Sand architecture interpretation and modeling with few wells in the offshore — Case study of X36 area in the Xihu Depression, East China Sea, China

Abstract

The sand architecture interpretation and modeling of the different orders of sedimentary bodies are of great significance for the efficient development of the unconventional reservoir. However, sand architecture interpretation and modeling using a small amount of observation information are extraordinarily difficult. We took the X36 gas field in Xihu Sag as an example to study the distribution and superimposition characteristics of sandbodies under the influence of tides. We proposed a set of architecture characterization and modeling methods suitable for the condition of a few wells. First, we extracted a variety of seismic attributes from the original seismic data, and we fit the correlations between seismic attributes and sandstone thickness interpreted by logging. Then, we classified and integrated the seismic attributes with a high correlation to calculate the fusion seismic attributes. The fusion seismic attribute has a higher correlation with sandstone thickness. The boundary of the sandstone in the fusion seismic attribute is clearer than a single attribute. We established the sand body distribution model of the study area with the constraints of the fusion seismic attribute and the distance attribute volume. The results indicated that the sand body distribution in the model was more consistent with the sand body development model under the influence of the tide. The results can guide architecture characterization and remaining oil potential tapping of the oil and gas fields offshore.