Auswahl der wissenschaftlichen Literatur zum Thema „Synthetic seismic modeling“

Kirchhoff‐type, isochron‐stack demigration is the natural asymptotic inverse to classical Kirchhoff or diffraction‐stack migration. Both stacking operations can be performed in true amplitude by an appropriate selection of weight functions. Isochron‐stack demigration is closely related to seismic modeling with the Kirchhoff integral. The principal objective of this paper is to show how demigration can be used to compute synthetic seismograms. The idea is to attach to each reflector in the model an appropriately stretched (i.e., frequency‐shifted) spatial wavelet. Its amplitude is proportional to the reflection coefficient, transforming the original reflector model into an artificially constructed true‐amplitude, depth‐migrated section. The seismic modeling is then realized by a true‐amplitude demigration operation applied to this artificially constructed migrated section. A simple but typical synthetic data example indicates that modeling by demigration yields results superior to conventional zero‐order ray theory or classical Kirchhoff modeling.

Abstract Ambient seismic noise tomography is one of the most widely used methods in seismological studies today, especially after a comprehensive Earth noise model was published and noise analysis was performed on the IRIS Global Seismographic Network. Furthermore, the Power Spectral Density technique was introduced to identify background seismic noise in the United States. Many studies have been carried out using the ambient seismic noise tomography method which can be broadly grouped into several groups based on the objectives and research targets, such as to determine the structure of the earth’s crust and the upper mantle, to know the thickness of the sedimentary basins, to know the tectonic settings and geological structures, to know volcanic systems and geothermal systems, knowing near-surface geological features and as a monitoring effort the Ambient Noise Tomography method carried out by repeated measurements or time lapse. In this study, we investigate the characteristics of the ambient noise seismic tomography method, both its advantages and limitations of the method by utilizing synthetic data modeling using a simple geological model. Synthetic data is generated based on 1D dispersion curve forward modelling and the forward modeling of surface waves travel time for each period, which is then convoluted with the wavelets of each periods, then doing reverse correlation using a reference signal to produce synthetic recording data. We found that the estimate target depth and vertical resolution depend on the recorded data periods and the synthetic data modeling can be used as a basis in determining the acquisition design.

The terrestrial Arctic is warming rapidly, causing changes in the degree of freezing of the upper sediments, which the mechanical properties of unconsolidated sediments strongly depend upon. This study investigates the potential of using time-lapse surface seismics to monitor thawing of currently (partly) frozen ground utilizing synthetic and real seismic data. First, we construct a simple geological model having an initial temperature of −5 °C, and infer constant surface temperatures of −5 °C, +1 °C, +5 °C, and +10 °C for four years to this model. The geological models inferred by the various thermal regimes are converted to seismic models using rock physics modeling and subsequently seismic modeling based on wavenumber integration. Real seismic data reflecting altered surface temperatures were acquired by repeated experiments in the Norwegian Arctic during early autumn to mid-winter. Comparison of the surface wave characteristics of both synthetic and real seismic data reveals time-lapse effects that are related to thawing caused by varying surface temperatures. In particular, the surface wave dispersion is sensitive to the degree of freezing in unconsolidated sediments. This demonstrates the potential of using surface seismics for Arctic climate monitoring, but inversion of dispersion curves and knowledge of the local near-surface geology is important for such studies to be conclusive.

The one-dimensional convolution model or synthetic seismogram provides more information about the seismic waveform expression of hydrocarbon reservoirs when petrophysical data (porosity, shale volume, water saturation, etc.) are systematically integrated into the seismogram generation process. Use of this modeling technique, herein called Incremental Pay Thickness (IPT) modeling, has provided valuable insights concerning the seismic response of several offshore Gulf of Mexico amplitude anomalies. Through integration of the petrophysical data, comparisons between seismic waveform response and expected reservoir pay thickness are extended to include estimates of gross pay thickness, net pay thickness, net porosity feet of pay, and hydrocarbons in place. These 1-D synthetic data easily convert to 2-D displays that often show exceptional waveform correlations between the synthetic and actual seismic data. Anomalous observed waveform responses include complex tuning curves; diagnostic isochron measurements even in unresolved thin-bed reservoirs; and extreme variations in the seismic expression of hydro-carbon-fluid contacts. While IPT modeling examples illustrate both the variability and nonuniqueness of seismic responses to hydrocarbon reservoirs, they often show good seismic predictability of pay thickness if the appropriate choice of amplitude-isochron versus pay thickness is made (i.e., peak amplitude, trough amplitude, or average amplitude versus gross pay thickness, net pay thickness, net porosity feet of pay, or hydrocarbons in place).

Deep learning (DL) applications of seismic reservoir characterization often require the generation of synthetic data to augment available sparse labeled data. An approach for generating synthetic training data consists of specifying probability distributions modeling prior geologic uncertainty on reservoir properties and forward modeling the seismic data. A prior falsification approach is critical to establish the consistency of the synthetic training data distribution with real seismic data. With the help of a real case study of facies classification with convolutional neural networks (CNNs) from an offshore deltaic reservoir, we have highlighted several practical nuances associated with training DL models on synthetic seismic data. We highlight the issue of overfitting of CNNs to the synthetic training data distribution and propose regularization strategies to address it. We demonstrate the efficacy of our proposed strategies by training the CNN on synthetic data and making robust predictions with real 3D partial stack seismic data.

We study the spectral-decomposition response to reservoir fluids from a deepwater West Africa reservoir through a systematic modeling approach. Our workflow starts from selecting the seismic data (far-angle seismic images) that show more pronounced fluid effect based on amplitude-versus-offset (AVO) analysis. Synthetic seismic forward modeling performed at the control well established the quality of the seismic well tie. Reservoir wedge modeling, spectral decomposition of the field and synthetic seismic data, and theoretical analyses were conducted to understand the spectral-decomposition responses. The reservoir fluid type is a main factor controlling the spectral response. For this deepwater reservoir, the amplitude contrast between oil sand and brine sand is higher at low frequencies [Formula: see text]. In addition, synthetic modeling can help identify the possible frequency band where the amplitude contrast between hydrocarbon sand and brine sand is higher. When properly included in a comprehensive direct-hydrocarbon-indicator (DHI)–AVO evaluation, spectral decomposition can enhance the identification of hydrocarbons.

