Barite Sag Potential Determination and Management in Iranian High Pressure Directional Wells with New Experimental Apparatus

Barite sag is the undesirable fluctuations in mud weight that occur due to downhole settling of the weighting agent. Barite sag has been exacerbatedby the increased frequency of high-angle wells with the associated increase in particle settling rate which occurs in directional wells. Settling of weighingmaterials may lead to problems such as stuck pipe, lost circulation, well control difficulties and poor cement jobs. Since in high pressure deviatedwells torque and drag is high in comparison to vertical wells, oil based muds are used for reduction of friction factor. High mud weight drilling fluidpreparation with oil based muds increases solid content and may be creates some problems, for this reason in some oilfields such as Iran waterbase mud is used inevitably. In this paper, after setting up an experimental apparatus the effect of inclination is investigated and critical range isdetermined in static condition. Main purpose of this work is management of barite sag due to using new water based drilling fluid formulations. It is seen that barite sag potential reduced with using these drilling fluids

Keywords:

Barite sag , Mud weight variation , weighing material , Settling , Drilling fluid