Waveform acoustic logging tool АVАК-11

The tool has the following modifications by max operating temperature T _max and upper value of borehole hydrostatic pressure P_max : 
 by temperature: 120, 150°С,
 by pressure: 80, 100, 120 МPа.
Designed to measure propagation parameters of compressional, shear and Stonely waves including measuring in low-velocity sections and through the casing string.

Used for open and cased holes filled with water- or oil-base mud; operates with a three-conductor logging cable up to 7000 meters long.

Applications:
 well section lithological identification;
 determination of rocks porosity factor and type;
 permeable formations identification;
 estimation of rocks elasticity modulus;
 evaluation of near-borehole zone acoustic anisotropy and filtration properties. 

The measuring sonde includes: transmitter unit and two receiver units divided by acoustic insulators. The transmitter unit contains three monopole transmitters IM1, IM2, IM3 and two dipole transmitters in one cross-section ID1, ID2 (cross-dipole). IM1 transmitter is cylindrical and magnetostrictive with basic frequency of 20 kHz;   IM2  transmitter is piston and magnetostrictive with basic frequency of 8 kHz and radiation pattern solid angle at the level of 0.5¸60°;   IM3 transmitter is piston and magnetostrictive with basic frequency of 2.5 kHz. Transmitters ID1, ID2 are piezoelectric ceramic with basic frequency of 4 kHz. The receiver units are identical and each of them contains one monopole receiver PM1 and PM2 and two dipole receivers PD1 and PD2 (cross-dipoles). Sondes formulas:  
for monopole transmitter with basic frequency of 20 kHz: PМ₂0.5PМ₁1.5IМ₁;
for monopole transmitter with basic frequency of 8 kHz: PМ₂0.5PМ₁2.0IМ₂;
for Stonely wave excitation: PМ₂0.5PМ₁2.0IМ₃;
for dipole transmitter: PD₂0.5PD₁1.7ID.