Abstract: Reservoirs in“КенКияк”oilfield are high pressured reservoirswith oil formation pore pressure coefficients between 1. 90 -1. 94. Because carbonate rock in Carboniferous system which wasmain reservoirs develop many cracks that caused not only mud loss but alsowell kick, and had narrow safety densitywindow of drilling fluid, first lost circulation then well blowout is easily to happened, so drilling fluid rheological property became as the important factor of affecting pressure balance in wel.l But high density saltdrilling fluid with high solid phase content and low solid capacity limitgenerally possess high rheologicalparameter, therefore itwas difficult to contro.l Based on analyzing the influence factor, a setofsystematic technologies for control rheological property of high density salt drilling fluid were proposed
that included: elimination of solid pollution; maintenance of chemical inhibitive characteristic; stabilization of salt content and low pH. By adopting these technologies in three well drillcal propertywas obviously improved.

Key words: rheological property, solid phase, inhibitive characteristic, safety densitywindow, lost circulation