Characterizing Geometrical Anisotropy of Petrophysical properties in the middle Shahejie formation, Liaohe Depression, China.
No Thumbnail Available
Date
Journal Title
Journal ISSN
Volume Title
Publisher
Research India Publications
Abstract
Description
Knowledge of reservoir body lateral extent is important information for estimation of hydrocarbon initially in place and the recoverable quantity. This study reports a stepwise approach to evaluate geometrical anisotropy of the rapidly changing alluvial fan Shahejie formation of Eocene age. This is towards understanding reservoir geometry of the deposit beneath the flank of Bohai bay, Northern China. Computation of Sand net to gross (Volume of shale), porosity and permeability was done on well logs as an initial analytical step, followed by computation of sample variograms, data transformation and property modeling. Computation of semivariance was based on first geometrical anisotropy for autocorrelation by finding major and minor directions of data consistency. Autocorrelation of data with distance of location made upscaled data useful for stochastic simulation.
Minor data direction is almost perpendicular to the major direction with the bandwidth of not less than 4000. In the vertical direction, average bandwidth is 50. Porosity for the modeled zone is consistent with values between 17% and 35%. Permeability is consistent briefly away from well location but higher in shale units. These oil impregnated shale units are laterally consistent in the up-dip portion but were overtaken by the clastic units in the distal portion. This made draining of hydrocarbon better done in the down-dip portion of the area. An excellent comparative analysis was made of the litho-facies model, petrophysical properties, and inversion results obtained from the vintage seismic. This has yielded a good result in characterizing variation in rock properties of the subtle laterally inconsistent synsedimentary lithofacies of this are
Keywords
TA Engineering (General). Civil engineering (General), TP Chemical technology