5 keys to the successful remediation of sustained annular pressure
Shahab Akhtar
Maintenance Manager (Wellhead) Offshore at National Iranain Drilling Company
As developed wells continue to produce, these completed assets undergo thermodynamic cycling consistent with the production life of the well. The constant loading on these wells induces stresses that are ultimately transmitted to the annular cement sheaths that were intended to provide isolation of formation fluids from the surface. If these cementitious barriers become compromised, integrity issues proliferate and transmit downhole pressures to the surface. These problems are exasperated if the primary cement job is compromised during initial placement due to such complications as losses. Channels and micro-annular leak paths are responsible for these phenomena of observed pressure at the surface.
To remediate these integrity challenges, the unconventional application of resins has proven to be a cost-effective solution for the restoration of isolation.
1. Ensure proper functionality of wellhead gate valves
2. Injectivity analysis and annular pressure diagnostics should be performed separately and ahead of schedule.
3. During annular diagnostics, every annulus should be monitored for any potential pressure response at the surface.
4. Always remediate sustained casing?pressure from inner annuli outwards.
5. Pneumatic-driven liquid pumps are preferred over high-pressure triplex pumps