Abstract
This paper discusses the successful development of thin/tight layers in a Middle Eastern field with a production history of more than 50 years supported by peripheral water injection. The reservoir is characterized as a carbonate formation and consists of four major layers, namely 1, 2, 3 and 4. Layers-2 and 3 constitute the main reservoir body and are the most prolific layers.
Layer-1, which is the focus of this paper, exposed to production using vertical wells, was not contributing due to its limited thickness and low reservoir quality compared to the other layers.
With the advancement in drilling and geosteering accurate well placement became a reality. Therefore, a multidisciplinary team proposed a pilot well targeting Layer-1 alone to exploit its potential. This pilot was an existing producer in an area where layers-2, 3 and 4 were swept and Layer-1 remaining oil saturation showed the most developed porosity thickness in the field. A geological model was built to evaluate various scenarios to ensure good planning and successful well placement. A proactive geosteering tool was exploited to confront well placement challenges. As a result, the well was drilled with 100% reservoir contact. Post-sidetracking performance was encouraging and opened new opportunities to develop this layer.
This achievement sets the beginning of a new milestone to improve recovery in this field. This paper discusses three major aspects related to this achievement. First, it highlights the pre-assessment of the target location. Also, it discusses the geosteering technology that was utilized to maintain the entire horizontal section across the target layer. Finally, it presents the production performance after the well re-completion.
