川北地区大安寨段低孔渗油气层地质特征及勘探方法

THE GEOLOGICAL CHARACTERS OF THE TIGHT OIL/GAS RESERVOIRS IN DAANZHAI SECTON NORTHERN SICHUAN AND THE EXPLORATION TECHNIQUE FOR IT

王当奇

Wang Dangqi

地质矿产部西南石油地质局地质大队

Southwest China Bureau of Petroleum Geology, Ministry of Geology and Mineral Resources.

介屑灰岩是川北地区大安寨段主要储集岩,它的基质孔隙度、渗透率低;孔隙结构差,次生溶蚀孔洞、缝则是油气赋存与富集的主要空间。介屑油气藏是主要类型,具明显的非层状、非均质体特征。介屑相带是控制油气富集带的基础。

Coquina is the main reservoir rocks in Daanzhai Section of northern Sichuan,but its porosity, permeability and pore geometry are quite poor. The secondary dissolution pores, caves and fractures constitute most of the space for the storage and accumulation of oil/gas. The main type of the facies of oil/gas pools is shelly bank with nonstratified and inhomogeneous characters. The shelly bank facies controls the enriched oil/gas zones. The local structures and fractures formed in the later stage of the tectonic movement did not rework much the shelly bank oil/gas pools and did not significantly redistributed the previously formed oil and gas pools. Therefore,the exploration of commecial oil/gas pools in the section of northern Sichuan should be focused on the main body of the shelly bank located in the interior zone of shallow water lacustrine facies surrounding the sub deep-deep water la-custrine facies of the oil-generative depression.

https://doi.org/10.11781/sysydz198702134