Drilling Risk Management

Solving geomechanical problems and wellbore stability analysis for directional and horizontal well drilling. The software helps minimize drilling risks.

Software versions for Windows and Linux are availableInformation on the software price and purchase conditions will be provided upon requestListed in the Unified Register of Russian Programs for Electronic Computers and Databases
RN-SIGMA - Drilling Risk Management

What’s new in RN-SIGMA 2.0 (1D)

We constantly work to improve RN-SIGMA , releasing new versions regularly.

02/07/2024 Version

02/07/2024 Version

We added:

  • a curve selection window when exporting to the well logging set file;
  • export to mud logging data file by depth (*.las, *.xlsx) and by time (*.xlsx);
  • the function of mask creation from the list of zone names into the well logging calculator (zone_mask operation);
  • processing different names of output fields in custom correlations into “Calculation by zones and facies” method of WBS window (now it is not necessary to give the same names to all output fields).

Besides:

  • there are more options of mask creation by the zone name in the correlation editor (it is now possible to transfer to a function multiple names separated by commas);
  • icons of the corresponding elements and context menu items in the project tree have been added into the main software window for tabs.
12/12/2023 Version

12/12/2023 Version

We added:

  • calculation by zones and facies in "Horizontal stresses" section of WBS window;
  • display and interactive editing of the ECD curve on the log plot in "Well stability in dynamics" section of WBS window;
  • captions for stress diagrams and stereograms of mud density in "Wellbore stability" section of WBS window;
  • negative check when importing maps from RN-KIN;
  • importing several maps simultaneously (it is now possible to select multiple files during import);
  • setting the axes style for histograms and crossplots (available by LMB double-clicking on the axis);
  • UID field for all objects in WITSML client preview.

Besides:

  • the number of polygons in the set is now displayed in the project tree (previously the number of rows was displayed);
  • dialogs for creating sets of mud logging, well logging and point data are made modeless (i.e., while working with the dialogs, the access to the main project window is available).
10/9/2023 Version

10/9/2023 Version

We added:

  • accounting for the time zone during time data import to the server (WITSML client);
  • checking to receive all elements of input curves to calculate user’s correlations (WBS window);
  • a window for selection of wells to be calculated with the possibility of optional well shutting-in (Workflow manager);
  • the possibility to export angular geometry data in RESCUE format to an individual folder.

Besides:

  • "Injection induced fracture height" module moved from the well context menu to the "Well operation" tab of WBS window;
  • Workflow manager window is improved (now there is no dependence on well logging names in methods, well names are specified in drop-down lists in the manager window and may differ);
  • the methods in the workflow can now be optionally disabled (Workflow manager);
  • the reports can now be generated using 1D geomechanical models;
  • the user manual has been updated in the section of geological 3D objects.
08/11/2023 Version

08/11/2023 Version

We added:

  • accounting for time zones in WITSML client (working with time data in the local time zone).

Besides:

  • the search in the element tree on the server is not case sensitive now (WITSML client);
  • the minimum number of data rows is reduced in one request (Settings, WITSML client section).
07/25/2023 Version

07/25/2023 Version

We added:

  • multi-well import of trajectories/well logging into the project tree;
  • the ability to expand/collapse the entire subtree of the project tree selected element;
  • automatic recognition of curve types and UOM on the server (WITSML client).

Besides:

  • the well trajectory is now not necessary to open well logging settings (time log plot);
  • statistics in histograms are now displayed taking into account UOM.
05/30/2023 Version

05/30/2023 Version

We added:

  • copy/paste connections (Settings, WITSML client section);
  • the ability to re-import child elements of a node (WITSML client, element tree on the server);
  • activity check mark on the icons of trajectories and sets of curves (WITSML client, element tree on the server);
  • different icons for curve sets with different index types, one-dimensional curves and images (WITSML client, element tree on the server);
  • the ability to change the sorting order via the tree header (WITSML client, element tree on the server);
  • import of well data (trajectories, well logging, well logging interpretation results) and structural maps from RN-KIN database;
  • "Rock density" field into the group of "Stress state" parameters (1D model).

