基于储层孔喉匹配的非均相复合驱技术研究与矿场实践——以胜坨油田一区沙二段1-3砂组聚合物驱后单元为例

Research on heterogeneous combination flooding technology based on matching between system and reservoir pore throat and its field application:A case of post-polymer flooding Es21-3 in Sheng1 area,Shengtuo Oilfield

非均相复合驱油体系与储层孔喉匹配性是实现驱油体系有效注入和大幅度提高原油采收率的关键因素,基于物理模拟研究,建立黏弹性颗粒驱油剂与多孔介质孔喉匹配关系图版。优选胜坨油田一区沙二段1-3砂组聚合物驱后油藏典型单元作为先导试验区,在目标储层孔喉特征分析的基础上,依据所建立的匹配关系图版,研制适合目标储层的黏弹性颗粒驱油剂,联同聚合物与阴非两性表面活性剂构建适合目标储层的高效非均相复合驱油体系。研究结果表明,非均相复合驱技术能有效动用不同类型、不同孔径孔隙中的剩余油,提出非均相复合驱油体系对剩余油的微观动用机制。矿场实践证实,试验区注入井注入压力上升了4.7 MPa,启动压力上升了5.1 MPa,平均阻力系数达1.7,矿场油藏压力分布更加均匀,驱替更加均衡;截至2020年5月,试验区已取得显著降水增油效果,生产井综合含水率下降了6.3%,日产油量由39 t/d升至141 t/d,数值模拟预测在聚合物驱后可进一步提高原油采收率7.6%,非均相复合驱技术具有广阔的推广应用前景。

The matching between the heterogeneous combination flooding system and the reservoir pore throat is the key factor for realizing the effective injection of the flooding system and dramatically enhancing oil recovery.Based on physical simulation research,a matching relationship chart of the viscoelastic particle flooding agent and reservoir pore throat is established.The 1st to 3rd Submembers of the 2nd Member of Shahejie Formation(Es21-3)in Sheng1 area,Shengtuo Oilfield was preferred as the pilot area,which was the typical post-polymer flooding reservoir.Based on the analysis of the reservoir pore throat characteristics and the established matching relationship chart,the viscoelastic particle flooding agent suitable for the target reservoir in the pilot area was developed,and the efficient heterogeneous combination flooding system suitable for the target reservoir in the pilot area was constructed based on the combination of the polymer and the anionic and nonamphoteric surfactants.The research results show that the heterogeneous combination flooding technology could effectively mechanism of the heterogeneous combination flooding system is proposed.Field application has confirmed that the average injection pressure of injection well was increased by 4.7 MPa,and the average starting pressure was increased by 5.1 MPa.The drag resistance coefficient reached 1.7.The pressure distribution was more uniform,and the displacement was more balanced.As of May 2020,the significant water-cut reduction and production rate increment have been achieved in the pilot area.The comprehensive water-cut of the production well was decreased by 6.3%,and the production rate in the pilot area increased from 39 t/d to 141 t/d.The numerical simulation prediction shows that the oil recovery rate could be further increased by 7.6%after polymer flooding,which has broad prospects for popularization and application.