The Principles of Geosteering | Geosteering Best Practices

Active Geosteering

After the well has spud, the process of Active Geosteering will require the GeoSteering Team to constantly think ahead of the bit. The Team should follow these guidelines closely.

1. Prioritize lateral length against reservoir exposure before the well lands in section.
2. Segregate data into that which will be useful for geosteering versus that which will be useful for a full reservoir evaluation. Interpret only the data required to make a steering decision when the well is drilling. Save the rest of the data for later, when time is at less of a premium.
3. Have all data in hand when making decisions! It is usually better to wait until you are sure of the wellbore position, rather than rushing to judgment and making unneeded changes.
4. Communicate with the Directional Driller (who is in the best position to know how the well is drilling). This is a two-way exchange, in which the Team describes expected conditions ahead of the bit, while the Driller reports present conditions:
   • Wellbore conditions
   • BHA performance-
     • How much build up and down?
     • Will he be able to change angle while rotating?
     • Will he be able to change angle using WOB?
     • Will he be able to change angle using ROP?
   • When will torque & drag problems make it impossible to slide?
   • Give the Directional Driller as much flexibility in changing targets as is possible.
   • Communicate targets that are possible, simple, quantitative, and based upon stratigraphy.
5. Realize that every target change may affect the remainder of well.
   There are consequences for every target change, so weigh the consequences, make a decision, and live with the results. Do not second guess as long as the best decision was made using all of the data.
6. Do NOT over-analyze the data. Though tempting, this practice will generally cause over-reaction and will definitely cause you to loose sleep for no reason.
7. Rest assured that you will be wrong on occasion.
   When you are, don’t try to ignore it or explain it away.
   Instead, just correct the mistake as soon as possible to keep from compounding it.
8. Make as few target changes as possible to meet objectives.