- Home
- Conferences
- Conference Proceedings
- Conferences
EAGE/SEG Research Workshop 2017
- Conference date: 28 Aug 2017 - 31 Aug 2017
- Location: Trondheim, Norway
- ISBN: 978-94-6282-222-1
- Published: 28 August 2017
36 results
-
-
Caprock and Well Integrity Monitoring Using Fiber Optic Cable - Distributed Strain Measurement at a Shallow Well during Water Extraction Tests
By Z. XueWe have been developing a new technology to monitor the caprock and wellbore integrity at CO2 injection sites by utilizing the Distributed Fiber Optic Sensing (DFOS).
-
-
-
CCS Monitoring Technology Innovation at the CaMI Field Research Station, Alberta, Canada
Authors D.C. Lawton, K.G. Osadetz and A. SaeedfarThe Containment and Monitoring Institute (CaMI) of CMC Research Institutes, Inc. and the University of Calgary have constructed a Field Research Station for research into monitoring technologies for containment and conformance of subsurface fluids, particularly CO2. The field research station is a platform for development and performance validation of technologies intended for measurement, monitoring and verification of CO2 storage. Outcomes of the research will also have adjacent applications such as assessing and monitoring cap rock integrity in oil sands during production, assessing fugitive emissions in shale gas production and monitoring CO2-enhanced oil recovery programs. The project will undertake applied research into monitoring technologies, graduate student and industry professional training, as well as public outreach and engagement activities.
-
-
-
Seismic Interferometry for Marine Leak Detection - Controlled Release Experiment at Oseberg
Authors M. Dean, P. Hatchell, S. Bussat and F. HansteenIn 2016 a controlled release experiment was jointly conducted by Shell and Statoil at the Oseberg PRM installation to evaluate the possibility of using passive seismic interferometry methods to detect and locate CO2 or hydrocarbon gas emissions to sea. The intention was to efficiently monitor CO2 storage sites, as well as ensuring safe operations and early hydrocarbon leak detection at producing oil fields. In contrast to leak detection systems based on active sonar technology, this method would leverage existing permanent reservoir monitoring (PRM) for both reservoir and containment monitoring purposes without requiring additional source mobilization. The interferometry results showed no clear and easily detectable effects from the generated bubble curtain. Potential reasons for this range from non-stationary vessel noise, location and strength of the line source, and large number of fish attracted by the release.
-
-
-
Detecting and Mapping Gas Leakage Events in Shallow Marine Sediments
Authors M. Landro, D. Wehner, N. Vedvik and P. RingroseRepeated site survey data acquired before and after an underground blowout that occured when exploration well 2/4-14 was drilled in 1989 are used to map the migration of gas from the deep reservoir into shallow sediments. We use 4D difference sections to map the extent and vertical position of gas being trapped in various overburden sand layers. A dedicated sand tank experiment is conducted to improve our understanding of gas flow through the uppermost layer situated 100 m below seabed. This laboratory flow tests are compared to videfilms acquired close to the well.
-
-
-
Imaging the Long-term Loss of Faulted Caprock Integrity - In-situ Experiments in the Mont Terri Rock Laboratory, Switzerland
Authors C. Nussbaum, Y. Guglielmi, L. De Barros and J. BirkholzerUnderstanding fault reactivation is crucial during CO2 injection and storage because they may result in enhanced fault permeability, potentially inducing fluid leakage from the injection zone through overlying caprock, and possibly triggering shallow earthquakes. We present results from a decametre-scale, controlled field stimulation experiment conducted in the Mont Terri underground rock laboratory (Switzerland) in a natural fault zone intersecting the Opalinus Clay, a shale formation considered as a reference low-permeability caprock-like formation. We demonstrated that a 0.4 mm fault slip could be triggered and continuously monitored while the pore pressure was increased by ca. 2.0 MPa above the initial pressure exhibited by the stimulated fault zone. We also observed that an exponential permeability increase from 10E-17 to 10E-13 m2 occurred in the fault and interpret this to be associated to creep, episodic slow slip of the fault, and a low magnitude earthquake swarm. Based on the encouraging results from the FS experiment, we propose a new experiment aiming at imaging long-term fluid flow, as well as permeability and stress variation through a ruptured minor fault, to assess CO2 storage safety and the integrity of reservoirs caprocks.
