Welltec® designed the operational process around the simulation modelling to ensure there was no risk of bursting the WAB® and the operations team collaborated with the offshore drilling and fluids team to create the procedure. During the drilling of the 12 1/4” section of a well, the operator encountered a shallow gas zone at approximately 1,050 ft. Operationally, the WAB® was set within this 12 1/4” open-hole section, within green cement, by applying pressure against the primary cement plug. Specifically, the WAB® was deployed with the 9 5/8” casing and positioned directly above the gas zone. Primary cementing operations were then conducted and the WAB® was set after these operations.
The client then requested two weeks to monitor the B annulus for gas migration. Two weeks after installation and cement curing, the B annulus on this well continued to read steadily at 0 psi.
The WAB® proved to be an effective solution for the client, setting within the soft formation, preventing gas migration, and maintaining well integrity. The client’s confidence in moving forward with this trial well resulted from the simulation modelling demonstrating the WAB’s performance in this unique environment as well as Welltec’s strong case history and track record in similar applications.
The WAB® eliminates sustainable annulus pressure (SAP) in the B annulus. This solution improves well integrity, enhances environmental safety, and removes the need for costly operations to lubricate and bleed off B annulus pressure. Ultimately, the WAB® prevents the need for the well to be shut in because of SAP, thus ensuring there will be no deferred production revenue.
The setting time for this application was 15 minutes and so there is minimal impact to the total operational time. Incorporating the WAB® simplifies the installation process when compared to alternative products with far more complex setting procedures.