Drilling Risk Management

Solving geomechanical problems and wellbore stability analysis for directional and horizontal well drilling.


What's new

New versions of RN-SIGMA are released every 4 weeks.

The Basic Process of Building a 1D Geomechanical Model


RN-SIGMA software product algorithms and approaches are based on the best world practices. RN-SIGMA contains all the necessary algorithms and interface solutions for constructing a one-dimensional geomechanical and wellbore stability model. RN-SIGMA includes a number of relevant non-standard capabilities, such as elastic and strength properties anisotropy, temperature influence on stress state, etc.

Full Well Stability Modeling Cycle

RN-SIGMA introduces a full cycle workflow from data gathering, analysis and preliminary processing to 1D geomechanical model construction. A safe drilling mud density range can be calculated based on the simulation algorithms, and prediction of complications while drilling can be made for further well trajectory and construction optimization.

Custom Processing Templates of Typical Calculations

RN-SIGMA introduces a workflow creating — a sequence of calculation methods for processing a set of wells with similar characteristics and logs.

This tool can significantly reduce the project development time in the presence of several reference wells.

Additional Non-Standard Features

RN-SIGMA core allows to calculate wellbore stability for anisotropic media. The implemented algorithms make it possible to take into account the elastic and strength properties anisotropy.

RN-SIGMA core allows to calculate wellbore stability taking into account thermal effects.

Custom Python Programming Solutions

RN-SIGMA allows to implement and transfer user-own calculation methods using the built-in correlation editor and well log calculator. These tools use the Python programming language that is simple to learn due to minimal syntax. Well log calculator allows to make a quick one-time calculation, and the correlation editor is designed to add and edit permanent custom calculation methods. The transferring option can significantly increase the rate of experience exchange among different users and project groups.

Real-time Geomechanical Tracking

WITSML server data acquisition while drilling will clarify the pre-drilling geomechanical model and improve complications prediction quality in unstable rock intervals

Structural Changes in Rocks Over Time

The solutions with time-dependent properties will allow the wellbore stability calculations to be performed with the dynamic conditions during the drilling process in the near-wellbore zone. Dynamic modeling main advantage is estimating the acceptable time between the moment of opening an unstable interval to the time of well casing.

Intuitive and Simple Interface

The developers of RN-SIGMA tried to design the interface so that it could be accessible and understandable from the very beginning of use. Based on the actual users feedback RN-SIGMA is successfully developing and becoming a more simple and flexible tool.

Solving Problems Easily

A set of implemented tools allows to perform a full cycle workflow on data gathering, analyzing and pre-processing, building and transferring one-dimensional geomechanical models, predicting drilling complications arising from geological reasons, optimizing the wellbore trajectory and construction and calculating a safe drilling mud density range.


New versions of RN-SIGMA are sent out every 4 weeks.

  • Geomechanical 3D Well Modeling

    3D modeling allows solving the problems of rock stress-strain state around the wellbore and joints.


    • Wellbore stability assessment in difficult geological conditions
    • Prediction of complications while drilling complex wells
    • Improving model accuracy and predictive ability
    • Prediction of complications while drilling through rock intervals with nonlinear elastic behavior
  • Geomechanical 4D Field Modeling

    4D modeling includes the functionality of geomechanical and hydrodynamic simulators to account for geomechanical effects during field development.


    • Prediction of changes in stress and deformation fields, rock destruction during development
    • Accounting for the stress state influence on reservoir quality
    • Prediction of reservoir productivity changes caused by geomechanical effects
    • Accurate transfer of the mechanical properties model from the reference well to the design trajectory
  • Assessment of Sand Production Risk

    Advanced algorithms for sand production prediction define higher risk zones, calculation of maximum allowable depression cubes and optimal perforation position and orientation.

  • Assessment of Reservoir Compaction and Day Surface Subsidence

    Provides simulation of reservoir rock deformations, over- and underlying rocks, day surface.

Training Courses

Regular training activities help to improve the efficiency of use and acceleration of the process of RN-SIGMA software product implementation in workflows.

Who Uses (Clients)

RN-SIGMA software is used by geomechanical specialists from more than 10 Rosneft subsidiaries (100+ license).