A New Method and Its Application for Building Underground Geological Knowledge Database for Strongly Heterogeneous Reservoirs

Abstract

Braided river reservoirs occupy a large proportion in domestic tight sandstone gas reservoirs, which were represented by the tight gas reservoir of sulige gas field in ordos basin, and the reservoirs are heterogeneous. The establishment of braided river reservoir geological knowledge data-base is very important for reservoir prediction between Wells. Under the guidance of braided river sedimentary prototype model based on outcrop anatomy and Google Earth satellite image analysis of modern sedimentary, by analyzing the logging data of horizontal Wells, and studying the relationship between the horizontal well trajectory and the sand cap/bottom structure, the lithology, GR and gas measurement comparison methods of parameters in the geological knowledge database of tight reservoirs were established, which can be used to quantitative anatomy of underground geological knowledge data-base. The results show that the four sand drilling modes of the horizontal section are established. And the effective drilling effect of the horizontal section can be effectively improved by relying on tracking the structural fluctuation of the sand cap/bottom based on the four sand drilling modes. Using actual lateral horizontal well anatomy to establish reservoir geological knowledge database can effectively reflect the braided river dense sandstone reservoir heterogeneity, and the prediction of reservoir “sweet spot” between Wells is realized. In this way, the establishment and application method of reservoir underground geological knowledge database on horizontal wells are proposed, and the inter-well reservoir prediction and the three-dimensional spatial simulation characterization from the five-stage channel to the three-stage internal configuration of diara are realized, which is of great significance for horizontal well deployment and geological guidance.