伊拉克格拉芙油田Mishrif储层长筒取心技术

格拉芙油田Mishrif储层渗透率高，钻井过程中压差卡钻和井漏等井下故障频发，并且地层夹杂泥灰岩和黄铁矿，取心时很难保证取心收获率和取心质量。在分析该油田地层特点和取心技术难点的基础上，制定了适用于Mishrif储层的长筒取心技术措施:设计采用泄压式铝合金内筒和具有防倒扣功能的内筒稳定装置，以提高取心收获率；应用滑轮组吊装系统和岩心伽马扫描技术，以实现岩心的快速高效处理。格拉芙油田3口井的取心作业共计取心309.00 m，平均取心收获率达到92.5%。应用结果表明，该长筒取心技术有效解决了格拉芙油田Mishrif储层的取心技术难题，对今后中东地区Mishrif储层的取心作业具有一定的参考借鉴作用。 

Long-Barrel Coring Technique for the Mishrif Reservoir in the Garraf Oilfield,Iraq

Due to high permeability,differential pressure sticking and lost circulation are often occurred in the Mishrif Reservoir of the Garraf Oilfield during the course of drilling.In addition,the Mishrif Reservoir contains marl and pyrite,which makes it extremely difficult to ensure desirable core recovery and coring quality.On the basis of analyzing the formation characteristics and coring technical difficulties in the oilfield,a long barrel coring technique appropriate for the Mishrif Reservoir has been developed,nd designed the aluminum alloy inner barrel with pressure relief function,as well as inner barrel stabilizer with protection against back off,which raised the core recovery.Application of the pulley hoisting system and the core gamma scanning technique has resulted in fast and high efficient core processing operations,and performed total coring footage of 309.00 m in three wells of Garraf Oilfield,with average core recovery up to 92.5%.Results of the application demonstrated that the coring technique can effectively solve the technical problem of coring in Mishrif Reservoir of Garraf Oilfield,and provide certain reference of coring operations in Mishrif Reservoirs of the Middle East in the future.