Abstract. Deep learning has been widely used for various kinds of data-mining tasks but not much for seismic stratigraphic interpretation due to the lack of labeled training datasets. We present a workflow to automatically generate numerous synthetic training datasets and take the seismic clinoform delineation as an example to demonstrate the effectiveness of using the synthetic datasets for training. In this workflow, we first perform stochastic stratigraphic forward modeling to generate numerous stratigraphic models of clinoform layers and corresponding porosity properties by randomly but properly choosing initial topographies, sea level curves, and thermal subsidence curves. We then convert the simulated stratigraphic models into impedance models by using the velocity–porosity relationship. We further simulate synthetic seismic data by convolving reflectivity models (converted from impedance models) with Ricker wavelets (with various peak frequencies) and adding real noise extracted from field seismic data. In this way, we automatically generate a total of 3000 diverse synthetic seismic datasets and the corresponding stratigraphic labels such as relative geologic time models and facies of clinoforms, which are all made publicly available. We use these synthetic datasets to train a modified encoder–decoder deep neural network for clinoform delineation in seismic data. Within the network, we apply a preconditioning process of structure-oriented smoothing to the feature maps of the decoder neural layers, which is helpful to avoid generating holes or outliers in the final output of clinoform delineation. Multiple 2D and 3D synthetic and field examples demonstrate that the network, trained with only synthetic datasets, works well to delineate clinoforms in seismic data with high accuracy and efficiency. Our workflow can be easily extended for other seismic stratigraphic interpretation tasks such as sequence boundary identification, synchronous horizon extraction, and shoreline trajectory identification.

We propose a simple acoustic model explaining the main features of gas chimneys. The main elements of the model consist of gas diffusing from a connected fracture network and into the surrounding shale creating an inhomogeneous gas saturation. The gas saturation results in an inhomogeneous fluctuating compressional velocity field that distorts seismic waves. We model the fracture network by a random-walk process constrained by maximum fracture length and angle of the fracture with respect to the vertical. The gas saturation is computed from a simple analytical solution of the diffusion equation, and pressure-wave velocities are locally obtained assuming that mixing of shale and gas occurs on a scale much smaller than seismic wavelengths. Synthetic seismic sections are then computed using the resulting inhomogeneous velocity model and shown to give rise to similar deterioration in data quality as that found in data from real gas chimneys. Also, synthetic common-midpoint (CMP) gathers show the same distorted and attenuated traveltime curves as those obtained from a real data set. The model shows clearly that the features of gas chimneys change with geological time (a model parameter in our approach), the deterioration of seismic waves being smallest just after the creation of the gas chimney. It seems likely that at least some of the features of gas chimneys can be explained by a simple elastic model in combination with gas diffusion from a fracture network.

In an effort to understand better the amplitude variation with offset for reflections from an oil sand and the sensitivity of the AVO response to shear‐wave velocity variations, I studied synthetic and field gathers collected from an onshore field in the Gulf of Mexico basin. A wave‐equation‐based modeling program generated the synthetic seismic gathers using both measured and estimated shear‐wave velocities. The measured shear‐wave velocities came from a quadrupole sonic tool. The estimated shear‐wave velocities were obtained by applying published empirical and theoretical equations which relate shear‐wave velocities to measured compressional‐wave velocities. I carefully processed the recorded seismic data with a controlled‐amplitude processing stream. Comparison of the synthetic gathers with the processed field data leads to the conclusion that the model containing the measured shear‐wave velocities matches the field data much better than the model containing the estimated shear‐wave velocities. Therefore, existing equations which relate shear‐wave velocities to compressional‐wave velocities yield estimates which are not sufficiently accurate for making quantitative comparisons of synthetic and field gathers. Even small errors in the shear‐wave velocities can have a large impact on the output. Such errors can lead to an incomplete and perhaps inaccurate understanding of the amplitude‐versus‐offset response. This situation can be remedied by collecting shear‐wave data for use in amplitude‐versus‐offset modeling, and for building databases to generate better shear‐wave velocity estimator equations.

We have performed a deep seismic reflection study, DACIA-PLAN, based on the data recorded along a crooked line across the southeastern Romanian Carpathians. The signal-to-noise ratio (S/N) of these data varies along the seismic profile, and its variation is considered to be an effect of the rough topography, complex subsurface geology, and varying surface conditions encountered during seismic data acquisition. The migrated time section that covers the mountainous area is clear, without visible reflections, making the geologic interpretation very difficult. We used a seismic modeling technique to explain the poor S/N of the recorded data and to generate synthetic seismic sections that can be useful for the geologic interpretation of the field seismic section (migrated time section). We used ray-tracing modeling to obtain the expected seismic expression of horizons of interest. Subsurface illumination modeling indicates that the complex subsurface geology and irregularly deployed sources and receivers are responsible for the incomplete and/or uneven illumination of the subsurface and can lead to strong amplitude variations. We then used 2.5D acoustic finite-difference modeling to analyze the effect of a crooked line on seismic wave propagation. The synthetic shot gathers prove that crooked line arrival times for reflected and head waves contain static time shifts relative to a straight line regular sampling geometry. Some geologic interfaces of interest are not well-imaged on the synthetic seismic section, and this is considered to be an effect of poor positioning during seismic data acquisition. We used the velocity model from the tomographic inversion of first-arrival traveltimes and synthetic and field crooked line deep seismic reflection data to create a structural image for the southeastern Romanian Carpathians and the Focsani Basin, which tie well with the geologic model built for this area on the basis of geologic and well data only.

The presented research investigated the viability of a double-braided synthetic fiber rope for providing improved performance of steel moment frames subjected to earthquake-induced ground motions. A series of experimental tests, including a 1:3-scale dynamic test and 1:6-scale shaking table tests, was conducted using Northridge ground-motion input. A series of nonlinear dynamic analytical studies, using DRAIN-2DX, was conducted to develop the experimental tests. Throughout experimental testing, the ropes exhibited a hyper-elastic loading response and a reduced-stiffness unloading response. A conditioning cycle was defined as a loading cycle induced in the rope above the highest load expected to be experienced by the rope, and was determined to be requisite for ropes intended to be used for the stated objectives of the research program. After experiencing a conditioning cycle, the rope response returned to initial conditions without permanent deformation, demonstrating repeatability of response through several loading cycles below the conditioning load. In the 1:6-scale shaking-table experiments, the ropes drastically improved the performance of the steel moment frames. Maximum and residual drift were reduced significantly, with a corresponding minimal increase to the maximum base shear. Base shear was reduced at several peaks subsequent to the initial pulse of the Northridge ground-motion input. The analytical model developed was excellent for predicting elastic response of the 1:6-scale shaking table experiments and adequate for the purpose of planning shaking table studies. Correlation of peak rope forces between the analytical model and experimental results was poor, and was attributed to limitations of the pre-defined elements used to represent the rope devices in the software program. The inability of the elements to capture the complex unloading response of the rope was specifically noted.
Ph. D.

