Integrated Reservoir Characterization of Thin Bed Reservoir in Desert Area

Abstract

Located in the center of Taklimakan Desert, the seismic data in Tarim Oilfield are of low SNR and low resolution. As an oil field with more than two decades' production, Tarim Oilfied faces with the problems of complex structural pattern, reservoir heterogeneity, declining production and rising water cut as well. Aiming at these problems, an integrated reservoir characterization workflow is formed during this study. This method integrates the techniques of surface seismic, VSP, well logging and reservoir dynamic analysis to solve reservoir development issues and reduce the uncertainty in the prediction of remaining oil in the reservoir. Among the techniques, the resolution enhancement procedure with VSP-driven processing and relative preserved processing is the basis for the subsequent steps. This measure can best remove the influences of earth absorption and near surface impact to get a high-resolution image while relatively preserving reservoir amplitude, frequency, phase and wave form. Based on the high-resolution seismic data and well logging data, with correct geological concept and proper interpretation technique, several minor faults are detected and both the structural and sedimentary isochronous stratigraphic frameworks are established. Under this isochronous stratigraphic framework, the reservoir static model is established with the calibration of well logging and seismic data. Finally, under this reservoir static model, the reservoir production data analysis is carried out to detect thin inter-bed reservoirs, to predict the distribution of residual oil and to optimize the development plan. The integrated reservoir characterization workflow proposed in this paper has been successfully applied to Tarim Oilfield. Four stages of fault activities are recognized and several minor faults which affecting the oil-water relation are found during the study. And the drilling results show that the relative error between wells and structural map is controlled within 1.29% using the integrated methods mentioned above. Finally, with the analysis of reservoir production data and seismic inversion results, the spatial distribution of residual oil is predicted and several favorable areas are pointed out. This paper provides an effective way of seismic data processing, structure interpretation and reservoir characterization for oilfields in desert area with thin inter-bed reservoirs and long production history.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017