After we’ve learnt several topics in regard to horizontal well control, today we will talk about how to prevent well control situation both while drilling and while tripping. Since the horizon well control is quite tricky when compared to normal well control due to long reach horizontal section, the best way is to prevent it.
How To Prevent Kick While Drilling (Horizontal Wells)
- After drilling into a pay window, it might be a good idea to flow check in order to check if the mud weight is good for well control before drilling deeper into the zone.
- Plan the horizontal section to penetrate only one known reservoir pressure. Minimize uncertainty of crossing the faults.
- Most of the time, sand in horizontal well has good porosity therefore you might have a chance of losses. The mitigation plan must be in place to deal with this issue.
- Minimize swabbing possibility by BHA design which has the clearances between hole and drilling tool as large as possible.
- Don’t stop the pump while moving pip off bottom. This will prevent swabbing before making up connection.
- Optimize hole cleaning by use proper mud property, flow rate and drilling practices. The well with less cutting bed will have fewer tendencies to swab the kick into the well.
How To Prevent Kick While Tripping in (Horizontal Wells)
- Use a trip tank and a trip sheet to monitor well while tripping in/out.
- Recommend to pump out of hole for the horizontal section. This will reduce a chance of swabbing the well in. Ensure consistency of mud weight while pumping out.
- Pump out with rotation will minimize cutting build up issue. Once pump out of the horizontal section, you may need to circulate bottom up.
- Trip in with proper speed in order to minimize surge issue. Too much surge pressure can fracture formation and it will result in loss of drilling fluid into the well.
- Maximize number of trips for drilling the horizontal zones.
Reference books: Well Control Books