LDI Density logging tool while drilling

LDI sends gamma rays to the formation through the 137Cs gamma ray source installed on the instrument, the instrument detector measures the amount of the gamma-ray photon reaching the instrument after formation attenuation, and calculates to obtain the formation density and photoelectric index(Pe). The instrument adopts Cs-137 gamma ray source and NaI detector, and is equipped with 16-sector azimuthal measurement imaging technology, and is installed with ultrasonic transducer for acoustic standoff detection and compensation.

Tool specifications
Tool OD: 6.75″
Max. body OD: 210 mm
Hole size range: 8.5~9.875″
Max. operating temperature: 150℃
Max. working pressure: 20,000 psi
Flow rate: 225~650 gpm
Vibration: ≤20 grms(5Hz-1 kHz)
Shock: 500 g@1ms half sine
Bulk density measurement

Operating range: 1.0~3.0 g/cm3
Measurement accuracy: ±0.025 g/cm3(1.7~3.0 g/cm3)
Vertical resolution: 6.5″ (vertical formation)
Imaging: 16 sectors (≤120 rpm)

PE measurement

Operating range: 1~20
Measurement accuracy: ±5%
Vertical resolution: 6.5″ (vertical formation)
Imaging: 16 sectors (≤120 rpm)

Acoustic standoff measurement

Operating range: 1~50 mm
Measurement accuracy: ±2 mm(2~50 mm)


Formation density measurement
Photoelectric index Measurement