摘要
气体钻井由于其机械钻速快,能有效防止水敏性泥页岩坍塌,杜绝井漏。然而在气体钻井中井筒内岩屑的运移机理还不是十分清楚,为此,从气固两相流基本理论出发,对气体钻井过程中岩屑的重复破碎和细岩屑聚团过程进行了分析,并对接单根后岩屑的运移模式进行了描述,指出由于岩屑聚团的崩裂速度远远超过理论计算的相应初始运移速度,在接完单根后为使井底得到清洁,应增大注气量。另外,还提出了气体钻井过程中岩屑间协同作用的物理模型,指出从含少量细岩屑时的粗岩屑表面改性向大量细岩屑聚团过渡中,存在一个最佳点,该点携岩效率最好。通过研究,对气体钻井过程中岩屑的运移机理有了更进一步的认识。
The gas drilling technology is increasingly applied these days due to its high ROP, effective prevention of the cave-in of water-sensitive shales and the capability to eliminate lost circulations. However, the cuttings migration mechanism in the well bore during gas drilling is still not understood very well. Therefore based on the basic principles of the gas-solids 2 phase flow, analysis is made on repetitive crushing of cuttings and conglomeration of fine cuttings, and the cuttings migration mode after pipe connection is described. It is also explained that gas injection rate should be increased in order to clean up the well bottom after making a connection, because the cracking speed of the cuttings conglomerates is far greater than the corresponding theoretic initial migration rate of cuttings. And a physical model is put forward in this article showing the synergetic effects between cuttings during gas drilling, which indicates during transition from coarse cuttings to large amounts of fine cuttings there exists an optimal point where best cuttings transport can be obtained. Through this study, the cuttings migration mechanism during gas drilling is further understood.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2006年第6期66-67,共2页
Natural Gas Industry
基金
四川石油管理局"大塔场构造沙一段浅层气藏钻井及完井工艺技术研究"项目(编号:2005KTZ13)。
