Formation Sidewall Density

Dual and triple spaced density


This combinable sonde is suitable for quantitative formation density measurements in uncased holes. It uses a bottom loading gamma ray source (Typically 100 mCi activity) and a set of two or optionally three detectors at different spacing to detect the gamma rays scattered by the formation. The amount of scattered gamma rays is a function of the electron density of the formation material and hence, a function of its bulk density. This relationship is used to calibrate the density sonde and then use it to log the bulk density of the formations crossed by the borehole. In order to optimize performance, the sonde is designed with three main features: A side-walling caliper to ensure that the detector measures only the radiation scattered by the formation. A detector mandrel diameter that is large enough to minimize the sonde and bore hole curvature mismatch and improve sonde to formation contact to minimize the effect of the bore hole fluid. An efficient detector shield to prevent gamma rays from travelling up, inside the sonde body.


Weight: 26.0kg
Length: 2.06m
Detectors: x2, NaI crystals Spaced at 47
and 25 cm (Opt. additional at 14 cm)
Source: 137Cs or 60Co
Max. Temp. 80ºC
Max. Press. 20MPa