塔河奥陶系缝洞型碳酸盐岩油藏开发对策探讨

A discussion on development strategies for the Ordovician fractured-vuggy carbonate rock reservoirs in Tahe oilfield

塔河油田奥陶系油藏为典型的缝洞型碳酸盐岩油藏,生产动态与对比研究均表明油藏存在管流特征和渗流特征。油藏储集空间和流动空间主要为大型溶洞及与之相连的裂缝带,大型缝洞体内流态为典型的管流,微小孔缝内流态为渗流特征。以流态和生产特征研究为依据,以缝洞体模型为基础,研究管流与渗流条件下的动态特征、产能特征、见水特征、递减特征以及注水开发特征等,初步探讨采速、产能、布井方式、压锥、堵水、注水开发等缝洞型油藏开发技术对策,对塔河奥陶系油藏开发和综合治理有一定指导意义。

The Ordovician reservoir in Tahe oilfield is a typical fractured-vuggy carbonate reservoir. Both production performance and correlation studies show that conduit flow and seepage flow coexist in the reservoir. Caverns and associated fracture zones serve as flow and storage space for these reservoirs. The flow regime is characterized by typical conduit flow in the caverns and by seepage flow in minute fissure-pores. Based on flow regime and production characteristics, this paper, supported by fractured-vuggy reservoir model, studies the dynamic characteristics, production performances, water breakthrough, production decline and waterflooding under conduit flow and seepage flow conditions. It also discusses optimal production rate, productivity, and well pattern, and presents technical solutions of coning prevention,water plugging, and waterflooding for developing fractured-vuggy reservoirs. They can serve as guidance in the development and comprehensive management of the Ordovician reservoirs in Tahe oilfield.