Segmented Plug and Abandonment System for Well Isolation
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Solution Overview
Problem
The existing plug and abandonment systems for oil and gas wells face challenges in efficiently forming upper plugs that ensure complete isolation of all annuli, particularly due to the requirement for larger and heavier well-control equipment, which increases costs and operational complexity.
Innovation Solution
A plug and abandonment system comprising a lower tool segment with a landing structure and a well control package, and an upper tool segment with seal rams and cutting means, allowing for precise formation of openings in the casing to create upper plugs without the need for large bore well-control packages, thereby facilitating efficient isolation of annuli.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional plug and abandonment systems are used to form upper plugs, then complete isolation of all annuli is achieved, but larger and heavier well-control equipment is required, increasing costs and operational complexity
Solution Approach 1:
The system divides the well-control function into two separate segments: a well control package positioned in the wellhead housing and a plug formation tool positioned in the wellbore. This segmentation allows the well control package to remain compact while the plug formation tool handles the complex plug formation operations, resolving the contradiction between reliable annuli isolation and reduced equipment complexity
Solution Approach 2:
The system introduces an intermediary communication mechanism (such as wireline or magnetic coupling) between the well control package and the plug formation tool. This intermediary allows control signals and data to be transmitted without requiring direct physical connection or large bore equipment, enabling reliable plug formation with simplified well-control packages
2Reliability
If larger bore well-control packages are used to ensure complete annuli isolation, then plug formation reliability is improved, but operational costs and equipment size increase
Solution Approach 1:
The system separates the heavy plug formation tool from the well-control package, placing the tool in the wellbore where it can be supported by the wellbore structure itself. The well-control package remains lightweight and positioned in the wellhead housing, controlling the segmented tool through the intermediary communication mechanism, thus achieving reliable plug formation without increasing well-control package weight
Solution Approach 2:
The system moves the heavy plug formation operations from the well-control package dimension to the wellbore dimension, where the tool operates independently using wellbore-supported positioning and power. This dimensional shift allows the well-control package to remain lightweight while still ensuring reliable plug formation through coordinated control
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 system enables effective formation of upper plugs that isolate all annuli, reducing the need for large bore well-control packages and minimizing operational costs, while ensuring compliance with regulatory requirements for well abandonment.
Implementation Method 1
at least one seal ram adapted to engage an outer surface of the upper tool segment
Implementation Method 2
at least one cutting means coupled to the lower segment and adapted to be actuated to cut at least one opening in at least one section of casing within the well
Data Source
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AI summary
A system for forming an upper plug in a well, the system, comprising lower tool segment (54) that is adapted to land within a wellhead housing (15) under open water conditions, a well control package (14) that is adapted to be positioned above the lower segment (54) and coupled to the wellhead housing (15), the well control package (14) comprising at least one seal ram (38), an upper tool segment (52) that is adapted to be positioned through the well control package (14) (i.e., after the well control package (14) has been attached to the wellhead) and operatively coupled to the lower tool segment (54) wherein at least one seal ram (38) of the well control package (14) is adapted to engage an outer surface of the upper tool segment (52) and at least one cutting means (57, 59, 61, 62, 150) that is coupled to the lower segment (54) and adapted to be actuated to cut at least one opening in at least one section of casing (16, 18, 20, 22) within the well.