Individual design and application of PDC bit for glutenite in Shengli Oilfield in the northern zone of Dongying

In view of the technical challenges like strong abrasiveness of rocks in lower glutenite formations of Shasi Section in Fengshen-1 Block and Yan-227 Block of Shengli Oilfield in the northern zone of Dongying, poor drillability, low ROP and short life of drilling bits, the individual design of rotational flow PDC bits and their application research were carried out. Through indoor experiment, the type of PDC cutting teeth suitable for such formations was selected. The design of the crown profile of the bit, its cutting structure and the caster angle of cutting teeth was optimized. A rotary jet nozzle was developed, and a new PDC bit was designed and trial-produced which breaks the rocks jointly by hydraulic and mechanical forces. A drilling experiment was conducted in glutenite formation in Ping 1-Well of Fengshen-1 Block. Compared with other types of PDC bits, its ROP is increased by 46.8%, and footage of single bit is up by 69.6%. Compared with roller bit, its ROP is increased by 48.1% and footage of single bit is up by 156.5%. Promotion and application of this bit in glutenite interval in Well Yan 227 also result in significant speeding effectiveness, for example, the ROP was up by 26% and the average footage of single bit was up by 102 m. The research findings are of some guiding significance to the individual design of PDC bits and are of promotion value for accelerating in formations with strong abrasiveness.