The use of expandable screens simplifies completion procedures. Many operators perceive that screen performance depends on whether it is fully compliant with open hole; however, it is impossible to guarantee total compliance. Evidence indicates that, in addition to filling the micro-annuli and plugging the screen, mobile fines and sand have the potential to create hot spots and erode the screen, thus creating sand-production problems.
This paper presents laboratory results that illustrate the feasibility of applying a curable, low-viscosity composition to stabilize and strengthen unconsolidated formations. Overdisplacement is not necessary in this process. The composition forms a tacky, ultra-thin film, creating bonds between grains that cure with time and temperature once coated onto the surfaces of formation particulates. Unconsolidated formation sands, even those with high content of clay fines, were consolidated with negligible loss of initial permeability.
The results obtained from this study demonstrate the importance of stabilization of the formation. The screens, whether wire-wrapped, pre-packed, expandable, or simply slotted pipes, serve as a mechanical support to prevent collapse of the wellbore. A combination of treating unconsolidated formations with an ultra-thin, curable composition and installing a mechanical liner should provide an economical and reliable means for sand control. The use of such curable sand-stabilization treatments may therefore eliminate the perceived need for compliant expansion, placing a premium on the mechanical strength of the sand-control technique selected.