Part One

Part Two

Underbalanced drilling (UBD) has evolved from a drilling technique  into a reservoir exploitation tool. The primary benefits of UBD driving its increasing consideration are enhanced productivity through mitigation of invasion damage, and reservoir characterization using UBD data. However, selection and valuation of UBD candidates still remains a largely arbitrary and heuristic process. In this lecture, we present a rigorous, reservoir-based probabilistic approach to evaluate the UBD candidature of a reservoir.

The benefits and risks (particularly contra-indicators) of UBD are first articulated through numerous examples. The emerging art of reservoir characterization using UBD data is also presented with examples.  Since the fundamental premise of UBD is that it mitigates damage, it is important to first characterize the damage from conventional drilling, and evaluate the potential for UBD to improve performance.  We present a novel approach that combines special core tests with dynamic invasion modeling using fine-grid simulators to assess invasive damage and its impact on production. We also illustrate this using movies that show invasive damage.

Finally, we present a rational valuation approach that uses probabilistic productivity estimation tools together with unstructured-grid simulation methods to obtain production curves expected when UBD is applied. Use of these methods in appropriate candidate selection is discussed. The lecture provides a broad coverage of recent developments in reservoir application of UBD.

BladeCast

Is Underbalanced Drilling the Right Answer for your Reservoir?

 

A video podcast

Presented by Suri Suryanarayana

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203.7 MB (32m11s)

179.4 MB (28m52s)

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