GeoFusion is a Laterolog style device.
Laterolog tools need a complete electrical circuit to work.
Current passes from an emitting electrode, through the borehole into the formation and back to the tool via a return electrode on the tool. Resistivity is a function of voltage drop between return electrode and source, and source current. Laterolog tools have to make electric contact with the formation through either a conductive drilling fluid or by direct physical contact.
Laterolog resistivity measurements are ideal for formation evaluation as they have excellent thin bed reponse, they are azimuthally focused and relatively unaffected by anisotropy effects.
Structural and Strategraphic features
High resolution, detailed images of structural and stratigraphic features allow for accurate determination of faults, bedding dip and fracture orientation.
Understanding dip orientation helps geosteering experts to position the wellbore accurately in the desired formation. Further, the dip can be estimated and extrapolated for update to the geologic model.
The 128 sector full wellbore images with 0.4" vertical resolution reveals fracture locations, density and orientation.
A reservoir level approach to this new data source reveals fracture patterns, fracture behaviors, and fracture networks potentially meaning fewer wells could be drilled as these fracture networks become intentionally exploited by future wells.
Accurate Formation Evaluation
GeoFusion has 3 focused resistivity measurements which are all azimuthally focused and have outstanding vertical resolution, in addition to this, the measurement range of the tool is 20,000 ohm-m and the measurement is relatively unaffected by anisotropy meaning that accurate formation evaluation is possible where other technologies suffer.
Geostopping and Wellbore Safety
With its bit resistivity measurement, certain drilling risks can be largely mitigated, such as detection of geopressure anomalies, such as depleted formations before bit penetration by identifying the different resistivity characteristic of that particular formation.
This enables casing to be set and sealed, allowing BHA and mud weight changes to be made before penetrating the next section. With this particular drilling risk eliminated, the drilling team can focus on the next challenge.
Complimentary environmental measurements such as shock and vibration, RPM and temperature enhance decision making in tough drilling environments.
Using Images for borehole condition
Keyseats are a small diameter channel, worn into the side of a larger diameter wellbore.When larger diameter components such as drillpipe joints or BHA parts try to pass through the channel, they can become stuck. Images can locate the exact position of keyseats and other ledge problems.
Keyseats can be mitigated in realtime by intentionally reaming at the correct depth to remove the keyseat.
Wellbore instability - breakout
Wellbore instability events such as breakout are due to shear stress exceeding the rock shear strength in the wellbore wall. Chunks of rock breakoff leading to an oval hole which is filled with conductive drilling fluid. As the image rotates around the wellbore, this charcteristic ovalisation is easy to spot.
Breakout is a signal that a non-optimum mud weight is being run over a particular section. Identifying the direction of breakout can improve decision making for future well planning.