降低井底岩石抗钻能力的钻速提高方法研究及钻头设计  

Research on the Method of Improving ROP and Designing Drill Bits to MitigateDrillability of Bottomhole Rocks

作　　者：刘永旺[1] 李坤 管志川[1] 毕琛超 霍韵如 于濮玮 LIU Yongwang;LI Kun;GUAN Zhichuan;BI Chenchao;HUO Yunru;YU Puwei(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong,266580,China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《石油钻探技术》2024年第3期11-20,共10页Petroleum Drilling Techniques

基　　金：国家自然科学基金面上项目“油气井筒内管柱载荷对其声传播的影响规律及调控机制”(编号:52074324);中国石油重大科技项目“深层复杂条件钻井提速方法与关键技术研究”(编号:ZD2019-183-005);页岩油气富集机理与高效开发全国重点实验室开放基金项目“页岩气钻井难钻地层井底诱导卸荷提高破岩效率机制及特性”(编号:10010099-19-ZC0607-0047)资助。

摘　　要：为解决深部地层岩石硬度大、研磨性强、地应力高及可钻性差导致的钻头破岩效率低、钻井速度慢的问题,在分析现有提速技术的基础上,提出了释放地层应力、降低井底岩石抗钻能力的钻井提速新思路,基于该思路设计了井底应力诱导卸荷钻头、聚能攻击卸荷井底应力钻头、差压式钻头、中心差压式钻头、诱导卸荷与磨料射流联合作用钻头、阶梯式钻头和自激轴冲与诱导卸荷耦合破岩钻头等7种新式钻头。通过室内试验、现场试验,验证了其中2种钻头的提速效果:中心差压式钻头在室内试验中提速30.01%,现场试验最高提速318.11%;诱导卸荷与磨料射流联合作用钻头在室内试验中钻进石灰岩和红砂岩时分别提速59.0%和336.0%。该方法的提出及钻头的研制,为解决深部难钻地层的提速问题提供了新途径。In order to solve the problems of low rock breaking efficiency of drill bits and low rate of penetration(ROP)caused by great hardness,strong abrasiveness,high in-situ stress,and poor drillability of deep formation rocks,a new method of improving ROP was put forward to release the in-situ stress and reduce the drilling resistance of bottomhole rocks based on the analysis of existing speed increase technologies.Based on this idea,seven new types of drill bits were designed:bottomhole stress-induced unloading drill bits,concentrated energy attack-type unloading bottomhole stress drill bits,differential pressure drill bits,central differential pressure drill bits,drill bits under the joint action of induced unloading and abrasive jet,stairs type drill bits,and coupled self-excited axial impact and induced unloading rock-breaking drill bits.The ROP increase effect of two types of drill bits were verified through laboratory and well-site experiments.The central differential pressure drill bit increased its ROP by 30.01%in laboratory experiments,and the highest ROP increase in well-site experiments was 318.11%.The drill bits under the joint action of induced unloading and abrasive jet increased the ROP of limestone and red sandstone by 59.0%and 336.0%in laboratory experiments,respectively.The proposal of this method and the development of drill bits provide new ways for the ROP increase technology in deep formation with poor drillability.

关 键 词：应力卸载 深部地层 机械钻速 PDC钻头 钻头设计 

分 类 号：TE245[石油与天然气工程—油气井工程]