Bit selection and application for granite rock of Well Pugu-1

Well Pugu-1 in Jidong Oilfield is an exploration well with CNPC rank risk at high position of Nanpu No. 4 buried hill block. The drilling of the well is to wildcat the oil and gas saturation status of Archaean granite buried hill reservoirs. Granite rocks are buried deep, with high strength and poor ability of drilling, so the drilling operations in adjacent area come across the problems of short bit footage, short longevity, and low penetration rate. Based on the analysis on the granite formation properties, temperature, drillability, and the bit application on the adjacent wells, it was studied that the bit sealing type, cogging structure, protection on wheel and wheel carrier, and service life. And the monometallic sealing meteacarpal aggrandizement bit for slim hole was designed with long service life and high penetration rate. The technique made a new path for quickly penetrating granite rock in the area.