It should be noted that salvage value provisions typically overvalue equipment. The last two options will cost more, since the plugger assumes more risk. If actually selling the well, a change of operator notification should be filed, and a written agreement should spell out terms and time limits. Operators should research and discover what requirements the plugging operations must meet, and realize that notifications and paperwork may be required for multiple agencies. The operator, not the field inspector, must make decisions about the plugging procedure, or problems encountered, once operations are begun.
Good communication is central to resolving many problems.
Rules may vary by state, but typically plugs must be set to isolate any formation that bears hydrogen sulfide, oil or gas, or treatable water. Cement plugs are more applicable to shallower 3,000 to 4,000ft. wells. Open-hole plugs may be required at intervals of every 2,500 to 3,000 ft. as the casing is pulled. Mud used during plugging operations prevents blowouts and helps prevent cement plugs from falling. Blowout preventers may not be required, but are recommended.