Downhole Motor Thrust Generator for Extended Reach Drilling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In extended reach drilling operations, the weight of the drill string is insufficient to maintain the necessary weight on bit (WOB) for efficient cutting of formations, especially in deviated wellbores, due to drag forces and environmental factors.
Innovation Solution
A drilling assembly that utilizes a pressurized fluid-driven motor to generate both torque and thrust for the drill bit, including a stator housing, rotor, and a thrust generator with a rib on a connector, which translates within an enclosure to apply force to the drill bit, and a force application assembly to anchor the drilling assembly to the wellbore wall, allowing for localized WOB generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the drill string weight is used to provide weight on bit in vertical sections, then the drilling assembly can be simplified, but in deviated sections the available WOB diminishes due to drag forces
Solution Approach 1:
The patent employs a mud motor that converts hydraulic energy from drilling fluid into mechanical rotation and thrust. The motor receives pressurized drilling fluid through the drill string and converts this fluid power into rotational torque and axial thrust force at the drill bit, enabling WOB generation independent of drill string weight
Solution Approach 2:
The invention changes the operational parameters by introducing a thrust generator that converts the rotational motion and fluid pressure into axial thrust. The thrust generator utilizes the pressure differential and flow characteristics of the drilling fluid to produce controlled thrust forces, transforming the drilling system from weight-dependent to pressure-dependent operation
2Adaptability or versatility
If a mud motor is used to rotate the drill bit in coiled tubing operations, then drilling in deviated sections is enabled, but the drill bit rotation depends on fluid flow through the motor
Solution Approach 1:
The patent merges the functions of rotation and thrust generation into a single integrated mud motor system. The motor simultaneously produces both rotational torque for bit rotation and axial thrust for WOB, with both functions driven by the same fluid flow through the motor, improving overall energy utilization
Solution Approach 2:
The invention utilizes the pressure differential across the motor and the flow rate parameters to control both rotation speed and thrust magnitude. By adjusting fluid flow parameters, the system can independently optimize both rotational and thrust outputs to match drilling conditions
3Device complexity
If the drill string weight provides WOB in vertical sections, then no additional thrust generation mechanism is needed, but in extended reach operations the weight becomes insufficient
Solution Approach 1:
The mud motor system converts hydraulic energy from the drilling fluid into mechanical work, generating both rotation and thrust. This hydraulic-to-mechanical energy conversion provides sufficient thrust force to maintain efficient WOB in extended reach and deviated sections where gravity assistance is inadequate
Solution Approach 2:
The thrust generator modifies the operational parameters by converting fluid pressure and flow into controlled axial thrust. This parameter transformation enables dynamic adjustment of WOB based on drilling conditions, maintaining optimal cutting forces regardless of wellbore configuration
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 generates the necessary weight on bit for efficient cutting in deviated wellbores by using differential pressure to translate the rotor and apply thrust to the drill bit, enabling drilling in conditions where the drill string weight is insufficient, and can be dynamically controlled to optimize drilling parameters.
Implementation Method 1
The drilling motor is energized by a pressurized fluid and includes a stator housing and a rotor disposed in the stator housing. The rotor has a torque transmitting connection to the connector.
Implementation Method 2
The solution effectively generates the necessary weight on bit for efficient cutting in deviated wellbores by using differential pressure to translate the rotor and apply thrust to the drill bit
Implementation Method 3
a force application assembly selectively anchoring the stator to a wellbore wall
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An apparatus for forming a wellbore in a subterranean formation includes a drill bit, a connector connected to the drill bit and configured to transmit torque and thrust to the drill bit, and a drilling motor energized by a pressurized fluid. The drilling motor may include a stator and a rotor disposed in the stator and having a torque transmitting connection to the connector. The apparatus may also include a thrust generator associated with the rotor and having a pressure face in pressure communication with a fluid flowing through the drilling motor and a force application assembly selectively anchoring the stator to a wellbore wall. A related method uses the apparatus to drill a wellbore.