An Experimental study of particle size and concentration effects of calcium carbonate on rheological and filtration properties of drill-in fluids

Odabaşı, Aydın
Specially designed non-damaging Drill-In Fluids (DIF) are being effectively applied for drilling depleted zones worldwide. Shape, particle size distribution and concentration of materials like calcium carbonate (CaCO3) are key parameters determining the effectiveness of DIF. In this study, 3 different sized and 5 different concentrations CaCO3 are used to examine the effects of these factors on rheology and fluid loss of DIF. Sized calcium carbonates are used as major particles in different concentrations and in different particle size distribution. Rheological behavior of fluid, filter cake quality and filtrate volume are basic parameters to be evaluated in this study. All samples were aged at 120 ºF for 4 hours. After ageing, tests are performed at 75 °F and 100 psi of differential. It is observed that, the DIF showed certain Yield Power Law charcteristics and some parameters ( PV,m) was increased with increasing size and concentration whereas other parameters ( YP,k) decreased .