| 超低界面张力体系对低渗岩心非线性渗流规律的影响 |
| |
| 引用本文： | 曾羽佳,欧阳传湘,曾庆伟,李鑫羽,赵鸿楠.超低界面张力体系对低渗岩心非线性渗流规律的影响[J].地质科技通报,2021,40(5):307-315. |
| |
| 作者姓名： | 曾羽佳 欧阳传湘 曾庆伟 李鑫羽 赵鸿楠 |
| |
| 基金项目： | 国家青年科学基金项目51804039中国石油科技创新基金研究项目2017D-5007-0311 |
| |
| 摘 要： | 低渗储层中启动压力梯度导致流体渗流规律呈现非线性特征，使得低渗储层的开发方式与中高渗储层不同。为了研究新立油田低渗储层中的非线性渗流现象，以新立油田天然低渗岩心为研究对象，通过精密压力测试多孔介质渗流实验分析超低界面张力体系对新立油田低渗岩心中单相及两相流体启动压力梯度的影响。研究结果表明:对于任何流体，新立油田低渗岩心均表现出非线性渗流特征，存在着一定启动压力梯度；低渗岩心拟启动压力梯度的值高于启动压力梯度，且两者均随着渗透率的提高而降低且与渗透率之间均为幂关系；超低界面张力体系可以明显地降低低渗岩心最小启动压力梯度与拟启动压力梯度；对于不同渗透率的岩心，两相临界启动压力梯度与含水饱和度的关系均表现出相似的变化规律，即两相临界启动压力梯度随着平均含水饱和度的上升先上升后降低；在不同渗透率下，对比水驱和超低界面张力体系驱的临界压力梯度最高点，超低界面张力体系下的临界压力梯度最高点明显小于水驱，这表明界面张力的减小可以明显地降低驱油时产生的两相临界压力梯度，超低界面张力体系改善了油藏的注入性。本研究对新立低渗储层水驱后开发方式的选择提供了参考。
|
| 关 键 词： | 超低界面张力 启动压力梯度 多孔介质渗流 单相及两相流动 |
| 收稿时间： | 2021-01-29 |
Influence of ultra-low interfacial tension system on nonlinear seepage law of low permeability core |
| |
| Abstract: | The starting pressure gradient in low permeability reservoir leads to the nonlinear characteristics of fluid flow, which makes the development mode of low permeability reservoir different from that of medium and high permeability reservoir.In order to study the nonlinear seepage phenomenon in the low permeability reservoir of Xinli Oilfield, taking the natural low permeability core of Xinli Oilfield as the research object, the influence of ultra-low interfacial tension system on the start-up pressure gradient of single-phase and two-phase fluid in Xinli low permeability cores was analyzed through the porous media seepage experiment of precision pressure tests.The results show that for any fluid, the low permeability core of Xinli Oilfield shows nonlinear seepage characteristics, and there is a certain threshold pressure gradient.The value of pseudo starting pressure gradient of low permeability cores is higher than that of starting pressure gradient, and both of them decrease with the increase of permeability, and the relationship between them is power.The ultra-low interfacial tension system can obviously reduce the minimum starting pressure gradient and quasi starting pressure gradient of low permeability cores.For cores with different permeability, the relationship between the two-phase critical starting pressure gradient and water saturation shows a similar change law, that is, the two-phase critical starting pressure gradient firstly increases and then decreases with the increase of average water saturation.Under different permeability, the highest critical pressure gradient of water flooding and ultra-low interfacial tension system flooding is compared.The highest point of critical pressure gradient in ultra-low interfacial tension system is obviously smaller than that in water flooding.This shows that the decrease of interfacial tension can significantly reduce the two-phase critical pressure gradient during oil displacement, and the ultra-low interfacial tension system improves the injectivity of the reservoir.This study provides a reference for the selection of development mode after water flooding in Xinli low permeability reservoir. |
| |
| Keywords: | |
|
| 点击此处可从《地质科技通报》浏览原始摘要信息 |
|
点击此处可从《地质科技通报》下载全文 |
|
