Walnut Shell (walnut husk) is an additive used in drilling mud for oil well drilling operations. This biologically-based material is particularly used for controlling fluid loss (penetration of drilling fluid into the formation).

Fluid Loss Control: Walnut Shell is effective in blocking fissures and pores in the formation due to its structure and large cross-sectional area.

Environmental Compatibility: As a biological and plant-based material, it has no environmental impacts and is compatible with most drilling fluids.

Operational Safety: The use of Walnut Shell helps reduce the risk of cracking or failure of drilling equipment, given its soft and flexible nature.

Increased Efficiency: Walnut Shell contributes to enhancing the overall efficiency of drilling operations, including increasing drilling speed and reducing downtime.

This material meets NISOC standards and falls under the Loss Circulation Materials (LCM) category. Due to its insolubility in acid, it is used to control fluid loss in non-Payzone formations with multiple pores and to block fissures and cracks in the formation created during drilling operations.