Thesis (M.S.)--West Virginia University, 2004
Title from document title page. Document formatted into pages; contains xiii, 134 p. : ill. (some col.), maps (some col.). Vita. Includes abstract. Includes bibliographical references (p. 118-122).

La caractérisation des réservoirs dans les bassins frontières reste un défi en termes d’exploration et de production de la ressource. Le Bassin du Levant, situé dans la partie la plus orientale de la mer Méditerranée, représente un bassin frontière largement cartographié par des acquisitions sismiques mais qui manque de calibrations diagraphiques. Le manque de données entraîne des incertitudes dans l'interprétation sismique et l'évaluation des propriétés du réservoir. En l'absence de données de puits, les analogues d'affleurements apparaissent comme un outil essentiel pour la caractérisation des plates-formes carbonatées enfouies parfois sous plusieurs kilomètres de sédiments. L'objectif principal de cette thèse est d'intégrer des informations sédimentologiques avec des mesures géophysiques et pétrophysiques afin de caractériser une plate-forme carbonatée Cénomanienne-Turonienne située au nord du Liban. L'investigation de l'analogue d'affleurement permet de mieux contraindre les propriétés de la plate-forme carbonatée sur des données sismiques 2D. Cette approche d’abord été testée et appliquée aux calcaires du Bathonien moyen-supérieur de la carrière de Massangis (formation de l’Oolithe Blanche), représentant un analogue du réservoir géothermal « moyenne température » ciblé par de nombreuses communes de la région Ile-de-France. Une description sédimentologique et pétrographique est réalisée sur un affleurement de la carrière de Massangis. Un total de 1000 vitesses acoustiques sont acquises à une fréquence de 40 kHz ont servi à générer un sismogramme synthétique 2D. La caractérisation sédimentologique et acoustique de l'affleurement permet de comprendre l'influence des variations de faciès et des caractéristiques diagenétiques (firm ground, bioturbation, stylolites) sur les mesures acoustiques et la génération de réflecteurs sismiques. L'affleurement étudié à Kfarhelda au nord du Liban est une plate-forme carbonatée Cénomanienne – Turonienne déposée en environnement marin peu profond. Il représente les formations Sannine et Maameltein caractérisées par des accumulations de rudiste. Une description sédimentaire est réalisée pour la plate-forme carbonatée de 400 m d'épaisseur. La vitesse des ondes P été mesurée directement en surface des roches exposées et les propriétés pétrophysiques mesurées sur 44 échantillons représentatifs. Ces données de vitesses et de densités ont permis de générer un sismogramme synthétique 1D avec une ondelette de Ricker à 25 Hz. Les réflecteurs obtenus sont principalement : (1) des réflecteurs de forte amplitude à la limite entre deux faciès aux propriétés physiques contrastées renforcées par la diagenèse, (2) des réflecteurs d'amplitude modérée correspondant aux limites stratigraphiques à la transition entre faciès, et (3) des réflecteurs de très faible amplitude dans les unités karstifiées. L'intégration des données d'affleurement et des données sismiques se fait au travers du sismogramme synthétique. L'interprétation et l'analyse des faciès sismiques sont réalisées à partir du profil sismique terrestre 2D acquis en 2013. Une étape de calibration entre la sismique terrestre 2D et la sismique synthétique acquise sur affleurement est nécessaire. De cette calibration, deux réflecteurs se distinguent : le premier représente la "Marly Limestone Zone" associée à un fort contraste d'impédance acoustique, et le second représente le contraste entre des carbonates massifs et des carbonates avec des faciès de chenaux caractérisés par une porosité plus élevée. L'approche développée dans ce travail de thèse permettent de mettre en évidence l'importance de combiner des mesures sédimentologiques et acoustiques avec une modélisation sismique synthétique, pour identifier l'origine géologique des réflecteurs sismiques et améliorer l'interprétation sismique en termes de faciès et de propriétés de réservoir
Reservoir characterization in frontier basins remains a challenge for exploration efforts. The Levant Basin, located in the easternmost part of the Mediterranean region, represents a frontier basin that is extensively mapped in terms of seismic survey but lacks well log calibration. The sparse data coverage results in substantial uncertainties in seismic interpretation and evaluation of reservoir properties. In the absence of well data, outcrop analogues can play a key role in the characterization of subsurface carbonate platforms. The main objective of this thesis is to characterize a large-scale Cenomanian – Turonian carbonate platform located northern Lebanon based on integrating sedimentological characterization with geophysical and petrophysical measurements. The investigation of the onshore analogue outcrop allows to constrain the carbonate platform’s properties on onshore seismic data. The developed approach is first applied to the Mid – Late Bathonian limestones of Massangis quarry (Oolithe Blanche formation), representing an analogue of the geothermal reservoir targeted by many municipalities in the Ile-de-France region. Sedimentologic description is completed for the studied outcrop and petrographic analysis is accomplished for representative samples. A total of 1000 acoustic velocities are acquired at 40 kHz to generate a 2D synthetic seismogram. The sedimentologic and acoustic characterization of the section allows to understand the influence of facies variation and diagenetic features (firm grounds, bioturbation, stylolites, etc) on the acoustic measurements and the generation of seismic reflectors. The studied outcrop in Kfarhelda northern Lebanon is a Cenomanian – Turonian shallow marine carbonate platform representing Sannine and Maameltain formations. The formations represent bedded limestones with important Turonian rudist-rich rudstones. A thorough sedimentary description is completed for the 400 m-thick carbonate platform. P-wave velocity is acquired directly on the outcrop, and the petrophysical properties are measured on 44 representative samples. The data are used to generate a 1D synthetic seismogram with a 25 Hz Ricker wavelet. The resulting reflectors are mainly (1) high amplitude reflectors at the limit between two facies with contrasting physical properties enhanced by diagenesis, (2) moderate amplitude reflectors corresponding to stratigraphic limits at the transition between facies, and (3) very low amplitude reflectors in karstified units. The integration of outcrop and seismic data is based on the generation of the synthetic seismogram. Interpretation and seismic facies analysis are completed for the 2D onshore seismic profile acquired in 2013. The best fit between the synthetic seismic and seismic profile resulted in the identification of two distinctive reflectors related to the Marly Limestone Zone causing sharp contrast in acoustic impedance, and the overlying channel facies characterised by higher porosity. The approach developed in this thesis work highlights the importance of combining sedimentologic and acoustic measurements together with synthetic seismic modelling to identify the geological origin of seismic reflectors and improve the seismic interpretation in terms of facies and reservoir properties

Outcrop and laboratory analysis of the South Wales carbonate ramp validated the model hypothesis that a high rate of sediment transport is likely a dominant control on the development of a low gradient carbonate geometry. Several other ramp examples are also shown to portray diagnostic features similar to the South Wales ramp example, implying significant magnitudes of sediment transport in each case and further supporting the hypothesis that ramps are transport-dominated systems.

