川东北沙溪庙组硬质砂岩地层斧形PDC齿设计及破岩性能

Design and rock-breaking performance of axe-shaped PDC cutter for hard sandstone of Shaximiao Formation, northeastern Sichuan Basin

荣准 张航 陶垒 马亚超 张琦 颜爽 曾皓

RONG Zhun ZHANG Hang TAO Lei MA Yachao ZHANG Qi YAN Shuang ZENG Hao

中国石油西南油气田分公司川东北气矿 中国石油集团西部钻探工程有限公司工程技术研究院 西南石油大学机电工程学院

Northeast Sichuan Gas District, PetroChina Southwest Oil & Gas Field Company, Dazhou 635000, Sichuan, China Engineering Technology Research Institute of CNPC Xibu Drilling Engineering Company Limited, Karamay 834099, Xinjiang, China School of Mechanical Engineering, Southwest Petroleum University, Chengdu 610500, Sichuan, China

斧形PDC齿因其独特的齿形结构而具有优越的破岩性能，但对斧形PDC齿破岩性能与其齿刃角优化设计研究尚不明确。建立了切削齿切削与压入破岩结合的岩石破碎综合比能评价方法，利用破岩仿真模型，开展了斧形PDC齿齿刃角优化研究，并对优化后斧形PDC齿进行了破岩性能仿真。研究结果表明，随齿刃角逐渐增大，斧形PDC齿的岩石破碎综合比能呈“N”型变化趋势，齿刃角为130°的斧形PDC齿在硬质砂岩具有优异的破岩性能，其切削力较常规PDC齿降低了35%，切削破岩比能、压入破岩比能和岩石破碎综合比能分别较常规PDC齿降低20%、5.9%和10.5%。室内破岩试验表明斧形齿较常规齿切削破岩比能降低了35.2%，攻入性更强。该研究为川东北沙溪庙组硬质砂岩的个性化PDC钻头设计提供了理论基础。

Axe-shaped PDC cutter is well performed in rock breaking owing to its unique structure, but its rock-breaking performance and optimal working angle remain unclear. An evaluation method of total specific energy for rock breaking by cutting combining with pressing was established. By using the rock-breaking simulation model, the working angle optimization of axe-shaped PDC cutter was investigated, and a simulation was conducted on the axe-shaped PDC cutter with optimized working angle. The results show that the composite rock-breaking specific energy of the axe-shaped PDC cutter changes in an “N” pattern as the working angle increases. The axe-shaped PDC cutter with the working angle of 130° is excellently performed in hard sandstone, with the cutting force, cutting rock-breaking specific energy, pressing rock-breaking specific energy, and composite rock-breaking specific energy of 35%, 20%, 5.9% and 10.5% lower respectively than that of conventional PDC cutter. Laboratory experiment shows that the cutting rock-breaking specific energy of the axe-shaped PDC cutter reduces by 35.2% and shows a greater penetration. The research provides a theoretical foundation for customization of PDC cutter for hard sandstone of Shaximiao Formation in northeastern Sichuan Basin.

10.13639/j.odpt.202303002