Pevzner, Roman (Curtin University) | Urosevic, Milovan (Curtin University) | Popik, Dmitry (Curtin University) | Tertyshnikov, Konstantin (Curtin University) | Correa, Julia (Curtin University) | Kepic, Anton (Curtin University) | Glubokovskikh, Stanislav (Curtin University) | Ziramov, Sasha (Curtin University) | Gurevich, Boris (Curtin University) | Caspari, Eva (University of Lausanne) | Shulakova, Valeriya (CO2CRC and CSIRO) | Dance, Tess (CO2CRC and CSIRO) | Singh, Rajindar (CO2CRC ltd.)
Seismic monitoring has been successful in monitoring of large injections (millions of tonnes) of CO2 into the subsurface for several production-scale carbon capture and storage (CCS) projects (Chadwick et al., 2009, Ringrose et al., 2013). Pilot small-scale projects are required to investigate different aspects of CO2 geosequestration. The purpose of our study is to check the lower limits of CO2 amounts detectable by a meaningfully designed surface seismic monitoring program. An onshore 4D seismic experiment is performed with the aim of monitoring of a small scale borehole injection of supercritical CO2 into a saline aquifer at 1.5 km depth. The injection is done by CO2CRC in the framework of Stage 2C of Otway project in early 2016. The operations take place in Australian state Victoria. To increase signal to noise ratio and repeatability, a receiver array is installed at 4 m depth under the surface. The acquired time-lapse data is processed using model-guided approach. The final time-lapse seismic images show that an injection as small as 5,000 tonnes can be confidently detected via seismic monitoring from surface.
Presentation Date: Thursday, September 28, 2017
Start Time: 11:00 AM
Presentation Type: ORAL
A devastating rainfall, commencing on 13 May 2014, resulted in extensive flooding of Serbia, Bosnia and Herzegovina (BiH). Several days after the torrential rainfall a hundreds of landslides developed.
To investigate the landslides a suite of geophysical methods including reflection, refraction, Multi-channel analysis of surface waves (MASW) and Electrical Resistivity Tomography (ERT) were deployed. Seismic reflection surveys are deployed to map layers geometry and discontinuities. MASW to help with geotechnical properties. ERT to bring lithological information into the analysis.
Electrical Resistivity Tomography (ERT) is routinely used for the near-surface exploration of landslide areas. However, it rarely used in a time-lapse manner which is of interest for investigation of potential landslide reactivations and the mechanism of reactivation. This paper presents the results obtained from time-lapse 2D ERT (TL-ERT) for the investigation of landslides. Repeated 2D surveys are carried out to detect temporal (seasonal) changes of the content of fluids and to more fully understand influence on resistivity of the subsurface.
Presentation Date: Tuesday, September 26, 2017
Start Time: 9:45 AM
Presentation Type: ORAL
Dou, Shan (Lawrence Berkeley National Laboratory) | Ajo-Franklin, Jonathan (Lawrence Berkeley National Laboratory) | Daley, Thomas (Lawrence Berkeley National Laboratory) | Robertson, Michelle (Lawrence Berkeley National Laboratory) | Wood, Todd (Lawrence Berkeley National Laboratory) | Freifeld, Barry (Lawrence Berkeley National Laboratory) | Pevzner, Roman (Curtin University) | Correa, Julia (Curtin University) | Tertyshnikov, Konstantin (Curtin University) | Urosevic, Milovan (Curtin University) | Gurevich, Boris (Curtin University)
We present an analysis of a field dataset demonstrating the combined use of a permanent surface orbital vibrator source (SOV) and a trenched fiber-optic cable sampled using distributed acoustic sensing (DAS). We examine SOV signal characteristics, repeatability, and wavefield decomposition for a short duration test. We show the SOV source to have excellent spectral repeatability but asymmetric response depending on spin direction. Wavefield decomposition tests demonstrate that the rotating source can effectively be decomposed into equivalent horizontal and vertical forces, well-suited to isolation of wavefield components. Finally, quantitative analysis of repeatability metrics normalized rms difference (NRMS) and predictability (PRED) show that wavefield phases with sufficient signal-to-noise ratio (S and surface waves) have high repeatability. The combination of SOV & DAS appears to be a promising approach for high temporal resolution time-lapse monitoring efforts in a variety of contexts.
Presentation Date: Monday, October 17, 2016
Start Time: 4:10:00 PM
Location: Lobby D/C
Presentation Type: POSTER
Khoshnavaz, Mohammad Javad (Deep Exploration Technologies Cooperative Research Centre and Curtin University) | Chambers, Kit (Halliburton) | Bóna, Andrej (Curtin University) | Urosevic, Milovan (Curtin University)
Passive seismic events are generally made by fault displacement, drilling, and hydraulic fracturing during high-pressure fluid injection into boreholes. There are two general configurations of seismic receiver arrays for passive seismic event monitoring: surface and down-hole. Surface arrays provide a larger aperture and hence greater coverage of the focal sphere in comparison to down-hole arrays. However, surface location techniques generally require knowledge of the velocity model to be known a priori. An alternative approach is passive seismic localization which is the procedure of identifying the focal point for the seismic wave field, which in many situations will coincide with the true source position. Whilst these procedures do require assumptions about the nature of the velocity model, it is not required to be parameterized a priori. In this paper, we propose a surface passive localization technique which is applied to both 2D synthetic and 3D field data examples. This work verifies that despite the approximations a reliable event location is achieved. The uncertainty of the proposed technique in the localization of passive seismic events using the bootstrap method was also studied.
