THE USE OF SIZED BARITE AS A WEIGHTING AGENT FOR DRILLING FLUIDS

摘要

An additive that increases the density of fluids used in a wellbore during the construction or repair of oil, gas, injection, water, or geothermal wells comprises a wellbore fluid containing a sized barite weighting agent that has an increased density with improved suspension stability without a significant viscosity increase. The wellbore fluid as described herein has rheological properties comparable to a conventional wellbore fluids but does not exhibit problems with sag and resulting variations in density. An illustrative embodiment of the claimed subject matter is further directed to a drilling fluid comprising a fluid phase and a solid phase weight material for increasing the density of the drilling fluid, wherein the weight material is a ground particulate material and has a particle size distribution of at least 50% by weight particles in the range of about 1 µm to about 5 µm and at least 90% by weight particles in the range of about 4 µm to about 8 µm. The invention also pertains to a method of drilling a subterranean well utilizing the drilling fluid. Further the invention pertains to a method of increasing the density of a fluid phase of the drilling fluid by adding to the fluid phase the solid phase weight material.