Abstract
Solid expandable liners have been used extensively over the past 10 years as drilling liners in the beginning to production liners in the recent years, where the expandable liner may become differentially or mechanically stuck as soon as it reaches the end of the planned wellbore section. This environment requires the liner to be cemented and expanded in one of the most (if not the most) challenging well conditions it can be subjected. The expandable liners discussed in this paper so far have shown most promising and successful field application status as production liners.
When an expandable liner that is not differentially stuck is expanded using a swage, it typically "shrinks" in length as it expands in diameter as part of material balance physics. This shrinkage is typically 4 to 6%. That is, if a 1,000 ft liner is expanded 5% in diameter, the expanded length would be reduced to ~950 ft. To compensate for this shrinkage, an additional length of liner is run to ensure that the final length of liner required is delivered. However, when the expandable liner becomes differentially stuck or cannot move along the length of the wellbore during expansion, it cannot gain the material for its growth in diameter from the liner's length. Therefore, the material volume change required is accommodated within the liner's wall and its connectors. This environment is considered one of the most strenuous a solid expandable liner can be subjected to during expansion.
By combining insightful engineering with a stringent qualification regime of the expandable system and the tubulars and connectors that it uses, solid expandable production liners can be installed successfully that will service these types of challenging wells.
While extensive engineering and lab testing of an expandable system is critical, the ultimate testing is in multiple field applications to best develop effective reservoir sweeping of a mature field. Several case histories of field installations will be reviewed in this paper. The installation, zonal isolation, and tubular performance of these liners will be evaluated and reviewed using downhole tubular inspection logs, observed installation phenomenon, and performance over time. This empirical data will give the potential end users fundamental knowledge and good case history information on how to best qualify and use solid expandable liners for the ultimate benefit of gaining more oil production and reducing overall well cost.
