How can differential sticking be best controlled?

• A. Increase mud weight without limit.
• B. Maintain proper mud weight, ensure good hole cleaning, monitor pressure changes, and minimize pipe-wall contact.
• C. Drill faster without regard to hole cleaning.
• D. Use dry drilling mud.

Answer: (B)

Differential sticking happens when the pressure difference between the formation and the drilling mud pushes the drill string against the borehole wall, and a mud cake or filtrate buildup further grips the pipe. The way to prevent it is to keep the differential pressure in a safe range while removing the factors that push the pipe into the wall.

Maintaining proper mud weight within the recommended window helps balance formation pressure and mud pressure, reducing the suction that pulls the pipe toward the wall. Ensuring good hole cleaning keeps the borehole clear of cuttings and filtrate that can form a sticky bridge between the pipe and wall. Monitoring pressure changes lets you detect changes in formation pressure or mud filtration early so you can adjust as needed. Minimizing pipe-wall contact—by centralizing the string and avoiding sections where the pipe run rubs or sticks to the wall—reduces the friction and grip that cause sticking.

Together, these actions address the root causes of differential sticking and are the most effective way to control it. Increasing mud weight without limit or drilling recklessly without hole cleaning would worsen the problem, and using dry drilling mud would remove lubrication and filtration control, offering no real solution.