2008/2009
È stato affrontato il problema della definizione della pericolosità sismica utilizzando il metodo neo-deterministico (NDSHA), che si basa sul calcolo di sismogrammi sintetici realistici. Considerando modelli strutturali medi e un set di sorgenti distribuite internamente alle zone sismogenetiche, possono essere definite delle mappe di scuotimento al bedrock complementari alla mappa di pericolosità di tipo probabilistico (PSHA) sulla quale è basata la normativa antisismica italiana. L’analisi di stabilità effettuata ha dimostrato che l’informazione disponibile sui terremoti del passato può non essere rappresentativa per i futuri terremoti, anche se si hanno a disposizione cataloghi estesi nel tempo (∼ 1000 anni). Ciò non è sorprendente se si tiene presente la scala dei tempi dei processi geologici, ma tale consapevolezza è spesso ignorata in PSHA. NDSHA permette di superare questo limite mediante l’uso di indicatori indipendenti sul potenziale sismico di un’area (e.g. nodi sismogenetici e faglie attive) che consentono di colmare le lacune nella sismicità osservata. Il confronto tra le mappe di pericolosità PSHA e NDSHA sul territorio italiano ha evidenziato che NDSHA fornisce valori maggiori di PSHA nelle aree caratterizzate da forti terremoti osservati e in corrispondenza dei nodi sismogenetici. I valori massimi di NDSHA sono confrontabili con quelli di PSHA per lunghi periodi di ritorno (T≥2475 anni). D’altro canto, PSHA tende a sovrastimare, rispetto a NDSHA, la pericolosità sismica in aree a bassa sismicità. È quindi auspicabile una revisione della normativa che tenga conto di questi fatti. Gli scenari di scuotimento sono utili sia per la ricostruzione delle caratteristiche di sorgente dei terremoti del passato (es. terremoto del 1117) che per la previsione degli effetti degli eventi futuri. Quest’ultimo aspetto, importante per le azioni di prevenzione della Protezione Civile, è stato sviluppato nell’ambito del progetto ASI-SISMA mediante la generazione di scenari dipendenti dal tempo a diversa scala di dettaglio. L’applicazione della tecnica analitica di calcolo dei sismogrammi sintetici in mezzi anelatici tridimensionali, per la cui è stata messa a punto una subroutine per la gestione automatica dell’input, è stata applicata allo studio di eventi di profondità intermedia, avvenuti in Vrancea (Romania), considerando sia serie temporali registrate (accelerogrammi) che intensità osservate.
The problem of the definition of the neo-deterministic seismic hazard assessment (NDSHA), based on the computation of realistic synthetic seismograms, has been capably addressed. Considering average structural models and a set of sources distributed within the seismogenic zones, ground shaking maps at the bedrock, complementary to the probabilistic seismic hazard (PSHA) map on which the Italian seismic code is based, can be defined. The stability analysis performed showed that the available information from past events may not be well representative of future earthquakes, even if long earthquake catalogues (< 1000 years) are available. This is not surprising if we consider the geological times, but this awareness is often ignored in PSHA. NDSHA can easily overcome this limit since it allows to take into account, in a formally well defined way, not only the observed seismicity but also independent indicators of the seismogenic potential of a given area like the seismogenic nodes and active faulting data. The comparison between PSHA and NDSHA maps over the Italian territory evidenced that NDSHA provides values larger than those given by PSHA in areas where large earthquakes are observed and in areas identified as prone to large earthquakes (i.e. seismogenic nodes). The maximum values of NDSHA are consistent with those of PSHA for long return periods (T≥2475 years). Comparatively smaller values are obtained in low-seismicity areas. Therefore a revision of the code taking into account these facts is desirable. Ground shaking scenarios are useful in order to detect the main characteristics of the past earthquakes (e.g. the 1117 earthquake) and to predict the expected ground shaking associated with future earthquakes. The last aspect, which constitutes a useful tool for the rescue actions of the Civil Protection, has been developed in the framework of the ASI-SISMA Project by means of the generation of multi-scale time-dependent seismic hazard scenarios. The application of the analytical technique for the computation of synthetic seismograms in three-dimensional anelastic models, for which a subroutine for the automatic generation of the input has been developed, has been applied to the study of intermediate-depth Vrancea (Romania) earthquakes, considering both recorded time series (accelerograms) and observed macroseismic intensities.
XXII Ciclo
1982

This research evaluates the seismic demands for a three-span curved bridge crossing fault-rupture zones. Two approximate procedures which have been proved adequate for ordinary straight bridges crossing fault-rupture zones, i.e., the fault-rupture response spectrum analysis (FR-RSA) procedure and the fault-rupture linear static analysis (FR-LSA) procedure, were considered in this investigation. These two procedures estimate the seismic demands by superposing the peak values of quasi-static and dynamic bridge responses. The peak quasi-static response in both methods is computed by nonlinear static analysis of the bridge under the ground displacement offset associated with fault-rupture. In FR-RSA and FR-LSA, the peak dynamic responses are respectively estimated from combination of the peak modal responses using the complete-quadratic-combination rule and the linear static analysis of the bridge under appropriate equivalent seismic forces. The results from the two approximate procedures were compared to those obtained from the nonlinear response history analysis (RHA) which is more rigorous but may be too onerous for seismic demand evaluation. It is shown that the FR-RSA and FR-LSA procedures which require less modeling and analysis efforts provide reasonable seismic demand estimates for practical applications.

