深水浊积岩油藏提高采收率方法研究

Study on Enhanced Oil Recovery Method in Deep-Water Turbidite Reservoirs—A Case Study of X Reservoir in Angola

牟汉生 陆文明 曹长霄 宋兆杰 石军太 张洪

MOU Hansheng LU Wenming CAO Changxiao SONG Zhaojie SHI Juntai ZHANG Hong

中国石化东北油气分公司，吉林长春 130062 中国石化石油勘探开发研究院，北京 102206 中国石油大学（北京）非常规油气科学技术研究院，北京 102249 中国石油大学（北京）石油工程学院，北京 102249

Northeast Oil & Gas Branch of Sinopec, Changchun, Jilin, 130062, China Sinopec Petroleum Exploration and Production Research Institute, Beijing, 102206, China Unconventional Petroleum Research Institute, China University of Petroleum, Beijing, 102249, China College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing, 102249, China

深水浊积岩油藏储层非均质性强，平面矛盾突出，注水开发过程中易出现油水前缘不稳定，形成窜流。气为明确气水交替驱与氮气泡沫驱在平面非均质油藏的适用性及其提高采收率机制，结合油藏地质资料，设计制作了不同渗透率级差的岩心模型，开展了气水交替驱和氮气泡沫驱试验，分析了2种提高采收率方法的驱油效果，结合数值模拟研究，探索了驱替过程中不同渗透率条带的流体波及规律。研究结果表明，当岩心模型渗透率级差较小时，气水交替驱可表现出良好的提高波及系数及降低出口端含水率的能力，但当岩心模型渗透率级差较大时，该方法控制气体流度能力降低，提高采收率效果变差。氮气泡沫驱在岩心模型渗透率级差较大时，仍可发挥泡沫堵大不堵小、堵水不堵油以及表面活性剂洗油的多重特性，有效抑制高渗条带中的流体窜逸，使氮气泡沫在低渗条带呈现活塞式驱替，从而实现深部调驱、大幅度提高采收率的目的。因此，氮气泡沫驱可有效提高深水浊积岩油藏采收率，为该类油藏的经济高效开发提供技术支持。

Due to severe planar-heterogeneity, water-displacing-oil front in deep-water turbidite reservoirs is unstable and may cause water channeling during water flooding. In order to investigate the feasibility and enhanced oil recovery mechanisms of water and gas alternating flooding and nitrogen foam flooding in planar-heterogeneous reservoirs, artificial core samples with different permeability contrasts were designed according to the geological data in core flooding experiments. Based on the history matching of experimental data via numerical simulation, fluid flow behavior was discussed in the heterogeneous core samples. The results showed that water and gas alternating flooding presented good ability in improving sweep efficiency and reducing water cut when the permeability contrast was small; however, its ability in controlling gas mobility was depressed and the enhanced oil recovery effect was decreased when the permeability contrast was large. Due to the selective plugging of nitrogen foam and the surfactant’s improving displacement efficiency, nitrogen foam flooding could still delay fluid channeling in high-permeability streaks of severe planar-heterogeneous core samples while presented the piston-like displacement in low-permeability streaks so as to achieve in-depth profile control and oil recovery improvement. Thus, nitrogen foam flooding could effectively enhance oil recovery in deep-water turbidite reservoirs and provide technical support for the economical and efficient development of such reservoirs.

国家科技重大专项“安哥拉深水浊积岩油藏高效开发技术”（编号：2016ZX05033-003-005）部分研究内容

https://doi.org/10.11911/syztjs.2021025