Ported Sub Cementing with Dropped Balls for Liner Hanger Setting
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Solution Overview
Problem
Traditional liner cementing methods face challenges in ensuring adequate cement distribution, particularly in weak formations, and require significant time between the conclusion of top-down cementing and setting the liner hanger/packer, which can lead to non-productive time events due to potential cement sticking with the running tool.
Innovation Solution
The method involves cementing the liner bottom-up and then top-down, using a ported sub with strategically dropped or pumped balls to set the liner hanger/packer with pressure, and employing darts with leading or trailing balls to control the opening and closing of ports for efficient cement placement and tool release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If top-down cementing is performed followed by setting the liner hanger/packer, then adequate cement distribution is achieved, but significant time is lost due to waiting for cement to set and potential cement sticking to the running tool
Solution Approach 1:
The ported sub is pre-positioned in the running string before cementing operations begin. The ports are initially closed, allowing top-down cementing to be performed, then quickly opened to allow pressure to set the liner hanger/packer without waiting for cement to set, thereby reducing non-productive time while maintaining reliable cement distribution
Solution Approach 2:
The cementing process is segmented into distinct phases: first performing top-down cementing with ports closed, then opening ports to apply pressure for setting the liner hanger/packer, and finally closing ports again. This segmentation allows each operation to be performed optimally without the other interfering, resolving the time loss issue while maintaining cement distribution integrity
2Stress or pressure
If ports are closed to apply pressure for setting the liner hanger/packer, then setting pressure can be applied, but the running tool must be released from the liner hanger/packer afterward adding to the time constraint
Solution Approach 1:
The ported sub acts as an intermediary device that facilitates pressure application for setting the liner hanger/packer while being designed to allow automatic or quick release of the running tool. The intermediary mechanism enables the setting operation to be completed and the running tool released in a single continuous operation rather than separate steps, reducing time loss
Data Source
AI summary
A liner is cemented bottom up and then top down followed by setting the simultaneously set liner hanger/packer and releasing the running tool. In one embodiment the ported sub for top down cementing has ports opened and then closed with multiple dropped or pumped balls one of which lands in the running tool to set the hanger packer with pressure before running tool removal. A dart with a leading ball can follow the top down cement to close the ported sub and thereafter land in the liner hanger/packer to set it with pressure. A dart can lead the top down cement and open the ported sub followed by a second dart behind the top down cement to close the ported sub and land in the liner hanger/packer to set it and to release the running tool. The ported sub can be operated in other ways such as motors responsive to a remote signal.