4D simultaneous PP-PS prestack inversion in the Edvard Grieg field, Norwegian North Sea

Daneshvar, Sima; Simmons, James; Todd, C. Payson; Tura, Ali; Dhelie, P.E.

doi:10.1190/segam2020-3426908.1

Cited by 4 publications

(7 citation statements)

References 83 publications

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“…The first field data study we discuss is the Edvard Grieg field (North Sea). The results of time‐lapse joint PP/PS inversion for this field were discussed in Daneshvar (2020), Dhelie et al. (2021) and Tura et al.…”

Section: Application To 4d Offshore North Sea Field Datamentioning

confidence: 93%

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Time‐lapse PS‐wave time‐shifts and quantitative pressure‐saturation discrimination applications

Tura

Simmons

Damasceno

et al. 2023

Geophysical Prospecting

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We show that time-lapse (4D) time-shifts from PS-wave data are valuable as they are very sensitive to pressure changes, whereas 4D time-shifts from PP-wave data are sensitive to both pressure and saturation changes. This gives another opportunity from using 4D amplitudes alone to understand and discriminate areas of pressure changes from areas of saturation changes in field data. 4D PS time-shifts sense transmission related changes taking into consideration propagation through the altered medium, whereas amplitude changes are reflection or backscattered signals from the boundary. Therefore, these two attributes will be complimentary in 4D interpretation. Rock-physics-based time-shift cross-plots are generated to analyse how pressure and saturation changes in a reservoir impact PP-and PS-wave time-shifts. The developments of 4D time-shifts are shown fixing the reservoir properties and varying reservoir layer thickness. Synthetic seismic data from a wedge is modelled to understand differences between 4D amplitude and time-shift changes and the value of PS time-shifts. Cases with pressure changes only and saturation changes only are also analysed with the wedge model. The method is next applied to two 4D field data sets. One is in the North Sea and the other offshore Brazil. In these field data sets, with different levels of noise in the 4D data, we see interpretable results from PS-wave time-shifts that can help in 4D signal understanding and improve reservoir characterization and monitoring practices. We believe that with modern acquisition and processing, this technology is realizable and provides quantitative and accurate 4D interpretations. It is shown that the use of PS-wave data can lead to a larger chance of success in placing development wells.

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Section: Application To 4d Offshore North Sea Field Datamentioning

confidence: 93%

“…Joint inversion of PP and PS amplitudes and its use for 4D interpretation has been demonstrated on synthetic and field data (e.g. see Damasceno, 2020; Damasceno et al., 2021; Daneshvar, 2020; Dhelie et al, 2021; Tura et al., 2022). However, 4D time‐shifts from PS‐wave data have not been studied in detail and very few examples exist.…”

Section: Introductionmentioning

confidence: 99%

Time‐lapse PS‐wave time‐shifts and quantitative pressure‐saturation discrimination applications

Tura

Simmons

Damasceno

et al. 2023

Geophysical Prospecting

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“…The acquisition and processing of the 4D seismic data for PP and PS waves was conducted by the field operator (see Held, 2023). 4D joint PP/PS inversion was applied to Baseline and Monitor 1 data and published by Daneshvar (2020), Dhelie et al (2021) and Tura et al. (2022).…”

Section: Edvard Grieg Fieldmentioning

confidence: 99%

“…After extensive testing, we also allowed equal weighting of PP and PS seismic data in the joint inversion results. Details of the inversion steps and test results of the parameters discussed above can be found in Held (2023).…”

Section: Value Of Joint Pp/ps Inversionmentioning

confidence: 99%

“…The value of joint inversion of PP and PS seismic amplitudes and its use for 4D interpretation have been demonstrated on synthetic and field data (e.g. see Damasceno et al., 2021; Daneshvar, 2020; Dhelie et al., 2021; Gaiser, 2016; Jenkinson et al., 2010; Tura et al., 2022; Veire & Landrø, 2006). In this paper, we first demonstrate the value of quantitative 4D joint PP and PS seismic inversion for P‐ and S‐impedance amplitude‐variation‐with‐offset (AVO) parameters (Aki & Richards, 1980), starting from stacked seismic data, progressing to pre‐stack PP seismic data, followed by joint inversion of PP and PS seismic data.…”

Section: Introductionmentioning

confidence: 98%

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Quantitative pressure and saturation engineering values from 4D PP and PS seismic data

Tura,

Held,

Simmons

et al. 2024

Geophysical Prospecting

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For field development and drilling decisions, production assets and reservoir engineers require dynamic reservoir properties, such as saturation and pressure changes of a reservoir from the pre‐production virgin state. To date, geophysicists have produced time‐lapse (4D) seismic attributes (mostly on stacked seismic data) rather than dynamic parameters directly. In this paper, we present a new method to estimate saturation and pressure properties from time‐lapse seismic data to provide to reservoir engineers. This new three‐step method is demonstrated over the Edvard Grieg field in the North Sea. We can realize this method thanks to advanced seismic multi‐component acquisition via PP and PS seismic data and processing that allows accurate estimation of amplitude‐variation‐with‐offset parameters P‐ and S‐impedances. With time‐lapse P‐ and S‐impedances optimally resolved, we estimate a stable set of axes identifying water saturation increase (water replacing oil), gas saturation increase (gas injection or gas out of solution), pressure increase (at injectors) and pressure decrease (at producers). Once these axes are obtained, we convert every 4D P‐ and S‐impedance data points into 4D pseudo‐saturation and pseudo‐pressure using a transformation of coordinates. We next use the rock physics relationships of this field to show that a linear relationship can be used to map any 4D change in the field from impedances to saturations and pressures. Key locations in the field with largest saturation and pressure changes are used to find calibration values at these extreme points. Next, from the pseudo‐seismic 4D data, a linear mapping is used to calculate actual reservoir property changes (fractions for saturation and bars for pressure). This allows us to obtain fieldwide dynamic values for water and gas saturations and injection and production related pressure changes. The results are shown, and dynamic changes are interpreted on the Edvard Grieg field data.

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Improving reservoir characterization and time-lapse seismic through joint inversion of PP- and PS-wave seismic data

et al. 2022

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We show on synthetic and field data examples that joint pre-stack AVA inversion of PP- and PS-wave data can significantly improve estimation of P-impedance, S-impedance and density. For reservoir characterization, improvements in these parameters can better identify reservoir rock and fluid properties. For reservoir monitoring time-lapse (4D) changes in P-impedance, S-impedance and density can lead to inversion of saturation and pressure changes. We see that, in the joint inversion, 4D S-impedance is better estimated and not coupled to 4D P-impedance. These claims are first demonstrated on synthetic data, and then shown on an onshore unconventional play from Colorado and on offshore 4-D -4-C dataset from the North Sea. Joint inversion of PP- and PS-wave data requires a higher level of care compared to PP-waves since the two wave-modes need to be acquired, processed and merged properly. This has diminished the use of converted waves in the past. However, modern acquisition and processing on land and offshore data make this technology quantitatively more accurate and realizable. As such, we also provide best practices for a successful project. We shown that joint inversion can lead to a larger chance of success in placing exploration and development wells.

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4D simultaneous PP-PS prestack inversion in the Edvard Grieg field, Norwegian North Sea

Cited by 4 publications

References 83 publications

Time‐lapse PS‐wave time‐shifts and quantitative pressure‐saturation discrimination applications

Time‐lapse PS‐wave time‐shifts and quantitative pressure‐saturation discrimination applications

Quantitative pressure and saturation engineering values from 4D PP and PS seismic data

Improving reservoir characterization and time-lapse seismic through joint inversion of PP- and PS-wave seismic data

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