Subsalt
You may have struggled with severe vibration when underreaming through salt. Vibration is usually the culprit for most of the twistoffs, downhole tool failures, and premature bit wear, leading to NPT and increased cost.
We have many years of experience minimizing this harmful vibration with our real-time drilling optimization service. We synchronize the pilot bit with our GaugePro™ XPR expandable reamer. This is very important when there are shale inclusions, which are commonly found toward the base of the salt.
Another important challenge is the varying build and walk tendencies when drilling through salt, which can compromise the planned wellbore trajectory. We overcome this deviation tendency with a fit-for-purpose BHA with our rotary closed-loop system and one of our stability-matched PDC bits. This type of BHA enables well path correction for any undesired deviation without compromising the borehole quality or performance or creating high dogleg severity.
Operator drills through more than 2 1/2 miles of salt and saves 10 days
One of the operator’s main objectives was to minimize connection times while drilling through this salt section in more than 3,000 ft of water. Previous average connection times on offset wells were 27 min. Downlinking on the fly and minimizing survey times were paramount to accomplish this goal. Verticality control through the first three hole sections called for closely monitoring near-bit inclination data and efficient downlinking to keep the assembly drilling straight.
In all hole sections, vibration control and mitigation were necessary. We used CoPilot™ real-time drilling optimization service to monitor downhole drilling dynamics. Kickoff and build from vertical in the salt were accomplished with our AutoTrak™ rotary closed-loop system.
The operator drilled 13,984 ft of salt (11,465 ft in vertical hole); the average connection time in salt was 17 min prior to gas intrusion or 37% less time compared with the offset wells. There was a smooth kickoff and build from vertical with excellent verticality and minimum vibration. The operator successfully identified two bases of salt in real time with our ZoneTrak™ bit resistivity LWD service. The vertical portion of the well was drilled 10 days ahead of AFE at an average spread rate of $800,000 per day.

































































