适合大港滨海区块硬地层的PDC钻头优化设计

大港油田滨海区块下部地层为含砂质泥质结构,岩石由泥质和砂质等组成,地层硬度高、研磨性强,单只PDC钻头进尺少、机械钻速低,制约了该地层的勘探开发进程。鉴于此,对PDC钻头的冠部轮廓、刀翼、布齿和水力性能等进行了优化设计,得到了适合该地层的M432215.9 mm七刀翼PDC钻头。大港油田滨海6井的现场试验结果表明,在同井段同尺寸情况下,M432215.9 mm七刀翼PDC钻头的平均进尺49.0 m,机械钻速1.540 m/h,牙轮钻头平均进尺22.5 m,机械钻速0.967 m/h;使用七刀翼PDC钻头提高了钻进速度,缩短了钻井周期。

Optimized Design of PDC Bit Suitable for the Hard Formation of Dagang Binhai Block

The formation of the Dagang Binhai block is characterized by high hardness,strong abrasiveness and low rate of penetration(ROP).It has used several kinds of PDC bit but the ROP improvement is not remarkable.The conventional PDC bit can only be effective in drilling soft to medium hard formation and the ROP is low or the bit’s service life is short in hard and soft-hard interlock heterogeneous formations.The paper analyzes and obtains the drillability and abrasiveness of the formation according to the core data and proposes the design concept of improving ROP by strengthening the wear resistance of PDC bit.The M432 215.9 mm PDC bit suitable for the lower formation of the Binhai block was designed.The field test of the PDC bit designed was conducted in Well 6 of Binhai.The test shows that compared with the average index for the application of roller bit to the same section and the same size in 4 wells of the Binhai block in 2009,the average bit footage improves by 2.18 times and the ROP by 1.59 times.The PDC bit has a slight abrasion after the test and it can be used after repair.The PDC bit designed remarkably improves the drilling speed,shortens the drilling cycle and saves the drilling costs.