莺歌海盆地东方区黄流组低渗储层特征及影响因素分析

Structural characteristics of micro-pores and factors controlling low-permeability reservoirs in the Huangliu Formation in the Dongfang area, Yinggehai Basin

谢玉洪 张亚 张哨楠 张迎朝 刘景环

Xie Yuhong Zhang Ya Zhang Shaonan Zhang Yingzhao Liu Jinghuan

中海石油(中国)有限公司 湛江分公司, 广东 湛江 524057 2. 中国石油 西南油气田分公司 勘探开发研究院, 成都 610041 3. 油气藏地质及开发工程国家重点实验室 (西南石油大学), 成都 610500 4. 西南石油大学 地球科学与技术学院, 成都 610500

Zhanjiang Branch of CNOOC, Zhanjiang, Guangdong 524057, China 2. Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, Sichuan 610041, China 3. State Key Laboratory of Oil and Gas ReservoirGeology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China 4. College of Earth Science and Technology, Southwest Petroleum University, Chengdu, Sichuan 610500, China

以恒速压汞实验为基础,对莺歌海盆地东方区黄流组储层微观孔隙结构特征以及影响因素进行分析。数据表明,东方区黄流组低渗储层平均孔隙半径约为100~140 μm,平均喉道半径约为1~5 μm,主流喉道半径小于5 μm。孔隙半径对渗透率影响较小,喉道半径以及主流喉道半径随着渗透率的降低而减小,分布范围变窄;孔喉比随着渗透率的降低而增大,分布范围变宽。研究区储层较低的渗透率主要是由于储层喉道半径较小造成,而较强压实作用以及自生黏土矿物堵塞喉道是研究区储层孔隙结构差,喉道半径较小的主要原因。

Characteristics of micro-pore structures and factors controlling the low-permeability reservoirs in the Huangliu Formation in the Dongfang area of the Yinggehai Basin were studied by mercury injection experiments with constant rates.The average pore radius of the reservoirs is about 100-140 μm, the average throat radius is about 1-5 μm, and the mainstream throat radius is less than 5 μm.The permeability is not correlated with pore radius, and reservoirs with different permeabilities can have similar pore radius distributions.In contrast, permeability is strongly associated with throat radius and its distribution.The throat radius and the mainstream throat radius decrease as permeability becomes lower, and the distribution range gets narrower.The throat to pore ratio increases as permeability decreases, and its distribution range becomes wider.The low permeability of rocks in the study area can be explained by their small throat radius.Strong compaction effects and authigenic clay minerals are the main factors which undermine the micro-pore structures and make the permeability low.

https://doi.org/10.11781/sysydz201505541