Geosteering
Encyclopedia
In the process of drilling a borehole
, geosteering is the act of adjusting the borehole position (inclination
and azimuth angles) on the fly to reach one or more geological targets. These changes are based on geological information gathered while drilling.
A well plan is a continuous succession of straight and curved lines representing the geometrical figure of the expected well path. A well plan is always projected on vertical and horizontal maps.
While the borehole is being drilled according to the well plan, new geological information is gathered from mud logging, Measurement While Drilling and Logging While Drilling
. These usually show some differences from what is expected from the model. As the model is continuously updated with the new geological information (formation evaluation
) and the borehole position (well deviation survey), changes start to appear in the geological substructures and can lead to the well plan being updated to reach the corrected geological targets.
Well drilling
Well drilling is the process of drilling a hole in the ground for the extraction of a natural resource such as ground water, natural gas, or petroleum...
, geosteering is the act of adjusting the borehole position (inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
and azimuth angles) on the fly to reach one or more geological targets. These changes are based on geological information gathered while drilling.
Description
From 2D and 3D models of underground substructures, deviated wells (2D and 3D) are planned in advance to achieve specific goals: exploration, fluids production, fluids injection or technical.A well plan is a continuous succession of straight and curved lines representing the geometrical figure of the expected well path. A well plan is always projected on vertical and horizontal maps.
While the borehole is being drilled according to the well plan, new geological information is gathered from mud logging, Measurement While Drilling and Logging While Drilling
Logging While Drilling
Logging While Drilling is a technique of conveying well logging tools into the well borehole downhole as part of the bottom hole assembly ....
. These usually show some differences from what is expected from the model. As the model is continuously updated with the new geological information (formation evaluation
Formation evaluation
In petroleum exploration and development, formation evaluation is used to determine the ability of a borehole to produce petroleum. Essentially, it is the process of "recognizing a commercial well when you drill one"....
) and the borehole position (well deviation survey), changes start to appear in the geological substructures and can lead to the well plan being updated to reach the corrected geological targets.