Besides:

  • the operation of a new curve creation taking into account the specified condition in the well logging calculator now accepts both individual numbers and well logging as input (if_else operation);
  • the element tree on the server is improved (WITSML client);
  • the list of tree elements is updated when adding/removing a set of curves (WITSML client, element tree on the server);
  • "Calculation of hydraulic fracturing gradients" chapter has been added to the user manual.
03/31/2023 Version

03/31/2023 Version

We added:

  • an embedded operation into the well logging calculator to create a new curve accounting for a specified condition (if_else operation);
  • calculation by zones and facies in "Synthetic Density" and "Synthetic Acoustics" sections of WBS window.

Besides:

  • error handling is improved when interacting with the server (WITSML client).
02/21/2023 Version

02/21/2023 Version

We added:

  • the ability to change grid spacing on the tracks and mark frequency on the axes (log plot);
  • icons for track context menu items (log plot);
  • optional displaying textures on the lithological column.

Besides, angular geometry statistic is extended.

12/28/2022 Version

12/28/2022 Version

We added:

  • calculation of ECD during RIH/POOH operation (available via the right-click menu of Well element);
  • assessment of cuttings distribution along the wellbore during drilling (available via the right-click menu of Well element);
  • "Frac ports arrangement" instrument (available from the menu Instruments – Special);
  • importing the set of curves to WITSML server;
  • fracture import from Petrel format file.

Besides:

  • display of additional parameters is added when creating a trend (trend equation, coefficient of determination);
  • an option of curve averaging is added: by facies or interlayers;
  • stereogram visualization is added into "Fracture reactivation" method;
  • multiple intersection is now taken into account when creating zones.
09/01/2022 Version

09/01/2022 Version

We added:

  • generation of a daily report on geomechanical drilling support in .xlsx format;
  • entry fields for the type and range of values into logging templates;
  • export/import of track group templates on the log plot;
  • support for local coordinate systems when importing the geological grid.

Besides:

  • it is now possible to change colors of histogram blocks;
  • "Data type" field is added into the property cube statistics window.
06/01/2022 Version

06/01/2022 Version

We added:

  • a beta version of mud logging curves analysis by depth or time;
  • the ability to stop one-time synchronization of values in WITSML-client;
  • statistics visualization using curves on the log plot track;
  • the ability to hide captions for zone markers using Application Settings;
  • the ability to determine the orientation of zone captions using Application Settings;
  • the ability to add a curve with undefined values into the well logging set;
  • a converter to convert curves of "Pressure" type into curves of "Density" type and vice versa;
  • calculation of equivalent circulating density into "Density integral" method in "Geostatic pressure" section of WBS window;
  • "Poroelastic model with pore pressure change" method into "Horizontal stresses" section of WBS window;
  • saving the log plot depth range within each method in WBS window;
  • the ability to display fault properties in a tabular form;
  • a button into the log plot toolbar and an item into the track menu to enter display boundaries by depth/time.

Besides:

  • working with projects located on a network drive is stabilized;
  • interactive setting of stitching points depths is added into the window for stitching well logging curves;
  • "Collapse all" button is added for the project tree;
  • support for integer interpolation of property cube values is implemented.
03/10/2022 Version

03/10/2022 Version

We added:

  • new features for exporting a log plot image to .pdf with the ability to split into several pages;
  • entering the size in pixels using sheet format selection when exporting a log plot image;
  • the ability to add, edit and delete comments on the log plot;
  • eccentricity and ovality calculation into multifinger caliper analysis;
  • tool type "Arbitrary" for processing caliper data with an arbitrary number of fingers into multifinger caliper analysis;
  • imaging during selection of tool type "Arbitrary" into multifinger caliper analysis;
  • the ability to get properties of wells and boreholes into WITSML-client preview area;
  • displaying tables with values for trajectories and curves into WITSML-client preview area;
  • setting the maximum number of data rows imported as part of the curve preview in WITSML-client;
  • method of combining curves by zones in "Geostatic pressure" section of WBS window;
  • well logging operation "Integrating".

