Zhao Wenjing, Wang Jing, Wu Tianjiang, Erik Ronald Omara, Qi Zhongyang, Liu Huiqing
State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China.
Oil and Gas Technology Research Institute of Changqing Oilfield, China National Petroleum Corporation, Xi'an 710018, China.
Gels. 2025 Aug 27;11(9):686. doi: 10.3390/gels11090686.
Pan-connected interlayers are widely present in oil reservoirs, forming flow channels at different positions. However, conventional profile control agents struggle to plug deep interlayer channels in reservoirs, limiting the swept volume of injected water. Additionally, a clear methodology for physically simulating pan-connected reservoirs with interlayer channels and calculating interchannel flow rates remains lacking. In this study, a physical model of pan-connected interlayer reservoirs was constructed to carry out deformable gel particles (DGPs) plugging experiments on interlayer channels. A mass conservation-based flow rate calculation method for interlayer channels with iterative solution was proposed, revealing the variation law of interlayer channel flow rates during DGP injection and subsequent water flooding. Finally, oil displacement and DGP profile control experiments in pan-connected interlayer reservoirs were conducted. The study shows that during DGP injection, injected water enters the potential layer through interlayer channels in the middle and front of the water-channeling layer and bypasses back to the water-channeling layer through channels near the production well. With the increase in DGP injection volume, the flow rate of each channel increases. During subsequent water flooding, DGP breakage leads to a rapid decline in its along-path plugging capability, so water bypasses back to the water-channeling layer from the potential layer through all interlayer channels. As the DGP injection volume increases, the flow rate of each channel decreases. Large-volume DGPs can regulate interlayer channeling reservoirs in the high water cut stage. Its effectiveness mechanism involves particle migration increasing the interlayer pressure difference, which drives injected water to sweep from the water-channeling layer to the potential layer through interlayer channels, improving oil recovery by 19.74%. The flow characteristics of interlayer channels during DGP injection play a positive role in oil displacement, so the oil recovery degree in this process is greater than that in the subsequent water flooding stage under each injection volume condition. The core objective of this study is to investigate the plugging mechanism of DGPs in pan-connected interlayer channels of high-water-cut reservoirs, establish a method to quantify interlayer flow rates, and reveal how DGPs regulate flow redistribution to enhance oil recovery.
泛连通夹层广泛存在于油藏中，在不同位置形成流道。然而，传统的调剖剂难以封堵油藏深部夹层通道，限制了注入水的波及体积。此外，目前仍缺乏一种清晰的方法来对具有夹层通道的泛连通油藏进行物理模拟并计算通道间流速。在本研究中，构建了泛连通夹层油藏物理模型，对夹层通道进行了可变形凝胶颗粒（DGP）封堵实验。提出了一种基于质量守恒的夹层通道流速计算方法并进行迭代求解，揭示了DGP注入及后续水驱过程中夹层通道流速的变化规律。最后，开展了泛连通夹层油藏的驱油和DGP调剖实验。研究表明，在DGP注入过程中，注入水通过窜流层中部和前部的夹层通道进入潜力层，并通过生产井附近的通道回流至窜流层。随着DGP注入量的增加，各通道流速增大。在后续水驱过程中，DGP破碎导致其沿程封堵能力迅速下降，因此水通过所有夹层通道从潜力层回流至窜流层。随着DGP注入量增加，各通道流速降低。大剂量DGP可在高含水期调控夹层窜流油藏。其作用机理为颗粒运移增加了层间压差，促使注入水通过夹层通道从窜流层向潜力层波及，提高采收率19.74%。DGP注入过程中夹层通道的流动特性对驱油具有积极作用，因此该过程的采收程度大于各注入量条件下后续水驱阶段。本研究的核心目的是探究DGP在高含水油藏泛连通夹层通道中的封堵机理，建立夹层流速量化方法，揭示DGP如何调控流体重分布以提高采收率。
