Mud Motor Stator Lining via Contoured Mandrel
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Solution Overview
Problem
The service life of mud motors in the resource exploration and recovery industry is shortened due to localized stress zones created by holes in the stator, leading to frequent repairs and replacements, which are time-consuming and costly.
Innovation Solution
A method of forming a mud motor stator by introducing a liner material into its passage and using a mandrel with a contoured surface to form an elastomeric liner on the inner surface, which extends the service life by reducing stress zones and improving durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If holes are formed in the stator to inject lining material, then the lining can be applied to the passage, but localized stress zones are created that shorten the service life of the mud motor
Solution Approach 1:
The invention removes the holes from the stator structure entirely. Instead of injecting lining material through holes in the stator, the lining is applied by introducing it into the passage and using a mandrel with contoured surface to distribute the material evenly along the passage length, eliminating the source of localized stress zones while maintaining the lining application capability
Solution Approach 2:
The mandrel serves as an intermediary tool that enables lining material application without requiring holes in the stator. The mandrel is inserted into the passage, and the lining material flows over its contoured surface, which distributes the material evenly along the passage. The mandrel is then removed, leaving a complete lining without any holes in the stator structure
2Ease of operation
If a liner is provided on the stator to enable relative rotation with the rotor, then the mud motor can operate, but the holes required for liner injection create stress zones that reduce durability
Solution Approach 1:
The invention extracts the holes from the stator structure that cause stress concentration. The lining is applied through a different mechanism using a mandrel as a temporary form, eliminating the need for permanent holes in the stator while maintaining the ability to provide a complete liner for relative rotation operation
Solution Approach 2:
The mandrel is inserted into the passage before lining material application. This preliminary placement of the mandrel establishes a contoured surface that guides the lining material to flow evenly along the entire passage length, ensuring complete coverage without requiring holes in the stator structure
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 method significantly prolongs the service life of mud motors by reducing stress zones and enhancing durability, thereby minimizing the need for repairs and replacements, resulting in cost savings and increased operational efficiency.
Implementation Method 1
flowing the liner material over the contoured surface of the mandrel from the one of the first and second ends toward the other of the first and second ends to form a liner on the inner surface of the passage
Data Source
AI summary
A method of forming a mud motor stator having a passage including a first end defining a first opening, a second end defining a second opening and an intermediate portion extending therebetween includes introducing a liner material into the passage at one of the first end and the second end of the stator, inserting a mandrel having a contoured surface into the passage through one of the first end and the second end of the stator, shifting one of the mandrel and the stator relative to the other of the mandrel and the stator, and flowing the liner material over the contoured surface of the mandrel from the one of the first and second ends toward the other of the first and second ends to form a liner on the inner surface of the passage.