Vurdering av seismisk AVO-respons i slumpområder Classification: Statoil internal Status: Draft I5B-segmentet Vurdering av seismisk AVO-respons i slumpområder

Top Cook depth map. Seismic profiles indicated as red lines L2881

Increasing amplitudes with offset indicates oilfilled reservoir Line 2881, I4 segment 1999 full stack mid near far Increasing amplitudes with offset indicates oilfilled reservoir Top Brent Top Cook Top Statfjord Yellow/red represents a decrease in acoustic impedance Base Crt.

Randomline, I4 segment 1999 full stack mid far near Note the opposite avo response due to the pressure effect (blue arrow) and oilfilled reservoir (red arrow) Top Brent Top Cook Top Statfjord Yellow/red represents a decrease in acoustic impedance Base Crt.

Top Cook depth map. Seismic profile indicated as red line L2995 Top Brent Top Cook Top Statfjord Yellow/red represents a decrease in acoustic impedance Base Crt.

Line 2995, I5B segment (prospect) 1985 1996 1996 1999 Top Brent Top Cook Top Statfjord Yellow/red represents a decrease in acoustic impedance Base Crt.

Line 2995, I5B segment (prospect), offset stacks 1985, full stack mid near far Top Brent Top Cook Top Statfjord Yellow/red represents a decrease in acoustic impedance Base Crt.

Classification: Statoil internal Status: Draft Cook-2 and Cook-3 How much does geological setting affect seismic response? Model the seismic response in a three-layer setting with varying thicknesses and fluids

How much does geological setting affect seismic response? Cook-2 and Cook-3 are very different reservoirs, both in a geological sense and from a production point of view Cook-2 is 50-60 meters thick, while Cook-3 is 15-50 meters thick, both thinning towards north In the east the formation is eroded by the BCU. We know that we can observe pressure build-up in Cook on 4D seismic We want to predict how water flooding will appear in the 4D seismic, but our model has probably been to coarse, mixing Cook-2 and Cook-3 properties

How much does geological setting affect seismic response? Cook-2 Cook-3 BCU Drake Shetland Interfaces Uneroded: Drake->Cook-3 “Uneroded”: Shetland->Cook-3 Eroded: Shetland->Cook-3 Eroded: Shetland->Cook-2 Fluids Brine, oil, gas Thickness variations Cook-2: 0-60 meters Cook-3: 0-50 meters Task: Determine the seismic response in a 3-layer model with varying thicknesses and fluids Get parameters from geomodel!