Which sampling method is described as continuous sampling of cuttings in air rotary drilling in unconsolidated formations?

• A. Split-Spoon Sampling
• B. Drilling Fluids/Polymers
• C. Continuous Sampling of Cuttings
• D. Core Sampling

Answer: (C)

Continuous sampling of cuttings is used in air rotary drilling of unconsolidated formations because the compressed air lifts the freshly cut material to the surface, allowing a continuous trail of visible samples as drilling progresses. This approach gives a nearly continuous lithology record and grain-size indication, which is especially useful in loose sands and gravels where retrieving intact, undisturbed samples is impractical. Split-spoon sampling, by contrast, relies on discrete samples taken at specific depths with a drive sampler and isn’t aligned with the continuous flow of air-rotary drilling. Core sampling aims for undisturbed, cylindrical samples, which is difficult in unconsolidated formations and not the typical method used with air rotation. Drilling fluids/polymers pertain to the drilling fluid system rather than a sampling method.