中国渤海湾の石油地質
沙河街層三段砂岩油層
1989 年 54 巻 1 号 p. 33-42
詳細
1989 年 54 巻 1 号 p. 33-42
The Shahejie Third Member (Es3) was deposited in the most part of Gulf of Bohai during early Oligocene in age.
In this paper, we discussed the relation between the sedimentary environments and the reservoir qualities of the Es3 sandstones concentrated on BZ 34 area.
The Esa sandstones are interpreted as deposits under the wave dominated delta environment which is divided into four facies, such as (1) open lacustrine, (2) sand flat/distributary mouthbar, (3) lagoon/bay/washover and (4) distributary channel/crevasse/overbank swamp, from the results of facies analyses with cores and wireline log date. It is considered that there have been five delta cycles which prograded northeastward or northward during early Oligocene.
On the other hand, it is suggested that the most important factor to control the reservoir qualities of Es3 sandstones is grain size which is related to the sedimentary facies. From these discussions, we concluded that sandstones with large grain size have the best reservoir qualities in the Shahejie Third Member of this area. These sandstones were deposited under distributary channel, sand flat and distributary mouthbar environments.
