Stage Cementing Tool Mandrel Slots Packer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing well cementing processes face challenges in achieving universal cement placement and efficient cancellation of cement stages, particularly in subterranean wells, due to limitations in current staging tools that often result in incomplete cementing or require additional cement pumping during cancellation.
Innovation Solution
A stage cementing tool with a mandrel featuring circumferentially spaced longitudinal slots and a packer system, allowing for controlled cement flow and easy cancellation through a plug-based mechanism that prevents communication between the central flow passage and annulus during cancellation, ensuring complete cement placement and efficient stage management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single stage cement process is used, then the cementing operation is simpler, but it is impossible or impractical to cement the entire well
Solution Approach 1:
The patent divides the cementing operation into multiple stages using a casing string with a staging tool. The first stage cements the lower portion of the wellbore, and the second stage cements the upper portion. This segmentation allows the entire well to be cemented reliably while keeping each individual stage manageable and practical to execute.
2Reliability
If staging tools are used to enable multi-stage cementing, then complete well cementing becomes possible, but the tool structure becomes more complex and requires additional mechanisms for cement diversion
Solution Approach 1:
The patent combines the packer and the cement diversion valve into a single integrated staging tool assembly. The packer isolates the lower wellbore section, while the valve controls cement flow diversion to the annulus. This merging of functions into one tool reduces the number of separate components needed and simplifies the overall tool string configuration.
Solution Approach 2:
The staging tool is designed to perform multiple functions: it acts as a packer to isolate the lower wellbore, a valve to control cement diversion, and a structural element to support the casing string. This multi-functionality reduces the need for multiple separate tools and simplifies the overall cementing process.
3Reliability
If cement staging tools are used, then section-by-section cementing is achieved, but cancellation of a stage requires additional cement pumping and complicates the process
Solution Approach 1:
The staging tool incorporates a dynamic valve mechanism that can be actuated to change its position and function. During cancellation, the valve is actuated to close the central flow passage and divert all cement flow to the annulus, allowing easy cancellation of the stage without requiring additional cement pumping operations.
4Stability of the object's composition
If the opening sleeve and setting sleeve are connected with pins extending through longitudinal slots, then the sleeves can move together as a unit, but the connection mechanism becomes more complex
Solution Approach 1:
The connecting pins are nested within the longitudinal slots of the mandrel, allowing the opening sleeve and setting sleeve to move together along the slots while maintaining their relative positioning. This nested arrangement provides stable coordinated movement without requiring complex external connection mechanisms.
Data Source
AI summary
A stage cementing tool for use in a wellbore comprises a mandrel having a plurality of circumferentially spaced first longitudinal slots and a plurality of circumferentially spaced second longitudinal slots. An opening sleeve is disposed in the mandrel in a first position and movable relative thereto. A setting sleeve disposed about the mandrel is connected to the opening sleeve and movable therewith. A drive sleeve disposed in the mandrel above the opening sleeve is connected to and movable with a closing sleeve disposed about the mandrel.