Загрузил Олег Лютиков

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During rotary drilling, the well constantly circulates the flow of a liquid that was
previously considered only as a means for removal of destruction products
(cuttings). Nowadays it is perceived as one of the main factors that ensure efficiency
of the entire drilling process.
Drilling mud, besides cuttings removal, should perform other equally important
functions, aimed at efficient, economical and safe performance and completion of
drilling process. For this reason, the composition of drilling mud and evaluation of
its properties has become the subject of a wide range of scientific and practical
research and analysis.
Today in the world practice there is a tendency of growth of drilling depths, and as
a result, the danger of various drilling problems increases. Besides, the
requirements to more complete exploitation of productive formations are
constantly increasing. In this regard drilling mud should have composition and
properties, which would provide an opportunity to fight most of possible drilling
problems and would not have a negative impact on reservoir properties of
productive horizons. Functions of drilling mud:
- to remove the products of drilling from the wellbore;
- prevent formation fluids from cross flowing;
- maintain stability of the wellbore walls;
- to cool and lubricate the drilling bit;
- transfer hydraulic force to the drilling bit.