INCL (Inclinometer Logging Tool)

Downhole logging sensor measuring the natural gamma emission from surroundings rocks

Measured property = gamma quants per second

SI	Oil Metric	Oil Field
R /s	μ R /hr = 2.8 ·10^-10 R /s	GAPI = 4.2^·10^-10R /s = 1.5^ μ R /hr

_{* – for scintillation detectors}

Scope of Applicability

Depth Matching between cased-hole and open-hole logs
Pick up radioactive anomalies caused by saline water invasion
Pick up radioactive anomalies caused by water invasion or radioactive tracers

Mathematical Model

$\begin{array}{l}\displaystyle GR = (1-\phi_e) \cdot GR_{m} + \phi_e \cdot s_w \cdot GR_w\end{array}$

where $\begin{array}{l}GR_w\end{array}$ is natural gamma radioactivity of formation water and $\begin{array}{l}GR_m\end{array}$ is natural gamma radioactivity of rocks:

$\begin{array}{l}\displaystyle GR_m = \sum_i GR_{mi}\end{array}$

where $\begin{array}{l}GR_{mi}\end{array}$ natural gamma radioactivity of i-th mineral.

Page tree

INCL (Inclinometer Logging Tool)

Scope of Applicability

Mathematical Model