The study area, Dhurnal oil field, is located 74 km southwest of Islamabad in the Potwar basin of Pakistan. Discovered in March 1984, the field was developed with four producing wells and three water injection wells. Three main limestone reservoirs of Eocene and Paleocene ages are present in this field. These limestone reservoirs are tectonically fractured and all the production is derived from these fractures. The overlying claystone formation of Miocene age provides vertical and lateral seal to the Paleocene and Permian carbonates. The field started production in May 1984, reaching a maximum rate of 19370 BOPD in November 1989. Currently Dhurnal‐1 (D-1) and Dhurnal‐6 (D-6) wells are producing 135 BOPD and 0.65 MMCF/D gas. The field has depleted after producing over 50 million Bbls of oil and 130 BCF of gas from naturally fractured low energy shelf carbonates of the Eocene, Paleocene and Permian reservoirs. Preliminary geological and geophysical data evaluation of Dhurnal field revealed the presence of an up-dip anticlinal structure between D-1 and D-6 wells, seen on new 2003 reprocessed data. However, this structural impression is not observed on old 1987 processed data. The aim of this research is to compare and evaluate old and new reprocessed data in order to identify possible factors affecting the structural configuration. For this purpose, a detailed interpretation of old and new reprocessed data is carried out and results clearly demonstrate that structural compartmentalization exists in Dhurnal field (based on 2003 data). Therefore, to further analyse the available data sets, processing sequences pertaining to both vintages have been examined. After great effort and detailed investigation, it is concluded that the major parameter giving rise to this data discrepancy is the velocity analysis done with different gridding intervals. The detailed and dense velocity analysis carried out on the data in 2003 was able to image the subtle anticlinal feature, which was missed on the 1987 processed seismic data due to sparse gridding. In addition to this, about 105 sq.km 3D seismic data recently (2009) acquired by Ocean Pakistan Limited (OPL) is also interpreted in this project to gain greater confidence on the results. The 3D geophysical interpretation confirmed the findings and aided in accurately mapping the remaining hydrocarbon potential of Dhurnal field.

This thesis integrated geology, geophysics, and petroleum engineering data to build a detailed reservoir characterization models for three gas pay sands in the Grand Isle 33 & 43 fields, offshore Louisiana. The reservoirs are Late Miocene in age and include the upper (PM), middle (QH), and lower (RD) sands. The reservoir models address the stratigraphy of the upper (PM) sand and help delineate the lower (RD) reservoir. In addition, this research addresses the partially depleted QH-2 reservoir compartment. The detailed models were constructed by integrating seismic, well log, and production data. These detailed models can help locate recoverable oil and gas that has been left behind. The upper PM model further delineated that the PM sand has several areas that are shaled-out effectively creating a flow barrier within reservoir compartments. Due to the barrier in the PM-1 reservoir compartment, an area of potentially recoverable hydrocarbons remains. In Grand Isle 33, the middle QH sand was partially depleted in the QH-2 reservoir compartment by a series of development wells. Bottom hole pressure data from wells in Grand Isle 32 & 33 reveal that the two QH fault compartments are in communication across a leaking fault. Production wells in the QH-1 compartment produced reserves from the QH-2 compartment. The lower RD sand model helped further delineate the reservoir in the RD-2 compartment and show that this compartment has been depleted. The RD model also shows the possible presence of remaining recoverable hydrocarbons in the RD-1 compartment. It is estimated that about 6.7 billion cubic feet of gas might remain within this reservoir waiting to be recovered. A seismic amplitude anomaly response from the QH and RD sands is interpreted to be a lithologic indicator rather than the presence of hydrocarbons. Amplitude response from the PM level appears to be below the resolution of the seismic data. A synthetic seismogram model was generated to represent the PM and surrounding sands. This model shows that by increasing the frequency of the seismic data from 20 Hz to a dominant frequency of 30 Hz that the PM and surrounding sands could be seismically resolvable. Also the PM-1 compartment has possible recoverable hydrocarbons of 1.5 billion cubic feet of gas remaining.

