Abstract:

The understanding of single sand body distribution is unclear and the prediction of lithologic prospects is difficult in Fuyu oil layer in the northern Honggang area, Songliao Basin. Using core data of 8 wells, analysis and test results of 226 core samples and logging data of 386 wells, this paper studied the genesis types, contact relationships and distribution patterns of single sand body in the northern Honggang area. The results show that the single sand body types of Fuyu oil layer are mainly distributary channel, subaqueous distributary channel and mouth bar sand bodies. In the plane, multi?branch distributary channel, subaqueous distributary channel and mouth bar sand bodies are distributed in a dense and narrow band. The vertical single sand body distribution is controlled by sediment supply and sedimentary evolution, and it shows the characteristics of“vertical subsection”and“differentiation between the north and the south”. The superimposed pattern of the distributary channel sand bodies is complex, which results in complex reservoir single sand body distribution in Fuyu oil layer. The contact relationship between different distributary channel and subaqeuous distributary channel sand bodies in Fuyu oil layer can be divided into four types, such as overlapping,stacking, migrating and isolated contact. The contact relationship between the distributary channel, subaqueous distributary channel sand bodies and thin sand bodies or the mouth barsand bodies is mainly an abrupt contact. Multi?phase thin sand bodies or mouth bar sand bodies are often in a“stacking”contact relationship. These results can provide an important basis for the prediction of lithologic traps and study on oil/water distribution rule of Fuyu oil layer in the northern Honggang area.

Key words: water cut prediction, waterflooding characteristic curves, decline equation, Rayleigh model