Laboratory Comparative Evaluation of Fat'ha Formation Clays and Commercial Bentonite for Producing Drilling Mud Fluids Suitable for Oil Field of Iraq Conditions

This research focuses on the properties of the claystone for the Fatha Formation and their suitability to use as raw materials in the manufacturing of Drilling mud. Clay samples from the Fatha Formation were gathered from four sites: clay deposits on both banks of Mosul Governorate, Hamrin Anticline in Salah Addin Governorate, and the Dibbs Clay in Kirkuk Governorate. These samples were processed, crushed, and sieved to a particle size of less than 75 microns to ascertain the characteristics of such clay samples even if they might be utilized as locally available substitutes for making drilling mud in various water conditions. All clay sample properties were measured viscosity, density, pH, and fluid loss. The results showed, that when polymers and chemical activators are added in multi-concentration, This could enhance the rheological properties of the clays. Accordingly, the study found that polymers like carboxymethyl cellulose (CMC-LV) could be used as additives to increase viscosity and reduce fluid loss in the drilling fluids. However, The properties of the prepared drilling fluid from the studied Fath Formation clay can be improved by chemical additives as well as polymer.