Purely numerical methods based on the Finite Element Method (FEM) are becoming increasingly popular in seismic modeling for the propagation of acoustic and elastic waves in geophysical models. These methods o er a better control on the accuracy and more geometrical exibility than the Finite Di erence methods that have been traditionally used for the generation of synthetic seismograms. However, the success of these methods has outpaced their analytic validation. The accuracy of the FEMs used for seismic wave propagation is unknown in most cases and therefore the simulation parameters in numerical experiments are determined by empirical rules. I focus on two methods that are particularly suited for seismic modeling: the Spectral Element Method (SEM) and the Interior-Penalty Discontinuous Galerkin Method (IP-DGM). The goals of this research are to investigate the grid dispersion and stability of SEM and IP-DGM, to implement these methods and to apply them to subsurface models to obtain synthetic seismograms. In order to analyze the grid dispersion and stability, I use the von Neumann method (plane wave analysis) to obtain a generalized eigenvalue problem. I show that the eigenvalues are related to the grid dispersion and that, with certain assumptions, the size of the eigenvalue problem can be reduced from the total number of degrees of freedom to one proportional to the number of degrees of freedom inside one element. The grid dispersion results indicate that SEM of degree greater than 4 is isotropic and has a very low dispersion. Similar dispersion properties are observed for the symmetric formulation of IP-DGM of degree greater than 4 using nodal basis functions. The low dispersion of these methods allows for a sampling ratio of 4 nodes per wavelength to be used. On the other hand, the stability analysis shows that, in the elastic case, the size of the time step required in IP-DGM is approximately 6 times smaller than that of SEM. The results from the analysis are con rmed by numerical experiments performed using an implementation of these methods. The methods are tested using two benchmarks: Lamb's problems and the SEG/EAGE salt dome model.
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In the last decades digital modelling applied to geological research is getting increasing attention (Alaei, 2012; Tomassetti et al., 2018; Trippetta et al., 2020; De Franco et al., 2019; Mascolo and Lecomte, 2021). Indeed, relevant implications both in scientific and economic terms could be inferred by using this technique. In particular, the application of digital models in complex geologic scenarios is critical for the understanding of potentially exploitable systems from multiple perspectives. Starting from the most classical model application for the exploitation of oil and gas fields passing through the implementation of extraction strategies - by reducing uncertainties (Macgregor & Moody, 1998; Racey 2001) - digital models find new place in latest applications such as natural gas storage. Recently, models are also applied for the study of geological bodies, potential reservoirs for the CO2 or hydrogen injection (Dockrill and Shipton, 2010; Trippetta et al., 2013; Aminu et al., 2017; Heinemann et al., 2018). Modelling contribute and facilitate to capture and store gases in the subsurface, balancing their release into the atmosphere. Digital modelling represents one of the major innovative strategies in the control of greenhouse gases concentration in atmosphere, a currently trending topic from media, public opinion, and political points of view. Another possible application of digital models for subsurface gas storage involves the monitoring of reservoirs in order to ascertain and quantify gas leakage through fault or fracture systems (Wang et al., 2018). Moreover, radioactive waste storage could be integrated as current and powerful employment of digital models (Malvić et al., 2020). In particular, the technological tools used for these purposes are called forward models since their outcomes gives predictive results on the processes happened in the past and protracted towards the future. They appear extremely suitable for the study of geological subsurface formations that can be also applied to an emerging field such as the development of geothermal energy power plants (De Franco et al., 2019). All these are topics of great actuality since world governments' plans are1 directed towards the total replacement of classic energy sources from hydrocarbons with green energies. However, digital modelling needs input data such as geometries and rock properties that should be well constrained. Seismic exploration is probably the most powerful tool for investigating subsurface rock formations (Avseth et al., 2010). Important progress has been made in recent years, but significant problems remain in the geologic interpretation of seismic data. The reflections that can be read in seismic data depend on the Acoustic Impedance (AI) contrast in the transit of the P-wave between layers in the subsurface. AI depends on the density (ϼ) and the P-wave velocity (Vp) of the medium through which wave propagates (AI= ϼ Vp). These petrophysical characteristics, in turn, are controlled by structure, texture, porosity, and boundary conditions of the rocks (Dvorkin et al., 2014; Tomassetti et al., 2018; Trippetta et al., 2020; Brandano et al., 2020). These two links, one between rock structure and its elasticity and the other between elasticity and signal propagation, form the physical basis of seismic interpretation (Anselmetti and Eberli, 1993; Eberli et al. 2003; Weger et al. 2009; Hairabian et al. 2014; Dvorkin et al., 2014). Dealing with these relationships, we are facing the so- called inverse problem. We see from seismic sections the resulting seismic images of rock formations where the same signal can be the result of a combination of different features. It should be, thus, very useful to well understand what are the features that lead to a certain seismic image. Synthetic seismic modelling (or forward modelling) is a fundamental prospecting method for understanding the features leading to the corresponding seismic images of subsurface structures and reservoir architectures (Alaei, 2012). Forward modelling methodology, as approach to the interpretation of seismic data, involves the detailed characterization of lithology, density, porosity, seismic velocity and fluid in the rock, as well as the reservoir geometry. As a result, the corresponding seismic properties are calculated, and then synthetic seismic traces are generated. These issues became essential for lithologies characterized by a complex seismic interpretation (Al-Salmi et al., 2019). In addition, synthetic seismic forward models allow accurate analysis of fault zones. The study of seismic response in fault zones is crucial since the2 fracturing or compaction that faults create strongly modifies the petrophysical characteristics of rocks by affecting their properties (Botter et al., 2017; Kolyukhin et al., 2017). Synthetic seismic forward models are, therefore, mandatory for the comprehension of faults behaviour through seismic imaging. Faults play a key role in reservoirs by increasing or limiting fluid flow. Even if interpretation of seismic data is a pivotal method for studying the subsurface, the internal structure and properties of fault zones are often below the limit imposed by seismic resolution (Botter et al., 2017). Despite the impact of faults on reservoir permeability, modelling tools and workflows still lack for realistic representation of fault zones in models (Tveranger et al., 2005; Braathen et al., 2009; Manzocchi et al., 2010). With facies analysis and petrophysical data it is possible to build field-based digital models fundamental in understanding architectures of carbonate sedimentary bodies which often constitute reservoir surface analogues of buried world-wide petroleum systems, CO2, hydrogen, radioactive waste storage sites and geothermal fields. Surface analogues are rocks with depositional, textural, and petrophysical characteristics similar to those constituting the petroleum system, but they outcrop on the surface. Starting from petrophysical characteristics of facies, forward models can be built. In this thesis, as a case study for the development of a forward model, rocks belonging to the carbonate realm, more specifically carbonate ramps, were analyzed. Carbonate ramps constitute important hydrocarbon deposits in North Africa (Macgregor & Moody, 1998), Venezuela, and many other regions of the World (Racey, 2001) due to their excellent porosity and permeability characteristics. However, the depositional model that is the basis for a proper interpretation produces many uncertainties arising from the difficulty in attributing different facies to a depositional environment and process due to the poor occurrence of sedimentary structures (Buxton and Pedley, 1989; Pomar and Kendall, 2008; Burchette, 2012; Bassi et al., 2013; Tomassetti et al., 2018; Tomassetti et al., 2022). In addition, strong lateral heterogeneity in terms of petrophysical characteristics, components, structure, and texture leads to complex distinction of facies belts (Tomassetti et al., 2018; Trippetta et al., 2020; Brandano et al., 2020). To overcome these issues, quantification of3 petrophysical characteristics can be crucial in understanding facies heterogeneity from a physical perspective to be incorporated in synthetic seismic forward models building. Carbonate rocks are often difficult to interpret seismically because the slight acoustic impedance contrast at the interface between carbonate facies in subsurface does not allow a clear resolution of major reflectors and reservoir formations. Strong constraints are often imposed by geophysical survey techniques characterized by low resolution especially in carbonates and interpretation capabilities that depend on the interpreter skill (Tomassetti et al., 2018; Trippetta and Geremia, 2019; Faleide et al., 2021). These constraints can be overtaken through the modelling of surface analogues allowing a detailed analysis on the facies association but also their petrophysical characteristics and seismic properties such as acoustic impedance (Tomassetti et al., 2018; Lipparini et al., 2018; Trippetta and Geremia, 2019; Brandano et al., 2020). In order to analyse the petrophysical characteristics and seismic response of the carbonate realm through modelling two carbonate ramps both belonging to the Adria plate were considered as case studies. The first is the Chattian carbonate ramp of the Porto Badisco calcarenite outcropping in the southern Salento peninsula, the southernmost portion of the Apulian carbonate platform. The Porto Badisco carbonate ramp is an excellent surface analogue of exploited oil and gas field in the offshore Venezuela, Philippine and South China Sea (Zampetti et al., 2005; Sattler et al.,2004; Fournier and Borgomano, 2007; Lallier et al., 2012; Marini and Spadafora, 2014; Pomar et al., 2015; Valencia and Laya, 2020) as well as fields in offshore Adriatic Sea such as Ombrina Mare field (Campagnoni et al., 2013). In this carbonate system firstly the analysis of outcropping facies was carried out observing over 100 thin sections produced. Consequently facies association modelling was performed through Petrel software (mark of Schlumberger) using TGSim stochastic approach algorithm adopting the depositional model based on field data. This model is useful for qualitatively understand the broad facies spacial distribution which reflects the abrupt heterogeneity from a sedimentary point of view. To physically quantify the lateral facies heterogeneity the petrophysical characteristics such as porosity, density and seismic velocity were measured and analyzed through a multi-analytical approach. Density4 measurements were carried out with the helium pycnometer. Porosity was firstly calculated from the density data and then was additionally measured through image analysis and point counting to cross-correlate the values. Seismic velocity was measured by using an ultrasonic generator connected to piezoelectic transducers and to an oscilloscope. The analysis performed on the carbonate ramp outcropping in Porto Badisco offers the opportunity to analyze facies heterogeneity, modeling its distribution and physically quantifying it through petrophysical characterization. From the petrophysical data, it was possible to construct 2D models of the distribution of porosity and P-wave seismic velocity along the depositional model. This study, which can be applied globally to carbonate platforms, emphasizes with the modelling exercise how facies heterogeneity is an intrinsic feature of these systems. The petrophysical characterization which provides quantitative values to the heterogeneity allow to build more complex models such as seismic forward models discussed in the second chapter. The other case study is represented by the Cenozoic carbonate ramp outcropping on the Majella Massif in Abruzzi, the northernmost portion of the Apulian carbonate platform which gives the opportunity to study a carbonate ramp surface analogue of a buried reservoir. Also in Majella the Oligo- Miocene stratigraphic interval represented by the Bolognano Formation which is the reservoir of the system is considered an excellent surface analogue of the productive fields in the Adriatic Sea, offshore Venezuela, Philippines and many others worldwide (Tomassetti et al., 2021). Specifically, this system offers the opportunity to integrate the facies heterogeneity in the synthetic seismic forward modelling and understand its seismic response without the introduction of artificial noise to obtain additional information. On the Majella Massif a model of the facies heterogeneity to understand their seismic response was performed. After analyzing the facies and measuring their petrophysical characteristics, the data obtained were used as input for build a 3D property modelling in Petrel software representing the entire carbonate ramp from the topographic surface to the Upper Cretaceous from the platform top going towards the basin located northward from the Majella Massif. From the 3D model was cut a section whose data were used as input in Matlab (mark of Mathworks) in order to perform the synthetic seismic forward model5 with the geophysical codes provided by the CREWES consortium. The resulting forward model represent the seismic response of the facies heterogeneity of carbonate rocks. In addition, from the obtained seismic images it is possible to evaluate the presence of hydrocarbons and to identify how the presence of important bituminous impregnations – that can be appreciated in the field in Majella – modify the seismic response. The workflow developed to quantify the signature of the facies heterogeneity of carbonate rocks and the presence of infilling hydrocarbons is applicable to other systems worldwide, which is a large issue that is still open and can help in the problems relative to seismic interpretation associated with these systems. Given the presence of a buried normal fault system in the study area, a forward modelling in the fault zones was performed as well. By measuring the petrophysical characteristics of the fault rocks characterized by both fracturing or compaction, fault zones were modeled. Two end member scenarios with two opposite behaviors of the rocks belonging to the damage zone were modeled in Matlab. A scenario in which the damage zone is characterized by fracturing and therefore rocks affected by greater porosity than the host rock. In the other scenario was modeled a damage zone with lower porosity than the host rock caused by the presence of compaction bands. Consequently, the seismic response of these end members was compared to understand how faults affect the seismic response of carbonate ramp systems. Notoriously, fault systems globally characterize carbonate ramps, and understanding their seismic response facilitates interpretation of the deformation behavior that a fault can assume under different boundary conditions. This can lead to an understanding of whether faults behave as barriers or conduits for fluids with the important implications for the study of fluid leakage from reservoirs.