-
-
-
Containment and Monitoring Institute - Baseline Geophysics for CO2 Monitoring with Crosswell Seismic and Electromagnetics
Authors T.M. Daley, P. Marchesini, M. Wilt, P. Cook, B.M. Freifeld and D. LawtonThe Containment and Monitoring Institute (CaMI) has built a Field Research Station (FRS) near Calgary, Alberta, Canada, designed around small injections (up to 1000 tonnes per year) of CO2 at depths of approximately 300 m and 500 m. Baseline borehole geophysical surveys have been completed at the CaMI site as part of a larger monitoring effort aimed at detecting and monitoring the small (1-2 ton) gas phase CO2 plume as well as any vertical migration. Crosswell seismic and EM data, as well as borehole-to-surface EM data, were recorded and have sufficient data quality to proceed with time-lapse monitoring. Initial processing for quality control has been accomplished. Seismic processing to date includes initial travel time picking and indicates that data is sufficient for velocity inversion. EM processing includes comparison of acquired data (amplitude and phase) with a layered model based on resistivity logs with repeatability of ~2%. The use of fiberglass casing in one monitoring well supports the use of EM methods. Joint inversion of the seismic and EM measurements (i.e. P-wave velocity and electrical conductivity) is planned to improve the estimate of CO2 saturation in the subsurface.
-
-
-
Comparison of Magnetometric Resistivity and Electric Resistance Tomography for CO2 Storage Monitoring
Authors A. Bouchedda and B. GirouxIn this study, we compare the responses of downhole magnetometric resistivity (MMR) and downhole electric resistance tomography (ERT) due to changes in electric resistivity consecutive to CO2 injection in a saline aquifer. The results indicate that a smaller volume of CO2 is detectable with MMR, for noise levels inferred from field data. This is attributed to the fact that the MMR method is sensitive to current density variations and not to absolute values of resistivity. Consequently, the MMR response is not affected by the problem of noise in conductive media, as is the case for ERT (very weak electrical potential in conductive environments). Moreover, sensitivity maps show that the sensitivity patterns have broader extents for MMR.
-
-
-
InSAR for Ground Displacement Continous Monitoring
Authors A. Rucci, A. Ferretti and S. Del ConteWhenever fluids are injected or extracted from a reservoir, pore pressure and stress field change both in the reservoir and in the overburden. According to geomechanics, such variation in stress or pore pressure can produce a reservoir compaction, trigger pre-existing faults or even generate new ones. Al these events will translate into surface deformation, which turns to be a valuable information to better understand the subsurface phenomena. In the last few years, the analysis of multi-temporal SAR data sets represents an important layer of information, for reservoir monitoring and management, thanks to the possibility to provide surface deformation data with millimetre precision over large areas. In order to help decision makers in analyzing different scenarios and planning specific actions it is important to update ground displacement measurements every new satellite acquisition.
-
-
-
Time-Lapse Seismic as a Component of the Quest CCS MMV Plan
Authors V. Oropeza Bacci, A. Halladay, S. O'Brien, N. Henderson and M. AndersonThe Quest Carbon Capture and Storage (CCS) Project is a fully integrated CCS project located at the Scotford Upgrader in Alberta, Canada. As a part of the Athabasca Oil Sands Project (AOSP), Quest is capable of the capture, transport, injection and storage of over 1 million tonnes of CO2 per annum in the Basal Cambrian Sandstone (BCS). In the context of the Quest MMV Plan, time-lapse seismic data is applicable to both containment and conformance monitoring; it is used to verify the absence of CO2 above the ultimate seal of the BCS storage complex and to monitor the development of the CO2 plume inside the BCS storage complex. As of early 2017, this includes the use of 3D surface seismic, 2D surface seismic, and 2D DAS VSPs. This paper addresses the role of time-lapse seismic in the Quest MMV Plan, the survey acquisition and design, and the strategy for the deployment of the various methods.
-
-
-
Seismic Monitoring of a Small-scale Supercritical CO2/CH4 Injection - CO2CRC Otway Stage 2C Case Study
Authors R. Pevzner, M. Urosevic, K. Tertyshnikov, B. Gurevich, V. Shulakova, S. Glubokovskikh, D. Popik, J. Correa, A. Kepic, B. Freifeld, M. Robertson, T. Wood, T. Daley and R. SinghCO2CRC Otway project was the first Australian of CO2 geosequestration project. The project site is located 240 km away from Melbourne, Victoria. During the Stage 1 of this project ~66 thousand tons of supercritical CO2/CH4 gas mixture was injected into a depleted gas reservoir at approximately 2 km depth in 2008-2010 to prove that gas can be safely transported and stored in a geological formation. The ongoing Stage 2C of the project is focusing seismic monitoring capabilities and, also, on proving that the injected gas plume plume will stabilize over the period of time. A very limited amount of the same gas mixture (15 000 tonnes) was injected into a saline aquifer at ~1500 m. In order to monitor the gas injection a comprehensive 4D seismic program was rolled out. In this presentation we outline the monitoring program and show the time-lapse seismic results obtained after the first four monitor surveys, acquired at 5 000 t, 10 000 t, 15 000 t of the injection and, also, 9 months after completion of the injection.
