Abstract:

The present reservoir oil-water interface of each well in the Block Ⅰ, center of Junggar basin is predicted through analyzing the chemically extracted hydrocarbon residues and  Rock-eval data combining with comprehensive log interpretation.The frequency of mineral grains containing oil-bearing fluid inclusions (the GOI number) reflects the palaeo-oil saturation experienced in a sandstone reservoir irrespective of the present fluid phase. The location of the original oil-water interface of each well is defined through analyzing the detailed GOI mapping. It is concluded that the original oil-water contact is lower than the present contact；A detail study is undertaken to compare molecular parameters obtained from the analyses of core extracts and oil-bearing fluid inclusions. It is found that the molecular parameters of core extracts and oil-bearing fluid inclusions of well Zheng 1 are similar, while those of wells Sha 1 and Zhuang 1 are significantly different.Through the successful case study，it is predicted that the oils of well Zheng 1 are mainly derived from the source rocks of Changji sag in the south;  the oils of wells Sha 1 and Zhuang 1 are mixed oils, which are generated from the source rocks in the north and Changji sag.

Key words: Junggar basin, original oil-water contact, oil-bearing fluid inclusion, biomarker parameter