Recent Applications of Brines and Treated Brines in Permian Basin Drilling

From the earliest days of West Texas drilling, produced brines have been readily available. Drillers quickly realized, even in the early days, the advantages to be gained from drilling with clear brine. Today, good quality brine is conveniently available to most parts of the Permian Basin at a delivered cost of 25 cents to 50 cents per barrel. The advantages of using clear brine as a drilling fluid have been adequately documented. The more obvious advantages are: (1) improved penetration rate with a solids-free fluid as compared to a typical drilling mud; (2) clear fluid with a density of up to 10.0 ppg is available when needed for pressure balance; (3) the natural tendency of brine to "pickle" or inhibit the swelling of shaley formations, thus protecting production zones and hole condition in general; and (4) all these at a relatively low unit cost compared to conventionally formulated drilling fluids.