Solve the problem
- Lithological dismemberment of the section
- Determination of the ratio and type of porosity of rocks
- Allocation of permeable layers
- The calculation of the elastic moduli of rocks
- The calculation of the direction of anisotropy according to the cross-dipole probe
Advantages
- Eight receiving stations provide maximum accuracy of calculations in comparison with two-channel equipment, such as AVAC, MAC, etc.
- The low frequency of the dipole emitter (1.8 kHz) allows to reliably determine the parameters of transverse waves without correction for the velocity dispersion
- The diameter of the device 73mm allows you to work in small diameter wells (95 mm) and through the drilling tool
- Work on a three-core geophysical cable
The composition of the device
Receiver module
Eight 4-channel stations provide registration of wave packets
Emitter module
Two monopole and cross-dipole radiator
Own software "Optimus-Interpreter" for processing recorded materials
Scope:
- Separation of p, S and St wave velocities from the monopole emitter to obtain energy, elasticity, porosity and permeability coefficients.
- Obtaining the speeds of fast and slow transverse waves
- Determining the acoustic anisotropy and the azimuthal orientation
- Determination of the speed of fast and slow transverse waves and the orientation of their vectors
Processing step:
1. Preprocessing of data from the device memory, depth-linking.
2. Calculation of interval time of longitudinal, transverse and Stoneley waves.
3. Analysis of the results, the formation of the report.
An example of a tablet processing
It should be noted a good coincidence of the direction of propagation of the fast transverse wave determined by the cross-dipole acoustic logging, and the direction of the maximum horizontal voltage determined by the electric MicroScanner.
Applied algorithms
Calculation of interval time by STC (semblance) | |
Construction of dispersion map of velocities | |
The determination of the direction of anisotropy by the method of Alford |
Comparison 8АД data MPAL
- Interval time of longitudinal waves according 8АД and MPAL well agree among themselves
- the difference between them does not exceed 5%
- Interval times of the fast and slow shear waves according 8АД and MPAL well agree among themselves
- the difference between them does not exceed 10%
- The difference in the direction of propagation of the fast transverse wave is mainly 15 degrees
- With the direction of maximum horizontal stress, determined according to the EMS, better aligned the azimuth of the fast propagation of the shear wave is obtained according Karsar 8АД.