Three‐Dimensional Modelling of a Multi‐Layer Sandstone Reservoir: the Sebei Gas Field, China

Abstract

Multi‐layer sandstone reservoirs occur globally and are currently in international production. The 3D characteristics of these reservoirs are too complicated to be accurately delineated by general structural‐facies‐reservoir modelling. In view of the special geological features, such as the vertical architecture of sandstone and mudstone interbeds, the lateral stable sedimentation and the strong heterogeneity of reservoir poroperm and fluid distribution, we developed a new three‐stage and six‐phase procedure for 3D characterization of multi‐layer sandstone reservoirs. The procedure comprises two‐phase structural modelling, two‐phase facies modelling and modelling of two types of reservoir properties. Using this procedure, we established models of the formation structure, sand body structure and microfacies, reservoir facies and properties including porosity, permeability and gas saturation and provided a 3D fine‐scale, systematic characterization of the Sebei multi‐layer sandstone gas field, China. This new procedure, validated by the Sebei gas field, can be applied to characterize similar multi‐layer sandstone reservoirs.

Modes of Shale‐Gas Enrichment Controlled by Tectonic Evolution

“…As demonstrated in Fig. 1, a shale gas reservoir is enriched through the source-reservoir-seal system within a specific domain, over which the spatiotemporal relationship holds (Ou Chenghua et al, 2016a;Ou et al, 2016b). Within this domain, static and dynamic factors interact to establish an enrichment system of complex internal structures and relationships (see Fig.…”

“…In addition, strata uplift reduces both the burial depth and the formation pressure, desorbing vast amounts of gas. The expanding free gas abruptly increases the pore pressure inside the gas reservoir, forcing the opening of lamellation fractures inside the reservoir (Ou, 2015;Ou Chenghua et al, 2016a, 2017aOu et al, 2016b).…”

“…Owing to the high gas potential energy from large-scale hydrocarbon generation and the strong gas diffusion capabilities, the shale layer and the top and bottom seal formations must be tightly sealed; otherwise, shale gas will escape from the shale layer and become a gas source for other areas, preventing enrichment of the shale layer. Finally, if the spatiotemporal relationship is ignored in the shale-gas enrichment Ou Chenghua et al, 2016a;Ou Chenghua et al, 2016b) and only the hydrocarbon generation is considered, the shale gas accumulation and enrichment are insignificant. The generated shale gas must fill the high-quality shale reservoir over the same duration and extent and must be continuously sealed by the top and bottom seal formations (Ren Bo et al, 2016).…”

Stream, Lake, and Reservoir Management

“…Models of the development structure, sand body structure and microfacies, repository facies and properties including porosity, penetrability and gas immersion and gave a 3D fine-scale, precise portrayal of the Sebei multilayer sandstone gas field, China utilize a method of twostage basic displaying, two-stage facies demonstrating and demonstrating of two sorts of supply properties system. This new technique, approved by the Sebei gas field, can be connected to portray comparable multi-layer sandstone reservoirs (Chenghua et al, 2016).…”

Pore Structure and Permeability Variations during Gas Displacement in Unconsolidated Sandstone Reservoirs through CT Reconstruction Analysis

“…How to get a better development effect becomes crucial to extracting more resources. Among all types of natural gas reservoirs in China, the development of unconsolidated sandstone gas reservoirs such as the gas fields in the Qaidam Basin, western South China Sea, and Baoshan Basin [4][5][6] has been confronted with kinds of problems including sand production, water channeling, and more serious heterogeneity [7][8][9], further affecting the productivity. These problems result from the changes in the petrophysical properties of the unconsolidated sandstone, especially the changes in the pore structure and permeability [10,11].…”