Pulsed lithologic logging tool PILK-76
Designed to carry out borehole pulsed neutron logging techniques. Pulsed neutron generator at high frequency radiates geological materials around the borehole tool. At double distance from pulsed neutron source thermal neutron detectors (modification of 2INNK (2ИННК)) record thermal neutron count rate during neutron pulse and thermal neutron flux drop time spectrum after neutron pulse finishing.
Applied in wells with open or cased hole with any circulation fluid type.
Active tasks:
- determination of current oil saturation on oil fields with oilfield brine over 20 g/l and porosity over 12;
- determination of gas-liquid contact;
- determination of hydrogen content and effective reservoir porosity;
- lithologic sectional layering.
Detector units – proportional or corona helium counter tubes (He-3).
High-frequency neutron pulsed generator MFNG-601 (МФНГ-601) with gas-filled neutron tube AREV-40 (АРЕВ-40) is used as neutron source with energy of 14 MeV. Neutron output (at neutron pulse oscillating frequency of 400 Hz) – up to 2´108 neutrons/sec.
If necessary it can be equipped with gamma-ray logging channel to measure natural radioactivity of geological materials and with collar locator to measure boring casing integrity and/or tubing.
| Measured parameters | Range | Accuracy |
| Natural gamma-ray EDR for gamma-ray logging channel | 0÷250 μR/h | 15 % |
| Neutron-capture cross-section | 3÷55 c.u. | 1.5 % |
| Hydrogen content measurement range | 0÷40 % | 4.2+2.3(40/ КA-1) % |
| Collar locating | at least seven times signal level increasing when passing through a collar | |
| General technical specifications | ||
| Tool overall length, mm | 4013 | max |
| Tool diameter, mm | 76 | max |
| Total tool weight, kg | 73 | max |
| Maximum ambient temperature, °C | 120 | |
| Maximum hydrostatic pressure, MPa | 80 | |
| Neutron frequency of oscillation, kHz | 400÷1000 | |
| Logging speed, m/h | 100÷800 | |
| Combinability | terminal / transit | |
| Position in well | free | |