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Epslog has developed a suite of softwares for data analysis as well as real time algorithms that could be implemented on any platform.

DREAM Advanced

DREAM is a software developed for the processing, analysis and interpretation of time and depth-based data. The code provides a modular user interface to analyze large data sets from different sources using toolboxes.
The main functionalities are

  • multi user, flexible platform
  • time & depth based data
  • synchronized navigation through several plots
  • and much more…


Epslog Torque and Drag software uses a softstring model that takes into account exact effect of fluid pressure and a “wall climbing effect”:

  • The hydrostatic pressure of the drilling fluid acts normal to the surface in contact with the fluid and should therefore be directed towards the center of curvature of the drillstring rather than being purely vertical as commonly considered in most commercial codes.
  • As the pipe rotates against the borehole wall, it tends to climb-up due to the friction, hence the location of the contact force shifts from the low side of the borehole to a position up along the side of the hole.

The main features of the software are

  • Any 2D or 3D well profiles
  • A drill string with various cross-sections (ID and OD)
  • A boreholes geometries defined by piecewise-constant representation
  • A drilling mud represented as a Newtonian fluid with a constant density
  • A section of the well being cased
  • Desired controlled parameters WOB, RPM, ROP

Two types of simulations can be run

  • Surface torque & drag versus depth in RIH or POOH conditions: this is the conventional approach allowing to predict maximum torque and drag at TD.
  • Single simulation: this mode gives a complete evaluation of stresses experienced by the drillstring/BHA from the surface to the drilling bit for a given set of drilling parameters.

Finally Epslog also developed a full finite element torque and drag model for planar well trajectory, providing contact forces and locations. Further developments are ongoing to extend the usage of the code to compute dominant frequencies (lateral vibrations) of the BHA (estimate possible critical RPM), as well as explore the effect of BHA tools such as underreamers on the system.


Epslog has developed a range of algorithms for the automatic processing of drilling data both in real time and post-mortem. This development includes algorithms for

  • Correction of sheave effect
  • Correction of hydraulic lift
  • Correction of RPM effect
  • Detection of pick-up, slack-off, rotation events
  • Fit hydraulic model (flow-SPP)
  • Detection of connections
  • Estimate of hookload and torque tare values
  • Estimate of WOB, TOB, pressure drop at bit
  • Estimate of TOB from SPP if PDM in the BHA
  • Estimate of depth of cut, ROP, MSE@bit
  • Time to depth transfer
  • A range of tools to import data of different format

Algorithms were trained against weeks of drilling data (tenth of wells, thousands of connections). Epslog has also developed tools tailored to the analysis of bit-rock drilling response, as well a holistic tool to run predictive simulation based on the fitting of simple models (torque and drag, bit-rock interface, hydraulic, hole cleaning, etc…) with data.


The expertise of Epslog includes

  • Extensive experience in the processing of mud-logging data
    • import, review and QC data
    • selection of appropriate filters, time scales to process the data
  • Extensive experience in the analysis of drilling data (surface and downhole)
    • Step-by-step methodology for in-depth analysis of drilling performance
  • Expertise in rock cutting (single cutter, groove geometry, back-rake, side rake angles, chamfer properties)
  • Comprehensive model of bit-rock interface (PDC-roller cone – impregnated)
  • Extensive experience in analysis of laboratory drilling data
  • Effect of pore and mud pressure
  • Torque and drag model (L. Perneder, V. Denoel)
  • Stick-slip vibrations (T. Richard and C. Germay, PhD thesis)
  • Directional drilling model (L. Perneder, PhD thesis)
  • PDC bit design (T. Richard and C. Tilman)
  • Design of downhole sub (T. Richard and C. Tilman)

Quote request and demo request can be sent to

start.txt · Last modified: 2022/02/09 16:15 by christophe