In geotechnical engineering, drilling fluid is used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells. Liquid drilling fluid is often called drilling mud. The three main categories of drilling fluids are water-based muds (which can be dispersed and non-dispersed), non-aqueous muds, usually called oil-based mud, and gaseous drilling fluid, in which a wide range of gases can be used.
The main functions of drilling fluids include providing hydrostatic pressure to prevent formation fluids from entering into the well bore, keeping the drill bit cool and clean during drilling, carrying out drill cuttings, and suspending the drill cuttings while drilling is paused and when the drilling assembly is brought in and out of the hole. The drilling fluid used for a particular job is selected to avoid formation damage and to limit corrosion.
Water based drilling mud represses hydration and dispersion of clay – There are 4 types: high pH lime muds,low pH gypsum, seawater and saturated salt water muds.
REGYP supplies fine ground gypsum products which are suitable for water based drilling muds. SuperFlocc Gypsum is fine ground Calcium Sulfate Dihydrate, which functions as an inexpensive source of calcium and alkalinity in gyp‐based drilling fluids. It is used as an alternative to lime as a source of calcium when high alkalinity or pH is not desired in a drilling mud .Gypsum is frequently added to fluids to precipitate high levels of carbonates when additions of lime would raise pH above desired levels. The solubility of Gypsum will increase at higher chloride levels.
Advantages of using Gypsum in drilling muds:
- Precipitate soluble carbonates from water‐based drilling muds
- Supplies calcium to inhibit hydration of shales and clays
- Basis for Gypmuds
- Treat Trona water and CO2 contamination in water‐based systems