Unlike active seismic imaging, passive seismic imaging does not depend on the use of a dedicated controlled seismic source. Earthquakes caused by fault displacement, micro-earthquakes (micro seismic) caused by hydraulic fracturing, and vibration generated by drilling, are considered as passive seismic sources. Analysis of the distribution of passive seismic events has proved a useful tool in mining exploration as well as unconventional reservoir development in oil and gas industry (Chambers et al., 2014). It has been used in the mining industry for over a century with different applications: a) estimating seismic velocity down the bore hole in seismic-while-drilling methods (Sun et al., 2014), b) monitoring mining-induced seismicity for the management of hazards in deep hard rock mines (Mikula et al., 2008) and c) detecting the position of drill-bit in the subsurface, such as in the case of coil tube (CT) drilling, when there is uncertainty about the position caused by the flexibility of the tube (Mokaramian and Rasouli, 2013).
There are two methods of passive seismic monitoring: down-hole and surface (Maxwell et al., 2010). Surface passive monitoring provides higher fold and wider aperture above the desired target and allows the possibility of monitoring larger volumes (Chambers, 2010, Duncan and Eisner, 2010). The intrinsic S/N for this technique is low but post-stack S/N can be vastly improved with the fold of the data. However, accuracy of location algorithms depends on the subsurface velocity model which is often not available (Pavlis, 1986).
Pevzner, Roman (Curtin University, CO2CRC) | Tertyshnikov, Konstamtin (Curtin University, CO2CRC) | Shulakova, Valeriya (CSIRO, CO2CRC) | Urosevic, Milovan (Curtin University, CO2CRC) | Kepic, Anton (Curtin University, CO2CRC) | Gurevich, Boris (Curtin University, CSIRO, CO2CRC) | Singh, Rajindar (CO2CRC)
Stage 2C of the CO2CRC Otway project aims to demonstrate the stabilization of a gas plume following the injection of approximately 15,000 tonnes of CO2-rich gas mixture into the saline aquifer and examine the capabilities of 4D seismic to detect and track the plume in the subsurface. The ability to detect and monitor the plume is controlled by both strength of the signal and level of the time-lapse noise. Extensive modeling and field trials show that the use of buried receiver arrays for long-term monitoring of the CO2 geosequestration has the potential to reduce both land impact for landowners and cost impact to the project.
To this end, a buried receiver array was designed and deployed at the CO2CRC Otway site. The array comprises ~900 high-sensitivity geophones deployed at 4 m depth below the surface. Preliminary benchmark tests show a significant improvement in raw data quality compared to surface geophones.
Absence of cables and other seismic infrastructure on the surface (with the exception of eleven cross-line boxes) significantly reduces the impact of the survey on farming activities as only the sources will need access to the farmland for the future monitor surveys.
The CO2CRC Otway project is the first Australian demonstration of safe geological storage of carbon dioxide. The first stage of the project, concluded in 2010, was focussed on injection of more than 66,000 tonnes of CO2/CH4 gas mixture (~80% of CO2, we refer it as Buttress gas, according to the name of gas field from which it is produced) into depleted gas reservoir located at approximately 2 km depth through a purposely drilled CRC-1 well. An extensive time-lapse seismic program was rolled out to prove absence of leakage and test various seismic monitoring techniques (Gurevich, et al., 2014). The program evaluated performance 4D surface seismic, 4D VSP, repeated surface 2D and offset VSP surveys (Pevzner et al. 2010; 2011). Significant field and numerical efforts were devoted to establishing the level of seismic repeatability at this site. Tests included variety of seismic sources and acquisition geometries (Pevzner et al., 2010), including surface and borehole ultra-high resolution seismic arrays (Al-Jabri and Urosevic, 2011).
Pevzner, Roman (Curtin University) | Galvin, Robert J. (Curtin University) | Madadi, Mahyar (Curtin University) | Urosevic, Milovan (Curtin University) | Caspari, Eva (Curtin University) | Gurevich, Boris (Curtin University) | Lumley, David (University of Western Australia) | Shulakova, Valeriya (CSIRO) | Cinar, Yildiray (University of New South Wales) | Tcheverda, Vladimir (Trofimuk Institute of Geology)
Ditkof, Julie (Bureau of Economic Geology) | Meckel, Tip (Bureau of Economic Geology) | Hovorka, Susan (Bureau of Economic Geology) | Caspari, Eva (Curtin University) | Pevzner, Roman (Curtin University) | Urosevic, Milovan (Curtin University)
Malehmir, Alireza (Uppsala University) | Juhlin, Christopher (Uppsala University) | Wijns, Chris (First Quantum Minerals Ltd) | Urosevic, Milovan (Curtin University) | Valasti, Petri (First Quantum Minerals Ltd) | Koivisto, Emilia (University of Helsinki) | Paananen, Markku (Geological Survey of Finland) | Kukkonen, Ilmo (Geological Survey of Finland) | Heikkinen, Pekka (University of Helsinki)
Pevzner, Roman (CO2CRC and Curtin University of Technology) | Bona, Andrej (CO2CRC and Curtin University of Technology) | Gurevich, Boris (CO2CRC and Curtin University of Technology) | Yavuz, Ismail (CO2CRC and Curtin University of Technology) | Shaiban, Ali (CO2CRC and Curtin University of Technology) | Urosevic, Milovan (CO2CRC and Curtin University of Technology)