Litho Neutron Density Caliper (LNDC)
LWD Triple Combo Tool
Product Overview
The LNDC tool delivers real-time formation density, neutron porosity, borehole caliper, and azimuthal imaging—enabling enhanced lithology identification, reservoir evaluation, and wellbore stability analysis while drilling. As a key component in a “triple combo” (with gamma ray and resistivity), it supports accurate formation characterization and reserves assessment.
Key Features
- 4 3/4" collar size with compact 13 ft design
- Integrated He-3 neutron detectors for ultra-sensitive formation response
- Measures bulk density, photoelectric factor (PEF), and standoff caliper
- 16-sector azimuthal density imaging for wellbore geometry and lithofacies recognition
- Near-bit neutron/density measurements corrected for environmental effects
Applications & Drilling Scenarios
- Real-time petrophysical evaluation in unconventional or complex reservoirs
- Quantitative understanding of porosity, mineralogy, and hydrocarbon types
- Wellbore stability monitoring for high-angle or unstable formations
- Combined with gamma and resistivity for complete triple combo logging
Advantages
- He-3 detector placement improves signal-to-noise response
- Short bit-to-detector offset enables early decision-making
- Calibrated for environmental conditions, reducing post-processing corrections
Compatibility
Compatible with common MWD/LWD telemetry systems and can be configured in conjunction with resistivity tools.
Technical Specifications
Tool Performance Specifications
| Measurement Type | Range / Performance |
|---|---|
| Azimuthal Litho-Density | Range: 1.5–3.1 g/cc; PEF: 1–7 B/e |
| Azimuthal Litho-Density | Accuracy: ±0.015 g/cc; ±0.25 B/e |
| Azimuthal Litho-Density | Repeatability (180 ft/hr): ±0.01 g/cc @ 2.2 g/cc |
| Azimuthal Litho-Density | Repeatability (180 ft/hr): ±0.25 B/e @ 3 B/e |
| Neutron Porosity | Range: -5 to 100 p.u. |
| Neutron Porosity | Accuracy: ±0.5 p.u. (<10 p.u.); ±5% (10–40 p.u.) |
| Neutron Porosity | Repeatability (180 ft/hr): ±1 p.u. @ 20 p.u. |
| Caliper / Standoff | Range: 0–2" |
| Caliper / Standoff | Accuracy: ±0.1" |
Mechanical Specifications
| Feature | Specification |
|---|---|
| Collar OD | 4 3/4" |
| Length | 13 ft |
| Detector Type | He-3 thermal neutron detectors (external mounted) |
| Azimuthal Resolution | 16 sectors |