-
-
-
Evolution of the Aquistore Deep CO2 Plume from Time-lapse Seismics
Authors D. White, L. Roach, K. Harris, S. Cheraghi, C. Samson and B. RobertsAquistore is a commercial-scale CO2 storage and monitoring project that is injecting CO2 into a deep saline formation (Worth et al., 2014). The storage site is located in southeastern Saskatchewan, Canada. CO2 is captured at the nearby Boundary Dam coal-fired power plant and delivered via pipeline to the storage site. Since the start of CO2 injection in April-2016 until January 31, 2017, 107 ktonnes of CO2 have been injected at the site. 3D time-lapse seismic methods have spearheaded the monitoring efforts with the goal of tracking the distribution of CO2 within the storage reservoir. 3D DAS-based VSP and surface seismic data have been acquired in November-2013 (Baseline), February-2016 (Monitor 1) and November-2016 (Monitor 2), corresponding to injection quantities of 0, 36 and 102 ktonnes of CO2. Here, we present the resultant seismic images that document the spread of CO2 within the reservoir.
-
-
-
The UK GeoEnergy Test Bed – A New Facility for Collaborative Subsurface Low Carbon Energy Research
Authors C.J. Vincent, O. Kuras, B. Dashwood, D. Morgan, R. Luckett, P. Wilkinson, P. Meldrum, R. Swift, A. Butcher and M.R. HallThe UK GeoEnergy Test Bed (GTB) is a field laboratory founded by the University of Nottingham and The British Geological Survey (BGS) for subsurface research into fluid migration through natural pathways. The GTB was initiated with funding from the founding partners and has received capital investment from the UK Government’s Treasury as part of the Energy Research Accelerator (ERA) project. The GTB will act as a research hub to catalyse scientific collaboration between researchers from academic and industrial backgrounds. The aim of the GTB is to advance geoscientific research to support the global need for secure, sustainable and safe energy. Geophysical, geochemical, petrochemical and hydrogeological data have been collected during site characterization and used to build a conceptual geological model. Permission is being sought from the relevant authorities to inject a small amount of food-grade CO2. Surface and downhole technologies and techniques will be used to monitor site behaviour before, during and after fluid injection. The sensing capability at the GTB has been designed by the BGS to enable interrogation of the subsurface in 4D and to a level of detail commensurate with energy processes in the subsurface.
-
-
-
Monitoring Offshore CO2 Storage Using Time-lapse Gravity and Seafloor Deformation
Authors H. Ruiz, R. Agersborg, L. T Hille, M. Lien, J.E. Lindgård and M. VatshelleCombined 4D-gravity and seafloor-deformation surveys have been performed for monitoring hydrocarbon production in seven fields on the Norwegian continental shelf. In one of them, Sleipner, CO2 storage has also been monitored. The experience from that case demonstrates that gravity provides quantitative information on the lateral distribution of mass changes, which can be used to estimate CO2 density and the fraction of CO2 that is dissolved in brine. Surface deformation monitoring has been a focus of interest in recent years, due to increasing attention on fault activation and induced seismicity. The onshore In Salah CO2 storage project demonstrates that frequent and high resolution surface deformation data allow studying potential fault reactivation. This abstract reviews the principles behind the 4D-gravity and seafloor-deformation monitoring technology, and then discusses the value of gravity and surface deformation data for CO2 storage, by describing the cases of Sleipner and In Salah. An outlook on the recent and future developments of the technology is provided.
