Study on Favorable Reservoir Prediction of Fuyu Oil Layer in Qijiabei Area of Songliao Basin

Abstract

AbstractThe favorable reservoirs of Fuyu oil layer in Qijiabei area of Songliao Basin are mainly developed in FI oil layer group. However, due to the strong reflection of the top (T2) of Fuyu oil layer, the seismic response characteristics of favorable reservoirs are not clear, and effective prediction technology has not been formed yet. In view of the favorable reservoir prediction in this area, there are relatively few previous studies. Firstly, this paper carries out petrophysical analysis of the reservoir to clarify the logging response characteristics of the reservoir. Secondly, the seismic forward analysis is carried out when the favorable reservoir is far from the top of Fuyu oil layer and when the favorable reservoir is distributed in different strata to clarify the characteristics of seismic response, so as to guide the seismic reservoir prediction. The results show that the favorable reservoir in this area is characterized by low velocity and low density response. When the distance between the oil-bearing sandstone and the top of Fuyu oil layer is less than 6 m, the strong reflection event (T2) of the top of Fuyu oil layer has an obvious pull-down effect. When the distance is greater than 6 m, the pull-down effect is not obvious, but the amplitude becomes weak. When a single oil-bearing sandstone is developed in the middle and upper part of FI formation or a multi-layer oil-bearing sandstone is developed in FI oil layer group, the strong reflection event (T2) on the top of Fuyu oil layer is characterized by low frequency and weak reflection, and the minimum value attribute of wave peak can be optimized to predict the favorable reservoir distribution. The practical application shows that the coincidence rate of favorable reservoir prediction can reach 82.3%, which provides a better technical support for exploration in this area. In this paper, the logging and seismic response characteristics of favorable reservoirs are studied for the first time with the help of petrophysics and seismic forward analysis in this area, which provides theoretical guidance for reservoir prediction and provides a good reference for reservoir prediction in other areas.KeywordsSongliao BasinFuyu oil layerThe north of QijiaStrong reflectionFavorable reservoirSeismic forward modeling