Sealing Fluid Density and Viscosity Control for Deviated Well Annuli
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for setting packers in well annuli face challenges such as unsatisfactory sealing in deviating wells, high axial dispersion, and inability to function in annuli with active crossflow or eccentric shapes, particularly in horizontal wells.
Innovation Solution
A method involving a sealing fluid with adjustable density, viscosity, and setting time, specifically tailored to match the conditions of the well annulus, allowing for a full radial seal with minimal axial dispersion and adaptability to non-dormant and deviating well environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement is used to seal the annulus, then the sealing function is provided, but the material cannot spread evenly into the annulus in deviating wells and requires large quantities to be pumped
Solution Approach 1:
The invention changes the physical parameters of the sealing fluid by adjusting viscosity (to above 1000 cP at annulus temperature), density (matched within ±5% of annulus fluid), and setting time (2-30 minutes) to enable even distribution in deviating wells while maintaining reliable sealing function
2Reliability
If large quantities of cement are pumped to ensure effective sealing, then the hole is sealed, but the process becomes time consuming and expensive
Solution Approach 1:
The invention optimizes the sealing fluid parameters including viscosity above 1000 cP, density matching within ±5%, and controlled setting time of 2-30 minutes to achieve effective sealing with reduced fluid quantities, thereby decreasing time consumption and operational costs
3Reliability
If cement is used for sealing, then the annulus is sealed, but excessive axial dispersion occurs making it near impossible to remove production tubing
Solution Approach 1:
The invention controls axial dispersion by adjusting the sealing fluid viscosity to above 1000 cP at annulus temperature and setting time to 2-30 minutes, achieving effective sealing with minimal axial dispersion that allows future production tubing removal
4Reliability
If liquid epoxy material is used for plugging, then the zone is plugged, but the material exhibits undesirable axial dispersion and the well must remain dormant
Solution Approach 1:
The invention increases viscosity to above 1000 cP and controls setting time to 2-30 minutes to minimize axial dispersion, allowing the well to remain productive during the sealing operation without requiring the well to be dormant
5Reliability
If the sealing fluid density is not matched to the annulus fluid, then the sealing may not be effective, but adjusting density adds complexity to the preparation process
Solution Approach 1:
The invention adjusts sealing fluid density to match the annulus fluid within ±5% to prevent unwanted axial dispersion and ensure effective sealing, with the benefit that density adjustment is a straightforward parameter control rather than a complex process
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 enables reliable and efficient sealing of annuli in deviating wells and those with active crossflow, reducing the need for excessive fluid quantities and minimizing axial dispersion, while maintaining integrity in both concentric and eccentric annuli.
Implementation Method 1
adjusting the density of the sealing fluid to the density of the fluid in the annulus within ±5%
Implementation Method 2
adjusting the viscosity of the sealing fluid to above 1000 cP, such as between 1000 cP to 130000 cP
Implementation Method 3
a sealing fluid comprising an epoxy resin and a hardener characterised by a density of 0.97-1.08 g/cm³, an initial mixed viscosity of 5000-50000 cP and, a setting time of 2-30 minutes
Data Source
AI summary
A method and a sealing fluid for setting a packer in an annulus between a well bore and a well tubular is provided, which by adjusting i.a. the density, viscosity and setting time of the sealing fluid is able to provide among other things a full radial seal with an acceptable axial dispersion, in particular in highly deviated wells and/or in wells having eccentric annuli.