-
-
-
Uncertainty Quantification in Waveform-based Monitoring Methods - A Case Study at Sleipner
Authors P. Eliasson and A. RomdhaneFull Waveform Inversion (FWI) and Controlled Source Electro-Magnetic (CSEM) inversion can provide quantitative estimates of useful subsurface properties. In the context of CO2 monitoring, FWI has the capability to characterize velocity changes induced by CO2 injection, while CSEM can be useful to determine the CO2 saturation. Quantifying the uncertainty of the reconstructed parameters is however challenging. In this study, we assess the reliability of the results obtained using CSEM and FWI when monitoring CO2 storage at the Sleipner pilot in the North Sea. The uncertainty evaluation methodology is described in a first stage. In a second stage, two CO2 monitoring examples are presented, one synthetic case using CSEM and one real data case using FWI. For the synthetic CSEM case, the inversion of the EM data has a clear effect on the uncertainty, reducing the covariance of the probability distribution for possible conductivity models. For the real, rather large-scale FWI case, computationally efficient strategies are considered. The covariance is not reduced to the same extent as for the CSEM case, but an improvement is observed. In both cases, the quantification approach provides a means to assess the quality of the derived models.
-
-
-
VSP Azimuthal Travel Time Analysis at the Field Research Station near Brooks, AB
Authors A.J. Gordon Ferrebus, D.C. Lawton and D.W. EatonAs part of the Containment and Monitoring Institute (CaMI) CO2 injection project, 3C Vertical Seismic Profile data (VSP) were acquired at the Field Research Station in May 2015. A half walk-around VSP survey was acquired and processed for an azimuthal analysis. Obtaining the first break traveltime variations with azimuth, was the first step. Statics corrections and median filters were applied to help differentiate a sinusoidal trend in the data. The fast velocity direction, estimated from the trend, is at an azimuth of approximately 45 degrees, which is similar to the Western Canada stress orientation (NE-SW). An estimation of the anisotropy parameter epsilon (ε) yield a value of 0.02, indicative of weak anisotropy.
-
-
-
Feasibility Study of Time-lapse-seismic Monitoring of CO2 Sequestration
Authors M. Macquet, D.C. Lawton, J. Donags and J. BarrazaBackground studies are made prior to the beginning of the injection to ensure the security of the geological sequestration of CO2. In the CaMI.FRS site near Brooks, Alberta, numerous wells give the information about the lithology, the porosity, the permeability, the velocities (and others parameters) of the medium. In addition to logs data, seismic surveys were conducted in order to characterize the subsurface. After acquiring well logs information and baseline seismic surveys, we applied numerical simulations in order to characterize the feasibility of the time-lapse seismic monitoring. Indeed, once the injection begins, seismic survey will be made at regular intervals to monitor the CO2 injection. Fluid simulations allow us to work on synthetic models, but yet are close to what it is expected in the reality. We use Gassmann fluid substitution to obtain the elastic parameters (VP, VS and density) at different injection times (1 year after the beginning of the injection and 1 year after the end of the injection), for a 300m depth CO2 reservoir. In those 3D models, synthetic data are generated then processed. This work give us a good approximation of the feasibility of a time-lapse seismic monitoring, considering the conditions of CaMI.FRS project.
-
-
-
CO2 Storage Site Characterisation at the Location of Harvey-3 Well, Harvey, Western Australia
Authors M. Urosevic, S. Ziramov, R. Pevzner, K. Tertyshnikov, D. Popik and D. Van GentThe South West Hub is the first commercial scale CO2 capture and sequestration project in Australia. The project aims to capture CO2 from several significant polluters that are located around the town of Harvey, Western Australia. The potential CO2 reservoir is the prominent Lesueur sandstone formation while the Harvey-3 well is likely to be utilised for the first geo-sequestration test. Unfortunately, due to survey restrictions imposed in 2014, the area around the Harvey-3 well is void of seismic information. New developments have given rise to new seismic investigations which had to be designed in a unique manner due to limited access to the site. The data acquisition program is comprised of 2D surface and borehole surveys (550 OVSP points) and 3D surface and VSP surveys. Results will be discussed in detail.
-
-
-
Fault Characterisation from an Ultra-high-resolution Seismic for CO2 Injection Experiment
Authors M. Urosevic, S. Ziramov, R. Pevzner, K. Tertyshnikov, D. Popik and A. FeitzAn ultra-high-resolution mini 3D survey was acquired at the Otway site to characterise structures and discontinuities in a depth range of 0-100 m for the controlled CO2 fault plane release experiment. The survey demonstrated that very high spatial data density is essential for imaging and characterisation of shallow structures. Nevertheless, significant processing efforts were required to precisely image shallow fault geometry and the extent of fault tips. The main fault F1 and the accompanied discontinuities were clearly imaged with a PSDM routine after a 3D velocity model was derived from 3D tomography and then further improved through an iterative process. Fault F1 now appears more complex and additional studies are needed. Further assessment of the fault F1 and its associated discontinuities will be conducted using three component seismic data.
