塔河油田缝洞型油藏耐高温耐高盐强化泡沫体系研制与性能评价

Preparation and performance evaluation of reinforced foam system with high temperature resistance and high salt tolerance in fracture-cavity reservoirs in Tahe Oilfield

塔河油田缝洞型油藏实施氮气驱后面临单向受效、气窜等突出问题。为有效控制气窜及扩大波及体积,研制了新型耐高温耐高盐强化泡沫体系——双重交联高分子凝胶泡沫体系,并在塔河油田东部老区开展了强化泡沫复合氮气驱试验。室内实验和矿场试验表明:新型强化泡沫体系采用0.3%阴-非/阴离子复合型协同增效起泡体系和0.7%高分子凝胶稳泡体系合成,凝胶大分子团聚体在泡沫液膜上发生二次交联,形成双重交联高分子凝胶泡沫体系。该强化泡沫体系能在温度为140℃、矿化度为240 g/L、含油饱和度为50%的条件下强稳定,满足了塔河油田缝洞型油藏地质条件的需求。矿场实施强化泡沫复合氮气驱试验10井次,其中9井次有效控制了气窜并扩大了波及体积,增产效果显著,从而证实强化泡沫复合氮气驱技术是一项可行的适用于缝洞型油藏的提高采收率技术。

The fracture-cavity reservoirs in Tahe Oilfield are faced with prominent problems,such as unidirectional effects and gas channeling after nitrogen flooding.In order to effectively control gas channeling and expand the swept volume,a new reinforced foam system with high temperature resistance and high salt tolerance,namely a dual-crosslinked high polymer gel foam system is developed.In addition,reinforced foam with nitrogen flooding flooding tests are carried out in the eastern old area of Tahe Oilfield.Laboratory experiments and field tests show that the new reinforced foam system is synthesized by 0.3%mass concentration of anionic-nonionic/anionic composite synergistic foaming system and 0.7%mass concentration of polymer gel foam-stabilizing system.The aggregations of gel macromolecules undergo a secondary cross-linking on the liquid film of the foam,forming a dual-crosslinked high polymer gel foam system.The reinforced foam system can be strongly stable under the reservoir conditions with a temperature of 140°C,a salinity of 240 g/L,and an oil saturation of 50%.It is suitable for the geological conditions of fracture-cavity reservoirs in Tahe Oilfield.The reinforced foam test with nitrogen flooding is carried out in 10 wells in Tahe Oilfield.Specifically,gas channeling is effectively controlled,and the swept volume is expanded in nine wells,with the production increasing significantly.Therefore,it is proved that the reinforced foam with nitrogen flooding technology is a feasible way to enhance oil recovery of fracture cavity reservoirs.