西南石油大学学报(自然科学版)

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Research of Structural Reservoir in No.5 Unit of Lenghu Area

  

  • Online:2013-08-01 Published:2013-08-01

Abstract:

Based on core observation,cast thin section,scanning electron microscopy and Hg-injection analysis and so on,we
studied reservoir characteristics of structural reservoir in No.5 Unit of Lenghu Area in Qaidam Basin. The results show that the
structural reservoir in No.5 Unit of Lenghu Area are mainly fine-grained sandstone and siltite,a small part of medium sandstone
and coarse-grained sandstone of delta facies. The rocks were mainly experienced compaction,cementation and dissolution,
and the diagenesis characteristics of the study area are medium compaction and dissolution,stronger cementation,the main
cements are carbonate,sulfate,siliceous and clay mineral cement. Reservoirs are in A stage of late diagenesis. Pore types
of the study area are residual intergranular pores and dissolution expand holes. Reservoir properties are both controlled by
sedimentary facies and diagenesis,high quality reservoir is delta distributary channel sand,subaqueous distributary channel
sand and sheet sand;Diagenesis also influences the reservoir properties in which compaction and cementation decrease the
porosity,dissolution increases secondary porosity.

Key words: No.5 Unit of Lenghu Area, Shangganchaigou Formation, diagenesis, reservoir characteristics, pore evolution