Welcome to Drisana Geotechnical Consultancy!

  • 93/C, Ganguli Bagan (E), Kendua, Kolkata-700084
  • Mobile: 9433338146
  • dgconsultancy015@gmail.com

downhole shear wave test

Equipments and Accessories

  1. Seismograph : Signal enhancement type fully digital 24 channel seismograph
  2. Geophones : Borehole 3D Geophone
  3. Cable : Geophone spread cables, 1m spacing, and water proof joints
  4. Hammer : Downhole hammer
  5. Software : Win_Downhole

Principles

A tri-axial geophone is moved down into a borehole connected with a seismograph regularly, the geophones are jammed into the hole. On the ground surface, P and S wave are generated usually with a sledge hammer hitting a beam. P waves are done hitting vertically an aluminium plate on the ground. To create S waves, we can strike a piece of wood firmly blocked (below cars tire for example).

Data acquisition

  1. For field data collection we will use the following I) Triaxial géophones (10 Hz) II) Digital seismograph III) Software (Win_Downhole)

Win_Downhole

This software is designed to process downhole seismic using a tri axis geophone clamped into the hole and energy source at the surface. P-Wave and S-Wave are generated and recorded in order to compute the Elastic properties.

For analysis the field data using Win_downhole following step require

  1. Conversion to SU format
  2. Depth and type (P, S1, S2) input for all traces
  3. Extraction of P, S1, S2 traces
  4. FBP picking on P and S traces
  5. Velocity / Depth Diagram
  6. odulus computation

Formula:

From downhole test we calculate the following Dynamic properties.

Photograph

Over 12 years of experience we’ll ensure you get the best guidance.