A field study to assess the value of 3D post-stack seismic data in forecasting fluid production from a deepwater Gulf-of-Mexico reservoir

This dissertation describes a study undertaken to appraise the reliability of spatially complex hydrocarbon reservoir models constructed with the use of 3D post-stack seismic amplitude data and well logs. Developments center about the interpretation of data acquired in an active hydrocarbon field in the deepwater Gulf of Mexico. The availability of measured time records of fluid production and pressure depletion provides an independent way to quantify the accuracy and reliability of several methods commonly employed to construct static reservoir models. We make use of geostatistical inversion to construct spatial distributions of porosity and permeability that simultaneously honor well logs and 3D post-stack seismic amplitude data. The constructed reservoir models are compared against models constructed with standard geostatistical procedures that do not make use of seismic amplitude data or else that use a simple statistical correlation between reservoir properties and seismic-inverted acoustic impedances. We perform multiphase fluid-flow simulations to assess the consistency of the constructed reservoir models against the measured time record of flow rates of gas/water and shut-in well pressures. For the hydrocarbon field under consideration, the joint stochastic inversion of well logs and 3D post-stack seismic amplitude data consistently yields the closest match to dynamic measurements of fluid production and pressure depletion. Our study also compares the influence of petrophysical and rock fluid parameters on the reliability and accuracy of the predicted fluid production against the influence of spatial variability of porosity and permeability.