Thermal Multigate Decay-Lithology Logging Tool
| The TMD-L
tool is a new-generation pulsed-neutron logging tool
which measures the thermal neutron capture
cross-sections (sigma) of both the formation and the
borehole. The sigma parameter is a measure of the
ability of the formation to absorb thermal neutrons.
Because of the strong correlation between the open hole
resistivity log and the sigma log, the sigma log is
considered to be the cased hole equivalent of the
conductivity log. |
|
| Using
induced gamma spectroscopy and decay time measurement,
the TMD-L tool determines oil saturation in reservoirs
with high salinity. Reservoir monitoring includes
measurement of initial and current fluid contacts and
predicts how the fluids will move in the future.
Accurate monitoring of fluid movement in a producing
hydrocarbon reservoir can also yield major economic
benefits through improved recovery (such as better
reservoir management, better placement of infill wells,
and break-through deferral) as well as lower costs from
fewer wells and reduced water and gas handling. |
|
| Other
primary applications of the TMD-L tool include: |
- Cased hole formation evaluation
- Lithology determination
- Enhanced oil recovery monitoring
- Gas vs. tight determination
- Water-flow detection
|
| The TMD-L
tool differs from the competition by applying
alpha-processing which optimally combines near and far
detector responses to provide a sigma curve with the
accuracy of the far detector and the vertical resolution
and precision of the near detector. |
|
| This
leading-edge detector technology results in full
spectrum monitoring for greater amounts of information,
faster logging speeds, and higher accuracy. |
|
| » TMD-L
Tool Features |
| Important
technical improvements associated with the TMD-L tool
include: |
- Larger diameter detectors to produce higher count
rates
- Recording of each detector's decay curve with 61 time gates. These time gates span the entire burst cycle—from build up through decay
- A different background measurement scheme to sample the background more frequently
- Recording of gamma ray spectra for the farspaced or near-spaced detectors during several time windows
- Ability to mount gamma ray detector below the generator and running the tool inverted to facilitate water-flow measurements
|
| The TMD-L
tool also contains these additional features: |
- Simultaneous inelastic and capture spectral
measurements
- Modular hardware design allows custom configurations
- Combinable with production logging
sensors
|
|
|
 |
| Example of gravel pack
evaluation with silicon activation. |
|
| » TMD-L
Tool Benefits |
| The TMD-L
tool offers the following benefits: |
- Accurate water saturation interpretation over a
broad range of borehole conditions and
porosities
- Improved interpretation to help distinguish between gas reservoirs and low-porosity formations
- Improved repeatability, lithology determination, enhanced oil recovery monitoring, and spectral water-flow determination
- Quality indicators for monitoring tool operation and algorithm performance
- Combinable with standard PL sensors to provide
extensive interpretation support, save time at the rig
site and provide special tool configurations for
special challenges
- Identifies problems earlier so production downtime
is reduced
- Combines services for quick, cost effective solutions and reduced production costs
- Can help recommend remedial activities, such as further stimulation or conformance operations to:
-
Optimize production
-
Estimate reserves for better financial planning
-
Explore old wells for additional reserves
-
Help maximize customer return on
investment
|
|
| » Associated
Answer Products |
| The
following answer products are associated with TMD-L: |
| SigmaSat—Sigma Saturation
Analysis |
|
|
| Length |
Diameter |
Maximum Pressure |
Maximum Temperature |
Weight |
| (ft) |
(m) |
(in) |
(mm) |
(psi) |
(Mpa) |
(°F) |
(°C) |
(lb) |
(kg) |
| 25.2 |
7.7 |
1.687 |
4.28 |
20,000 |
137.9 |
350 |
176.7 |
140 |
63.5 |
|
|
|
