The drilling fluid is mainly composed of liquid phase, solid phase and chemical treatment agent. Liquid phase can be water (fresh water and salt water), oil (crude oil, diesel oil) or emulsion (mixed oil emulsion and invert emulsion fluids); solid phase includes useful solids (bentonite, weighting materials) and useless solid (rock); chemical treatment agents including inorganic, organic and polymeric complexes. The types of drilling fluid are mainly:
(1) water base drilling fluid. It is a kind of with water as the dispersion medium, to clay (bentonite), increasing agent and a variety of chemical treatment agent for the dispersed phase sol suspension mixed system. Its main components are water, clay, weighting agent and a variety of chemical treatment agent, which can also be divided into fresh water drilling fluid, salt water drilling fluid, calcium treatment drilling fluid, etc..
(2) oil continuous phase drilling fluid. Habit called oil based drilling fluid, is a kind of oil (mainly diesel oil or crude oil) as the dispersion medium, in order to increase the agent, a variety of chemical treatment agent and water as the dispersed phase of the sol suspension mixing system. Its main components are crude oil, diesel oil, weighting agent, chemical treatment agent and water.
(3) fresh water drilling fluid. Developed in the 1980s of the fresh water drilling fluid is a new drilling fluid system, which using polymer as the main body, with reducing viscosity agent, filtration reducing agent, anti sloughing agent and lubricant and so on many kinds of chemical treatment agent. The drilling fluid. Including the cation polymer drilling fluid, zwitterionic polymer drilling fluid, cationic polymer drilling fluid, deep polymer drilling fluid and positive colloid drilling liquid.
(4) gas and foam drilling fluid. After the eighties of the 20th century, developed the gas drilling fluid is to air or natural gas as the circulation of drilling fluid, the drilling fluid; foam drilling fluid is uses the foam as the circulation of drilling fluid drilling fluid, mainly composed of liquid, gas and foam stabilizer.