Highly deviated or horizontal wells are usually drilled to improve the productivity of a field where long-term zonal isolation is essential to helping ensure the economic viability for the life of the well. This paper describes the use of two new technologies designed to help improve zonal isolation in extreme conditions of the well:
Cement with elastic and self-sealing properties to help prevent the formation of a microannulus and help ensure complete zonal isolation. This is accomplished either by resilient deformation while the cement is under stress or by swelling of additives in the cement when in the presence of hydrocarbons, depending on the situation of the well.
A swellable packer tool (water swellable), located just below the upper aquifers.
This paper discusses the application of cementing technologies that can be used to minimize interventions for maintenance, and possibly prevent the need to repair unwanted communication between zones. This study also is complemented with simulations based on finite element analysis (FEA), which helps predict the various stresses that the cement sheath will be subjected to during the life of the well and help identify the mechanical properties that the cement sheath will need to prevent cement failure in the stages of curing, pressure testing, hydraulic fracturing, completion, and during production of the well.