EXPERIMENTAL INVESTIGATION OF THE EFFECT OF SODIUM CHLORIDE SALT ON FORMULATED DRILLING FLUID PROPERTIES AT INCREASING TEMPERATURE FORMATIONS

ABSTRACT

Temperature increases with depth as we drill through or within deep formations; therefore, producing from such high temperature zones involves several challenges to petroleum engineers in terms of drilling, completion, and production. This makes it necessary to study the rheology of drilling fluids and h ow it is affected by these changes. The cost ofdrilling fluid has been a major issue during operation and the effect of salinity on the additives has also resulted into investigation of determine if other additives can be used as a substitute to the predominant used ones. To that effect, this work was focused to determine the effect of salinity on the rheological properties of mud type prepared with Carboxyl-methyl cellulose (CMC) and cocoyam. From this study, salinity effect shows that as the salinity ofdrilling mud are increased, the effectiveness of the polymer decreases. This has a negative effect onthe rheological properties of drilling mud. Plastic viscosity decreases with increasing temperature and yield point increases with increasing temperature. Also, the thixotropic property (gel strength) of both cocoyam and CMC muds increases with temperature but decreases on the introduction of salt.It can also be deduced that the ability to suspend cuttings for both NaCl and CMC mud are unique. From this work, temperature has a remarkable effect on properties of drilling mud. Proper knowledge of the key factors governing the selection of drilling mud is critical for appropriate drilling mud selection because the behavior of the drilling mud under high temperature is extremely important for drilling geothermal wells and for drilling deep wells.