Successful construction of oil and gas wells is largely determined by the composition and properties of drilling fluids, primarily designed to remove drill cuttings from wells and to cool drilling tools. Drilling mud
is a multicomponent disperse system (suspension, emulsion or aerated fluid), which properties are chosen depending on geological and physical conditions.
To penetrate productive formations with different geological and physical conditions drilling fluids are used on the basis of:
- bentonite (a mineral of the clay group);
- foaming agent (biopolymers);
- sapropel (organic-mineral raw material, concentrated in lakes and sediments underlying peat deposits).
Drilling muds, prepared from sapropel, have satisfactory technological properties and can be used without additional treatment with chemical reagents for uncomplicated drilling conditions. The sapropel drilling muds in many cases can be used without the use of toxic polymer reagents or with a small amount of them compared to traditional muds based on bentonite or foam reagent.