Changes

* Excessive weight on bit, which results in cuttings being ground into a fine powder

* Excessive weight on bit, which results in cuttings being ground into a fine powder

* Insufficient mud [[viscosity]], which results in cuttings not being transported to the surface; can be a significant problem in highly deviated and horizontal wells

* Insufficient mud [[viscosity]], which results in cuttings not being transported to the surface; can be a significant problem in highly deviated and horizontal wells

* Improper mud chemistry, which results in (1) a high percentage of cavings that can mask the true drilled lithology, (2) loss of soluble minerals such as gypsum and salt and some shales, and (3) a high percentage of contamination by cement, lost circulation material (LCM), and metal.

* Improper mud chemistry, which results in (1) a high percentage of cavings that can mask the true drilled lithology, (2) loss of soluble minerals such as [[gypsum]] and salt and some shales, and (3) a high percentage of contamination by cement, lost circulation material (LCM), and metal.

Drill cuttings samples can be laid out in small partitioned trays so that vertical changes in rock properties are easier to observe and interpret. The first occurrence of a specific lithology reflects the highest possible position of that bed. However, because the borehole may tend to cave or slough during drilling, a lithology may continue to be present in samples from deeper drilled depths.

Drill cuttings samples can be laid out in small partitioned trays so that vertical changes in rock properties are easier to observe and interpret. The first occurrence of a specific lithology reflects the highest possible position of that bed. However, because the borehole may tend to cave or slough during drilling, a lithology may continue to be present in samples from deeper drilled depths.