Zone Isolation Assembly for Subsurface Well Fluid Sampling
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Solution Overview
Problem
Conventional drilling technologies for subsurface wells fail to effectively isolate well bore fluids between the riser pipe and fluid inlet structure, leading to non-representative fluid samples due to mixing of stagnant fluid from the riser pipe with the desired fluid, necessitating costly purging procedures to achieve representative results.
Innovation Solution
A zone isolation assembly that includes a fluid receiving pipe, a docking receiver, a docking apparatus, and sealers to create a fluid-tight seal between the pipe and the casing, isolating two distinct zones within the well, allowing for selective fluid sampling and reducing purge volumes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drilling technologies are used to install monitoring wells, then well installation is achieved, but fluid isolation between the riser pipe and fluid inlet structure is not provided, causing stagnant fluid to mix with sampled fluid
Solution Approach 1:
The well structure is segmented into distinct zones using sealers (packers) that divide the well bore into isolated sections. This segmentation prevents mixing between stagnant fluid in the upper portion and fresh fluid at the sampling zone, ensuring sample representativeness without requiring complex isolation mechanisms.
Solution Approach 2:
A sealer (packer) is introduced as an intermediary element between the riser pipe and fluid inlet structure. This intermediary component creates the necessary fluid isolation, allowing the system to maintain simple overall structure while achieving reliable zone separation for accurate sampling.
2Measurement precision
If fluid purging is performed to remove stagnant fluid, then representative fluid samples are obtained, but substantial quantities of fluid are removed at significant cost
Solution Approach 1:
By segmenting the well into isolated zones using sealers, the system eliminates the need for extensive purging. Only the fluid in the specific sampling zone needs to be sampled, not the entire well volume, thereby maintaining sample accuracy while minimizing fluid loss.
Solution Approach 2:
The sealers are installed in advance to pre-establish fluid isolation before sampling begins. This preliminary action prevents stagnant fluid from contaminating the sample zone, eliminating the need for subsequent purging operations and reducing both time and fluid loss.
3Measurement precision
If zone isolation is implemented using sealers, then fluid mixing is prevented and sample accuracy is improved, but the device complexity and installation requirements increase
Solution Approach 1:
The sealers are designed to be deployed through the existing well structure using simple deployment devices that can be lowered and retrieved easily. The sealers self-activate or self-position within the well, reducing the need for complex installation procedures and specialized equipment, thereby maintaining ease of manufacture and installation.
4Ease of manufacture
If smaller diameter direct push drilling is used, then installation costs are reduced, but fluid isolation between zones is still not achieved
Solution Approach 1:
The invention adds segmentation capability to the simple direct push well structure by introducing sealers that divide the well into isolated zones. This maintains the cost advantages of small-diameter drilling while achieving the previously missing fluid isolation functionality through relatively simple, low-cost sealer components.
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 zone isolation assembly enables more accurate and cost-effective fluid sampling by preventing fluid mixing, reducing the volume of fluid that needs to be purged, and ensuring that samples represent the actual fluid conditions without dilution or contamination.
Implementation Method 1
The first sealer selectively forms a fluid-tight seal between the fluid receiving pipe and the casing to divide the fluid zone into a first zone and a spaced apart second zone
Data Source
AI summary
A zone isolation assembly for a fluid monitoring system in an existing subsurface well includes a fluid receiving pipe, a docking receiver, a docking apparatus and a first sealer. The fluid receiving pipe includes a pipe interior and a fluid inlet structure. The fluid receiving pipe receives a fluid through the fluid inlet structure into the pipe interior. The docking receiver is connected to the fluid receiving pipe. The docking apparatus moves between (i) a docked position wherein the docking apparatus is docked with the docking receiver, and (ii) an undocked position wherein the docking apparatus is undocked with the docking receiver. The first sealer is spaced apart from the docking apparatus. In certain embodiments, the first sealer selectively forms a fluid-tight seal between the fluid receiving pipe and the casing to divide the fluid zone into a first zone and a spaced apart second zone. The first zone and the second zone are not in fluid communication with one another when the docking apparatus is in the docked position.