缝洞油藏内的调流剂速度分布模型及在流道调整中的运用

Velocity Distribution Model of Plugging Agent in Fractured-cave Reservoir and Its Application in Channel Adjustment

舒 政 梁旭伟 钱 真 叶仲斌 朱诗杰

SHU Zheng LIANG Xuwei QIAN Zhen YE Zhongbin ZHU Shijie

向地层内注入调流剂是改善缝洞油藏水驱效果的重要手段，明确调流剂在油藏内的速度分布是调流施工设计以及效果评价的关键之一。基于简化的裂缝模型，推导出调流剂在碳酸盐岩缝洞型油藏裂缝内不同位置的速度分布，评价了不同流速下调流剂在裂缝中的运移规律，建立了流道调整效果与施工排量之间的关系。结果表明，在现场施工排量下，随着流动半径由1 m增至1/3井距（620 m），调流剂流速由25 m/s逐渐降至0.025 m/s。随着调流剂速度降低，堆积形成的位置更加靠前，堆积高度增加，堆积体的致密程度增加，调流剂流速低于0.25m/s时可以形成有效的堆积体。对于TH缝洞油藏某典型井组，要实现调流剂在主流线方向100 m位置可以有效封堵裂缝，施工排量应小于0.487 m3/min。结合调流剂速度分布模型和调流剂在裂缝中的运移规律模拟结果，建立了流道调整效果与施工排量之间的关系，对缝洞油藏调流作业具有指导意义。

Injecting plugging agent into formation is an important method to improve waterflooding effect of fractured-cave reservoir. Figuring out the velocity distribution of plugging agent is the key of construction design and effect evaluation of channel adjustment. Based on the simplified fracture model，the velocity distribution of plugging agent at different positions in the fracture of carbonate fractured-cave reservoir was deduced，the migration characteristic of plugging agent with different velocity in fracture was evaluated and the relationship between the adjustment effect and construction displacement was established. The results showed that under the displacement of field application，the velocity of plugging agent gradually decreased from 25 m/s to 0.025 m/s with the increase of flow radius from 1 m to 1/3 of well spacing（620 m）. With decreasing velocity of plugging agent，the position of accumulation was more forward and the height and density of accumulation raised. Effective accumulation could be formed when the velocity of plugging agent in formation was less than 0.25 m/s. For the typical well group of TH fractured-cave reservoir，in order to block the fractures efficiently from 100 m in the direction of main flow line，the injection rate of plugging agent should be less than 0.487 m3 /min. Based on the velocity distribution model and the migration simulation result of plugging agent in fracture， the relationship between adjustment effect and construction displacement was established，which could guide the channel adjustment work in fractured-cave reservoir.