The roller cone bit is the most widely used tool in petroleum drilling and water well drilling. Tricone bit has the function of impacting, crushing and shearing rock in formation, so it can adapt to soft, medium and hard formation. The cone bit can be divided into milling cone bit and TCI cone bit according to the type of teeth. IADC Parameters Rock formation Wob(kn/mm) Rpm(r/min) 116 117 0.35-0.8 150-80 Low compressive strength extremely soft formation of high drillability, such as clay, mudstone, chalk 126 127 0.35-0.9 150-70…