Geosteering Office (GO) is a complete suite of integrated software tools for steering horizontal and highly deviated wells.
GO operates both with real-time data streams and in disconnected mode. It is designed to deal with various complexities using the logging and measurements taken while drilling (LWD/MWD). It maximizes the efficiency of geosteering by integrating all the necessary data with the correlation and modeling tools. You can steer a well with confidence either by using a single gamma-ray log or a full set of LWD measurements.
GO is logical and practical. For example, its drilling interface provides a cross-section of the subsurface model along the planned horizontal well, the horizontal panel with observed and synthetic logs, and a vertical panel with the logs and markers from the offset well—all in one integrated display!
The engineer will load the following data into a project to prepare a geosteering model:
- Offset wells: header, logs, trajectory, markers, fluid contacts. Note: GO supports multiple offset wells in a project.
- The planned well header and trajectory.
- Any 3D structural surfaces delineating the subsurface.
All the data loaded can be quality controlled, and corrected if necessary, in spreadsheets or graphically in GO's Well Correlation, Map or 3D windows.
Well log data from the offset well is posted in the vertical track for correlation to the depth domain. Next, an engineer creates the geosteering scenario. A scenario is based on the subsurface model with log properties derived from the offset well logs along the selected structural surfaces. Such a model provides the prediction of the LWD measurements — synthetic logs.
The synthetic logs are displayed in the horizontal track showing the scale of the planned well trajectory.
Via a URL link provided by the logging operator, the engineer will establish WITSML connectivity to the future real-time data stream. It is also possible to load the LWD logs via data files. Newer data can be appended to previously loaded data.
Geosteering in Real-Time
While you are drilling, actual LWD/MWD data is streaming into the GO software. The data will be displayed in the horizontal track in the Scenario window. The synthetic logs are automatically calculated along the actual trajectory.
The engineer will compare the actual and synthetic logs. A match suggests the correctness of the geological model. A mismatch of the logs requires a correction to the model. The engineer will interactively correct the model by adjusting the dips and/or depths of the formation surfaces, either via bulk shifts or segment by segment. Any such correction instantaneously updates both the subsurface model and the synthetic logs so the engineer can reevaluate the borehole position in real-time. Based on the evaluation, the engineer can recommend trajectory corrections to the drilling crew. In the example below, a 0.3° dip correction was applied to correct the subsurface model. The borehole remains in the zone and requires less upward steering than could have been suggested without using GO.
A geosteering engineer can also predict the drilling bit location with the built-in planning tool.
Geosteering with LWD Borehole Images
Any available real-time log data can be utilized in GO including mud logs and borehole image logs.
You can easily load multiple image logs, format them for better visualization, and choose formation dips. The formation dips in the chosen cross-bedded features are automatically displayed on the geosteering cross-section for more accurate structural updates.
Combining the synthetic logs with the information about the formation dips clarifies the structure behavior and therefore reduces the uncertainties of the geosteering decisions.
The red segments in the cross-section represent formation dips chosen from the upper track of the image log.
3D Structural Model Update
GO allows you to update 3D structural surfaces while you are drilling.
Conventional structural modeling is based on the data derived from wells penetrating modeled structures. GO provides an easy to use functionality that allows you to easily apply such predictive corrections to the structural surfaces without crossing the bottom layer of the reservoir zone. GO uses the corrected surface segments to update the structure surfaces in real-time. Engineers can use either the 3D or the Map Windows for comprehensive data visualization and manipulation. A surface modification procedure can be performed anytime during the drilling to get accurate structure information at that moment or to get the final 3D structure after the well has reached TD. The updated surfaces obtained by using GO can be easily exported back to the geological model in any geomodeling software.
In our geosteering scenario, we performed a structure correction to fit the model to the LWD data. The corrected surface segment was then used to update the reservoir top surface for future reservoir modeling.
Other Useful Features
All project data and canvases are saved automatically. This helps to avoid data and time losses while drilling.
Universal data import/export
GO's universal data loader automatically recognizes and imports survey and log data in commonly used formats without preliminary editing, including LAS and DLIS for well logs.
Structural surfaces can be imported and exported in CPS-3 or IRAP classic grid formats.
The GO software generates automatic reports with recorded recommendations for drilling, selected snapshots of the data, and geosteering scenarios.
Using free-format formulas, an engineer can introduce derived logs and evaluate reservoir properties while drilling using GO.
Hundreds of successful wells have proven GO to be:
- Robust. All the functionality you need is in one package.
- Reliable. GO has been tested on a variety of workstations and laptops. GO features an auto-save function and is regularly updated with software fixes and enhancements.
- Fast. GO gives you truly real-time performance.
- User-Friendly. GO was created by geosteering engineers for geosteering engineers.
Geosteering Ltd. is the official distributor for GO software.