基于火山岩地层钻井岩心资料的PDC钻头设计改进

Design optimization of PDC bit based on core information of volcanic layer

PDC钻头在钻进火山岩地层过程中，技术性能常得不到充分发挥，针对火山岩地层岩心资料，从复合片、切削齿受力、齿型、切削齿的角度等方面设计和改进了PDC钻头。研究分析了剖面形状、布齿、切削齿工作角等设计对PDC钻头性能的影响。提出了以加强钻头的稳定性、耐磨性和提高钻速为目标的设计观点。研制的新型钻头采用抛物线形剖面，中密度布齿，切削齿后倾角在10°-15°范围内变化。结果表明：与牙轮钻头相比，PDC钻头钻速提高了约20％，每米钻井成本降低了27％。

The PDC （ polycrystalline diamond compact） bit can not perform well during the drilling of volcanic rock. Based on the volcanic rock core information,design optimization of PDC bit was conducted in the aspects of PDC quality,forces on the cutters, cutter profile, angle of the cutters etc. Impact of the performance of the cutter,the crown profile, the distribution of the cutters, and the cutter angle was researched. The points of reinforcing the PDC bit＇s stability as well as the abrasion resistance, and elevating rate of penetration were suggested. The new manufactured drill adopts parabolic profile, medium distribution density of the cutters, and angle of the cutters from 10°to 15°. Actual application shows that the ROP （rate of penetration）increased by about 20% , the drilling cost was reduced by 27% per meter.