Editing Baryte (section)

===In oil and gas drilling===

Worldwide, 69–77% of baryte is used as a weighting agent for [[drilling fluid]]s in [[oil and gas exploration]] to suppress high formation pressures and prevent [[blowout (well drilling)|blowouts]]. As a well is drilled, the bit passes through various formations, each with different characteristics. The deeper the hole, the more baryte is needed as a percentage of the total mud mix. An additional benefit of baryte is that it is non-magnetic and thus does not interfere with magnetic measurements taken in the borehole, either during [[logging-while-drilling]] or in separate drill-hole logging. Baryte used for drilling petroleum wells can be black, blue, brown, or gray depending on the ore body. The baryte is finely ground so that at least 97% of the material, by weight, can pass through a 200-mesh (75&nbsp;μm) screen, and no more than 30%, by weight, can be less than 6&nbsp;μm diameter. The ground baryte also must be dense enough so that it has a [[specific gravity]] of 4.2 or greater, is soft enough to not damage the bearings of a tricone drill bit, is chemically inert, and contains no more than 250 milligrams per kilogram of soluble alkaline salts.<ref name="usgs"/> In August 2010, the [[American Petroleum Institute]] published specifications to modify the 4.2 drilling grade standards for baryte to include 4.1 SG materials.