Casing and liner drilling is widely regarded as a method to overcome challenges related to formation instability. Its use and experience is gradually gaining foothold as its benefits and functionality in many cases can be the solution and risk mitigation to overcome some of the Oil & Gas industry's challenges related to drilling wells with narrow drilling margins, depletion and formation instability challenges in traditional well construction.
The technology has now been matured over the last 5+ years and, even though the full potential has yet to be fully explored, several "un-drillable" wells have been made drillable by using its ability to combine the drilling and logging in complex 3D wells while simultaneously securing the wellbore.
The second generation of the technology is currently being field trailed as 7in system, but several different configurations are already available, including a 6 × 8 ¾″ Integrated Underreamer, inner BHA repositioning functionality to remove 6″ rathole for the BHA along with several simple but very robust solutions for liner reaming purposes.
The traditional Steerable Drilling Liner System (SDL) is available for 8 ½ and 12 ¼″ holes sizes, whereas the second generation will initially be available for 8 ½ – 8 ¾″ hole sizes.
This paper will focus on benefits and experiences from using the technology along with an update on the new features that is gradually being made available as part of the second generation SDL technology.