-
-
-
Rock Physics Characterization and Monitoring Feasibility Study of a CO2 Storage Reservoir in the Rock Springs Uplift, Wyoming
Authors D. Grana, E. Campbell-Stone, F. MacLaughlin, K. Ng, V. Alvarado, S. Mallick and J. KaszubaIn this work, we present a rock physics modelling workflow for seismic reservoir characterization and monitoring feasibility analysis and its application to a carbon dioxide sequestration study in the Rock Springs Uplift, a potential storage site in Southwestern Wyoming. The study includes the calibration of a facies-dependent rock physics model using well log data and core samples in two potential reservoirs, and the application of the model to a 3D volume of seismic attributes through a Bayesian rock physics inversion method for the pre-injection reservoir characterization. The study also focuses on the derivation of a rock physics model to predict the changes in the seismic response due to saturation and pressure variations during injection for the reservoir monitoring feasibility study based on time-lapse seismic data.
-
-
-
Case Study of a Time-lapse Seismic System Using Buried Receivers for CO2 EOR Monitoring in a Desert Environment
Authors R. Smith, A. Bakulin and M. JervisTime-lapse seismic in a desert environment is a major geophysical challenge due to the complex and changing nature of the near surface that inhibits both imaging and data repeatability. In this study, the problem is further compounded by the injection of CO2 into a stiff carbonate reservoir which results in small changes in reservoir acoustic impedance. Therefore, a highly repeatable acquisition system was required to detect these weak 4D signals. A hybrid system using deep buried receivers and surface vibroseis sources was found to provide the optimum solution. Along with careful survey design and acquisition, a specialized data processing workflow was developed to overcome the challenges faced by single source, single receiver data. In particular, the stacking of neighboring shots in a process known as supergrouping is essential for the reduction of 4D noise. Using this system, highly repeatable data has been achieved with mean NRMS of 6% between dry season surveys separated by more than one year. This level of repeatability allows small variations that may be related to CO2 injection to be observed.
-
-
-
Results from the First Monitor VSP Survey at the Quest CCS Operation
Authors V. Oropeza Baacci, A. Halladay, S. O'Brien, M. Anderson and N. HendersonThe Quest Carbon Capture and Storage (CCS) Operation is a fully integrated CCS project, designed to safely capture, transport and store more than a million tonnes of CO2 annually. Time-lapse seismic is a key technology deployed by the Quest MMV Plan to ensure both the current and long term security of CO2 storage in the injection zone, the BCS saline aquifer. In the first few years of operation, VSPs are a practical and economical alternative to 3D surface seismic, and as of 2016 a baseline and one monitor 2D DAS VSP survey have been acquired. A summary of the first monitor VSP is presented in this paper, along with a discussion of the acquisition geometry, processing and imaging results. The first monitor VSP was able to conclusively demonstrate the presence of CO2 in the injection zone. An interpretation of the time-lapse results is compared to the dynamic reservoir modelling prediction for the extent of CO2 in the injection zone.
-
-
-
Optimizing Monitoring Strategies for Contrasting Offshore CO2 Storage Sites
Authors A.K. Furre, S. Bussat, P.S. Ringrose and R. ThorsenA feasibility study for a full scale CCS demonstration project in Norway was conducted in spring 2016, aimed at identifying at least one technically feasible CCS chain (capture, transport and storage). The storage part of the feasibility study investigated three potential storage locations in the North Sea. The main deliverable was a suitability recommendation of the localities, based on technical (capacity and containment) evaluations and an economic assessment. Recommendations for monitoring each potential site were also given in the feasibility study, based on the specific storage reservoir and infrastructure at each site. We discuss optimised sub-surface and environmental monitoring based on regulatory storage requirements, proposing a monitoring plan mainly focussed on seismic and environmental surveys acquired at pre-defined times, such as a baseline prior to CO2 injection, a certain number of surveys acquired during injection, and at least one post-injection survey. These could be towed seismic streamers or a permanent installation, or an optimized combination of the two. In addition, we envisage trigger surveys to be conducted in the case where an anomaly is detected. Continuous downhole pressure gauges in the injection well would provide the primary operational monitoring method, along with conventional surface facility pressure flow rates and compositions.
