Weighting of new starch-polymer salted mud with PT-23 polymer

Abstract

Rheological properties of mud should assure high rate of penetration and supply maximal hydraulic power to the hole bottom. From this point of view drilling mud should have as little density and viscosity as possible and also minimal solid phase fraction. By the reason of the hole depth and geological conditions in the region it often occurs that maintenance of low density is impossible and drilling mud have to be treated with weighting materials. The process may cause change of mud rheological parameters and cause decrease of penetration rate. In case of weighted mud there is also a problem consisting in sedimentation of weighting material. During these project realization there was developed recipe of new mud for well completion with new PT-23 polymer. The next step was testing of possibilities of weighting the mud with different weighting materials: barite with grain size lower than 75 µm, barite with grain size lower than 25 µm, commercial barite, hematite, bridging agent M-25. Barite with grain size lower than 75 µm and barite with grain size lower than 25 µm were conditioned in water, then wet separated into fractions.