EC-Drill^® Improves Production from Gas Producer

Improve production from Gas Provider

One well was drilled and completed offshore Norway. The gas rate from the production test was disappointing, with the well producing well below expectations. The reservoir section was drilled with a light OBM. The drilling window was below 0.2 sg. The lower completion was with standalone sand screens.

Due to the disappointing production rate, it was decided to re-drill and make a gravelpack lower completion using water-based mud - a concept successfully used previously on the field with EC-Drill®. 

During drilling and completion there would be a high risk of losses, since the lightest available WBM drilling mud and brine was about 0.2 sg higher than the OBM used when drilling the original well. The MW with WBM was slightly higher than the expected minimum horizontal stress gradient. Making a successful open-hole gravel pack would not be possible due to losses, as the formation would be fractured.

EC-Drill® as solution

The solution was to use EC-Drill®, which reduced the effective mud weight by reducing the mud level in the riser. For the re-drill, the mud level was reduced to almost 400m below RKB which brought the Equivalent Mud Weight (EMW) down by about 0.2 sg, equalling the MW of the OBM used when drilling the original well. This reduction in riser level effectively prevented any losses while drilling and during pumping of the gravel pack.

The gas production test after completing the well with gravelpack and Controlled Mud Level (CML) was successful. The initial gas production test was limited by the size of the flare, so the maximum flow capacity was at this point unknown. Results from this first limited test showed a gas production rate five times higher than the original well.  

Learn more about the EC-Drill® here. 

Challenge solved

The well was drilled and completed with EC-Drill® while facilitating the use of a higher-density water-based drill-in fluid and Gravel Packing as completion method.

The re-drill was completed faster and without losses when using EC-Drill, resulting in a production rate more than five times higher than the original well.

EC-Drill® is now used consistently for gravel packing.

Benefits

• Drill in depleted fields
• Eliminate losses
• Use desired drill-in and completion fluid
• Increased production

Conclusion

• EC-Drill® enabled drilling in depleted field
• EC-Drill® reduced operational time and prevented losses
• EC-Drill® facilitated the use of a water-based drill-in fluid
• EC-Drill® facilitated using gravel pack as completion method
• EC-Drill increases production when used for completion

Curious to learn more about the benefits of the EC-Drill®? Have a look at this webinar presenting case histories from global operations.