18.11.2014 Views

STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

MWD and LWD 973<br />

Figure 4-269. Example of good similarity displayed between the MWD<br />

gamma ray log and the wireline log.<br />

Spectral Gamma Ray Log. This log makes use of a very efficient tool that<br />

records the individual response to the different radioactive minerals. These<br />

minerals include potassium-40 and the elements in the uranium family as well<br />

as those in the thorium family. The GR spectrum emitted by each element is<br />

made up of easily identifiable lines. As the result of the Compton effect, the<br />

counter records a continuous spectrum. The presence of potassjum, uranium<br />

and thorium can be quantitatively evaluated only with the help of a computer<br />

that calculates in real time the amounts present. The counter consists of a crystal<br />

optically coupled to a photomultiplier. The radiation level is measured in several<br />

energy windows.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!