Seal potential of shale sequences through seismic anisotropy: Case study from Exmouth Sub-basin, Australia
MetadataShow full item record
Sedimentary rocks with sealing potential can cap a reservoir by impeding the upward movement of hydrocarbons. An effective seal should have three qualifying factors of geometry, integrity, and capacity. Mapping seismic horizons and faults across the area of study reveals much about the geometry and integrity of the sealing unit. Capacity, however, depends on capillary pressure measurements of core and cuttings samples. Modeling capacity of seals away from and between wells has traditionally involved simple gridding techniques or association with most likely geologic or seismic facies. We have developed a different approach in using seismic data and applying it to the evaluation of sealing potential. Shales are the most common seals in petroleum systems. Seismically, well-developed shale units that have undergone compaction are likely to be anisotropic and are typical vertical transverse isotropic media. Seismic data with suitable acquisition parameters were processed to extract Embedded Image and Thomsen’s parameters of weak seismic anisotropy, tied to the vertical seismic profile data at wells. The spatial distribution of Embedded Image has shown a good correlation with capillary measurements of well samples. Hence, 3D modeling of epsilon was used as a weight factor to guide the capillary pressure (Embedded Image) values away from the wells. Capillary pressure values were then mapped on the fault planes to high grade the analysis of sand-shale juxtaposition. Our results helped to explain the distribution of successful wells and dry holes within the study area.
Showing items related by title, author, creator and subject.
Pervukhina, Marina; Rasolofosaon, P. (2017)© 2017 European Association of Geoscientists & Engineers.Shales comprise more than 60% of sedimentary rocks and form natural seals above hydrocarbon reservoirs. Their sealing capacity is also used for storage of nuclear ...
Identification of fault and top seal effectiveness through an integration of hydrodynamic and capillary analysis techniquesUnderschultz, James Ross (2009)Fault and top seal effectiveness has proved to be a significant risk in exploration success, and creates a large uncertainty in predicting reservoir performance. This is particularly true in the Australian context, but ...
Compaction of quartz-kaolinite mixtures: The influence of the pore fluid composition on the development of their microstructure and elastic anisotropyBeloborodov, R.; Pervukhina, M.; Luzin, V.; Delle Piane, C.; Clennell, M.; Zandi, S.; Lebedev, Maxim (2016)Shales play important roles in sedimentary basins, acting as both seals and reservoir rocks, and knowledge of their anisotropic velocity trends is of practical importance for correct seismic image processing and inversion, ...