What is used to plug a tube at either end of a well to prevent air circulation?

• A. Rubber plug
• B. Cork
• C. Tape
• D. Purge paper

Answer: (D)

Preventing air movement in a tube during well purging requires a temporary, reliable seal that can be easily inserted and removed. Purge paper is designed for this exact use in purge operations: it can be packed into the tube ends to fill the bore and stop air circulation, then removed cleanly when the purge is finished. This makes it the most practical choice for sealing in this context.

Other materials don’t fit as well. A rubber plug can be harder to remove and may not hold up well in oilfield fluids or under varying pressures. Cork can crumble or shift, which risks leaks or debris in the line. Tape can fail in moist, oily environments and does not always provide an airtight seal. Purge paper’s design for line sealing during purge tasks gives it the reliable, temporary performance needed in this scenario.