An integrated workflow to reservoir characterisation<br>providing direct input to the reservoir model of the Muda-Tapi and Jengka Fields

An integrated workflow was designed by CPOC and Odegaard to produce high quality 3D inputs to be used in the reservoir modelling of the Muda-Tapi and Jengka fields located within MTJDA. The detailed workflow is shown in Figure 1 but can be summarised into the following key stages:<br>-Petrophysical and rock physics analysis.<br>-Simultaneous AVO inversion.<br>-Lithology/fluid probability classification.<br>-Reservoir modelling.<br>It is essential to have reliable and quality controlled well log suites when embarking on an AVO inversion and lithology prediction study. Hence, the project was initialised by evaluating the petrophysical data available with a focus on the elastic properties of the reservoir intervals. The petrophysical analysis involved log editing, volume of clay interpretation, porosity and water saturation calculations on a total of sixteen different wells. Accurate volume of clay interpretations are the corner stone to the overall well log interpretation as they influence the porosities and saturations. A dual VCL indicator was utilized by using the gamma ray log and neutron versus density crossplots and this produced a set of VCL estimates which were consistent among wells. These resulting curves are then used to define the different lithologies and the fluids they contain in the reservoir interval.