1. Stephen Farrington, PE (Transcend)
SCIMPI Overview
Kate Moran, PhD, PE (URI)
Stephen Farrington, PE (Transcend)
Jim Newman, (WHMSI)
Ian Kulin, PE (URI)
Tania Lado Insua (URI)

2. SCIMPI Program Summary
Funded by IODP as a complement to the CORK where appropriate
Objective is to develop an inexpensive seafloor observatory system installable in unlined IODP boreholes
Based on modular design
Included in several IODP proposals

3. SCIMPI Team
University of Rhode Island – Overall development and deployment
Transcendev – Module design and prototype construction
Woods Hole Marine Systems, Inc. – Development of buoyant cable from SCIMPI to command module
Stress Engineering – Deployment tools and procedures
Lamont-Doherty Borehole Research – Deployment tools and testing assistance

4. SCIMPI: Simple Cabled Instrument for Measuring Parameters In-Situ
Modular instrument design enables sensor emplacement at custom depth intervals
Deployable through IODP drill string directly into borehole without re-entry or a ROV
Eventual borehole collapse provides contact with formation
Powered via cable or modular battery packs
When not cabled to an observatory, data are retrievable via ROV

5. SCIMPI From the Bottom Up
500-lb “pig” maintains cable tension, is sensible to winch operator
Structural cable
Measurement Modules with Intervening Buoyant Cable
ROV-serviceable wet-mate connector
Cable from the wet-connect to
Cabled observatory infrastructure or
Command Module
Buoyancy (syntactic foam beads) maintains cable tension, keeps wet-mate connector and Command Module above seafloor while the drill pipe is “stripped”
Buoyancy

6. SCIMPI Pressure Housings
Modular scheme
Design pressure
60 Mpa (8760 psi)
Testing to 72 Mpa (10,500 psi)
Chamber dimensions
Inner diameter: 60mm (2.375”)
Outer diameter: 76.2mm (3.0”)
Inner length: 235mm (9.25”)
Material
17-4PH Stainless, condition H1025
Unfilled PEEK for electrical insulation
FEA performed as design precaution

7. SCIMPI Datalogger Controls power to and commands measurement modules
Auto mode sensing and switching:
Deployment vs. In Situ
Deep sleep mode < v
Leverages .NET Micro Framework
Includes file system, RTC, DIO, SD card driver, UARTS
ROV exchangeable

8. SCIMPI Sensors
Pressure: Paroscientific 401k-101 DigiQuartzTM sensor (0-10k psi, ppb accuracy)
Temperature: Sea-Bird SBE-38 precision oceanographic thermometer
Resistivity: custom Wenner 4-electrode cell and precision electronics
Modular design enables additional sensors

9. SCIMPI Sensor Arrangement
Pressure Sensor Port
Precision Thermometer
Resistivity Contacts

10. SCIMPI 3rd Party Sensors
Temperature: Sea-bird SBE-38
Range: -5 to +35 °C
Absolute accuracy: °C
Resolution: °C
Drift: <0.001 °C in 6 mos.
Pressure: Paroscientific 410k-101
Range: 0-10,000 psi (0-69MPa)
Accuracy: 1 psi (6.9 kPa), 0.01% FS
Resolution: 0.1 psi (690 Pa)0.0001% FS

11. SCIMPI Resistivity Sensor
Wenner style 4-electrode configuration
Custom circuitry
μ-Processor controlled
Cell constant: 1 cm-1
Electrodes of 316 SS
PEEK insulating material
Parts per million precision
Calibration to NIST traceable standards

12. SCIMPI Battery Packs 14.4v, 25Ah per pack Packs are shared in parallel
Lithium thionyl chloride primary cells
Dimensions
Length: 203mm (8.0”)
Circumscribed diameter: 56mm (2.2”)
Each pack designed to power:
Entire SCIMPI for 1 yr (at 20°C)
One measurement module with Pressure for 5+ yrs (at 20°C)

13. Approximate SCIMPI Equipment Costs (US$)
Measurement Module (with buoyancy): $30k w/pressure, $20k w/o pressure
Borehole Cables $3000 ea plus $30 per meter
Command Module $20k
Wet Connect ~$30k per assembly
Example: 7 Measurement Modules plus Command and 300m of cables, ~$350k