Impact of model and data resolutions in 4D seismic data assimilation applied to an offshore reservoir in Brazil

Rosa, Daiane Rossi; Schiozer, Denis José; Davólio, Alessandra

doi:10.1016/j.petrol.2022.110830

Cited by 3 publications

(1 citation statement)

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“…Thus, information obtained from 4D seismic data can be used for qualitative and quantitative interpretations, the first to infer dynamic changes related to 4D seismic anomalies [6,7] and the later can be used alongside production data to calibrate reservoir models through data assimilation (or history matching) processes [8,9]. Although time-lapse seismic data is sparsely sampled in time compared to production data, it presents a densely spatial sampling in the field scale [10]. Thus, uncertainties in the reservoir model related to spatial and temporal distributions can be assessed and reduced through 4D seismic data assimilation [11].…”

Section: Introductionmentioning

confidence: 99%

Efficient proxy for Time-Lapse Seismic ForwardModeling using U-Net Encoder-Decoder Approach

Diniz,

Maleki,

Cirne

et al. 2023

Preprint

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The time-lapse seismic (4D seismic) forward modeling provides crucial data for calibrating reservoir models through the reservoir data assimilation method. Unfortunately, conventional 4D seismic forward modeling methodology is time-expensive and entails significant computational resource consumption. To address these drawbacks, in this work, our goal is to develop a proxy model for the 4D seismic forward modeling using a class of machine learning algorithm named U-Net encoder-decoder. We applied the developed proxy model to a benchmark carbonate reservoir using an ensemble of reservoir simulation models from UNISIM IV (a synthetic benchmark based on real data of a Brazilian pre-salt field). Moreover, we aim to introduce seminal strategies for interpreting the proposed proxy model operation, its outputs, and possible correlations between input and output variables. To achieve this, we trained and tested two versions of U-net-based models and applied methods for explainable AI, such as Grad-CAM and Forward Feature Selection. The experiments showed good results when applied to the test dataset. The R-squared values were in the range of 0.7 to 0.9, showing the efficiency of the proxy model to replace the 4D seismic forward modeling. Additionally, the qualitative analysis helped us identify which input properties and regions of the reservoir are more relevant for the model's inference. These results are a valuable preliminary step toward a robust, explainable machine learning-based proxy forward modeling.

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Section: Introductionmentioning

confidence: 99%

Efficient proxy for Time-Lapse Seismic ForwardModeling using U-Net Encoder-Decoder Approach

Diniz,

Maleki,

Cirne

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

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Evaluating the impact of 4D seismic data artefacts in data assimilation

Rosa

Schiozer

Davólio

2023

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Time-lapse or 4D Seismic data (4DS) are important constraints in reservoir studies because they enable monitoring of saturation and pressure changes that result from hydrocarbon production. 4DS have been quantitatively added, along with production data, in history matching or data assimilation (DA) procedures to reduce uncertainty and improve production forecasts. Before performing quantitative studies, it is important to ensure that the 4DS are reliable, with minimal artifacts such as side-lobe effects, that can disturb the identification of anomalies. In this work, we propose different ways of treating 4DS in DA for a real reservoir. Explicitly, we evaluated the impact on DA results when considering different amounts of 4D information and three treatments to the identified artifacts. The treatments were: ignoring them, excluding them from DA, or defining no seismic changes at their locations. The results show that well and seismic matches are improved when 4DS are assimilated, also improving the production predictions. Despite being a thin reservoir, assimilating two single-layer maps allowed us to predict relevant observed dynamic behaviour, such as the evolved gas trapped in the lower interval. Furthermore, when a treatment was applied to the artifacts, they produced better models than using a single two-layer map (with lower production errors and visually closer impedances to the observed data). Our recommendation is the assimilation of well and 4DS data, with the exclusion of unreliable information, for better life-cycle decisions.

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Data Assimilation of Production and Multiple 4D Seismic Acquisitions in a Deepwater Field Using Ensemble Smoother with Multiple Data Assimilation

Rosa

Schiozer

Moura

2023

SPE Reservoir Evaluation &Amp; Engineering

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Summary In recent years, time-lapse (4D) seismic (4DS) data have been widely used for reservoir monitoring to provide relevant information on dynamic changes occurring during production. In complex reservoirs, multiple seismic monitor surveys are usually available. Updating reservoir models with these data can be very beneficial to improve the field’s management. In the quantitative integration of 4DS data into the data assimilation (DA) process, it is crucial to define how to deal with more than one seismic monitor. In this work, we continue a series of investigations about seismic DA procedures and expand on them by analyzing ways to assimilate more than one seismic monitor. More specifically, we evaluate different ways of using production data and two monitor surveys (M3 and M5) to calibrate the dynamic models of a real Brazilian reservoir using the ensemble smoother with multiple data assimilation (ES-MDA) method. We performed the following experiments: (1) sequential assimilation of M3 and M5 with parts of well history divided according to the seismic acquisition dates; (2) assimilation of M3 with the entire well history and subsequent assimilation of M5; (3) assimilation of well and M3 data; and (4) assimilation of well and M5 data. For comparison purposes, we also assimilated only well data. From the results, we observed that well and 4DS data misfits were reduced when assimilating both monitors, compared to the cases where only a single monitor (any of them) was used with production data. This conclusion is also true in the comparison with results obtained when only assimilating well data. This indicates that both seismic monitors are important data to be quantitatively considered in DA. In this particular field, using a previous DA run to solely assimilate the newly available monitor (Case 2) delivered better models and long-term forecasts. Therefore, this would be our recommendation. This study highlights the importance of several 4DS acquisitions for reservoir monitoring and management and shows the challenges of their application in seismic DA for better life cycle field applications.

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Impact of model and data resolutions in 4D seismic data assimilation applied to an offshore reservoir in Brazil

Cited by 3 publications

References 38 publications

Efficient proxy for Time-Lapse Seismic ForwardModeling using U-Net Encoder-Decoder Approach

Efficient proxy for Time-Lapse Seismic ForwardModeling using U-Net Encoder-Decoder Approach

Evaluating the impact of 4D seismic data artefacts in data assimilation

Data Assimilation of Production and Multiple 4D Seismic Acquisitions in a Deepwater Field Using Ensemble Smoother with Multiple Data Assimilation

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