Besides:

  • settings of zone display styles on the log plot are expanded, they can be now saved to the project file;
  • property tables for trajectories, curves and curve sets are expanded in WITSML-client preview area;
  • object update modes in WITSML-client are improved.
12/03/2021 Version

12/03/2021 Version

We added:

  • restoring windows opened from project tree elements;
  • importing trajectories from files of arbitrary format;
  • exporting a log plot image of a given size in a given data display range;
  • selecting a curve in the project tree while selecting this curve on the log plot;
  • displaying the well construction in depth on the log plot;
  • creating an exponential type trend for "Create a trend" well logging operation;
  • "Extrapolation" well logging operation;
  • group selection/removal of filters, selection/removal of similar filters in different wells when working with a histogram and a crossplot;
  • clustering with an arbitrary set of curves.

Besides:

  • "Angle" type curves are available for selection in "Combine curves" method of WBS window "Strength properties" section;
  • operating with a workflow file copy is implemented;
  • an option to copy/paste workflows is added into the workflow manager;
  • saving point data and track of zones is implemented in the track group template;
  • during well logging, interpolation is performed only for intermediate values of the initial curve, not at its ends;
  • an asynchronous operation mode of WITSML-client is implemented;
  • new features are implemented: automatic setting of a new project element type (a new mud logging curve (depth/time)) and curve UOM description while dragging the curve into WITSML-client mapping table;
  • the user manual is updated.
09/03/2021 Version

09/03/2021 Version

We added:

  • creating the curve of destruction criterion by zones and taking this curve into account during WBS calculation
  • calculating and displaying the curve of maximum wellbore wall shear stress during WBS calculation with "Synthetic Image" additional option
  • accounting for the zone cube, constant or trend cube when interpolating cubes
  • depth derivative/lateral cube calculation into the cube calculator

Besides:

  • error messages now appear in a popup while calculating scripts
  • the first update cycle for project items starts immediately during auto synchronizing initiation in WITSML client
07/30/2021 Version

07/30/2021 Version

We added:

  • selecting zones/lithotypes when calculating wellbore stability with additional options
  • importing, storing and displaying fractures, faults and points in space
  • supporting import of data on surfaces, polygones and points in CPS-3, Z-MAP, XYZ formats
  • data export in RESCUE format
  • a variogram analysis tool
  • calculating property cubes using Python scripts
  • the ability to set and change the dataset display name
  • the ability to use the context menu to change WITSML protocol connection
  • visualization of maximum trajectory TVD
  • optional output parameter calculation for the Traugott method ("Synthetic density" section) and for the method of calculating dynamic elastic moduli from interval velocities ("Dynamic properties" section) into the wellbore stability element
  • accounting for the domain when inserting zones

Besides:

  • creating the cubes using well logging data can now be performed simultaneously for various datasets, if the algorithms coincide completely
  • saving curves in the well logging calculator is fixed
  • the report on multivariate modeling is modified
  • now the sludge diagram data is displayed on one log plot track by default
  • sludge diagram visualization is fixed and accelerated
  • the trajectory determination area boundaries are now taken into account when entering and inserting zones
06/02/2021 Version

06/02/2021 Version

We added:

  • acounting for UOM when setting the well logging palette in 3D window
  • step-by-step curve import with the ability to set the maximum number of data lines requested at a time (WITSML-client)
  • time recording ang additional recording into mud logging interval (WITSML-client)
  • defining the mud window taking into account breakout width into WBS window
  • recoding into the lithology column
  • multivariate calculations using selected parameters into the Geomechanical model
  • an option to enter the scale into Visualization window (mud logging data vs time)

Besides:

  • now there is no need to recalculate safe mud window when Synthetic image and Synthetic caliper options are enabled in "Well stability" section of WBS window
  • the curves from a removed set are automatically combined into one project set in WITSML-client
  • "Combining curves" method has been returned to the available methods lists in "Static elastic properties" and "Strength properties" sections of WBS window
  • in the Eaton and Bowers methods the lithocolumn is plotted according to the averaged curve during gamma ray logging averaging (previously, averaging had no effect on lithology) in "Pore pressure" section of WBS window
  • the values entered in the table are automatically saved without pressing Enter in Zone editing window
04/09/2021 Version

