BHA Cutter Scraper Telescoping Jack Tubular Removal
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Solution Overview
Problem
Existing methods for cutting and removing tubular sections from boreholes face difficulties due to the powerful grip of cement, requiring surface-mounted jacking devices and additional steps like reaming and plugging, which are inefficient and complex.
Innovation Solution
A bottom hole assembly (BHA) that uses a downhole motor-driven cutter and a telescoping jacking tool, where a scraper cleans the area for the spear to engage, allowing pressure buildup to exert an uphole force on the cut segment, enabling its removal without surface string rotation or additional steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If surface-mounted jacking devices are used to remove cut tubular sections, then the cutting operation can be performed, but the overall process complexity increases and additional steps (reaming, plugging) are required
Solution Approach 1:
The invention combines the cutting function and the jacking/removal function into a single bottom hole assembly. The BHA includes both a cutter assembly with downhole motor and a telescoping jacking tool with spear, allowing both operations to be performed in one integrated device rather than requiring separate surface-mounted equipment and multiple operational steps.
Solution Approach 2:
The diverter valve acts as an intermediary mechanism that controls fluid flow between the downhole motor and the telescoping jack. By redirecting hydraulic flow from the motor to the jack, it enables the transition from cutting mode to jacking mode within the same assembly, eliminating the need for surface-mounted control systems and additional plugging/reaming steps.
2Strength
If cement is used to secure tubular sections, then the tubular is firmly anchored, but the cement exerts a powerful grip that makes removal after cutting more difficult
Solution Approach 1:
The invention extracts the removal function from the surface equipment and places it directly at the bottom of the hole with the telescoping jacking tool. The spear penetrates the cut tubular section and the telescoping jack applies concentrated force directly to break the cement grip and pull the section free, rather than relying on surface-mounted devices that must overcome the full cement adhesion force.
Solution Approach 2:
The scraper cleans the area where the spear will engage before the cutting is completed. This preliminary cleaning action ensures that the spear can achieve proper engagement with the cut tubular section, allowing the jacking force to be effectively transmitted to break the cement grip without interference from debris or irregular surfaces.
3Ease of operation
If a telescoping jack with spear is used for downhole jacking, then removal can be achieved without surface string rotation, but the system requires complex flow reconfiguration mechanisms
Solution Approach 1:
The diverter valve is designed with a movable mandrel that can shift position to dynamically reconfigure fluid flow paths. The mandrel movement transitions the system from a state where fluid flows to the downhole motor (during cutting) to a state where fluid flows to the telescoping jack (during jacking), allowing the system to adapt its function without requiring complex mechanical reconfiguration or additional control mechanisms.
Data Source
AI summary
A bottom hole assembly (BHA) incorporates a tubular cutter driven by a downhole motor. A scraper moves into a smaller tubular to clean an area where a spear will later be engaged to the cut tubular portion. The scraper has a relatively movable mandrel that allows straight through flow into the motor or closes flow to build pressure to a telescoping jack to exert a pull force on the cut tubular after the cut is made. The spear is articulated with mandrel manipulation to grab the cut segment and weight is set down to shift the mandrel in the scraper to allow pressure buildup with rig pumps turned on to retract the jack as the BHA is held with anchors in the larger tubular. The cut segment is pulled uphole to loosen it so it can be removed from the borehole.