Commonly, seismic data processing procedures, such as stacking and prestack migration, require the ability to detect bad traces/shots and restore or replace them by interpolation, particularly when the seismic observa...Commonly, seismic data processing procedures, such as stacking and prestack migration, require the ability to detect bad traces/shots and restore or replace them by interpolation, particularly when the seismic observations are noisy or there are malfunctioned components in the recording system. However, currently available trace/shot interpolation methods in the spatial or Fourier domain must deal with requirements such as evenly sampled traces/shots, infinite bandwidth of the signals, and linear seismic events. In this paper, we present a novel method, termed the E-S (eigenspace seismic) method, using principal component analysis (PCA) of the seismic signal to address the issue of reliable detection or interpolation of bad traces/shots. The E-S method assumes the existence of a correlation between the observed seismic entities, such as trace or shot gathers, making it possible to estimate one of these entities from all others for interpolation or seismic quality control. It first transforms a trace (or shot) gather into an eigenspace using PCA. Then in the eigenspace, it treats every trace as a point with its loading scores of PCA as its coordinates. Simple linear, bilinear, or cubic spline 1 dimensional (1D) interpolation is used to determine PCA loading scores for any arbitrary coordinate in the eigenspace, which are then used to construct an interpolated trace for the desired position in physical space. This E-S method works with either regular or irregular sampling and, unlike various other published methods, it is well-suited for band-limited seismic records with curvilinear reflection events. We developed related algorithms and applied these to processed synthetic and offshore seismic survey data with or without simulated noises to demonstrate their performance. By comparing the interpolated and observed seismic traces, we find that the E-S method can effectively assess the quality of the trace, and restore poor quality data by interpolation. The successful processing of synthetic and real data using the E-S method presented in this approach will be widely applicable to seismic trace/shot interpolation and seismic quality control.展开更多
Petroleum resource assessment using reservoir volumetric approach relies on porosity and oil/gas saturation characterization by laboratory tests.In liquid-rich resource plays,the pore fluids are subject to phase chang...Petroleum resource assessment using reservoir volumetric approach relies on porosity and oil/gas saturation characterization by laboratory tests.In liquid-rich resource plays,the pore fluids are subject to phase changes and mass loss when a drilled core is brought to the surface due to volume expansion and evaporation.Further,these two closely related volumetric parameters are usually estimated separately with gas saturation inferred by compositional complementary law,resulting in a distorted gas to oil ratio under the circumstances of liquid hydrocarbon loss from sample.When applied to liquid-rich shale resource play,this can lead to overall under-estimation of resource volume,distorted gas and oil ratio(GOR),and understated resource heterogeneity in the shale reservoir.This article proposes an integrated mass balance approach for resource calculation in liquid-rich shale plays.The proposed method integrates bulk rock geochemical data with production and reservoir parameters to overcome the problems associated with laboratory characterization of the volumetric parameters by restoring the gaseous and light hydrocarbon loss due to volume expansion and evaporation in the sample.The method is applied to a Duvernay production well(14-16-62-21 W5)in the Western Canada Sedimentary Basin(WCSB)to demonstrate its use in resource evaluation for a liquid-rich play.The results show that(a)by considering the phase behavior of reservoir fluids,the proposed method can be used to infer the quantity of the lost gaseous and light hydrocarbons;(b)by taking into account the lost gaseous and light hydrocarbons,the method generates an unbiased and representative resource potential;and(c)using the corrected oil and gas mass for the analyzed samples,the method produces a GOR estimate close to compositional characteristics of the produced hydrocarbons from initial production in 14-16-62-21 W5 well.展开更多
文摘Commonly, seismic data processing procedures, such as stacking and prestack migration, require the ability to detect bad traces/shots and restore or replace them by interpolation, particularly when the seismic observations are noisy or there are malfunctioned components in the recording system. However, currently available trace/shot interpolation methods in the spatial or Fourier domain must deal with requirements such as evenly sampled traces/shots, infinite bandwidth of the signals, and linear seismic events. In this paper, we present a novel method, termed the E-S (eigenspace seismic) method, using principal component analysis (PCA) of the seismic signal to address the issue of reliable detection or interpolation of bad traces/shots. The E-S method assumes the existence of a correlation between the observed seismic entities, such as trace or shot gathers, making it possible to estimate one of these entities from all others for interpolation or seismic quality control. It first transforms a trace (or shot) gather into an eigenspace using PCA. Then in the eigenspace, it treats every trace as a point with its loading scores of PCA as its coordinates. Simple linear, bilinear, or cubic spline 1 dimensional (1D) interpolation is used to determine PCA loading scores for any arbitrary coordinate in the eigenspace, which are then used to construct an interpolated trace for the desired position in physical space. This E-S method works with either regular or irregular sampling and, unlike various other published methods, it is well-suited for band-limited seismic records with curvilinear reflection events. We developed related algorithms and applied these to processed synthetic and offshore seismic survey data with or without simulated noises to demonstrate their performance. By comparing the interpolated and observed seismic traces, we find that the E-S method can effectively assess the quality of the trace, and restore poor quality data by interpolation. The successful processing of synthetic and real data using the E-S method presented in this approach will be widely applicable to seismic trace/shot interpolation and seismic quality control.
文摘Petroleum resource assessment using reservoir volumetric approach relies on porosity and oil/gas saturation characterization by laboratory tests.In liquid-rich resource plays,the pore fluids are subject to phase changes and mass loss when a drilled core is brought to the surface due to volume expansion and evaporation.Further,these two closely related volumetric parameters are usually estimated separately with gas saturation inferred by compositional complementary law,resulting in a distorted gas to oil ratio under the circumstances of liquid hydrocarbon loss from sample.When applied to liquid-rich shale resource play,this can lead to overall under-estimation of resource volume,distorted gas and oil ratio(GOR),and understated resource heterogeneity in the shale reservoir.This article proposes an integrated mass balance approach for resource calculation in liquid-rich shale plays.The proposed method integrates bulk rock geochemical data with production and reservoir parameters to overcome the problems associated with laboratory characterization of the volumetric parameters by restoring the gaseous and light hydrocarbon loss due to volume expansion and evaporation in the sample.The method is applied to a Duvernay production well(14-16-62-21 W5)in the Western Canada Sedimentary Basin(WCSB)to demonstrate its use in resource evaluation for a liquid-rich play.The results show that(a)by considering the phase behavior of reservoir fluids,the proposed method can be used to infer the quantity of the lost gaseous and light hydrocarbons;(b)by taking into account the lost gaseous and light hydrocarbons,the method generates an unbiased and representative resource potential;and(c)using the corrected oil and gas mass for the analyzed samples,the method produces a GOR estimate close to compositional characteristics of the produced hydrocarbons from initial production in 14-16-62-21 W5 well.
