Abstract
We develop a methodology, based on rock-physics templates, to effectively identify reservoir fluids in ultra-deep reservoirs, where the poroelasticity model is based on the double double-porosity theory. P-wave attenuation, the ratio of the first Lamé constant to mass density (λ/ρ) and Poisson ratio are used to build the templates at the ultrasonic and seismic frequency bands to quantitatively predict the total and crack (soft) porosities and oil saturation. Attenuation on these frequency bands is estimated with the spectral-ratio and frequency-shift methods. We apply the methodology to fault-controlled karst reservoirs in the Tarim Basin (China), which contain ultra-deep hydrocarbon resources with a diverse pore-crack system, low porosity/permeability and complex oil-water spatial distributions. The results are consistent with well-log data and actual oil recovery. Crack porosity can be used as an indicator to find regions with high oil saturation, since high values implies a good pore connectivity.
Highlights
With the depletion of relatively shallow conventional reservoirs, ultra-deep resources will become an important target for oil and gas exploration
Attenuation, Poisson’s ratio, and λ/ρ can be obtained from seismic data, and a quantitative prediction of total porosity, crack porosity, and oil saturation can be achieved by overlapping the data on the template
We have implemented a double double-porosity theory to build Rock-physics templates (RPT) in order to estimate the properties of deep carbonate reservoirs
Summary
With the depletion of relatively shallow conventional reservoirs, ultra-deep resources will become an important target for oil and gas exploration. We choose P-wave attenuation, Poisson’s ratio and the ratio of the first Lamé constant to mass density (λ/ρ) to build the templates at ultrasonic and seismic frequencies, based on the DDP theory, and associate the total and crack porosities and oil saturation to the seismic properties. Attenuation, Poisson’s ratio, and λ/ρ can be obtained from seismic data, and a quantitative prediction of total porosity, crack porosity, and oil saturation can be achieved by overlapping the data on the template. The storage space of fault-controlled karst reservoirs is formed by the dissolution of water or These findings are consistent with the actual characteristics of the reservoirs, indicating that the proposed method can be successfully applied
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
