First multi-well simultaneous vertical seismic profiling project to assist in monitoring enhanced oil recovery
OptaSense, the global leader in Distributed Acoustic Sensing (DAS), has contracted with Petroleum Development Oman (PDO) to provide the industry’s first multi-well 4D DAS vertical seismic profiling (VSP) system.
OptaSense will deploy its industry proven DAS fibre-optic technology to monitor and map the performance of up to 12 steam-injected oil wells in a brownfield development at South Oman Salt Basin. The service contract for time-lapse measurements is for three years, with a further two optional years and scalable scope of work, for deployment in multiple production settings.
Salim Rawahi, PDO GeoSolutions Manager said: “We see this as a start of deployment of DAS technology in different reservoir monitoring programmes in PDO ranging from 4D, micro seismic to fluid flow measurements. The versatility of the fibre-optic technology will not only provide us with potentially more accurate data in different hostile subsurface environment, but will also provide us with a means of measuring different reservoir and fluid properties simultaneously”.
OptaSense will record seismic signals from fibre-optic cables attached to each well’s production tubing, permanently installed and linked to a surface data gathering centre. The final processed data set will be integrated into PDOs reservoir models, and assist in the determination of fluid substitution through production and hence contribute towards the positioning of infill wells.
Vertical Seismic Profiling (VSP) in 3D is a recognised alternative to surface seismic data acquisition in challenging environments of accurate subsurface imaging. Weighed against the use of geophones, OptaSense’s DAS technology provides benefits in 3D VSP which include:
- Low-cost on-demand acquisition: permanent cable installation allows VSP delivery at any time significantly simplifying time-lapse measurements
- Non intrusive: slim line cables can be deployed in wells inaccessible to geophones, with no well intervention required once the fibre-optic cable is installed
- Synergies with other systems and retrofitting capabilities: existing fibre-optic cabling can be used for VSP
- Full vertical coverage: the DAS cable extends over the entire length of a well, allowing for increased lateral imaging
- Simultaneous VSP acquisition of multiple contiguous wells, without the need to repeat surface source effort.
OptaSense Managing Director Magnus McEwen-King said: “This contract is a key milestone for OptaSense and for the acceptance of DAS as a highly accurate, cost effective solution in seismic monitoring. Above all it represents a breakthrough to enhanced oil recovery, where well infrastructure can create significant challenges to surface seismic data capture and geophones provide only limited well cover. In this situation, only DAS-VSP is capable of delivering a field-scale commercial application by providing accurate coverage of multiple wells.”
OptaSense’s DAS technology is deployed in a wide range of applications in the oil and gas industry including hydraulic fracture profiling, production flow monitoring and VSP. The company’s business focus is on delivering innovation in hardware performance, software and data interpretation and it is transforming the industry’s ability to understand, in real-time, activity along the well bore and beyond.