西南石油大学学报(自然科学版)

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Mixing Reservoir Characteristic of Limestone Member in West  Slope of Jinhu Depression

Liu Chensheng1,2*, Yu Wang1,2   

  1. 1. MOE Key Laboratory of Metallogenic Prediction of Nonferrous Metals,Central South University,Changsha,Hunan 410083,China
    2. School of Geosciences and Info-physics,Central South University,Changsha,Hunan 410083,China
  • Online:2015-08-01 Published:2015-08-01

Abstract:

Limestone member is the important oil production layer,but its reservoir is of strong heterogeneity. Based on
cores,physical property test and casting slice data,reservoir feature and controlling factors can be analyzed. Three deposition
cycles comprise limestone member. The lower part of every cycle consists of mudstone and marlstone;the upper part consists
of biolithite limestone and muddy biolithite limestone. With average porosity of biolithite limestone of 12.7%,and average
permeability of 21 mD,the reservoir falls into low porosity and low permeability type. The relationship between porosity and
permeability is poor,so secondary pores develop well,with little primary pores. Reservoir space mainly consists of dissolving
pore distributed inter-grains,and dissolving pore distributed inner-grains and mold pore are little. Cracks are filled or half filled
by calcite. Based on casting slice data,pore and throat of reservoir is of poor sorting and strong heterogeneity. Physical property
and heterogeneity of reservoir are controlled by sedimentary facies,M level cycle and diagensis. Horizontally,biolithite
limestone developed well on high structural point,and physical property is good and heterogeneity is poor. Vertically,biolithite
limestone developed well on upper M level cycle,with good physical property.

Key words: Jinhu Depression, limestone member, reservoir, heterogeneity, milankovitch cycle