Seismic Geological Modeling Study on Tight Sandstone Gas Reservoir in Ordos Basin

Abstract

Su xx block is located in the west of Sulige gas field, Ordos Basin. He8 target zone shows tight reservoir, strong heterogeneity, complex gas-water relationship, low well control degree, and high risk of remaining reserves utilization. Based on the seismic, geologic and production performance data, a geological modeling method combined with object modeling and multi-point facies simulation was proposed. Under the constraints of structure model, seismic sandstone prediction results and geologic knowledge base, 3D reservoir geological models were built. Through comparison and verification, the model results reflect the drilling situation of actual sand-body better, and the predictions of channel bar between wells have a good fit with the drilling situation of effective reservoir in drilled horizontal wells. Optimizing the attributes modeling under the constraints of multiple static and dynamic parameters, the established Sg model reflects actual gas-bearing reservoir distribution preferably, and much more match with gas well production performance. Based on the modeling results, the reservoir development obtained better implementation results including the screening of enrichment areas, deployment of target zones, selection of well locations, and horizontal wells’ trajectory design, tracing and production. For the low-permeability tight sandstone gas reservoir with complex gas-water relationship and low well control degree, it will has very important guiding significance to realize avoiding water development effectively, and enhance reserves utilization degree and development effect.