-
-
-
Repeatability of P-Cable 3D Seismic Data
Authors M.W. Waage, S.B. Bünz, A.P.F. Plaza-Faverola and K.A.W. WaghornFor the first time, we test the repeatability of high-resolution P-Cable seismic data at three sites with different geological and environmental settings to evaluate its potential as a time-lapse tool. Results are positive and indicate ideal setting for using P-Cable as a time-lapse tool is typical marine sedimentary deposition where the data can be processed to obtain quantitative repeatability measures similar to conventional 3D seismic (NRMS < 0.4; Predictability > 0.9). Repeatability is slightly worse in areas of harder or more chaotic sediments and where the seismic attenuation is large or surface topography steep or rough (NRMS > 0.6 and Predictability > 0.8). 4D anomalies at the active seepage site the Vestnesa ridge are commonly restricted to areas where fluid flow is likely to occur, i.e. that is the chimneys or along the BSR (Bottom Simulating Reflector). The overall results gives us increased confidence that we will be able to interpret real (geological/physical) changes from time-lapse P-Cable seismic data if the right pre-conditions and geological restrictions are faced.
-
-
-
Applications and Possibilities in Real-time Overburden Surveillance Using Permanent Seismic Sensors
By S. BussatThere is an undeniable need in monitoring of oil and gas operating fields for HSE purposes and optimization of recovery. Currently, only seismic methods provide high resolution images to properly locate subsurface changes. Passive seismic data acquired with permanent seismic receivers could enable us to monitor the subsurface and detect changes in real-time. Hence, by maturing methods to analyse and use passive seismic data in real-time, we aim to improve our understanding of the subsurface, detect problems early, and therefore support mitigating measures to reduce the possible imposed risk. PRM systems can provide real-time seismic data A workflow is presented to continuously analysis passive seismic data for an overburden surveillance, ensuring that only analysed data get deleted. This approach should allow handling more PRM data in the future. The initial experiences gained from the small caprock monitoring system at Oseberg (Bussat et al. 2016), are being transferred to a full-field PRM system with thousands of nodes. New mini-PRM installations for different purposes at various fields are being evaluated and one possible sparse receiver-layout is presented to mitigate problems with strong (platform) noise in the vicinity. Ongoing efforts will investigate the full potential of passive seismic methods in the near future.
-
-
-
CO2 Monitoring by Using VSP-FWI - Synthetic Study on CO2-saturation and Pressure-buildup Differentiation
Authors T. Tsuchiya, N. Yamada, U.P. Iskandar, M. Kurihara, C. Barnes and M. ChararaSynthetic study on CO2-saturation and pressure-buildup differentiation by using VSP-FWI is conducted in a virtual CCS site. Geophysical and Reservoir simulation works are first implemented to create geophysical models before and after CO2 injection. Virtual VSP-FWI monitoring experiment is then implemented on the models. In parallel with this, simple linear equations to estimate CO2-saturation and pressure-buildup are derived. Inverted P- and S-wave velocities through the VSP-FWI are found to be highly accurate, and used in the derived equation. As a result the saturation change and reduction of differential pressure are estimated consistently with the values after reservoir simulation. This result indicates that CO2-saturation and pressure-buildup can be differentiated around the well, if both P- and S-wave velocities are accurately inferred by applying VSP-FWI and relevant rock-physics model is known.
-
-
-
Carbon Dioxide Saturation Estimates at Sleipner Using Seismic Imaging and Rock Physics Inversion
Authors B. Dupuy, A. Romdhane, P. Eliasson, H. Yan, V. Torres, E. Querendez and A. GhaderiWe present an integrated approach combining Full-Waveform Inversion and rock physics inversion to estimate CO2 saturation at Sleipner. Acoustic FWI provides high-resolution P-wave velocity images where the uncertainty is quantified using posterior covariance matrix analysis. The seismic properties and their associated uncertainties are used as input to the rock physics inversion. At the fairly large distance of the injection point (533m), we derive CO2 saturations lower than 30% and which are following a patchy mixing distribution.
-
-
-
CO2 Monitoring by Using VSP-FWI - Timelapse Elastic Parameters Estimation
Authors C. Barnes, M. Charara, T. Tsuchiya and N. YamadaGeological carbon sequestration involves large-scale injection of carbon dioxide into underground geologic formations. Changes in reservoir properties resulting from the CO2 injection and migration can be monitored using time-lapse seismic data. Conventional analysis of time-lapse surface and/or borehole seismic data only gives qualitative information about the changes of the acoustic impedance contrasts in the reservoir. In order to differentiate the pore-pressure from CO2 saturation effects, it is necessary to evaluate the changes in the elastic properties of the reservoir. Borehole seismic data contain strong converted shear waves at the level of the reservoir that will allow determining S-velocity changes. Elastic full waveform inversion (FWI) is the appropriate method to estimate elastic parameters. We demonstrate the feasibility of a timelapse multi-Offset VSP inversion for CO2 sequestration monitoring, by inverting synthetic seismic data based on a virtual CO2 injection site study. The timelapse FWI recovers P-wave and S-wave velocity for the baseline model, i.e., the reference model; and, the perturbations of the velocity models associated to 3 year of CO2 injection are also well recovered for a distance of a few hundreds of meters from the well.