04/09/2021 Version

We added:

  • an option of creating a 1D WBS model, which is a set of well logs containing information on mechanical, strength and other properties, including well stress state
  • importing only top zones or using marker data
  • custom point dataset creating tool
  • «Operations» module for point data
  • calculation of a derivative into well logging operations
  • description into the well logging window
  • cement ring destruction diagram into «Cement ring stability modeling» method
  • a movable depth mark line into «Cement ring stability modeling» and «Sand production modeling» methods
  • a tree for managing styles and visibility of objects into the 3D window
  • modeling clusters by lithology, with or without modeling by zones into «Clustering» module

Besides:

  • now calculations are performed in MD (in previous versions they were performed in TVD, which did not allow taking into account horizontal sections of the well)
  • «Fracture reactivation» and «Fracture reactivation potential» methods are now combined
  • Borehole geometry tool (two-finger caliper) data analysis is now available
  • «Fracture reactivation» method is supplemented by depth selection and the Mohr diagram visualization
02/16/2021 Version

02/16/2021 Version

We added:

  • a new mud log data vs time window, which allows forming individual polygonal chain and scale graphs and saving the resulting graph structure in templates
  • the ability to visualize zones in the form of a colored interval on an individual track within the log plot with the center caption

Besides:

  • the log plot filling option is modified, now it can be set with one color and on both sides of the curve simultaneously
  • the user manual is fully updated
12/21/2020 Version

12/21/2020 Version

We added:

  • a hole size and material grain dependence of strength into sand production simulation
  • saving the simulation result of one direction fracture propagation (injection induced fracture module)
  • managing the case of defined bottomhole pressure exceeding the pressure of crossing data availability interval (injection induced fracture module)
  • visualization of the reactivation density upper and lower limits in the «Wellbore stability analysis» method when «Weak plane» option is enabled

Besides:

  • the trend curve is now calculated for the entire well trajectory in the well log window (in the previous versions the trend curve was plotted only for the initial well log curve depths)
  • the calculation algorithm in «Porothermoelastic dynamic wellbore stability analysis» method was improved
11/09/2020 Verison

11/09/2020 Verison

We added:

  • wellbore shape 3D visualization into multifinger caliper analysis
  • an option of using caliper fingers positioning into multifinger caliper analysis and visualization
  • an operation of well log curve shifting along MD

We implemented:

  • dynamic modeling module with the option to select a function to describe time dependence of input parameters
  • «Porothermoelastic dynamic wellbore stability analysis» method
  • «Viscoelastic dynamic wellbore stability analysis» method (Burger's model)
  • Options in the «Wellbore stability analysis» method to account for mud cake influence and plastic material properties
  • «Sand production modeling» method (Hettema's and Wilson's models)
  • «Cement ring stability modeling» method
10/01/2020 Version

10/01/2020 Version

We added:

  • operations for averaging, shifting, stretching and clearing well log values
  • 3D window in the Tools menu and also the ability to save the state of this window into a separate project element
  • UOM converter

We implemented:

  • visualization of accumulated histograms and a cumulative curve and quantiles in the histogram window
  • Traugott's method for calculating synthetic density
  • modification of the dynamic addition to the mud density calculation
08/13/2020 Version

08/13/2020 Version

We added:

  • coloring by filters in the cross-plot window and in the histogram window;
  • displaying statistics on clusters in the clustering window;
  • Miller's method and Amoco empirical relation for calculating synthetic density;
  • linear transformation and stretching / compressing in well log curve operations.

We implemented:

  • tectonic regime determination module;
  • the ability to set overlapping sections in the construction window;
  • sorting by depth when importing well log curves.
07/17/2020 Version

07/17/2020 Version

We added:

  • the ability to define sections of the wellbore open part in the well construction window
  • visualization and editing trajectory parameters: rotary table height, ground level height, wellhead height, local sea level height
  • accounting for normal compaction trends during properties transfer
  • saving plotted polygons in the cross-plot window

We implemented:

  • optional display of the determination coefficient R ^ 2 in the curve formula on the graph as well as font selection for the caption with the formula in the cross-plot window
  • model of associated porothermoelasticity in critical densities calculation
06/22/2020 Version

06/22/2020 Version

We added:

  • calculation of injection induced fracture height in an injection well;
  • calculation of pore pressure in the sandbody in clays (accounting for centroid effect);
  • creation of dependencies in the cross-plot tool using multiple wells data;
  • possibility to import the trajectory, using three curves: depth, zenith, azimuth (WITSML-client);
  • information display table into the preview window (WITSML-client).

