Anti-channeling Pack-off Particles for Annular Sealing in Oil-Gas Wells
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Solution Overview
Problem
Current sectional flow control methods in oil-gas wells with perforated pipes fail to effectively seal the annular spaces between the flow control filter string and the perforated pipe, and between the perforated pipe and the borehole wall, leading to inadequate control of fluid flow and increased water production.
Innovation Solution
Filling the annular spaces with anti-channeling pack-off particles, such as high molecular polymer particles or styrene and divinylbenzene crosslinking copolymer particles, to prevent channeling and achieve a pack-off effect, using a particle-carrying fluid with a density matching the particles to ensure efficient filling and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the annular spaces are left unsealed in oil-gas wells with perforated pipes, then the device complexity is reduced, but the fluid flow control precision deteriorates leading to inadequate sectional flow control
Solution Approach 1:
The patent uses pack-off particles (porous material) to fill the annular spaces between the flow control filter string and perforated pipe, and between the perforated pipe and borehole wall. These particles create a permeable barrier that allows radial fluid flow while blocking axial channeling, achieving effective flow control without complex mechanical sealing structures.
Solution Approach 2:
The pack-off particles serve as an intermediary material that mediates between the flow control filter string and the surrounding structures. They provide the necessary sealing function in the annular spaces, enabling effective flow control while maintaining system simplicity.
2Manufacturing precision
If pack-off particles are used to seal annular spaces, then the flow control precision is improved, but the device complexity increases
Solution Approach 1:
The patent employs a particle-carrying fluid (hydraulic medium) to transport pack-off particles into the annular spaces. This hydraulic method simplifies the filling process compared to mechanical insertion methods, achieving effective sealing without complex positioning mechanisms or multiple components.
3Device complexity
If conventional flow control methods are used without pack-off particles, then the device complexity remains low, but the water production increases due to inadequate sealing
Solution Approach 1:
The pack-off particles create a porous barrier in the annular spaces that selectively allows radial fluid flow (oil and gas) while resisting axial water channeling. This porous structure effectively reduces water production by blocking the direct axial path that bottom water would otherwise take through high permeability zones.
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 effectively seals the annular spaces, reducing axial fluid flow and enhancing radial fluid flow, thereby improving oil-gas well production efficiency and oil recovery ratio by creating a high resistance to axial flow while allowing smooth radial flow, effectively functioning as a packer.
Implementation Method 1
injecting particle-carrying fluid with the anti-channeling pack-off particles into the annular space between the flow control filter string and the perforated pipe; the particle-carrying fluid carrying the anti-channeling pack-off particles passes through holes in the perforated pipe and enters into an annular space between the perforated pipe and the borehole wall
Implementation Method 2
The anti-channeling pack-off particles are accumulated both in the annular space between the flow control filter string and the perforated pipe and in the annular space between the perforated pipe and the borehole wall, so that the annular space between the flow control filter string and the perforated pipe as well as the annular space between the perforated pipe and the borehole wall are filled with and full of the anti-channeling pack-off particles
Data Source
AI summary
A method and a system for segmental flow control in an oil-gas well are disclosed. The oil-gas well includes a first annular space (111) and a second annular space (103). The first annular space (111) is formed with the space between the borehole wall (101) of the oil-gas well and a perforated tube (102) which is in the oil-gas well and extends along an axial direction of the oil-gas well; The second annular space (103) which is formed with the space between the perforated tube (102) and a flow-control filter string (105) which is in the perforated tube (102) and extends along the axial direction of the oil-gas well. The method includes filling anti-channeling isolating particles (109) in the first annular space (111) and the second annular space (103) to enable fluid to flow in the first annular space (111) and the second annular space (103) filled with the anti-channeling isolating particles (109) in the manner of seepage.