-
-
-
Results of a baseline magnetometric resistivity survey at the Field Research Station, Alberta
Authors B. Giroux, A. Bouchedda, A. Saeedfar and D. LawtonWith the magnetometric resistivity method (MMR), electrical property contrasts in the ground are obtained from the measure of the magnetic field induced by a galvanic source. Due to the fact that the measurements are done with a magnetic sensor, MMR offers many advantages for monitoring: easier deployment in boreholes (no contact needed) and problems related to electrode installation and corrosion are avoided, also the problem of noise in conductive media is reduced because the magnetic field is a function of current density and not conductivity. The Field Research Station (FRS) is an experimental site operated by the Containment and Monitoring Institute of Carbon Management Canada where are controlled CO2 release experiment is planned for the next 5 years. A preliminary numerical study showed that MMR is suitable for monitoring a CO2 plume at the FRS. In this contribution, we present the results of a baseline survey conducted at the FRS. To our knowledge, this experiment is the first field application of MMR for CO2 monitoring. The aim of the survey was to evaluate the noise conditions at the site and determine the optimal data acquisition parameters, in addition to providing baseline data for a monitoring program.
-
-
-
Initial Results from the Field on the Use of DAS as a Viable Microseismic Monitoring System of CCS Sites
Authors M. Wilks, A. Wuestefeld, P. Thomas, E. Kolltveit and V. OyeIn outdoor field-tests where a single optical fibre cable is used to make DAS recordings of hammer shots, coherent seismic arrivals are observed at up to 32 m from the hammer points with frequencies up to 600 Hz. Recording at higher sampling rates and decimating is preferable to downsampled data. Time domain SNRs of acquired DAS data at a given distance are ~1/2 those of complimentary geophones while in the frequency domain, the highest ratios are produced between 20 and 200 Hz. An automated STA/LTA trigger algorithm is able to define reasonable seismic onsets but is unable to identify the first-arriving energy on all traces. Shorter pulse widths produce lower RMS amplitudes for the noise windows while longer pulse widths produce higher RMS amplitudes for the signal windows. This means that the selection of optimum pulse width with respect to maximising the SNR is not clear. This work presents the initial results of field-tests that will be used to refine the use of the DAS system in further field and borehole experiments. This will ultimately be used to monitor the seismicity at active CCS injection sites in the future.
-
-
-
Baseline Microseismic Monitoring for CO2 Injection Sites
Authors A.L. Stork, J.-M. Kendall, A.C. Horleston and D.C. LawtonThis submission describes a baseline passive seismic monitoring experiment for the Field Research Station in Alberta. The analysis does not reveal any local seismicity and we estimate a minimum magnitude (M) of detection of -1.4 for a source-station distance of 500m during quiet periods. Injection tests indicate that the detection threshold will rise to M=-0.1 during injection. Using perforation shots in the injection well we find the array is able to locate seismic events at the planned injection point to within 20m.
-
-
-
A Passive Microseismic Monitoring Network at the Quest CCS Project
Authors V. Oropeza Bacci, S. O'Brien, M. Anderson, K. Dahlby and N. HendersonThe Quest Carbon Capture and Storage (CCS) Project is a fully integrated CCS project designed to reduce total greenhouse gas emissions from the Scotford Upgrader in Canada by up to 35%. As a component of the Quest MMV Plan, the downhole passive microseismic monitoring network at Quest was designed and installed to address and assess risks associated with induced seismicity, such as cap rock integrity and fault reactivation. A downhole microseismic array is deployed in a deep monitoring well at the central injection well pad, along with a pressure and temperature gauge. The array was designed and manufactured to be a semi-permanent, retrievable array to address any long-term maintenance issues. The technical design criteria were evaluated on the sensitivity based on observations from analog injection operations. This paper presents the details of the Quest microseismic array design and installation, and provides a description of the role passive seismic monitoring plays in the Quest MMV Plan.
