Description

Applications

Schematic illustration of the Azimuthal Density Neutron tool (LWD-ADN).

Specifications

ODP Logging Services, Lamont-Doherty Earth Observatory, Rt. 9W, Palisades, NY 10964

Logging-While-DrillingAzimuthal Density Neutron Tool

♦ In situ estimation of bulk porosity and permeability♦ Estimation of fluid pressure♦ Lithology estimation and rock chemistry

characterization♦ Provides information regarding the spatial varation

of physical properties around the borehole

The Azimuthal Density Neutron tool (LWD-ADN) is the latest generation density/neutron LWD tool offered by Schlumberger Drilling & Measurements. Similar to its predecessor, the Compensated Density Neutron tool (CDN), it is combinable with other LWD tools. Unlike the CDN, however, the ADN can be configured to provide real-time apparent neutron porosity, formation bulk density and photoelectric factor data to characterize formation porosity and lithology while drilling. These nuclear measurements are borehole compensated for improved accuracy, standoff, and photoelectric factor measurements while drilling.

Assembly of the ADN tool aboard the JOIDES Resolution.

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* Repeatability due to counting statistics at 2 samples/ft using 3-point averaging.** Sensor specifications. Actual data resolution depends on sampling rate.

0

100

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810

125 m

790CDP

Dep

th (

mbs

f)AB

Site 808 Holes

CI

Sand Turbidites

Volcanic Ash

Mud/Mudstone

Silt Turbidites

Basalt Basement

Lithology

Log dataCore data

Gamma ray (gAPI)

Density (g/cm3)

0 40 80 1 2 3

Rec

over

yFrontal thrust

Décollement

12/2003

Summary diagram showing combined results from a variety of measure-ments. From left to right: depth-converted seismic reflection data, core recovery, lithology, log gamma ray, and core and ADN density. (Figure courtesy of the ODP Leg 196 shipboard scientific party.)