Downhole Tool Acute Angle Nozzle for Vortex-Free Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional downhole tools, such as circulating subs, have limited cleaning and transport effects due to the formation of Vortices that cause solid particles to accumulate and potentially damage the borehole, and existing solutions either fail to provide continuous drilling fluid flow or are unsuitable for positions further up the drilling string.
Innovation Solution
A downhole tool with a housing featuring fluid conduits placed at acute angles relative to the longitudinal direction, including a second fluid conduit and an optional third fluid conduit, each with a nozzle system that directs bypassed drilling fluid into the annulus at specific angles to prevent Vortex formation and ensure continuous drilling fluid flow, allowing for improved cleaning and transport of solid particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the fluid conduit is placed at a perpendicular angle (90°) relative to the longitudinal direction, then the bypass fluid velocity is low and ECD is reduced, but the cleaning effect and lifting effect on solid particles is very limited
Solution Approach 1:
The patent changes the angle parameter of the fluid conduit from the conventional 90° perpendicular angle to an acute angle (specifically 30°-60°) relative to the longitudinal direction. This parameter change transforms the bypass fluid flow direction to align more with the annular flow direction, thereby improving both the cleaning effect and lifting effect on solid particles while still maintaining ECD reduction benefits.
2Productivity
If the fluid conduit is placed at an acute angle towards the drill bit, then the cleaning effect is improved, but a strong Vortex is generated causing solid particles to accumulate and cause packoff
Solution Approach 1:
The patent optimizes the acute angle parameter to a specific range (30°-60°) rather than using any acute angle. This optimized parameter range achieves the right balance: it provides sufficient cleaning effect by directing bypass fluid towards the annulus while avoiding the generation of strong Vortices that would cause particle accumulation and packoff.
3Speed
If a nozzle is added to increase bypass fluid velocity, then the ECD is lowered and annular flow is increased, but a strong Vortex is generated above and below the nozzle causing particle accumulation
Solution Approach 1:
The patent combines the nozzle velocity enhancement with an optimized acute angle configuration (30°-60°). The angle optimization ensures that the high-velocity bypass fluid from the nozzle flows in a direction that aligns with the annular flow, thereby achieving ECD reduction and increased annular flow velocity without generating harmful Vortices that would cause particle accumulation.
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 acute angle configuration enhances the cleaning and transport effects by directing all bypassed drilling fluid energy towards the annulus, reducing the risk of solid particle accumulation and erosion, while maintaining continuous drilling fluid flow, thus improving the overall efficiency and functionality of the downhole tool.
Implementation Method 1
This accelerated bypass flow directly hits the inner wall, thereby generating a jet impact effect which contributes to erosion of any filter cakes formed on the inner wall
Implementation Method 2
This solution has a very limited cleaning effect and lifting effect on the solid particles transported in the drilling fluid returning to ground level. Further, some of the bypass fluid follows a Vortex generated below the opening and, thus, flows back towards to the drill bit
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A downhole tool and a drill string (18") comprising such a downhole tool is disclosed. The downhole tool comprises a housing having a first end and a second end, wherein a first fluid conduit (5) extends from an opening in the first end to an opening in the second end. A second (8") and a third fluid conduit is further arranged in the housing, wherein the second (8) and third fluid conduits extend from an inner opening connected to the first fluid conduit (5) to an outer opening arranged in the outer side surface of the housing. The second and third fluid conduits (8, 24) are placed in acute angles relative to a longitudinal direction of the downhole tool. The second fluid conduit (8) is orientated so that it faces towards the first end. The third fluid conduit (24) is orientated so that it faces towards the first or second end. This provides an improved cleaning effect and transport effect without generating a Vortex around the outer opening of the second and third fluid conduits (8, 24).