辽河油田D66块火驱开发储层取心技术

为了提高火驱开发地层岩心收获率，分析了火驱对D66块地层的影响，在此基础上，有针对性地对取心工具进行了改进，对钻井参数进行了优化，并完成了3口井的取心实践。研究表明，火驱对D66块杜家台油层改造作用较大，主要表现在3个方面:一是火驱导致地层温度大幅度升高；二是高温烘烤作用使蒙皂石快速脱水后，遇水快速膨胀，胶结物因此裂开失去胶结作用，导致地层变得松散；三是火驱形成的高温强碱环境，使岩石骨架颗粒石英发生溶解，导致地层变得松散甚至垮塌。针对火驱后的高温松散地层综合应用耐高温密闭液、防冲蚀钻头、复合式岩心爪、铝合金内筒和PVC内衬管等取心工具，结合“高钻压、低钻速、小排量”的钻井参数设计，岩心收获率可以达到77.96%～88.32%，比常规取心提高约44～54.36个百分点。本文旨在通过对D66块火驱后地层取心的成功经验进行总结，为其他地区火驱后地层的取心提供借鉴。

Research and application of coring technology for fire flooding formation in D66 block,Liaohe Oilfield

This paper carries out the research of the drilling coring technology for the fire flooding formation, in order to improve the core harvest rate of fire development formation. On this basis, the coring tools had pointed improvement, drilling parameter had been optimized, and the coring practice of three wells had been completed. The research shows that the fire flooding plays an important role in reservoir reconstruction. It is mainly manifested in 3 aspects as follows: First, the fire flooding causes the formation temperature to increase greatly. Second, baking at high temperature causes rapid dehydration of smectite and rapid expansion smectite when exposed to water. As a result, cementitious materials break apart and loose cementation, resulting in loose formation. Third, the high temperature and strong alkali environment formed by fire drive can dissolve the rock skeleton grain quartz, leading to the loose formation or even collapse. For the high-temperature unconsolidated formation after fire flooding, the core harvesting rate can reach 77.96 to 88.32 persent, which is higher than the conventional coring rate from 44 to 54.36 percentage points, by comprehensively applying such coring tools as high-temperature sealing fluid, anti-erosion bit, composite core talons, aluminum alloy inner tube and PVC lined pipe, combined with the drilling parameter design of " high drilling pressure, low drilling rate and small displacement” . This paper aims to summarize the successful experience of coring in strata after fire flooding of D66 block and provide reference for coring job in other areas.