Finding, developing and exploiting oil and gas reserves hinges on continuous performance improvement, prudent technology applications, ongoing cost structure reductions and capital efficiency. Drilling and completion costs continue to be a major percentage of field development costs. With over 300 commercial installations in place, solid expandable tubular technology has proven to be a viable and economically feasible alternative to conventional drilling technology. This installation legacy, the evolving technology and applications spectrum and the omni-present need to "lower lifting cost and maximize recovery" have provided the impetus for the latest step-change toward the one-trip section, single-diameter wellbore.

The whole is greater than the sum of its parts. This truism is evident in the configuration for the latest test that validates individual components and the subsequent subsystem that will ultimately bring the single-diameter well to fruition. In addition to the unique equipment needed to expedite this game-changing technology, new processes, procedures and contingencies had to be developed and tested as well.

This paper will explain the overall design and testing approach and implementation essential in realizing the tool components, sub-systems and system necessary for the construction of a single-diameter well. The test program will be detailed as well as the results of the field trial. The paper will conclude with how this test and the resulting base building blocks will be used to fundamentally impact and facilitate changes in the dynamics of well construction.


The installation of successive single-diameter expandable liners will revolutionize the way many industry wells are designed and executed. The potential cost savings of an ultra-slim wellbore with smaller rig, reduced cuttings, smaller environmental footprint and maximized reservoir potential has been well documented.1, 2 What has not been fully delineated or explored is the full enabling possibilities of the technology in full blown field developments. This approach improves project economics in a variety of field development applications. Single-diameter technology offers the following benefits:

  • significant increases in potential lateral reach

  • large reduction in drilling-related risk and trouble time

  • vast improvements in capital efficiency on drilled wells and overall field development

This technology allows enhanced field-development flexibility and cost-structure reductions in many worldwide field developments. For example, increasing lateral reach and thus reservoir contact and drainage creates the potential for reduced well count and greater production/well. Reduced trouble time and risk lowers drilling costs. This drilling optimization can result in lower facility and project capital requirements and/or deferrals by allowing improved platform or subsea facility installation flexibility and phasing, while meeting project production goals with higher delivery or productive single-diameter wellbores.

Extensive and progressive testing by Enventure and Shell has rapidly improved single-diameter technology. This system is expected to be fully commercialized in 2006 with additional testing for an international operator and subsequent field development installations in 2005 and beyond.

Field Applications

The use of single-diameter expandable casing technology has the field-proven potential of significantly reducing a project's drilling and completion cost structure.

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