As underbalanced drilling becomes a mature technology in the Western Canadian Basin more underbalanced horizontal and vertical wells are being drilled in pressure depleted reservoirs. The timing is now right to investigate how this technology can be expediently applied in domestic and overseas markets. Many operators understand the concept of underbalanced drilling but do not understand the ‘process’ of gaining that knowledge, research, equipment and personnel to drill their own particular reservoirs underbalanced. This paper sets out to look at the basic procedures of putting together an integrated team and the steps required to take any reservoir from its present status to an improved condition by building cross functional units with the ultimate goal of applying the technology correctly. Included in the paper are updated procedures for handling underbalanced drilling occurrences using the engineering processes developed by the cross functional team for both onshore and offshore underbalanced drilling operations.


At the time of writing there have been more than 800 wells drilled underbalanced in the Western Canadian Basin, with the prospect of passing the 1000 mark over the winter drilling season. Most of these wells have been drilled with jointed pipe though there has been a significant emergence of coil tubing drilling technologies as an alternative approach to conventional underbalanced drill pipe techniques. The unique position that underbalanced drilling finds itself in Canada is the fact that the technology has been applied in many different types of reservoirs making the Western Canadian Basin a real life laboratory to look at operations first hand. New Operators and visitors can investigate the Western Canadian Basin to gain firsthand knowledge of how, why, when, and where this technology is being applied and get an up-front look by participating in a field trip to an actual operation as a direct result of the various Canadian operators and service companies willingness to share their ideas methods technology and results with other domestic operators and the rest of the world. As a reservoir driven technology, one is attempting to recover more hydrocarbons by correctly applying modern drilling techniques. In this regard the underbalanced drilling has moved into phase 2 of the evolution process where instrumentation and control both downhole and at surface have become major tools for the successful implementation of this state of the art drilling process. From these control processes, the data accrued during drilling and the post drilling analysis, a substantial knowledge base has been developed which has greatly assisted both the operators and the service companies to further improve on the underbalanced drilling results. The question now arises, having applied the technology correctly in various fields in Canada what are the benefits to applying this technology in more reservoirs domestically and various foreign oilfields. The true success results from a learning process which involves the building of correct cross-functional teams with highly motivated personnel who focus on their own reservoirs and come up with a system that will get their drilling solutions and reservoir optimization programs from A-Z in a timely and cost effective manner.

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