Oil & Gas Geology ›› 2001, Vol. 22 ›› Issue (3): 267-269.doi: 10.11743/ogg20010318

Previous Articles     Next Articles

CHARACTERISTICS OF POROSITY DEVELOPMENT OF JURASSIO SAND-STONE IN THE NORTH MARGIN OF QAIDAM BASIN

Liu Yuntian1, Yang Shaoyong2   

  1. 1. Changsha Institnte of Geotectonics, Chinese Academy of Sciences, Changsha, Hunan;
    2. Qinghai Oilfield Branch of Petro China, Dunhuang, Ganshu
  • Received:2001-01-09 Online:2001-09-25 Published:2012-01-16

Abstract:

The Jurassic sandstone in the north margin of Qaidam Basin consists of medium coarse size sandstone,conglomerate sandstone and fine sand with low content of cement.The reservoir spaces of the sandstone are mainly primary porosity with a small part of secondary porosity.Diagenetic compaction was the controlling factor of porosity evolution and preservation.The porosity reduction of the Jurassic sandstone caused by compaction at present burial depth is 20%~32%,and it is related to tectonic evolution history,especially to the maximal paleo burial depth and the maximun of post denudation.The present porosity formed during 65~12 Ma when the sandstone was in the maximun buried depth.So it is considered that the deeper of the sandstone buried,the smaller the porosity would be.

Key words: burial hisotry, diagenesis, sandstone porosity, Qaidan Basin, Jurassic

CLC Number: