Regionalized multiple-point stochastic geological modeling: A case from braided delta sedimentary reservoirs in Qaidam Basin, NW China

Abstract

Research on the depositional model of a braided delta in Kunbei oilfield, Qaidam Basin, was conducted with a fine geologic study in a dense well network area by combining sedimentary physical simulation to obtain statistical characteristic parameters and allocation relations of plane sedimentary facies units. On this basis, training images in different sedimentary regions of the braided delta were developed for reservoir modeling. In each sub-region, sequential conditional simulation in adjacent regions used different training images with angle revolving and scaling. This simulation succeeded in finely modeling the sedimentary microfacies of the braided delta. This method relaxed the requirement for a stationary training image in multipoint simulation and improved channel continuity as well as portability of the training image. In the fine reservoir description of the Kunbei oilfield, the model results were consistent with practical production and have the potential to guide effective water-flooding development. Effective application demonstrated the feasibility and practicability of the method. This paper presents a new method for accurately characterizing the braided delta using stochastic simulation. Key words: regionalized multi-point statistics, stochastic geological modeling, training image, sedimentary microfacies, braided delta, Qaidam Basin