摘要
塔里木盆地作为中国最大的含油气盆地,油气资源丰富,勘探开发潜力巨大。然而,塔里木盆地寒武系发育巨厚白云岩,其岩石强度大、可钻性极差,导致传统PDC(Polycrystalline Diamond Compact)钻头在白云岩地层中的机械钻速低、单只钻头进尺少。为此,针对塔里木盆地寒武系白云岩地层进行了包括内部结构、力学特性、研磨性与可钻性的综合研究和分析,然后结合已有的白云岩地层钻头结构,优选了主切削齿类型、冠部曲线及刀翼参数,在岩石塑—脆性临界破碎理论的指导下,优化了布齿参数、水力结构,最终形成了适用于寒武系白云岩地层的新型高效PDC钻头并开展了现场试验。研究结果表明:①白云岩地层非均质性强、结构致密、强度大,单轴压缩强度达221.51 MPa,具有中等研磨性并且在高围压条件下的可钻性极差;②PDC钻头采用“浅锥型冠部+长保径段”结构,能够有效降低扭矩波动,进而提升钻头在白云岩地层中的钻进稳定性;③基于塑—脆性临界破碎理论设计的高效破岩PDC钻头在寒武系白云岩层段的提速效果显著,总进尺为603 m,机械钻速为2.87 m/h。结论认为,设计的DS675H钻头经现场应用打破了目前塔里木盆地白云岩地层单只钻头进尺最长和机械钻速最快纪录,为后续寒武系及其以下地层高效钻井提供了技术储备,为深部难钻地层钻井提速提效提供了技术支撑。
The Tarim Basin,as the largest petroliferous basin in China,is rich in oil and gas resources and has great exploration and development potential.However,thick dolomite in the Cambrian of the Tarim Basin has high rock strength and extremely poor drillability,which leads to low rate of penetration(ROP)and single-bit small footage of conventional polycrystalline diamond compact(PDC)bits in dolomite strata.In this paper,the internal structure,mechanical properties,abrasiveness and drillability of the Cambrian dolomite in the Tarim Basin are comprehensively analyzed.On this basis,combined with the existing bit structure for dolomite strata,the main cutters'type,crown curve and blade parameters are selected.Furthermore,the cutters arrangement parameters and the hydraulic structure are optimized under the guidance of the plastic-brittle critical crushing theory.In this way,a novel efficient PDC bit suitable for Cambrian dolomite is developed,and then tested on site.The following results are obtained.First,dolomite strata have strong heterogeneity,compact structures,high strength(uniaxial compression strength up to 221.51 MPa),moderate abrasiveness,and extremely poor drillability at high confining pressure.Second,the structure of"shallow cone-shaped crown and long diameter maintenance section"applied in the PDC bits can effectively reduce torque fluctuation,so as to improve the drilling stability of the bits in dolomite strata.Third,the efficient PDC bit designed according to the plastic-brittle critical crushing theory has a remarkable ROP effect in the Cambrian dolomite,with a total footage of 603 m and a ROP of 2.87 m/h.In conclusion,the designed DS675H bit sets up a new record of the longest single-bit footage and the greatest ROP in dolomite in the Tarim Basin,and provides a technical reserve for the efficient drilling in the Cambrian and the strata below it,as well as a technical support for the ROP improvement in deep hard-to-drill strata.
作者
祝效华
胡海
刘伟吉
冯少波
何灵
田万顷
梁红军
ZHU Xiaohua;HU Hai;LIU Weiji;FENG Shaobo;HE Ling;TIAN Wanqing;LIANG Hongjun(School of Mechatronic Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Key Laboratory of Oil&Gas Equipment,Ministry of Education,Chengdu,Sichuan 610500,China;Geothermal Energy Research Center,Southwest PetroleumUniversity,Chengdu,Sichuan 610500,China;PetroChina Tarim Oilfield Company,Korla,Xinjiang 841000,China)
出处
《天然气工业》
北大核心
2025年第5期102-112,共11页
Natural Gas Industry
基金
国家自然科学基金杰出青年科学基金项目“钻井提速理论与方法”(编号:52225401)。
关键词
塔里木盆地
寒武系
白云岩
PDC钻头
异形齿
塑—脆性
高效破岩
钻井提速
Tarim Basin
Cambrian
Dolomite
PDC bit
Special-shaped cutter
Plastic-brittle
Efficient rock breaking
ROP improvement
