The reason is the borehole drilled by eccentricity PDC bit is over diameter.ROP is improved and the cost of drilling will be lowed as a result of using eccentricity PDC bit.

• 使用偏心PDC钻头在流动性盐岩地层中钻进，因偏心PDC钻头能钻出超尺寸井眼，没有发生卡钻头和下部钻具组合的事故，提高了钻井速度，降低了钻井成本。