Capabilities Overview

1312
Gamma Gun/CCL
Log (GG/CCL)
When the gamma-ray tool is combined
with setting tool devices or perforating
guns, it is referred to as a gamma gun.
The Gamma Gun/CCL Log provides depth
correlation when running perforating guns,
plugs, packers and other downhole devices
and can be enabled to pass either positive
(+) or negative (-) voltage and current to
an electric detonator which initiates the
explosive device.
Gamma Gun logging reduces rig time by
recording data in a single logging pass in
conjunction with a wide range of setting
tools and perforating devices for select-
fire or pump-down stage perforating
multipleintervals.
FORMATION EVALUATION
Our services team uses a Spectral Gamma
Ray and/or Compensated Neutron Logging
tool to detect specific information about
the properties of the zone of interest and
formation porosity. This information can
then be used to identify potential zones
of interest and help establish production
regimes that can significantly extend the
life of a well.
Spectral Gamma
Ray (SGR)
GE Oil & Gas has developed an advanced
technology digital Spectral Gamma Ray
Log. The Spectral Gamma Ray utilizes a
very high efficiency NaI2 crystal that is
able to differentiate between the thermal
energy levels of potassium, uranium, and
thorium elements found in formations.
With this ability to detect potassium and
thorium levels, it is useful in identification
of different clay types; with the ability
to detect uranium levels, we can
identify uranium salts associated with
movedwater.
In proven fields, the Spectral Gamma
Ray Log can be used in lieu of Open Hole
logs for formation identification, as in the
Permian Basin.
The Spectral Gamma Ray can also be
configured to detect any radioactive
isotope used in hydraulic fracturing
operations with very little effort.
Compensated
Neutron Log (CNL)
The Compensated Neutron Log standard
offering includes Gamma Ray/CCL and is an
API calibrated tool that provides neutron
porosities for sandstone, limestone, or
dolomite formations—using two very
efficient Helium-3 (He3) thermal neutron
detectors to lessen the effects of the
borehole environment. Two data channels
are sent to the surface computer, which
takes the ratio of the two neutron count
rates and calculates a neutron porosity
compensated for the borehole effects of
casing and cement.
A number of variables to correct porosity
values include cement thickness,
casing size, borehole size, and borehole
temperatures. The compensated neutron
tool includes a gamma ray tool and casing
collar locator.
This tool can be run by itself or in
combination with the radial bond tool.
When run in combination with the radial
bond tool, it acquires all data in a single
pass—and separate logs are produced with
several presentation options.
Applications
The compensated neutron log can be
applied to in-field drilling projects in lieu
of open-hole logs, in order to determine
formation porosity. It can also be used as a
correlation log if no open-hole logs exist.
Features and benefits
The Compensated Neutron Log can
measure formation porosity through
multiple pipe strings.
DEPTH CONTROL/CORRELATION
Gamma Ray/
Neutron Log
(GR/N/CCL)
Our services team has the capability to
combine gamma-ray and neutron logging
in order to obtain the best possible depth
correlation between open-hole and cased-
hole measurements.
A standard Gamma Ray/Neutron/CCL Log
is recorded and correlated to the original
open-hole log or any previously recorded
cased-hole gamma ray or neutron log. This
tool can be run by itself or in combination
with the radial bond log or dual-receiver
cement bond log tools.
Applications
Service specialists can also use this tool for
undefined sands and other situations where
the gamma ray tool alone cannot provide
clear correlation. The Gamma Ray/Neutron/
CCL is also an excellent indicator of possible
hydrogen content in the wellbore.