What to Expect
In carbon geosequestration projects, there is an essential need for effective monitoring of the carbon dioxide storage over decades to ensure safe containment of the CO2 plume in the reservoir. However, current seismic monitoring techniques usually involve a combination of various seismic surveys acquired using a large array of seismic receivers and moveable sources to image the emplaced gas plume. The complexity of such surveys results in expensive operations that are, at times, unviable for carbon geosequestration applications. Furthermore, errors in repeatability of source and receiver locations can limit its effectiveness. At the Otway Project, we are exploring the use of distributed acoustic sensing (DAS) combined with permanent surface orbital vibrators (SOVs) to acquire time-lapse seismic data at relatively low cost. DAS uses standard fibre-optic cables to form a series of distributed seismic receivers. Fibre-optic cables are relatively inexpensive, offer long durability and can operate in extreme conditions. In this presentation, I will show the applicability of using DAS technology for seismic imaging and permanent seismic monitoring in the context of CO2 geosequestration projects. Through the analysis of multiple DAS data sets, I demonstrate that DAS is the receiver of choice in many monitoring applications which would benefit from permanent receiver installation. DAS can outperform conventional geophones as a seismic sensor, particularly when used to conduct monitoring of the subsurface.
Julia is a Postdoctoral Researcher in the Energy Geoscience Division. Her research is focused on the use of fiber-optics sensing DAS and permanent surface orbital vibrators (SOV) for developing an alternative cost-effective monitoring system for application in CCS projects, unconventional reservoirs, and geothermal projects. She is involved in the optimization of acquisition and processing flows for DAS/SOV data, as well as in the development of new fiber-optic cable designs. Julia received her PhD in Exploration Geophysics from Curtin University, Australia. Her research focused on using distributed acoustic sensing (DAS) for seismic imaging and monitoring applied to the Otway Project. Before starting her doctorate studies, Julia worked as a Field Geophysicist with seismic acquisition and processing in projects offshore west Africa and Egypt. Julia received her BSc in Geophysics from Fluminense Federal University, Brazil.