Today's oil and gas sector is dealing with huge disruption on multiple fronts, including fluctuating oil prices driven by economic shocks, unprecedented demand drop due to COVID-19, more geologically complex fields, and the pressure from governments to take targeted action to tackle climate change.
To address these challenges, the oil and gas industry has entered an era defined by an atypically fast technology and innovation-led transformation. One such innovation is the advent of distributed fibre optic monitoring solutions for the world’s most demanding data acquisition challenges. Today’s systems are capable of 20dB or 100x improvements in signal to noise ratio compared to existing DAS (distributed acoustic sensing) systems. This improvement goes beyond incremental improvement for existing use-cases: it unlocks several new basin-specific solutions that have not been possible before.
Step-change in performance delivering cost-savings and environmental benefits
The significance of this step change in performance is most acute in applications with low acoustic signal levels such as is common with leak detection and production monitoring, where acoustic information can be present at, or below, the inherent system noise floor of the current technology and therefore difficult to detect.
Borehole seismic applications stand to benefit from greatly reduced source effort required to achieve high quality, densely sampled seismic data leading to significantly reduced operating time and costs. The higher sensitivity also paves the way for passive seismic and microseismic monitoring, enabling cost-effective real-time and/or continuous monitoring in several applications.
A permanently installed DAS system will give access to actionable information throughout the life of an asset. For in-well operations this translates as increased safety and substantial cost-savings as the fibre array can be used for multiple applications throughout the well life, delivering reliable in-well diagnostics without the need for costly intervention. Applications include 4D seismic, well-integrity and flow-profiling. This immediately reduces OPEX, and the system will deliver answers on-demand, if required remotely, without interrupting production. Eliminated downtime can be measured in the millions. As the fibre is the sensor, it offers full wellbore coverage, delivering ULTRA HD data along the entire length of the fibre, eliminating possible errors that could compromise well integrity when using point sensors, hence increasing the safety of operations.
Cost savings and environmental benefits are most substantial in permanent seismic applications. Such systems’ sensitivity enables seismic both offshore and onshore with lesser source effort or fewer shots. In marine seismic applications the reduction in costs can be in the millions and the environmental aspect is invaluable.
Lack of subsurface information typically creates a recovery factor gap from 7-15% between fields with subsea wells vs platform developments. Performing interventions in subsea wells is costly and risky, so production logging or Vertical Seismic Profiling is seldom performed. This leads to a lack of data to improve operational decisions. High-resolution reservoir imaging to enable accurate well placement in subsea fields, where wells are sparse and costly, is even more valuable. In fact, permanent ultra HD in-well seismic data for subsea tie-back allows operators to significantly improve their decision making, unlocking hundreds of millions of dollars of previously untapped potential.
A fibre optic cable is permanently installed with the well completion, enabling ultra-high definition 4D seismic data acquisition, on demand, along the entire subsea wellbore and throughout the well life, without additional operational costs and risks. Existing telecoms fibres in umbilicals can be accessed to bring data to a topside facility. This allows operators to perform more frequent seismic acquisitions on-demand at a much lower cost, enabling them to improve well placement, accelerate production and increase ultimate recovery.
A game-changing solution redefining shale operations
These advancements can be applied elsewhere in the oil and gas sector, such as the unconventionals energy market. Fibre-optic sensing can be used to create crosswell low frequency strain and microseismic monitoring services that accurately locates microseismic and strain events in real-time through wireline intervention. This enables operators to improve stimulation and completion designs on the fly. This can dramatically alter the ultimate recovery with a variance of 30% or higher.
By recording microseismic in real-time and integrating it with strain measurements, this approach allows for a more comprehensive understanding of the total stimulated reservoir volume. This in turn helps operators understand the development of Frac corridors between active and passive wells and enables them to optimise treatment designs and well spacing at a lower risk and a lower price than permanent fibre optic installations.
At a time when the industry is still reeling from the aftershocks of the pandemic and associated oil price crash, operators of both conventional and unconventional plays are looking for ways to safely and cost-effectively get the most out of their assets. Anything less constitutes an unacceptable business risk in the current climate. No doubt there will be various solutions or processes operators can invest in to help that goal, but a good place to start is always a profound understanding of assets and their operations – and that means pushing the previous limits of data acquisition. After all, better data means better decisions.
Read the article online at: https://www.oilfieldtechnology.com/special-reports/30112020/fibre-optic-innovation-revolutionising-oil-and-gas/