"Using MATLAB is the fastest and most efficient way to produce a quality product."
Dr. Daniel Moos, GeoMechanics International
To extract the maximum amount of oil from reservoirs worldwide, oil companies are drilling more complicated, deeper wells in more hostile environments. When wells run tens of thousands of feet underground, it is difficult to maintain stability in the borehole wall. Industry analysts estimate that drilling problems resulting from wellbore instability cost oil companies approximately $6 billion a year.
GeoMechanics International (GMI) has developed oil field tools that address wellbore instability problems. Among these is GMI• SFIB™ (Stress and Failure of Inclined Boreholes), a set of tools that enables engineers to evaluate how changes in wellbore trajectory, rock strength, and mud weight affect stability.
MathWorks software significantly reduces product development time and costs for GMI. "MATLAB is, by far, the easiest programming environment for scientific use," says Dr. Daniel Moos, senior vice president of GMI's Technology Department. "It enables us to develop robust products in the shortest time possible."
GMI set out to develop a tool that would enable oil companies to improve drilling efficiency by correctly gauging the density of drilling mud needed to minimize wellbore instability.
Drilling mud is a mixture of fluids, weighting material, and chemicals used to flush rock cuttings out of the well while drilling. To ensure wellbore stability, the mud must be of the right density: If the mud weight is too low, the hole will enlarge, leading to excess cuttings and eventual hole collapse. If the mud weight is too high, the formation will fracture, leading to losses of expensive drilling mud, reduced mud weight support, and possible hole collapse.
Gauging the correct density requires detailed understanding of the relationship between the stress field, natural fractures, rock strength, pore pressure, and borehole trajectories. Traditionally, oil companies use geophysical measurements and simplified models to develop mud weight recommendations.
Even in the best cases, standard approaches provide only a partial answer. GMI wanted to create a tool that would apply improved understanding of the causes of wellbore instability to enable more effective analyses. This tool had to be easy to use and make an inherently complicated problem straightforward enough for a drilling engineer to handle in the field.
Using MATLAB®, GMI built tools that perform rapid forward modeling and Monte Carlo simulations during drilling to assess risk and determine which variables have the most impact on reducing risk.
First, they developed a set of modules to constrain the complete stress tensor (the interplay of stresses in three dimensions during drilling). The input data to these modules included, for the first time, quantitative observations of failure in previously drilled wells where the drilling trajectory was known. They used MATLAB to test and find algorithms for determining which stress tensor was compatible with the observations and to design interactive GUIs for delivering interpretable results to the user.
A second set of program modules was developed to use this knowledge of stress to predict wellbore stability and find optimal drilling trajectories and mud weights. GMI used MATLAB to create a graphical interface to display the analysis results clearly and simply.
In the final stage, they used MATLAB Compiler™ to turn the MATLAB code into a standalone application that could be used even by engineers who did not know MATLAB.
“MATLAB Compiler enabled our development engineers to create the final product, removing one link in the development chain,” says Moos. “It also provides a straightforward way to protect our products and is platform-independent in terms of our source code, which is critical for us.”
To enable oil companies to minimize wellbore instability and extract the maximum amount of oil from a well
Use MathWorks tools to develop software that lets drilling engineers and geophysicists analyze key parameters and prevent wellbore failure