Removable Zonal Isolation for Sand Controlled Wells
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Solution Overview
Problem
Existing gravel packing methods in oil wells fail to effectively prevent the production of undesirable fluids, such as water, from entering the wellbore, especially from zones above or in the middle of the target zone, leading to contamination and reduced hydrocarbon production.
Innovation Solution
A process involving the installation of a removable plug and injection of a settable, low viscosity permeability poison into the sand or gravel filter element to create a longitudinal barrier, separating fluid-producing zones and allowing continued production from desired zones by removing treatment materials to regain access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gravel packing is used to prevent sand production, then sand control is improved, but the ability to selectively isolate fluid-producing zones is lost
Solution Approach 1:
The gravel pack is segmented into discrete treatable sections using settable isolators that create removable plugs at zone boundaries. This allows individual zones to be isolated and treated independently while maintaining the overall gravel pack structure for sand control.
Solution Approach 2:
A fluid seal comprising a gel phase and a foam phase is introduced as an intermediary substance within the gravel pack. The gel phase provides zonal isolation while the foam phase displaces hydrocarbons, enabling selective zone treatment without compromising sand control.
2Reliability
If a fluid seal is created to isolate zones, then cross-contamination is prevented, but access to deeper zones is blocked
Solution Approach 1:
The system uses dynamically controllable isolation through settable isolators that can be positioned and removed as needed. This allows the well to transition between isolated and accessible states, enabling zone-specific treatment while maintaining overall production capability.
Solution Approach 2:
Settable isolators are installed in advance to define treatment zones before fluid seal injection. This preliminary zonal definition enables precise control over where treatments occur while preserving access to other zones through the removable plug system.
3Adaptability or versatility
If treatment materials are injected into isolated zones, then zone-specific treatment is achieved, but treatment material may contaminate other zones
Solution Approach 1:
The wellbore is divided into discrete treatable zones using settable isolators that create physical barriers. This segmentation ensures treatment materials remain confined to target zones, preventing contamination of adjacent producing zones while enabling selective treatment.
Solution Approach 2:
Settable isolators function as disposable barriers that are installed for treatment, perform their isolation function, and then removed after treatment completion. This temporary isolation approach provides effective zone containment during treatment without permanent blockage of production pathways.
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
Effectively isolates undesirable fluid-producing zones from target zones, preventing cross-contamination and maintaining hydrocarbon production by creating a fluid seal within the sand control screen, allowing for selective zone isolation and treatment.
Implementation Method 1
The low viscosity permeability poison is converted into a fluid seal forming a longitudinal barrier against flow within the sand control screen in the annular production space
Implementation Method 2
The foam phase is capable of displacing hydrocarbons from the gravel pack so that treatment material can be delivered onto the formation at the isolated zone
Data Source
AI summary
A process for sealing off one or more segments of a gravel packed well to reduce the production of undesirable fluids. The process includes the installation of a removable plug and the installation of a removable sealant at a location in the gravel packing to separate portions of the formation that produce desirable products from portions that produce less desirable products. A flow poison is then squeezed into the portion of the formation that produces less desirable products. With wireline or other low-cost wellbore workover systems, access is re-engaged with the preferred formation including removal of plugs and sealants without mechanical drilling. The process allows increased production of preferred fluids by preventing less or non preferred fluids from displacing the preferred fluids and also reduces lifting costs that would otherwise be expended for lifting and expenses related to separating and disposing of non preferred fluids.