METHOD OF DRILLING USING A 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 In one illustrative embodiment the additive comprises a weighting agent, and more preferably an ultra-fine weighting agent. Another embodiment includes a wellbore fluid containing an ultra-fine weighting agent that has an increased density with improved suspension stability without a significant viscosity increase. The wellbore fluid as described herein has Theological properties comparable to a conventional wellbore fluid. An illustrative embodiment of the claimed subject matter is further directed to a method for making the ultra-fine weighting agent and a method for using such ultra-fine weighting agent in a wellbore fluid. In one preferred embodiment the additive has a particle diameter between 4 mum to 15 mum. In another preferred embodiment, the additive has a D₅₀ of approximately 3 mum (1 mum to 6 mum). In another preferred embodiment the additive has a D₉₀ of approximately 6 mum (4 mum to 8 mum). The additive may be used in any wellbore fluid such as drilling, cementing, completion, packing, work-over (repairing), stimulation, well killing, and spacer fluid, as well as in a dense media separating fluid or in a ship's or other vehicle's ballast fluid.