Integration of well and seismic data is a key component of optimal reservoir characterization for field development. In a green, partially appraised ultra deepwater field with few wells, the proper use of well data as calibration points for the seismic data becomes more important. The workflow can be complicated in instances of multi loop reservoirs with differing AVA signatures. An alternative to existing workflows is required for such reservoirs.

The current integrated workflow involves carrying out seismic inversion for reservoir properties; this is typically done for each reservoir model because of rock property differences between reservoirs. Reservoir properties are estimated from inverted PImpedance and S-Impedance through the use of rock property models. The rock models describe how the reservoir PImpedance and S-Impedance changes with variations in a particular reservoir property, such as net:gross or porosity.

With reservoirs of differing Amplitude Variation with Angle (AVA) signatures, different rock models must be applied to the inverted P and S-Impedance to generate varying versions of the same reservoir property, e.g. the rock model of an acoustically hard low porosity sand will vary from an acoustically soft high porosity sand. The varying version of the reservoir property will then be applied to different portions of the reservoir model.

While seismic inversion gives a non-unique solution, the integration of well data allows for derivation of a technically best fit solution, as well as an estimate of the associated uncertainty. The resulting inversion aids in the building of a reservoir model that honours geophysical, petrophysical and geologic data. This paper will present how the integration of well and seismic data was used to optimally characterize an offshore green field development and create a fit-for-purpose reservoir model.

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