A DISCUSSION ON THE COMPACTION OF ARGILLACEOUS ROCKS AND PRIMARY MIGRATION OF OIL AND GAS IN DONGYING SAG OF SHANDONG PROVINCE
Chen Heli Tang Xiyuan (Northwest University)
In the light of data of transit time-depth curves, this paper discusses the chara-cteristics of distribution of the anomalous compaction zones in the Dongying sag, on the basis of which the conditions of primary migration in the area are examined. It is proposed that the effective source bed in the sag is the third member of Eogene Shahejie formation, the middle and lower parts of which are more widely distributed than the upper.Their main stages of hydrocarbon expulsions are Guantao-Quaterary period and Minghuazhen-Quaterary period respectively. The direction of primary migration is mainly from the centre of source area toward the margin of the sag laterally, especially to the northeast, and upward vertically. Generally, the vertical distance is not more than 600 meters over the tops of the anomalous compaction zones. From the above-mentioned conditions of primary migration, some prospective areas are suggested.