在同一邮轮上进行相关的随钻测井(LWD)。后续数据恢复和仪器维修的船舶和潜水器作业将由日本技术机构JAMSTEC提供资金。

Becker 00-83156Recommended project is for acquisition and instrumentation costs for two Advanced Circulation Obviation Retrofit Kits (A-CORKs) that will be installed on Ocean Drilling Program (ODP) Leg 196. These will be used for sustained observations of subsurface fluid pressures in three stratigraphic regions of the Nankai Trough subduction zone- the oceanic basement of the subducting plate, the decollement between the accretionary wedge and the subducting crust, and in major faults within the accretionary wedge. The advanced CORKs use multiple packer strings to independently seal off several regions of the borehole, in contrast to the original CORK design that integrated fluid pressure measurements over the entire borehole length. The A-CORKs will also allow for eventual sampling of in-situ fluids. This proposal is part of a larger, multi-national effort that includes Canadian and ODP resources in designing and fabricating the A-CORKs, installation of the A-CORKs and associated, Japanese-funded instrument strings by the ODP JOIDES Resolution drillship, and related logging-while-drilling (LWD) occurring in conjunction on the same cruise. Ship and submersible operations for follow-up data recovery and instrument servicing will be funded by the Japanese technology agency JAMSTEC.***