巴彦河套新区异形齿PDC钻头研究与应用

Research and application of special‑shaped tooth PDC bits in Bayanhetao New Area

为了巴彦河套新区油气资源高效开发,(1)通过测井数据、岩心实验以及实钻数据,开展了该区地层岩性可钻性分析,表明白垩系埋深较深地层以及太古界片麻岩地层可钻性差;(2)调研了该区以及外部区块难钻地层异形齿钻头实钻情况,白垩系5000 m以深地层以及太古界地层单只钻头进尺少,机械钻速低,调研的外部区块塔里木塔河南难钻地层通过使用异形齿钻头,提速效果显著;(3)对比分析了平面齿、斧形齿、多棱齿以及锥形齿破岩机理,为后续钻头优化设计提供了理论支撑;(4)开展了异形齿PDC钻头现场实验,较常规PDC钻头单只进尺以及机械钻速均取得了显著的提升,其中有21口井实现二开“一趟钻”,总进尺30000余米。总之根据地层可钻性变化,优配平面齿、斧形齿、多棱齿以及锥形齿,提高钻头与地层的配伍性,可显著提高钻井效率。

For the efficient development of oil and gas resources in Bayanhetao New Area,research has been conducted on special shaped PDC bits.Based on well logging data,core assay and actual drilling data,the lithology analysis of the strata in this area is carried out,and finds that the drillability of the strata in the deep Cretaceous and the Archean gneiss strata is poor.The drilling results of special tooth bits in poor drillable formation in this area and the outer blocks are investigated,and show that the footage per bit in Cretaceous strata below 5000m and the Archean strata is small with low mechanical drilling rate,while drilling speed is remarkably increased in the Tarim Tahenan difficult area.The rock breaking mechanism of plane teeth,axe teeth,polygonal teeth and conical teeth is compared and analyzed,which provides theoretical support for subsequent optimization design of drill bits.Field tests were carried out on special‑tooth bits,which significantly improved the penetration and ROP compared to conventional PDC bits.Twenty‑one of the wells achieved“one‑trip”drilling for the second well section with a total footage of more than 30000m.In short,according to the formation drillability,to improve the drill bit and formation compatibility through the optimal matching of plane teeth,axe teeth,polygonal teeth and cone teeth can significantly improve drilling efficiency.