Horizontal Well Placement Benefits of High Resolution Images in Real Time, Case Study from UAE

Recent advancement in Logging While Drilling (LWD) imaging helped to resolve challenges, related to complex heterogeneous carbonate formations, of both well placement and reservoir characterization.

The Upper Jurassic carbonate sequence, offshore Abu Dhabi is formed of 4th order regressive cycles of sedimentation. The sequence is divided into four main highly heterogeneous units namely; A, B, C and D that are multi-layered themselves. Field development plans of reservoir unit-B and C are based on drilling horizontal drains in the relatively thin reservoir units (4-6 Ft vertically thick) to compensate for their low-range petrophysical properties (Porosity-Permeability).

Real time resistivity images, in combination with other LWD logs, accurately detected formation dips and intra-layers features within the target reservoir. They also revealed the existence of a few major discontinuous conductive and resistive fractures which enabled timely decisions regarding both well placement and completion design.