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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. [ABSTRACT FROM AUTHOR]

The added value of the joint pre‐stack inversion of PP (incident P‐wave and reflected P‐wave) and PS (incident P‐wave and reflected S‐wave) seismic data for the time‐lapse application is shown. We focus on the application of this technique to the time‐lapse (four‐dimensional) multicomponent Jubarte field permanent reservoir monitoring seismic data. The joint inversion results are less sensitive to noise in the input data and show a better match with the rock physics models calibrated for the field. Further, joint inversion improves S‐impedance estimates and provides a more robust quantitative interpretation, allowing enhanced differentiation between pore pressure and fluid saturation changes, which will be extremely useful for reservoir management. Small changes in reservoir properties are expected in the short time between the time‐lapse seismic acquisitions used in the Jubarte project (only 1 year apart). The attempt to recover subtle fourth‐dimensional effects via elastic inversion is recurrent in reservoir characterization projects, either due to the small sensitivity of the reservoirs to fluid and pressure changes or the short interval between the acquisitions. Therefore, looking for methodologies that minimize the uncertainty of fourth‐dimensional inversion outputs is of fundamental importance. Here, we also show the differences between PP only and joint PP–PS inversion workflows and parameterizations that can be applied in other projects. We show the impact of using multicomponent data as input for elastic seismic inversions in the analysis of the time‐lapse differences of the elastic properties. The larger investment in the acquisition and processing of multicomponent seismic data is shown to be justified by the improved results from the fourth‐dimensional joint inversion. [ABSTRACT FROM AUTHOR]

Despite of conventional morphological evaluation is the classical method for embryo selection it clearly has limitations. Recently, time-lapse monitoring allows the embryo quality classification based on morphokinetics. Moreover, Preimplantation Genetic Test for Aneuploidy (PGT-A) is applied to investigate the genetic status of the embryos and the selection of euploid embryos for transfer is supposed to lead to improved clinical outcomes. The association of morphokinetics and PGT-A opened new opportunities to refine blastocyst selection. However, knowledge of the impact of chromosome alterations on embryo morphokinetics need to be increased. The aim of this study was to correlate embryo score from time-lapse imaging with chromosome status of the embryos evaluated by PGT-A. This is a preliminary retrospective cohort study of prospectively collected data for 81 ICSI cycles performed at a private assisted reproduction center in Brazil, between April and November 2018. A total of 260 embryos developed into blastocysts suitable for biopsy and were analyzed in this study. Embryos were cultured in the Embryoscope® time-lapse imaging chamber (Vitrolife®) and the image acquisition system was set to capture images from each embryo every 15 minutes during the entire culture interval. Embryos were scored from zero to 10 based on the timings of cell divisions with the start of ICSI until the blastocyst formation and expansion on day 5 or 6 of development. PGT-A was elective, but strongly encouraged for patient's ≥37 years old, implantation failure, recurrent miscarriage or severe male factor cases. Embryos were biopsied at a blastocyst stage and PGT-A was carried out at a global reference laboratory (Igenomix Brasil) through NGS. The women age varied from 25 to 42 years (38.5±2.9) and 1 to 10 blastocysts were biopsied per patient (3.2±2.0). Of the 260 biopsied blastocyst, 38.7% were euploid. The embryos scores were slightly lower in aneuploid (5.9±2.1) than euploid (6.4±2.1) blastocysts with a marginally significant statistical difference (p=0.067). The number of altered chromosomes were annotated and inversely correlated to embryo score (Pearson correlation: r=-0.210; p=0.001). Then we classified the number of altered chromosomes as none (euploid), 1-2, 3-6 and more than 6 (chaotic). We only observed a significant difference between the time-lapse embryo score of chaotic (3.9±1.3) and euploid (6.4±2.1; p=0.026) blastocysts. The 1-2 (6.1±2.0) or 3-6 (5.4±2.3) alterations showed similar time-lapse embryo score to euploid embryos (p=1.000 and p=0.161, respectively). The multivariate linear regression model have confirmed the higher number of altered chromosomes lower the time-lapse embryo score (Coef=-0.149; p=0.026) adjusted for confounders as women age and time of culture. The findings of our study suggest the number of altered chromosomes affect the embryo morphokinetics, leading to a reducing time-lapse embryo score. Although there seems to be a relationship between the ploidy status and complexity of chromosome alterations with the embryo morphokinetics, time-lapse embryo score is not enough to predict chromosome alterations, and therefore, replace PGT-A. These are preliminary outcomes and further studies are being conducted to investigate the association of chromosome alterations with embryo morphokinetics and relate them with clinical outcomes. [ABSTRACT FROM AUTHOR]