Downhole Measurements

Overview

The Ocean Drilling Program runs the most advanced suite of routinely used downhole instruments of any scientific project in the world today. These tools change frequently and rapidly in terms of design and capabilities, and downhole tools specialists sailing on the JOIDES Resolution are often confronted with a bewildering array of instruments and procedures. For many of the downhole tools, fully detailed operating instructions written by the tool designers or manufacturers are available from ODP and onboard the JOIDES Resolution. Factors that are important in planning and conducting measurements are discussed in ODP Technical Note 10.

"ODP" is used here to refer to the ODP Science Operator at Texas A&M University and "LDEO" to the ODP Logging Contractor at Lamont-Doherty Earth Observatory. ODP and LDEO divide downhole measurement responsibilities as follows: LDEO is responsible for tools run on the logging cable (or "wireline") and logging while drilling, whereas ODP is responsible for those tools used with the drill string and/or the nonconducting coring line (or "sandline").

Advanced Planning

It is important to understand that just because a measurement is called "routine" does not mean that it can be made under all circumstances or without significant preparation by ODP technical support staff. Successful use of all downhole tools generally requires some warning prior to sailing, to make sure that proper supplies are available, and to undertake training of scientific and technical personell. To ensure successful use of specific ODP downhole tools on a particular leg, it is advisable to start planning at least one year precruise, and it is essential to keep two organizations fully informed: ODP itself, and the JOIDES panel structure via the Downhole Measurements Panel.

Documentation

Downhole Measurements Provided by LDEO (Wireline/LWD)

• Logging manual (PDF)
• Cookbooks, manuals, and data processing
• Logging tools

Downhole Measurements Provided by TAMU (Drill String)

• Fluid sampling
• Formation temperature measurements
• Orientation of APC and RCB cores
• Long-term observatories (CORK)
• Pressure core sampler (PCS)
• Permiability measurements using packers

Logging School

• Logging school manual (PDF)
• Logging School events
  • La Jolla, U.S. (FY86)
  • Palisades, U.S. (FY87)
  • Tokyo, Japan (FY87)
  • Cambridge, United Kingdom (FY87)
  • Paris, France (FY87)
  • Montreal, Canada (FY87)
  • Hanover, Germany (two events in FY87)
  • Denver, U.S. (FY89)
  • San Francisco, U.S. (FY89)
  • Washington, D.C., U.S. (FY89)
  • College Station, U.S. (FY90)
  • Houston, U.S. (FY90)
  • Townsville, Australia (FY91)
  • Tokyo, Japan (FY92)
  • San Francisco, U.S. (FY94)

Additional Resources

• Ship tour
• ODP Technical Note 10 (ODP web site)
• Thermal Data Collection and Heat Flow Recalculations for ODP Legs 101-180 (ODP web site)