Full Field Fracture Characterization and Compositional Dual Porosity Modeling of a Complex Fractured Volatile Oil Reservoir Sen Field, Mexico

Sen Field is a highly faulted and fractured volatile oil reservoir.  In terms of connectivity it is highly anisotropic, and the level of anisotropy varies areally in the field.  The matrix is very tight and it is mostly filled with water.  The matrix contribution to the oil production is not significant.  The fluid storage and flow are governed by the fractures and vugs that are present in the field.  Considering the factors that influence the oil recovery, the determination of the fracture distribution and connectivity became the primary focus of the reservoir characterization effort.

The necessary data (outcrop studies, FMI logs etc) required by the existing commercial fracture characterization software was not available for the Sen Field.  Therefore an alternative method was developed for fracture characterization.  The method utilizes the available data and provides a reliable fracture characterization that can be used in the reservoir simulation directly.  Based on the fracture characterization work, a dual porosity compositional simulation model was built to simulate the flow behavior of the field.

Since the reservoir pressure remained above the bubble point pressure, the observed static well pressure and the water cut data were used as the control points for the history matching exercise.  An excellent history match was obtained especially considering the steep water cut profiles that are historically observed in the wells.

In this paper we present the fracture characterization technology that was developed and the key history matching parameters of the numerical simulation model.