Synthetic aperture radar interferometry (InSAR) is a technology that has been widely used in many areas, such as topographic mapping, land and resource survey, geological exploration, disaster prevention and mitigation, volcanic and seismic monitor and so on. Landslide, as a representative geohazard, include a wide range of phenomena involving downhill ground movement. InSAR, a technology which can measure surface deformation at the millimeter level over serveral days or years, is suitable to detect landslides with chronical and widespread movements. In this chapter, we introduce main process methods of InSAR data, including Persistent Scatter Interferometry (PSInSAR) and Distributed Scatter Interferometry (DSInSAR). A study area, Daguan County Town, one of the most landslide-prone areas in China is induced to demonstrate the practicability of InSAR in detecting landslides. Combined InSAR results with geological, geotechnical and meterological data, the distribution of landslide in Daguan County in spatial and temporal dimensions would be displayed. We also coupling numerical modeling and InSAR for characterizing landslide movements under multiple loads. The numerical results revealed that body loads dominated the cumulative downhill movements by squeezing water and air from voids, and precipitation caused seasonal movements with the direction perpendicular to the slope surface.

Semberah field’s infill drilling activity to increase its recovery has been generally challenging because of limited seismic information to support the reservoir distribution characterization. Stratigraphic model building has been using mainly geological concept and well log analysis while undermines seismic information because of poor quality 2D lines. The best seismic quantitative interpretation uses in Semberah encompass amplitude mapping of extracted post-stack attributes. Semberah asset team recently suggests a new stratigraphic framework consists of isolated distributary sands and active delta switching sequences. The new framework allows seismic forward modeling method to constrain the sand boundaries. The seismic modeling workflow involves building rock physics models, performing synthetic modeling of varying channel facies over its elastic properties. The synthetic PP-reflectivity generation uses Semberah well’s wavelet extraction from Roy-White algorithm extraction which are later varied with several scenarios of fluid, porosity and random noise. The latest volumetric estimation from the integrated modeling produces significant oil and gas resources to justify Semberah further development. Both static model and seismic forward modeling suggest potentially finding wet sands during the SB-27 well drilling activities in July 2019. The well’s location uncertainty has been optimized by moving the well location to a structurally updip position from the existing well UKM-03 to avoid potential water level. A recommendation has also been put forward for the remaining five-well drilling proposals to sharpen the targeted stacked channels around the recommended areas. The seismic forward modeling technique has never been applied as part of the seismic quantitative interpretation method in Semberah, yet such process could be carried out with only 2D seismic lines. The result from seismic forward modeling provides better integration with the geological model and becomes a cost-effective option to optimize area with limited dataset such as Semberah. The updated geocellular model and the seismic forward modeling results have already been used to identify a number of prospect area and would invigorate the future Semberah well drilling proposals.

