Expanding Solutions for Improved Performance
Solid expandable technology continues to broaden its potential with applications that produce significant performance improvements such as attaining zonal isolation without cement while retaining hole size. An operator was two years into a multi-well drilling campaign with 40 installations of the 6 x 7-5/8 in. solid expandable openhole liners for a slimmer well profile. This slim well design enabled the use of 10-3/4 in. surface casing while still reaching TD at approximately 15,000 ft with 4-1/2 in. casing. Although this design improved the rate of penetration and reduced overall drilling costs approximately $1M per well, the operator wanted to build on the success and increase the benefits. Formation characteristics and solid expandable tubular efficiency enabled employing swellable elastomers in the hard rock and eliminating the need for underreaming and cementing. Zonal isolation was achieved by setting the elastomers at the shoe of the expandable liner. The operator estimated that by dispensing with underreaming and cementing, an additional four to six days of rig time was saved. Novel applications use the technology’s hole conservation and zonal isolation capabilities to create better fracture stimulations, improve completions, and increase recovery. In a recent 2008 installation to maximize production ID for a multi-zone fracturing operation, an expandable system with swellable elastomers provided both the production conduit and zonal isolation. The system improved perforating efficiency, optimized coil and annulus flow area, and enabled higher injection rates and better fracture initiation. This paper explains why re-evaluating how to use solid expandable tubulars benefits drilling and completion operations. Case histories are used to illustrate the increasing application realm of solid expandable tubulars. This paper also describes how incorporating these systems into the initial well design optimize the possibilities and potential of the technology.