Switchable Downhole Crossover Tool for Cementing
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Solution Overview
Problem
Conventional cementing methods in oil field recovery operations face challenges such as cement loss into weak formations due to high pressure, leading to increased costs and potential casing instability, and require longer job times with reverse circulation methods.
Innovation Solution
A crossover tool that switches between conventional and reverse circulation modes, allowing for controlled fluid circulation and cement placement, separating fluids in the wellbore and controlling flow paths to mitigate pressure issues and reduce job duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional circulation cementing is used to pump cement slurry down the casing string and back up the annulus, then cement placement is achieved, but high delivery pressures cause cement loss into weak formations and increase the risk of casing floating
Solution Approach 1:
The patent applies reverse circulation by introducing cement slurry into the annular space and returning it up the casing string, inverting the conventional circulation path. This inversion reduces delivery pressure requirements and prevents cement loss into weak formations while maintaining effective cement placement
2Loss of substance
If reverse circulation cementing is used to introduce cement slurry into the annular space, then delivery pressure is reduced and cement loss is minimized, but job duration increases significantly
Solution Approach 1:
The patent employs a dynamically switchable crossover tool that can transition between reverse circulation and conventional circulation modes. This dynamic capability allows the system to optimize for low pressure during cement placement and then switch to conventional circulation for faster return flow, reducing overall job duration
3Productivity
If crossover tools are used to enable reverse circulation from internal flow path into the annulus, then cement placement efficiency is improved, but the tool cannot switch flow path back to conventional circulation direction
Solution Approach 1:
The patent implements a dynamically switchable crossover tool with valve mechanisms that can transition between reverse circulation and conventional circulation modes. This dynamic switching capability provides adaptability for different wellbore conditions and operational requirements while maintaining cement placement efficiency
4Reliability
If high delivery pressures are applied to lift cement slurry up the annulus in conventional circulation, then cement placement is achieved, but the casing string floats upward and formation breakdown occurs
Solution Approach 1:
The patent applies reverse circulation by inverting the cement slurry flow path to enter the annular space directly and return up the casing string. This inversion eliminates the need for high delivery pressures to lift cement up the annulus, preventing formation breakdown and casing floating while ensuring reliable cement placement
Data Source
AI summary
A system, method, and tool for controlling fluid in a wellbore. The system comprises a tubing string locatable in the wellbore and a crossover tool for enabling reverse circulation in the wellbore. The crossover tool comprises a tool body, a sleeve, a drag block assembly, and a packer assembly. The tool body comprises a bore in fluid communication with the tubing string and a valve in the bore. The sleeve is located in the tool body and controls the valve based on the axial position of the sleeve in the tool body. The drag block assembly is coupled to the sleeve through the tool body and engages the wellbore to resist axial movement of the sleeve relative to the tool body. The packer assembly is coupled to the tool body and creates a fluid barrier in the annulus formed between the tubing string and the wellbore.