-
-
-
Improvement of Resistivity Imaging for an Offshore CO2 Storage by Filtering Out Seabed Pipeline Influence
More LessOn behalf of NGI, under FME SUCCESS, an MSc thesis at the University of Oslo has been conducted to finalize an inversion study of a CSEM dataset acquired in 2008 for the Sleipner CO2 storage project. The aim of the MSc thesis was to establish an inversion strategy that can be applied in order to resolve some of the various challenges related to inverting the dataset. This paper presents some of the work done related to the influence on the CSEM data from a pipeline network at seabed, with the objective of establishing a method to identify and filter out strongly influenced data, in order to improve inversion results.
-
-
-
Simulation Approach for the Time-lapse Imaging of CO2 Injected Zones Using a Few Seismic Sources and a Geophone Array
By J. KasaharaThe time-lapse study for the CO2 injection or CO2-EOR requires the excellent repeatability of the measurement system. Many factors control the repeatability. The overburden effects from a source to receivers can be reduced by fix source location. To obtain excellent repeatability, we assume single or a few ACROSS (Accurately Controlled and Routinely Operated Signal System) seismic source(s) which have such ultra-stable repeatability for the operation of long duration. Using residual waveforms before and after the injection of vapor or supercritical CO2 to reservoirs, we can image the time lapse of reservoir. We carried out simulations for a reservoir at 2 km depth. We assumed only one seismic source and a geophone array of variable spacings at the ground surface. The result of simulation gave a precise retrieval of image. For the simulated case, 200 m spacing is enough to resolve the target. In addition, we demonstrate the effect of physical property change in the nearsurface layer which causes interference in imaging of the deep target. Truncating surface-wave components in the residual waveforms could reduce the effect. The applications of our method to the real fields might greatly contribute to reduce the installation and time-lapse monitoring costs.
-
-
-
Microseismic Monitoring Results from CO2 Storage Operations at Quest
Authors V. Oropeza Bacci, S. O'Brien, M. Anderson, K. Dahlby and N. HendersonThe Quest carbon capture and storage (CCS) project is a fully integrated CCS project developed as part of the Athabasca Oil Sands Project (AOSP), a joint venture between Shell Canada Energy, Chevron Canada Limited, and Marathon Oil Canada Corporation. Although Quest is considered to be in an extremely quiet tectonic location, induced seismicity has been recognized as a potential risk in all large scale injection sites. As a result, microseismic monitoring is a key component of the MMV Plan to ensure the continued assessment of that risk and to provide early notice of any changes. This paper presents the results of passive monitoring at the Quest site through 2016, including the pre-injection baseline period, and the confirmation of the operational sensitivity of the array.
-
-
-
Integrating Active with Passive Seismic Data to Best Constrain CO2 Injection Monitoring
Authors B.P. Goertz-Allmann, M. Jordan, R. Bauer, V. Oye and S.E. GreenbergThe Illinois Basin - Decatur Project (IBDP) is to date one of the largest CO2 sequestration projects in the United States. So far, 1 Mio tonnes of CO2 have been injected over 3 years into the Mt. Simon sandstone formation at about 2 km depth. A suite of various active and passive seismic monitoring techniques have been applied at the site, providing a rich monitoring dataset. Time-lapse 3D surface seismic and VSP measurements were carried out to delineate the progression of the CO2 front. In addition, passive seismic monitoring revealed over 10’000 microseismic events. As a novel method, we attempt to combine the active and passive seismic data for seismic tomographic inversion for the 4D velocity- and attenuation structure in the reservoir. The combined aperture and higher resolution focuses on the reservoir and may allow a more precise mapping of the injected fluid over time. To investigate 4D changes of velocities and attenuation a similar source and receiver distribution is required. This is a particular challenge for microseismic events. High microseismic event location accuracy is essential, which we intend to improve by near surface material characterization, both from downhole petrophysical logging and seismic velocity logging within newly drilled shallow wells.
-
-
-
Joint Inversion for Improved CO2 Monitoring at the Ketzin Pilot Site, Germany
Authors M. Jordan, D. Rippe, C. Schmidt-Hattenberger and A. RomdhaneIn this paper we present the joint inversion method, its implementation, and first results of the application using synthetic FWI and ERT data sets for a realistic Ketzin model. This synthetic model was designed to capture the main features of the geology at the Ketzin pilot site and includes a hypothetical CO2 distribution, based on reservoir modelling. Our goal is to improve imaging and quantification of the injected CO2 at the Ketzin pilot site, as well as to improve knowledge about CO2 storage at Ketzin. Using real field data, we aim to mature the joint inversion technology further towards large-scale CO2 storage applications.
-