M-I-X II plugging agent bridges and seals permeable formations in water-, oil-, or synthetic-based mud systems. Bridging and sealing permeable formations reduces the differential-pressure sticking tendencies that can cause high torque and drag or stuck pipe. The product is particularly useful for preventing differentially stuck pipe when drilling depleted zones where high differential pressures exist. For added flexibility, M-I-X II plugging agent is available in fine (original), medium, and coarse grades so that the optimal particle size can be selected to bridge the pores and pore throats of permeable formations. Plugging agent additions have minimal effect on mud properties.