致密砂岩储层流体差异性赋存特征——以鄂尔多斯盆地三叠系延长组为例

Differential characteristics of fluid occurrence in tight sandstone reservoirs: a case study of Triassic Yanchang Formation in Ordos Basin

张亚东 高光辉 刘正鹏 廖海于 汪广轮 丁长灿 马宏伟 李泽亮

ZHANG Yadong GAO Guanghui LIU Zhengpeng LIAO Haiyu WANG Guanglun DING Changcan MA Hongwei LI Zeliang

中国石油 长庆油田分公司 勘探事业部, 西安 710018 川庆钻探工程有限公司 长庆井下技术作业公司, 西安 710018 中国石油 长庆油田分公司 第十二采油厂, 西安 710018 中国石油 长庆油田分公司 第三采油厂, 银川 750000 中国石油 长庆油田 苏里格南作业分公司, 西安 710018

Exploration Department, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China Changqing Downhole Technology Operation Company, Chuanqing Drilling Engineering Co., Ltd., Xi'an, Shaanxi 710018, China No. 12 Oil Production Plant, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China No. 3 Oil Production Plant, PetroChina Changqing Oilfield Company, Yinchuan, Ningxia 750000, China Sulige South Operation Branch, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710018, China

为探讨致密砂岩油藏储层流体差异性赋存特征，以鄂尔多斯盆地HQ地区三叠系延长组长6、长8油层组及HS地区长6、长8油层组为研究对象，利用核磁共振技术、高速离心实验，按渗透率区间、地区、目的层层位定量分析储层岩石可动流体含量、不同级别喉道控制的可流动孔隙空间等储层流体差异性赋存特征。不同渗透性级别的储层中，不仅总可动流体饱和度差异较大，而且可动流体赋存的喉道区间也存在较大差异。渗透性好，可动流体由较大喉道控制；渗透性差，可动流体主要由较小喉道控制。在较小喉道半径区间（小于临界喉道半径），随喉道半径增大，可动流体饱和度增加；在较大喉道半径区间（大于临界喉道半径），随喉道半径增加，可动流体饱和度降低。渗透性越好的样品，其临界喉道半径越大。不同地区、不同层位，总可动流体饱和度值由高到低的顺序依次为HQ长8、HS长8、HQ长6、HS长6。

In order to explore the differential characteristics of fluid occurrence in tight sandstone reservoirs, the Chang 6 and Chang 8 reservoirs in the Triassic Yanchang Formation in HQ and HS areas of the Ordos Basin were employed as research objects, the movable and non-movable fluid saturation of reservoir rocks were quantitatively analyzed with features including permeability interval, area and target strata by using nuclear magnetic resonance (NMR) test and high-speed centrifugal experiments. Results showed that the total movable fluid saturation, as well as the main throat intervals of movable fluid were different in reservoirs with different permeability levels. For the high permeability, movable fluid was mainly controlled by larger throat, while for the low permeability, movable fluid was mainly controlled by smaller throat. Movable fluid saturation positively correlated to the throat radius in the smaller throat radius range (< critical throat radius), and negatively correlated to throat radius in the larger throat radius range (>critical throat radius). The higher the permeability, the larger the critical throat radius.

国家自然科学基金项目 51974253;陕西省教育厅重点项目 18JS084;陕西省高校科协青年人才托举计划 20180703

https://doi.org/10.11781/sysydz2021061024