1. As a result of the API pilot tests performed on a mud sample in the laboratory, the desired rheological properties were obtained when 10 gr of lignosulfonate was used. Calculate how many sacks of lignosulfonate (50 LBM/sack) are needed in a tank containing 500 bbl of mud.

2. Consider two vertical tubing strings closed-ended. Both of the strings are identical and have a length of 5,000 ft and 2,000 psi of bottomhole pressure. One tubing is filled with methane (MW=16) and the other is filled with carbon dioxide (MW=44). Without making any calculations determine the gas that yields higher surface pressure, and why.

Answer rating: 100% (QA)

Drilling fluids or drilling muds have several functions including carrying bore cuttings to the surface cooling and lubricating the drill string and controlling subsurface pressures A simple water bas... View the full answer