Abstract:

Abstract: The tight gas sands in the Upper Palaeozoic in northern Ordos Basin feature in tightness, low porosity and low permeability. Their geophysical anomalies are often insignificant, characteristics of priori geological models are ambiguous, and constraints on corresponding geophysical data volume are poor. For these reasons, the final reservoir model can not reflect exactly the heterogeneity of the tight gas sands. In order to solve these problems in modeling of the tight gas sands in the study area, geologic research results and seismic information are fully integrated in reservoir modeling. A reservoir geology database is first created based on geologic research results and is used to quantify the priori geologic knowledge. Then, a database of seismic constraints which are sensitive to reservoir parameters is created through seismic attribute optimization and seismic inversion. Next, information of time and depth domains is matched by building a fine velocity model. Finally, an integrated geologic model of the tight gas sands is established based on structure modeling, sedimentary facies/ lithofacies modeling and continuous reservoir parameter modeling under the control sedimentary facies. Application to reservoir modeling of the tight gas sands in the Daniudi gas field verifies its effectiveness.