Browsing by Author "Zhang, Xianguo"

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    3D geocellular modeling for reservoir characterization of lacustrine turbidite reservoirs: Submember 3 of the third member of the Eocene Shahejie Formation, Dongying depression, Eastern China
    (Elsevier, 2022) Lutome, Marco Shaban; Lin, Chengyan; Chunmei, Dong; Zhang, Xianguo; Bishanga, Januarius Matata
    3D geocellular modeling is increasingly essential in the petroleum industry; it brings together all petroleum disciplines, and it is commonly used in simulation and production forecast. However, modeling slope and deep-water turbidite reservoirs using conventional modeling methods pose a significant challenge due to the structural complexity and thin-beds associated with these reservoirs. Through the innovative modeling technology of PaleoScan, the reservoirs in Sub member 3 of the third member of the Shahejie Formation are modeled to understand the structural framework. The resulting model is populated with petrophysical properties i.e., porosity and permeability to predict their lateral and vertical distribution within these sandstone reservoirs. The study suggests that the reservoir in the highstand system tract (HST) is characterized by the clinoforms configuration framework. The reservoir is highly faulted mainly in the northern and southeastern parts of the depression. The sedimentary layers are deposited across the slope and downlapping, thinning, and terminating toward to the west. The two isochore surface maps reveal sediment thickness variation and depositional trends within each individual depositional layer. The zones or areas that corresponds to low values on the thickness maps suggest minor uplifts associated with intensive faulting in the Eocene period. These topographical highs played a fundamental role in distributing the sediments delivered to the basin from distant sources. The maps reveal that sediments that filled the basin appear to come from different source points, primarily delivered from the north, southeast, and northeast of the basin with varying depositional trends. The modeled porosity and permeability indicate that the delta fed turbidite reservoirs are characterized by medium to high porosity values of 10e20% and low to medium permeability values of 30-410mD, respectively. The porosity values increase to the southeast and toward the basinwards (west) while permeability varies within the individual sedimentary layers. The distribution of porosity and permeability is not uniform vertically. This suggests the presence of mixed none-reservoir layers with locally and periodically deposited sandstone reservoirs within the stratigraphic during rapid delta progradation. The HST is characterized by six different delta progradation cycles; each phase produced locally deposited lacustrine turbidite sandstones in the basin, which are essential reservoirs in this Formation. The innovative PaleoScan interpretation technology has successfully created a high-resolution 3D reservoir model of this complex geology-such innovative technology is vital to similar complex geology globally.
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    Reservoir architecture and evolution of meandering belt: A subsurface case in the Jiyang depression, eastern China
    (Elsevier, 2020) Zhang, Xianguo; Zhang, Tao; Lin, Chengyan; Wu, Xiaoxiao; Huang, Derong; Lutome, Marco Shaban; Chen, Depo; Liu, Wei
    The reservoir architecture of a meandering river deposition can indicate the heterogeneity of the subsurface reservoirs and deposition and evolution of the paleo-river. Although outcrop study has been useful in characterizing reservoir architecture, the study of the subsurface reservoir is still a challenge due to its complicated reservoir geometry and forming process. In this work, a mature oil field in Bohai Bay Basin, eastern China was investigated to understand the reservoir architecture and evolution of a Neogene meandering belt using drilling cores, well logging, 3D seismic data, and oil production data. In the study area, five types of litho-facies were observed indicating the specific hydrodynamic conditions. The results obtained two types of point bar combination models focused on (1) the point bars migration in the same direction at equal elevation and (2) erosion and superimposition of the multi-phase point bars. Abandoned channels in study area are classified into two types: Type Ⅰ is the “Early and long-term abandoned channel” and Type Ⅱ is the “Late and short-term abandoned channel”. Well log facies of Type Ⅰ presents a low sandstone/mudstone ratio while that of Type Ⅱ has a high sandstone/mudstone ratio. Both models exhibited the weakening of the seismic reflection amplitude and changes in the waveform. Based on the well log curves, stratal slicing, and seismic facies analysis, single point bars are interpreted more accurately. The meandering river in the study area, which was previously interpreted as a large single point bar, was comprehended as a meandering belt formed by a multi-phase point bar complex with three single point bars in the meander. Erosion and overlapping can be observed between the first and second phases of the point bars. In modern river deposition, similar meander reservoir architecture and its evolution can be observed. Additionally, reservoir engineering analysis showed that there are flow barriers between point bars of different phases. The reservoir architecture of a meandering belt was characterized and the depositional evolution of the paleo-river was reconstructed. The methods proposed is significant for qualitative interpretations of reservoirs such as morphology channel recognition, reservoir connectivity analysis, and lithology and interlayer prediction.
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    Seismic sedimentology of lacustrine delta-fed turbidite systems: Implications for paleoenvironment reconstruction and reservoir prediction
    (Elsevier, 2020) Lutome, Marco Shaban; Lin, Chengyan; Chunmei, Dong; Zhang, Xianguo; Harishidayat, Dicky
    The deltaic-turbidite systems are common features in continental lacustrine rift basins. In the Bohai Bay rift Basin, Eastern China, the turbidite sandstones are the critical targets for hydrocarbon production and development. However, their intricate sedimentary patterns and the small size of the reservoirs introduces more challenge for their understanding and prediction. Through seismic sedimentology workflow, 90°-phase adjustment, strata slicing, spectral decomposition, RGB color blending technique, and geobody extraction, 3D seismic data and wireline log information data are integrated to understand the historical evolution of delta-turbidite systems and predicting the spatial and temporal distribution of sandbodies of the Es3m sub-member in the Shahejie Formation, dongying depression. The study identifies two system tracts in the study area, transgressive and highstand system tracts, from seismic and wireline logs interpretation. We identified six fourth-order sequences within the highstand system tracts, each of which corresponds to a different period of deltas progradation. Stratal slicing mapping on multiple deposition surfaces reveals the high-resolution historical evolution of the delta-turbidite systems and the distribution of their associated sandbodies. Interpretation of slices shows six stages of deltas development, which led to widespread delta-fed turbidite reservoirs. Three multi-delta-turbidite systems: the northern fan-turbidite systems and the southeast-turbidite systems are documented, which evolved throughout all stages of delta development. Rapid progradation of multi-deltas systems played an essential role in the evolution and development of thin-bedded reservoirs in the HST. Faults and local topographic lows controlled the spatial distribution of sandbodies in the area. The individual sandbodies range from 4.48 km2 to 16.49 km2 in size, and they vertically superimposed from bottom to top. The classification scheme presented in this work shows a successful application in terms of paleoenvironmental reconstruction and reservoir prediction of the delta-fed turbidite systems, which can be applied to similar systems worldwide.