We implemented:

  • algorithm for estimation of maximum and minimum horizontal stress components using borehole imager data;
  • algorithm for estimation of maximum horizontal stress and its direction using borehole imager data on breakout direction and width;
  • data synchronization when well logs changing (when simulating in the wellbore stability window, modeling workflow, when upgrading with WITSML-client).
05/19/2020 Version

05/19/2020 Version

We added:

  • an option of calculating and modeling critical density, stereograms, stress diagrams, synthetic images and the caliper taking into account elastic properties anisotropy;
  • static elastic properties calculation using the effective model of a layered medium;
  • an option of disconnecting from WITSML-server.

We implemented:

  • importing data by drag-and-drop on the element of the project tree;
  • viewing and editing parametres of methods in the workflow manager;
  • data curve operations window, including trend creating, interpolation, value averaging by wavelets, value averaging by facies.
04/22/2020 Version

04/22/2020 Version

We added:

  • loading and visualisation of cubes, maps and polygons;
  • clustering module, including clustering by machine learning methods;
  • exponent calculating methods for abnormal pressure zones prediction with Eaton's method.

We implemented:

  • cube building from WL set and properties profiles building from the cube;
  • operation of cube properties interpolation;
  • well shape visualisation using multifinger calipers data.

03/18/2020 Version

03/18/2020 Version

We implemented:

  • calculation of model properties by facies with / without zones;
  • methods for assessing the physical and mechanical properties of rocks according to well log and mud logs.

We added:

  • taking into account bedding planes while calculating critical densities;
  • fracture reactivation simulation.
02/14/2020 Version

02/14/2020 Version

We added:

  • an output of friction angle for each given Mohr circle to the strength certificate;
  • the ability to display the depth axis on the log plot with the time axis;
  • the ability to set input parameters from the keyboard at the selected depth in the stereogram window;
  • taking into account osmotic stresses in the calculation of critical densities.
01/15/2020 Version

01/15/2020 Version

We added:

  • new icons and a dark theme option;
  • filters by zones and lithotypes, display of the trend line equation to the cross-plot window;
  • "Create by Template" option to the log plot;
  • sorting and searching for deleted objects in the WITSML client.
12/18/2019 Version

12/18/2019 Version

We added:

  • several curves from different wells to histogram window;
  • filters by zones and lithotypes;
  • Pressure-Gradient, Gradient-Pressure converters to the tools.
11/21/2019 Version

11/21/2019 Version

We added:

  • the tree with data update settings to the online maintenance module to select a method for updating and installing the workflow;
  • preview to online tracking module.

Besides:

  • the online tracking module implements importing time-dependent data;
  • User Guide is updated.
10/25/2019 Version

10/25/2019 Version

We implemented:

  • online drilling support module;
  • loading, storage and display of mud log data, sludge traces.

Besides, the graph for drilling data has been modified: curves can be placed on separate tracks as on the log plot.

09/28/2019 Version

09/28/2019 Version

New improvements:

  • in the correlation editor variable names are checked for compliance with Python language rules;
  • the ability to load point data into a separate project element is added;
  • equivalent circulating density (ECD) curve and synthetic caliper curve are synchronized.
08/26/2019 Version

08/26/2019 Version

We improved:

  • the inclination and azimuth dependencies of critical densities;
  • the crosshole property transfer module.

Besides, the correlation library is complemented.

07/30/2019 Version

07/30/2019 Version

New improvements:

  • wellbore stability analysis with account of strength anisotropy is introduced;
  • project well property transfer with account of several reference wells is implemented;
  • well data and geomechanical model export toRN-GRID is added.
07/02/2019 Version

07/02/2019 Version

We introduced:

  • recovering horizontal deformations method using well imaging data;
  • a new pore pressure calculating method using point data of fluid density changes with depth;

Besides, new petroelastic modeling methods are expanded.

