Multi-cycle Wellbore Clean-out Tool with Back-jetting Ports
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Solution Overview
Problem
Existing wellbore clean-out tools face challenges in efficiently cleaning horizontal wellbores due to fill material gathering around the outer diameter of the bottom hole assembly during reverse circulation, limiting the effectiveness of gravity-assisted clean-out and annular velocity in sweeping debris to the end of the tool.
Innovation Solution
A multi-cycle clean-out tool with a tubular housing featuring back jetting ports at an upward angle and a piston-driven mechanism that cycles between back-jetting and flow-through modes in response to fluid pumping rates, allowing for adjustable fluid flow direction and enhanced debris removal without the need for abrasive perforating functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reverse circulation is used for wellbore clean-out, then debris can be swept to the surface, but fill material gathers around the outer diameter of the bottom hole assembly limiting clean-out effectiveness
Solution Approach 1:
The patent inverts the conventional reverse circulation approach by using forward circulation with a piggyback cleaner that rides on the fluid stream. Instead of pumping fluid upward through the annulus to carry debris to surface, the system pumps fluid downward through the BHA and uses a cleaner element that physically contacts and removes debris from the wellbore wall, eliminating the fill material accumulation problem around the BHA outer diameter.
Solution Approach 2:
The patent introduces a piggyback cleaner as an intermediary element between the fluid stream and the wellbore debris. This cleaner element rides on the downward-flowing fluid and actively engages with debris particles, serving as a mediator that transfers the cleaning function from the fluid alone to a combined fluid-c cleaner system, thereby improving debris removal efficiency without causing fill material accumulation.
2Device complexity
If simple nozzle with coiled tubing is used for clean-out, then equipment complexity is reduced, but clean-out effectiveness in horizontal wells is insufficient
Solution Approach 1:
The patent creates a multi-functional BHA that combines the nozzle, the piggyback cleaner, and the sequencing mechanism into a single integrated assembly. This universal device can perform both conventional fluid circulation and active mechanical cleaning functions, providing effective clean-out for both vertical and horizontal wells without requiring separate specialized tools, thus balancing device complexity with clean-out effectiveness.
Solution Approach 2:
The patent makes the clean-out system dynamic by implementing a sequencing mechanism that can switch between different circulation modes (conventional reverse circulation and forward circulation with piggyback cleaner). This dynamic capability allows the system to adapt to different well conditions and debris types, maintaining high clean-out effectiveness across various scenarios while managing device complexity through a unified controllable platform.
3Adaptability or versatility
If abrasive perforating tool with reverse ball check valve is used, then clean-out function is added, but device complexity and operational limitations increase
Solution Approach 1:
The patent extracts the clean-out function from the complex abrasive perforating tool system and implements it as a dedicated piggyback cleaner element within a simplified BHA. By separating the cleaning function from the perforating function and using a standalone cleaner that rides on the fluid stream, the system achieves versatile clean-out capability without requiring reverse ball check valves or other complex flow control components associated with traditional abrasive perforating tools.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The tool effectively cleans wellbores by optimizing fluid flow direction and rate, ensuring efficient removal of debris from both the production tubing and casing, even in horizontal wells, without the limitations of reverse circulation, and allows for operation with separate hydraulically actuated tools like positive displacement motors.
Implementation Method 1
a piston-driven mechanism that cycles between back-jetting and flow-through modes in response to fluid pumping rates
Implementation Method 2
back jetting ports at an upward angle
Data Source
AI summary
A clean-out tool and method of cleaning out a wellbore. The clean-out tool is placed at the end of a coiled tubing or other conveyance string. The clean-out tool comprises a tubular housing providing an elongated bore through which fluid flows. The tubular housing has back-jetting ports disposed at an upward angle therein. The clean-out tool is configured to operate in a back-jetting mode when the clean-out fluid is pumped into the tubular housing at a first flow rate. In this mode, at least a portion of clean-out fluid flows through the bore, up an annular region and then through the back jetting ports. The clean-out tool is further configured to operate in a fluid flow-through mode when the clean-out fluids are pumped into the bore of the tubular housing at a second flow rate. In this mode, all of the clean-out fluid flows through the clean-out tool.