摘要
密闭取心是一种特殊取心作业,通过密闭取心钻具与密闭取心钻头配合,在密闭液作用下实现岩心与钻井液隔离,可获得地层原始含油饱和度及油水动态等数据。密闭钻头设计为双流道结构,要满足钻井液过流冲洗冷却钻头唇面、携带岩屑要求,同时密闭液在井底可形成富集区域,有效保护岩心免受钻井液污染,密闭取心钻头流道参数是密闭取心钻头设计的关键。本文运用计算流体力学理论,采用k‑epsilon湍流模型及连续性方程对KM型密闭取心钻具配套密闭取心孕镶金刚石钻头的两相流井底流场进行数值模拟,研究钻头唇面两相流混流状态、流体压力、流速、剪切应力分布特征等,分析了流场特征对钻头密闭效果、钻进效率和寿命等的影响,验证了密闭取心孕镶胎块式金刚石钻头流道结构设计参数,提出了钻头两相流流道优化设计建议。
Sealed coring is a special kind of coring operation.Through the cooperation of the sealed coring tool and the sealed coring bit,the core and drilling fluid can be isolated under the action of sealed fluid,and in‑situ oil saturation and oil‑water dynamic data can be obtained.The sealed coring bit is designed as a double channel structure,which can meet the requirements of drilling fluid flushing,cooling the bit lip and carrying cuttings.At the same time,the sealed fluid can form an enrichment area at the bottom hole to effectively protect the core from drilling fluid pollution.The channel parameters of the sealed coring bit are the key to the design of the sealed coring bit.Based on the theory of computational fluid dynamics,the k‑epsilon turbulence model and continuity equation are used to simulate the two‑phase flow field in the bottom hole of KM type sealed coring tool with the sealed coring impregnated diamond bit.The mixed flow state,fluid pressure,flow velocity and shear stress distribution characteristics of the bit lip are studied.The influence of flow characteristics on sealing effect,drilling efficiency and service life of the bit is analyzed,the design parameters of the channel structure of the sealed coring impregnated block diamond bit are verified,and the optimization design suggestions are put forward for the two‑phase flow channel of the bit.
作者
曹龙龙
张恒春
王稳石
闫家
胡晨
CAO Longlong;ZHANG Hengchun;WANG Wenshi;YAN Jia;HU Chen(Institute of Exploration Techniques,CAGS,Langfang Hebei 065000,China;Deep Geological Drilling Technology Research Center,China Geological Survey,Langfang Hebei 065000,China;China University of Geosciences,Beijing 100083,China)
出处
《钻探工程》
2021年第11期35-41,共7页
Drilling Engineering
基金
中国地质调查局地质调查项目“松辽盆地资源与环境深部钻探工程”(编号:DD20160209)、“苏皖赣地区页岩油气战略选区调查(中国地质科学院勘探技术研究所)”(编号:DD20201171)
中国地质科学院勘探技术研究所科技项目“基于KT钻具的KM-216型密闭取心钻具及配套技术研究”(编号:YB202007)、“大直径孕镶金刚石取心钻头制备工艺研究”(编号:YB202003)、“孕镶金刚石取心钻头低成本生产关键技术研究”(编号:ZD202101)、“高效定向取心钻具及配套技术研究”(编号:ZD202103)。
关键词
密闭取心
金刚石取心钻头
CFD模拟
流场分析
数值模拟
sealed coring
diamond coring bit
CFD simulation
flow field analysis
numerical simulation