05/29/2019 Version

05/29/2019 Version

New improvements:

  • saving and display options for cross-plot and histogram objects are expanded;
  • equivalent circulating density (ECD) profile now can be edited using context menu option;
  • variables in log calculator now can be renamed.
04/30/2019 Version

04/30/2019 Version

New improvements:

  • the inclination and azimuth dependencies of critical densities are introduced;
  • the depth for stress diagrams and density stereograms now can be set interactively using 3D well trajectory window;
  • the correlation library is complemented.
12/04/2019 Version

12/04/2019 Version

New improvements:

  • all functions from pandas, scipy and numpy libraries can now be used under 'pd', 'sp', and 'np' aliases in well log calculator and correlation editor;
  • type and measurement units now can be corrected for loaded well log curve;
  • logical operations description is added to the correlation editor.

What’s new in RN-SIGMA 3.0 (3D/4D)

02/07/2024 Version

02/07/2024 Version

We added:

  • setting calculation accuracy and the number of iterations in the near-wellbore zone model (available via the well context menu, item Operations - Near-wellbore zone model);
  • saving the element position and size in 3D model tabs.

Besides:

  • the ribbon of steps in 3D model can now be shifted (via LMB);
  • icons of the corresponding elements and context menu items in the project tree have been added into the main software window for tabs.
12/12/2023 Version

12/12/2023 Version

We added:

  • negative check when importing maps from RN-KIN;
  • importing several maps simultaneously (it is now possible to select multiple files during import);
  • setting the axes style for histograms and crossplots (available by LMB double-clicking on the axis).

Besides:

  • the calculation folder is now removed during case removal in the 3D model (closing the program is now checked: calculation folders that are not linked to any case are removed);
  • the discrete palette for integer property cubes is fixed (now by default the palette contains only the values that are in the cube);
  • the project tree now displays the number of polygons in the set (the number of lines was displayed previously);
  • numbering of faults in the set is fixed (now integer numbering from 1);
  • the seismic data import window is updated.
10/13/2023 Version

10/13/2023 Version

We added:

  • accounting for inactive cells in the 3D model when calculating the stress-strain state with HDM;
  • calculation of the main values and invariants of the resulting tensors in “Calculation” tab of the 3D model (optional, enabled in case calculation options);
  • a warning before restarting the 3D model calculation that previous results will be removed;
  • specifying inclination and azimuth as cubes in “Wellbore stability analysis” tab of the 3D model (optional, specified in calculation parameters);
  • exporting angular geometry data in RESCUE format to a separate folder (optional, configured in the export dialog);
  • numerical calculation of stress-strain state and optional comparison with analytical calculation in the near-wellbore zone model (available via the well context menu, Operations - Near-wellbore zone model);
  • reactivation of faults and fractures in the near-wellbore zone model (available via the well context menu, Operations - Near-wellbore zone model).

Besides:

  • a toolbar with actions is now available on the tabs of the 3D model 3D window (saving the picture to a file/clipboard, resetting the camera);
  • the main 3D model tabs are renamed (“Filling in properties” -> “Stress-strain properties”, “Fracture modeling” -> “Faults/fractures”, “Pressure, Temperature, Saturation” -> “Pressure, Saturation, Temperature”);
  • the interface and core for calculating plasticity are updated in the 3D model (plasticity calculation parameters are separated into an individual group in the table of case calculation parameters);
  • calculation options in the 3D model are separated into an individual group (“Calculation” tab);
  • calculated 3D/4D cubes are now saved using the floppy disk icon in the upper right corner of the 3D model “Calculation” tab (cubes for 3D calculations and cubes for the last step of 4D calculations were previously saved in the tree automatically);
  • 4D calculation can now be stopped by clicking a stop button in the upper right corner of the 3D model “Calculation” tab;
  • window update when removing the selected well from the project is fixed in “Wellbore stability analysis” tab of the 3D model;
  • the view of a clicked region block button is fixed for “Default” theme in “Stress-strain properties” tab of the 3D model (a clicked button was previously no different from a non-clicked one);
  • transferring cubes from one angular geometry to another is fixed;
  • obtaining the new element name when saving the cut grid is fixed (angular geometries with the same names were previously created in the project root);
  • removing variables from the list is fixed in the Angular geometry cube calculator;
  • a default folder name in the project tree when importing a model from a file is fixed (Hydrodynamic model);
  • displaying sets of points in the 3D window is fixed (the size of the elements is increased);
  • reports on geomechanical 1D models can now be generated (available via the main project menu, Reports - On geomechanical models).

