Abstract
A laboratory investigation evaluates the benefits and problems associated with the use of itabirite (micaceous hematite) as a weighting material in water-based mud. Three different ranges of particle sizes of itabirite were selected for the test: (1) particle sizes between 74 and 125 microns, (2) particle sizes between 44 and 74 microns, (3) particle sizes smaller than 44 microns. Thirty-minute abrasion tests were conducted with a modified Hamilton Beach Blender at 9,800, 11,200, 12,570, and 14,350 rpm. Rheological properties, filtration properties, and abrasiveness were studied and analyzed.
Itabirite exhibited better rheological characteristics than barite and could increase the penetration rate since a lower solids content can be used to obtain proper weight. However, it did not exhibit good filtration properties and was found to be more abrasive. The feasibility of using itabirite as a weighting material was enhanced with a finer particle size distribution and by using a determined amount of Drispac Superlo polymer, which controlled filtration and acted as a coating agent to lower abrasiveness.