Abstract:

This paper is a case study on the Lower Karamay Formation. By analyzing  eight sealed coring wells with small distance and the architecture characteristics of twenty-four wells around, a 3D architecture model of target formation of the study area is built. Different architecture modeling methods practical to fans with different subfacies were derived. Fan head is extensive connecting body mainly composed of sheet-flow sandstone bodies, and the distribution areas of the architecture of different levels are small, so Object-based modeling method is used. The main architecture units of mid-fan are fine sheet-flow grains, braided channel and sheet-flow sandstone body.The braided channel and sheet-flow sandstone bodies have obvious contact belt. So Truncate Gauss Simulation method is used. The main architecture unit of the fan-margin is fine sheet-flow grains, as well as a small number of through-flow and sheet-flow sandstone bodies, so Sequence Indicator Simulation and Object-based modeling method are applicable. The 3D architecture model built can well embody the distribution areas and the contact relations of the architecture units of different levels in both horizontal and vertical directions, which can provide an evidence for the remaining oil prediction, as well as well-pattern adjustment and remaining oil tapping.

Key words: alluvial fan, architecture modeling, Truncate Gauss Simulation, Object-based modeling, Sequence Indicator simulation