RIL to Improve Accuracy of 4D Seismic Acquisition

A further step towards improving the accuracy of 4D seismic using towed streamer acquisition for monitoring oil and gas reservoirs during production is being introduced this summer by Reservoir Imaging (RIL). 

RIL's 4D Specialist's are due to start using the new version of RIL's Osprey suite of 4D technologies around the world for major oil companies which for the first time addresses the impact of waves, current and weather on the movement of towed streamers during a survey so that repeat surveys can effectively follow the so called 'feathering' pattern of previous surveys. Osprey software is expected to produce more economic, better quality data for monitoring reservoir performance at some of the most important oil and gas fields worldwide. 

There is no question that 4D seismic is emerging as a significant tool in reservoir management allowing geoscientists and engineers to compare the imaging results of repeat seismic surveys to track the behavior of hydrocarbons in the reservoir during production. Demand for 4D projects has remained remarkably resilient over the last two years and is expected to grow this year. 

A key challenge in a successful 4D is for subsequent 'monitor' surveys to replicate the feathering of streamers from the baseline survey to ensure good repeatability. Up until recently a target feather had to be computed for each line, and then during acquisition the 4D survey contractor had to predict and then match this feather as closely as possible. 

Development of the RIL software coincided with recent industry advances in the ability to steer both sources and streamers which also offer new opportunities to optimize the accuracy of 4D surveys. As a result RIL is bringing in a second generation of tunneling software which enables optimal 4D repeatability by ensuring the streamers are steered down the center of the tunnels. This meets the repeatability requirement more efficiently and ensures future monitor surveys will also be easier to repeat. 

The RIL software is about to be applied this summer on a large number of 4D projects in the UK, Norway, Gulf of Mexico, West Africa and the Far East. 

Keith Watt, managing director, RIL, said, "The development of our next generation 4D tools offers a significant opportunity to both improve the quality of a 4D monitor survey and to acquire it in a more efficient and cost effective manner. We are looking forward to seeing our clients benefit from the new technology in their 4D projects over the next few months."