Drill String Tubular Component Helical Impellers Cuttings Suspension
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Solution Overview
Problem
Settling of drill cuttings in the annulus during wellbore drilling impedes the movement of the drill string, particularly in deviated and directional drilling operations, where cuttings tend to accumulate and impede the drilling process.
Innovation Solution
A drill string tubular component with radial and axial impellers, featuring helical parts and ramps, is used to divert fluids radially outward, creating turbulent flow regions that keep drill cuttings in suspension, and axial impellers urge fluids toward the radial impeller to enhance suspension and prevent settling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If drilling fluid is pumped through the drill string to transport cuttings, then cuttings are carried away from the drill bit, but cuttings tend to settle out of suspension in the annulus during upward transport
Solution Approach 1:
The patent employs helical ribs on the drill string outer surface that rotate with the drill string, creating mechanical agitation and turbulence in the drilling fluid. This continuous mechanical disturbance prevents cuttings from settling by maintaining fluid motion and suspension forces throughout the annular space, directly addressing the suspension stability issue while preserving transport efficiency.
Solution Approach 2:
The patent utilizes the hydraulic flow of drilling fluid pumped through the drill string to carry cuttings. By optimizing the hydraulic parameters and introducing helical flow patterns through the ribs, the system enhances the fluid's ability to maintain cuttings in suspension during upward transport through the annulus, balancing transport capability with suspension stability.
2Adaptability or versatility
If the wellbore extends horizontally in directional drilling, then access to horizontal sections is achieved, but cuttings accumulate in cuttings beds on the lower side of the wellbore
Solution Approach 1:
In horizontal well sections, the rotating helical ribs create continuous mechanical agitation that prevents cuttings from settling and forming beds on the lower side of the wellbore. This mechanical vibration effect is particularly effective in horizontal sections where gravitational settling would otherwise cause accumulation, thereby maintaining drilling speed and productivity throughout the horizontal trajectory.
Solution Approach 2:
The helical shape of the ribs introduces a curved, three-dimensional flow pattern to the otherwise linear upward flow. This curvature creates centrifugal forces and secondary flows that redistribute cuttings uniformly across the annular space, preventing accumulation on the lower side of horizontal wellbore sections and enabling continuous drilling operation.
3Reliability
If impellers are attached to the outer surface of the drill string to keep cuttings in suspension, then cuttings remain suspended, but device complexity increases
Solution Approach 1:
The patent extracts the essential function of impellers (creating turbulence and fluid motion) and implements it through a simplified structure - helical ribs directly formed on the drill string outer surface. These ribs create the necessary fluid agitation and suspension forces without requiring separate, complex impeller assemblies, thereby achieving cuttings suspension stability with reduced device complexity.
Solution Approach 2:
The patent merges the drill string structural component with the cuttings suspension function by integrating helical ribs directly onto the drill string outer surface. This combination eliminates the need for separate impeller attachments while providing continuous mechanical agitation throughout the drill string length, simplifying the overall device structure while maintaining effective cuttings suspension.
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 solution effectively maintains drill cuttings in suspension, preventing accumulation and ensuring continuous drilling by accelerating cuttings into high-flow, turbulent zones, thereby maintaining efficient drilling operations, especially in horizontal sections of the wellbore.
Implementation Method 1
Fluids flowing axially up the annular area between the drill string and the wellbore typically encounter the ramp and are diverted by the ramp radially away from the outer surface of the tubular component. Diverting the fluids radially outward from the outer surface of the tubular component typically moves the fluids into a region of the annulus with more turbulent and/or faster flow.
Implementation Method 2
Fluids flowing axially up the annular area between the drill string and the wellbore typically encounter the ramp and are diverted by the ramp radially away from the outer surface of the tubular component. Diverting the fluids radially outward from the outer surface of the tubular component typically moves the fluids into a region of the annulus with more turbulent and/or faster flow.
Implementation Method 3
The axial impellers urge the fluid toward the radial impeller for diversion in a radial direction away from the axis of the tubular component.
Data Source
Figure 1~2
Figure 3a~3h
Figure 4~5
AI summary
A drill string tubular component for use in an oil or gas well, in the form of a tubular having a central bore and a mechanism for mobilising drill cuttings comprising at least one radial impeller (30) configured to apply radial thrust cuttings passing it, the radial impeller being located between first and second axial impellers (10, 20) configured to apply axial thrust to the fluids in opposite directions. Typically helical components of the first and second axial impellers extend in respective opposite directions, typically toward the radial impeller. Fluids are thus diverted radially away from the outer surface of the tubular component, and thereby enter a more turbulent region of the annulus, there reducing the tendency of the drill cuttings to settle out of suspension.