Characteristics of Alluvial Fan in Baikouquan Formation of Wuerhe Oil Field in Junggar Basin and Petroleum Prospecting Significance

Key words: 
• Wuerhe Oilfield

Abstract: Through the analysis of core, cast thin slice and wireline logging data, a typical retrograding sequence alluvial fan is found in Baikouquan Formation of Wuerhe Oilfield which is located in the Junggar Basin. Midfan intrafacies is developed in the lowermiddle part of affuvial fan and endfan intrafacies is developed in the upper part which remark the sedimentary environment that A/S (the ratio of available accommodation and sediment flux rate) increased under a transgression of the lake water body at early Trias. Microfacies include braided channel filling, sieve deposit, mudrock flow deposit and sheet deposit. Integrated with regional structure style, well testing data and production rate, braided channel filling in midfan intrafacies is the most favorable facies which controls hydrocarbon's accumulation and reservoir boundary. After the study, more appraisal wells were designed and drilled according to the distribution of favorable facies, and considerable hydrocarbon output in Baikouquan formation proved the accuracy of the conclusions. The laws summarized in this study will play an important role in the development of the reservoir for other oilfields.