塔河油田缝洞型油藏“一井多控”高效开发关键技术

Key Technologies for High-Efficiency One-Well Multi-Control Development of Fractured-Vuggy Reservoirs in Tahe Oilfield

塔河油田碳酸盐岩缝洞型油藏主要储油空间是溶洞,多轮次开发过程中溶洞的储量品质与规模不断下降,单井动用单洞的开发方式效益风险逐年增大。为此,基于地质工程一体化,研发了同时动用多套缝洞体的“一井多控”高效开发关键技术。该技术主要基于缝洞分级刻画描述技术,分级标定复杂缝洞体内部基岩与有效缝洞体的边界;针对缝洞型油藏缝洞空间展布存在的差异性,推进地质工程一体化,设计多种“串联”井眼轨道,尽可能贴近有效缝洞边界;研发适合缝洞型储层的分段改造一次动用完井技术,实现一个井眼沟通动用多个缝洞体的目标,进一步提高单井产能和单井开发效益。“一井多控”高效开发关键技术在塔河油田进行了现场试验,试验过程中对缝洞刻画、井眼轨道设计及完井技术不断迭代优化提升,支撑了“一井多控”评价井储量动用规模与产能的不断提升,储量动用规模达到直井动用储量规模的1.5倍以上,油井日产油能力提高10%以上。“一井多控”高效开发关键技术为塔河油田碳酸盐岩缝洞型油藏提供了一种新的开发方式。

The karst caves are the main oil storage space in the fractured-vuggy carbonate reservoirs in Tahe Oilfield.During multiple rounds of development,the reserve quality and scale of the karst caves keep declining,the benefit risk of the development method of single well producing single cave intensifies with each passing year.For this reason,high-efficiency development technologies of one-well multi-control that can simultaneously exploit multiple fracture-cave bodies were developed on the basis of geology-engineering integration.Specifically,the hierarchical characterization and description technology for fractures and caves was employed to hierarchically demarcate the boundaries between the internal bedrock and the effective fracture-cave bodies in the complex fracture-cave bodies.Due to the differences in the spatial distribution of the fractures and caves in fractured-vuggy reservoirs,a variety of“series”wellbore trajectories as close to the boundaries of the effective fractures and caves as possible were designed to advance geology-engineering integration.Furthermore,a completion technology featuring staged reconstruction and one-time production for fractured-vuggy reservoirs was developed so that one wellbore could connect and exploit production from multiple fracture-cave bodies to further improve the capacity and development benefit of single-well.Field tests of the one-well multi-control technologies were carried out in Tahe Oilfield.During the tests,fracture and cave characterization,trajectory design,and the completion technology were iteratively optimized,which supported the continuous improvement of the reserve production scale and productivity of the one-well multi-control evaluation wells.As a result,the reserve production scale of these wells reached more than 1.5 times that of the vertical wells,and the daily oil production capacity of the oil wells increased by over 10%.The proposed one-well multi-control technologies provide a new developing mode for the fractured-vuggy carbonate reservoirs in Tahe Oilfield.