The Basic Process of Building a 1D Geomechanical Model

Synthetic Density Calculation

Synthetic Density Calculation

Density curve is the basis for recovering a lot of reservoir parameters. The main source of information on rock density is density gamma-gamma-ray logging. This kind of logging cannot be held in the conductor area thus its log requires a recovery procedure up to the surface.

Geostatic Pressure Profile Building

Geostatic Pressure Profile Building

Geostatic pressure is the pressure of overlying rocks. The geostatic load is equivalent to the weight of the overlying stratum of sediments (rocks and fluids) at any point in the earth's crust and can be determined using density log recovered up to the surface.

Pore Pressure Calculation

Pore Pressure Calculation

Pore pressure is the fluid pressure in rock pores. Methods for determining pore pressure are hydrostatic pressure calculation, Eaton and Bowers methods with clay line determination, and also the method using pore pressure gradient data.

Elastic Properties Calculation

Elastic Properties Calculation

A saturated porous medium can be characterized by three elastic moduli: Young's modulus, Poisson's ratio, and poroelasticity coefficient. Dynamic elastic modules can be used to recover static ones.

Strength Properties Calculation

Strength Properties Calculation

Strength characteristics are parameters determining the critical loads , the excess of which leads to the material destruction. Three main parameters can be measured: uniaxial compression strength, tensile strength and internal friction angle.

Horizontal Stress

Horizontal Stress

Horizontal stresses are lateral stresses that arise in a rock under the rock pressure and tectonic forces influence. The main method of determination is direct calculation using function of rock and pore pressure and tectonic deformation values.

Safe Mud Density Window

Safe Mud Density Window

Safe Mud Density Window is the equivalent circulating density (ECD) range that guarantees the absence of critically dangerous incidents during well drilling operation, e.g. reservoir fluid inflow, borehole wall collapse, drilling mud loss and long crack formation.

Benefits

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 calculating 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 calculating wellbore stability taking into account thermal effects.

Custom Python Programming Solutions

RN-SIGMA allows implementation and transfer of 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 making 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.

Calculation of fracture and fault reactivation

The software helps determine critically stressed faults/fractures and calculate critical reservoir pressure for breaking fault/fracture stability.

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.

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 performing a full cycle workflow on data gathering, analyzing and pre-processing, building and transferring one-dimensional geomechanical models, predicting drilling complications and risks arising from geological reasons, optimizing the wellbore trajectory and construction and calculating a safe drilling mud density range.

Plans

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.

    Advantages:

    • 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.

    Advantages:

    • 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 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.

About Course

About Course

As a result of training, the course participants get knowledge about the subject and task of geomechanics in the drilling wellbore processes and skills of work with RN-SIGMA software.

The target audience of this course includes specialists in drilling planning and support, geomechanics and related fields.

Course Content

Course Content

Lecture on the theory of geomechanics with practical examples (3.5 + 3.5 hours).

Lecture on principles and general approaches to the construction of one-dimensional geomechanical models (2 hours).

Acquaintance with RN-SIGMA, work with tools (1.5 hours).

An example of building a one-dimensional model of wellbore stability (3.5 hours).

Independent work with a ready-made sample of data, or with examples of participants (5 hours).

Examples of working with auxiliary modules (2 hours).

Course Experience

Course Experience

We have conducted 9 trainings in Ufa, Moscow and Tyumen in 2 years. More than 100 participants attended our training courses.

Who Uses (Clients)

RN-SIGMA software is used by geomechanical specialists from more than 15 Rosneft subsidiaries (150+ license).