Diagenesis and reservoir quality of the fourth member sandstones of Shahejie formation in Huimin depression, eastern China |
| |
Authors: | Jin-liang Zhang De-yong Li and Zhi-qiang Jiang |
| |
Affiliation: | [1]College of Marine Geo-science, Ocean University of China, Qingdao 266100, China [2]College of Resources Science and Technology, Beijing Normal University, Beijing 100875, China [3]China National Offshore Oil Corporation, Shanghai 200030, China |
| |
Abstract: | Petrographic analysis combined with various techniques, such as scanning electron microscopy and X-ray diffraction, was used
to assess the timing of growth and original mineral cements, the controls on reservoir and reservoir quality of the fourth
member sandstones of Shahejie formation (Es4). The Es4 sandstones are mostly arkose and lithic arkose, rarely feldspathic
litharenite, with an average mass fraction of quartz 51.6%, feldspar 33.8% and rock fragments 14.6% (Q51.6F33.8R14.6). They have an average framework composition (mass fraction) of quartz 57.10%, K-feldspar 5.76%, sodium-calcium feldspar
13.00%, calcite 5.77%, dolomite 5.63%, siderite 0.95%, pyrite 0.30%, anhydrite 0.04%, and clay mineral 11.46%. The diagenentic
minerals typically include kaolinite, illite-smectite (I/S), illite, chlorite, authigenetic quartz and feldspar, and carbonate
and pyrite. Es4 sandstone has undergone stages A and B of eodiagenesis, and now, it is experiencing stage A of mesodiagenesis.
Reservoir quality is predominantly controlled by the mechanical compaction, for example, 45.65% of the original porosity loss
is related to compaction. The original porosity loss related with cementation is only 26.00%. The reservoir quality is improved
as a result of dissolution of feldspar, rock fragment and so forth. The porosity evolved from dissolution varies from 3% to
4%. |
| |
Keywords: | sandstone diagenesis kaolinite reservoir quality compaction Huimin depression |
本文献已被 维普 万方数据 SpringerLink 等数据库收录! |
|