Facies architectural analysis and three-dimensional modeling of Wen79 fault block, Wenliu oilfield, Dongpu depression, China

Wenliu oilfield is one of those typically structural reservoirs in Dongpu depression in China. Wen79 fault block is located in the south of Wenliu oilfield. Nowadays, it has entered the secondary oil recovery stage with a high water cut. Accumulated repository from long-term exploration and production makes the opportunity to fulfill a fine description of Wen79 fault block optimistic. Eight basic lithofacies types (Gt, St, Sp, Sl, Sh, Sr, Fl, Fm) were identified through core observation, and brief description and interpretation were given to each lithofacies. Assemblages of associated facies were arranged into four specified architectural elements (channel fill, proximal overbank, distal overbank, and shallow lake). For the purpose of quantified reservoir physical property characterization, a three-dimensional (3-D) architectural element model was firstly constructed by using the stochastic reservoir modeling technique, truncated Gaussian simulation (TGS). Subsequently, we used the sequential Gaussian simulation (SGS) method to capture probable distributions of reservoir porosity and permeability with the help of facies-controlled method. Meanwhile, non-facies-controlled physical property models were also built for a comparative study. Analysis of both kinds of models indicates that the facies-controlled physical property model is more reliable.