Abstract CO2 sequestration in depleted carbonate reservoir stipulate incorporation of comprehensive and trailblazing monitoring technologies. 4D time-lapse seismic is sine qua non for Monitoring, Measurement and Verification (MMV) planning to demonstrate the migration of CO2 plume within geological storage. An ingenious, adaptive and site specific MMV plan for monitoring CO2 plume is paramount to minimize possible subsurface and project integrity risks. Integration of dynamic simulation with seismic forward modeling aggrandize the capabilities of 4D seismic in CO2 sequestration projects. Depleted carbonate reservoir has been thoroughly studied and its geomechanical and geochemical modeling results were coupled into dynamic simulation. Reservoir porosity and fluid properties along with CO2 saturation and injection pressure distribution within each reservoir level were generated. The dynamic simulation results were integrated with seismic forward modeling to demonstrate the CO2 plume migration and its impact on seismic amplitude. Fluid acoustic properties were computed for carbonate reservoir using FLAG method. Selection of wells was based on availability of superior quality acoustic logs as well as those representing the reservoir best. Gassmann fluid substitution exercise was carried using dry rock modeling. Several scenarios were generated, and results were analyzed to demonstrate the effect of CO2 saturation and pressure build-ups within reservoir on the seismic amplitude due to continuous CO2 injection. Synthetic seismic AVO gathers were generated for angles ranging from 5 to 50 degree. Near, Mid and Far seismic amplitude response at the top of carbonate reservoir were analyzed with respect to in-situ condition for each scenario. Results reveal that CO2 saturation as low as 25 - 30% in depleted carbonate reservoir can be distinguished from 4D time-lapse seismic. With continuous CO2 injection, the reservoir pressure increases and this in turn controls the properties of both in-situ and injected fluids. The gradual changes in fluid properties and their impact on bulk acoustic properties of reservoir were modeled to assess the feasibility of using 4D seismic as a predictive tool for detection of localized and provincial pressure build-ups. Modeling results show that although observed changes in amplitude on synthetic gathers were subtle, it is expected that 4D seismic with high signal-to-noise ratio possibly be able to image such localized pressure build-ups. To monitor CO2 plume migration as well as localized pressure build-ups, we recommend acquiring multi-azimuth (MAZ) surface seismic in combination with 3D DAS-VSP for superior subsurface imaging. The integrated modeling approach ensures that 4D Seismic in subsurface CO2 plume monitoring is robust. Monitoring pressure build-ups from MAZ surface seismic and 3D DAS-VSP will reduce the associated risks.

Earthquake has severe effect on all kinds of structures. Usually, seismic isolation is done in case of high-rise buildings. But from the past experiences it can be observed that the effect of earthquake is not only restricted to high rise framed structures, but also to the low rise unreinforced masonry structures. In developing nations, it is very expensive to finance earthquake isolation measures to safeguard buildings which are not classified as important buildings, such as houses or other minor structures, making the adoption of this type of system almost unfeasible. By incorporating low horizontal stiffness devices into the structure, it is possible to reduce the impact of seismic loads on those structures. The elastomeric bearings, sliding bearings and hybrid systems are the most commonly used type of base isolators. Due to the presence of synthetic or natural rubber and high strength reinforcing cords, the Scrap Tyre Pad (STPs) exhibits substantial vertical stiffness and horizontal flexibility. Hence it can be used as a suitable seismic isolation material for structures. In the present study, experimental evaluation of variation of vertical stiffness of STPs is conducted and an empirical modal relating the percentage increase in stiffness to percentage increase in aspect ratio is proposed.

Abstract Monitoring of CO2 plume migration in a depleted carbonate reservoir is challenging and demand comprehensive and trailblazing monitoring technologies. 4D time-lapse seismic exhibits the migration of CO2 plume within geological storage but in the area affected by gas chimney due to poor signal-to-noise ratio (SNR), uncertainty in identifying and interpretation of CO2 plume gets exaggerated. High resolution 3D vertical seismic profile (VSP) survey using distributed acoustic sensor (DAS) technology fulfil the objective of obtaining the detailed subsurface image which include CO2 plume migration, reservoir architecture, sub-seismic faults and fracture networks as well as the caprock. Integration of quantitative geophysics and dynamic simulation with illumination modelling dignify the capabilities of 3D DAS-VSP for CO2 plume migration monitoring. The storage site has been studied in detailed and an integrated coupled dynamic simulation were performed and results were integrated with seismic forward modeling to demonstrate the CO2 plume migration with in reservoir and its impact on seismic amplitude. 3D VSP illumination modelling was carried out by integrating reservoir and overburden interpretations, acoustic logs and seismic velocity to illustrate the subsurface coverage area at top of reservoir. Several acquisition survey geometries were simulated based on different source carpet size for effective surface source contribution for subsurface illumination and results were analyzed to design the 3D VSP survey for early CO2 plume migration monitoring. The illumination simulation was integrated with dynamic simulation for fullfield CO2 plume migration monitoring with 3D DAS-VSP by incorporating Pseudo wells illumination analysis. Results of integrated coupled dynamic simulation and 4D seismic feasibility were analyzed for selection of best well location to deploy the multi fiber optic sensor system (M-FOSS) technology. Amplitude response of synthetic AVO (amplitude vs offsets) gathers at the top of carbonate reservoir were analyzed for near, mid and far angle stacks with respect to pre-production as well as pre-injection reservoir conditions. Observed promising results of distinguishable 25-30% of CO2 saturation in depleted reservoir from 4D time-lapse seismic envisage the application of 3D DAS-VSP acquisition. The source patch analysis of 3D VSP illumination modelling results indicate that a source carpet of 6km×6km would be cos-effectively sufficient to produce a maximum of approximately 2km in diameter subsurface illumination at the top of the reservoir. The Pseudo wells illumination analysis results show that current planned injection wells would probably able to monitor early CO2 injection but for the fullfield monitoring additional monitoring wells or a hybrid survey of VSP and surface seismic would be required. The integrated modeling approach ensures that 4D Seismic in subsurface CO2 plume monitoring is robust. Monitoring pressure build-ups from 3D DAS-VSP will reduce the associated risks.