非均相聚合物驱油藏防砂井近井挡砂介质堵塞机理实验研究

An Experimental Study on the Plugging Mechanisms of Sand-Preventing Medium in the Near-Well Zone of Sand Control Wells in Heterogeneous Polymer-Flooding Reservoirs

王力智 董长银 何海峰 曹庆平 宋雅君

WANG Lizhi DONG Changyin HE Haifeng CAO Qingping SONG Yajun

中国石油大学（华东）石油工程学院，山东青岛 266580 中国石化胜利油田分公司孤东采油厂，山东东营 257000 中国石油大港油田分公司石油工程技术研究院，天津 300450

School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong, 266580, China Gudong Oil Production Plant, Sinopec Shengli Oilfield Company, Dongying, Shandong, 257000, China Petroleum Engineering Technology Research Institute, PetroChina Dagang Oilfield Company, Tianjin, 300450, China

针对非均相复合驱油田开发出现的聚合物堵塞问题，利用非均相复合驱介质堵塞模拟实验装置，使用粒径中值0.15 mm地层砂和粒径0.6～1.2 mm砾石，分别采用清水、增黏基液、聚合物与PPG复配液等3种流体以及防砂油井中的聚合物堵塞物样品，开展了聚合物堵塞物对近井挡砂介质的堵塞模拟实验。结果发现：砾石层内聚合物堵塞物明显趋向于沿高渗透带运移，受液体剪切携带会剥落小尺寸黏团，挤入深部砾石层孔喉中，阻碍了地层砂运移，从而加剧了砾石层的堵塞程度，导致总体渗透率下降，且堵塞程度与堵塞物含量呈正相关。研究结果表明，非均相复合驱砾石充填防砂井近井地带堵塞是聚合物原液、聚合物堵塞物及固相颗粒的物理化学复合堵塞的结果，需尽早采取解堵措施，防止堵塞程度进一步加剧。

In light of the plugging problem in oilfield development using the heterogeneous polymer flooding, a simulation experiment to evaluate the plugging due to polymer plug in the sand-preventing medium in the near-well zone was carried out. It used a experimental simulation device of medium plugging of heterogeneous composite flooding. In the experiment, formation sand with grain sized averaging a diameter of 0.15 mm and gravel with a diameter range of 0.6–1.2 mm were used. In conjunction, three types of fluids, including clear water, a tackifying base fluid and a compound fluid contained PPG and polymer material were used. Further, the polymer plug samples in the sand control wells were used, respectively. The results showed that while it was in the gravel packing layer, the plug tended to migrate along the high permeability zone. Carried by fluid shear, the small viscous balls would be peeled off from the plug and then squeezed into the pores and throats in the deep gravel layer. These small, viscous balls impeded the migration of formation sand and intensified the degree of plugging degree in the gravel layer, which was positively related to the plug content. The outcome was a decrease in overall permeability. The results showed that the plugging in the near-well zone of gravel packed sand control wells treated by heterogeneous polymer flooding was a result of physical and chemical compound plugging of polymer dope, plug and solid particles. Early de-plugging measures should be taken to prevent plugging degree aggravation.

国家自然科学基金项目“弱胶结储层微观出砂机理与颗粒级尺度出砂过程模拟研究”（编号：51774307）资助

https://doi.org/10.11911/syztjs.2020118