Prepack Screen Assembly for Sand Control
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Solution Overview
Problem
Existing sand control methods in injection wells, such as standalone screens and prepack screens, face issues with plugging and erosion due to poor injection water quality and formation sand, leading to reduced hydrocarbon production and well integrity problems.
Innovation Solution
A prepack screen assembly is designed with an inner and outer screen and packing material with specifically selected pore sizes to prevent sand infiltration and erosion, featuring a multi-barrier system that includes check valves to trap formation material and maintain flow integrity during shut-ins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional prepack screens are used with gravel pack or resin-coated gravel pack, then sand control is improved, but plugging occurs during installation or production due to poor injection water quality and formation sand
Solution Approach 1:
The screen assembly is divided into multiple functional zones: a first screen with larger openings for initial sand filtration, a second screen with smaller openings for fine particle filtration, and a third screen with intermediate openings. This segmentation allows each screen to handle different size ranges of sand particles and contaminants, preventing any single screen from becoming completely plugged while maintaining progressive filtration efficiency.
Solution Approach 2:
The packing material is pre-placed between the screens during assembly, creating a pre-configured filtration system. The packing material with controlled pore sizes acts as a preliminary barrier that traps formation sand and contaminants before they reach the screens, reducing the load on the screen filtration system and preventing plugging during both installation and production phases.
2Productivity
If injection pressure is increased beyond fracture pressure to obtain desired injectivity, then injection performance is improved, but loss of annular gravel pack into fractures occurs resulting in erosion potential
Solution Approach 1:
The system uses a composite structure combining multiple screen materials with different properties (wire wrap screen, mesh screens, or slotted screens) with carefully selected packing materials. This composite approach creates a robust filtration system that can withstand high injection pressures and fracture conditions while preventing gravel pack loss into fractures, thereby eliminating erosion potential even when injecting beyond fracture pressure.
Solution Approach 2:
Different screen sections and packing material zones are designed with locally optimized properties - the first screen has larger openings suitable for coarse sand control, while the second screen has smaller openings for fine particle filtration. The packing material pore sizes are locally optimized between different screen zones to match the specific filtration needs at each location, preventing gravel loss at high pressure points.
3Reliability
If resin-coated sand/proppant is used to reinforce gravel pack, then gravel loss prevention is improved, but downhole temperature or stress curing is required adding complexity to design and operations
Solution Approach 1:
The system uses uncured, non-resin bonded packing material that functions as a sacrificial filtration medium. This packing material is designed to be replaced or cleaned if necessary, rather than requiring complex curing processes. The simplicity of using uncured material eliminates the need for downhole temperature or stress curing operations, reducing design and operational complexity while maintaining effective gravel pack stability through the mechanical structure of the multi-screen assembly.
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 prepack screen assembly effectively reduces sand production and plugging, enhancing well longevity by ensuring continuous flow and sand retention, even during shut-ins, thereby improving hydrocarbon production and well reliability.
Implementation Method 1
Packing material is disposed between the inner screen and the outer screen. The packing material includes pores having a pore size that is selected based, at least in part, on the outer size, the inner size, or both.
Implementation Method 2
A prepack screen assembly is designed with an inner and outer screen and packing material with specifically selected pore sizes to prevent sand infiltration and erosion
Data Source
AI summary
A method and systems for sand control in wells are described in examples. An example uses a prepack screen assembly comprising an inner screen comprising openings having an inner size and an outer screen comprising openings having an outer size. Packing material is disposed between the inner screen and the outer screen comprising pores with a pore size that is selected based, at least in part, on the outer size, the inner size, or both.