Inner String Cementing with Retractable Joint Pressure Testing
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Solution Overview
Problem
Existing cementing systems leave residual cement in the lower portion of the casing string, requiring drilling to remove it before further wellbore advancement, which can cause micro-cracks and delays in the well construction process.
Innovation Solution
A retractable joint and stinger system that allows fluid communication through the float shoe into the outer annulus without entering the inner annulus, enabling pressure testing without waiting for cement to harden and reducing the need for post-cementing drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is circulated through the inner string and float shoe into the outer annulus, then the outer annulus is properly cemented, but residual cement remains in the lower portion of the casing string requiring drilling removal
Solution Approach 1:
The stinger is extracted from the float shoe after cementing operations. By withdrawing the stinger through the retractable joint mechanism, the system removes the obstruction that was preventing fluid communication between the inner string and inner annulus, eliminating the need to drill out residual cement
Solution Approach 2:
The retractable joint provides a dynamic connection that can transition between engaged and disengaged states. When the stinger is withdrawn, the retractable joint allows the inner string to move independently, enabling fluid to bypass the float shoe and enter the inner annulus for pressure testing without waiting for cement to harden
2Reliability
If residual cement is left to cure and harden to block the float shoe for pressure testing, then pressure testing can be performed, but micro-cracks may form and wellbore advancement is delayed
Solution Approach 1:
The stinger is withdrawn and fluid communication is established before the cement fully hardens. This preliminary action of opening the flow path allows pressure testing to begin while the cement is still setting, rather than waiting for complete hardening, thus preventing micro-crack formation and accelerating wellbore advancement
Solution Approach 2:
The retractable joint acts as an intermediary mechanism that enables the transition from cementing mode to pressure testing mode. By allowing the stinger to be withdrawn, it mediates between the conflicting requirements of maintaining float shoe blockage for cementing and enabling fluid communication for pressure testing
3Reliability
If the stinger remains engaged with the float shoe, then fluid flow path is maintained, but the inner string cannot be supported by the hanger running tool during retraction
Solution Approach 1:
The connection between the inner string and stinger is segmented through the retractable joint. This allows the stinger to be separated from the float shoe while the inner string remains supported by the hanger running tool, enabling independent movement of each component without compromising the overall system integrity
Data Source
AI summary
A cementing system includes an inner string configured to be received into a casing string in a wellbore. The cementing system also includes a stinger coupled to the inner string and configured to be received into a float shoe connected to the casing string. The cementing system also includes a first retractable joint coupled to the inner string. The retractable joint is configured to reduce in axial length so as to permit at least part of stinger to be withdrawn from engagement with the float shoe while a weight of the inner string is supported by a hanger running tool and casing hanger connected to the casing. The inner string, the stinger, and the retractable joint form at least a part of a flowpath that extends through an end of the casing string at the float shoe.