Segmented Well Plug for Subterranean Zone Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for zone isolation in subterranean producing wells fail to effectively prevent undesired fluid flows between reservoir zones due to weakened barriers under pressure and temperature stress, leading to reduced or halted production, especially when water or gas coning occurs, causing damage to cement barriers and allowing unwanted fluid production.
Innovation Solution
A method involving the establishment of a balanced plug over a longitudinal section and across the entire cross-section of the well, using a perforation tool to create perforations, a washing tool to direct fluidized plugging material into the annulus between the pipe body and the surrounding well body, ensuring effective isolation by filling the pipe body and annulus with a plugging material, such as cement slurry or unconsolidated mass, to prevent fluid flow between zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cement barriers are used to isolate zones in subterranean wells, then zone isolation is achieved, but the barriers become damaged under pressure and temperature stress, leading to loss of integrity
Solution Approach 1:
The isolation system is divided into multiple segments: a primary cement barrier and a secondary mechanical barrier (plug). The plug is segmented into different functional zones including a filter pack section and a sealing section, allowing each segment to perform its specific function while sharing the isolation load, thereby preventing single-point failure under stress
Solution Approach 2:
The plug is positioned and secured in advance within the wellbore to provide preemptive protection against potential barrier failure. The filter pack is installed beforehand to stabilize the wellbore environment, creating a cushioning effect that reduces stress on the cement barrier before production begins, preventing damage before it occurs
2Productivity
If existing barriers are subjected to high pressure and temperature differences, then production control is possible, but the barriers suffer damage and integrity is ruined
Solution Approach 1:
The plug acts as an intermediary element between the high-stress production zones and the cement barrier. It absorbs and redistributes the pressure and temperature stresses, preventing direct transmission of harmful forces to the cement barrier while maintaining production control capability
Solution Approach 2:
The plug material properties are specifically designed to match and accommodate the extreme pressure and temperature parameters of the reservoir. By selecting materials with appropriate thermal conductivity, compressibility, and strength characteristics, the system can withstand harsh conditions without damaging the barrier
3Reliability
If a plug is established to isolate formation zones, then undesired fluid flow is prevented, but the well requires complex intervention operations to establish the plug
Solution Approach 1:
Multiple functions are merged into a single plug device: zonal isolation, wellbore stabilization, sand control, and pressure sealing are all integrated into one component. This eliminates the need for separate operations to install different barriers, reducing overall intervention complexity while maintaining reliable fluid flow isolation
Solution Approach 2:
The plug is designed as a universal device that can perform multiple functions simultaneously - it provides zonal isolation to prevent undesired fluid flow, stabilizes the wellbore through the filter pack, controls sand production, and seals against pressure differentials. This multi-functionality reduces the number of separate intervention operations needed
4Reliability
If the entire cross section of the well is plugged, then complete zone isolation is achieved, but production from the production zone may be blocked
Solution Approach 1:
The plug exhibits local quality variations along its length: the filter pack section provides permeability for sand control while the sealing section provides impermeability for zonal isolation. This spatial variation in properties allows the plug to perform different functions at different locations, achieving complete isolation without blocking 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
The method effectively isolates undesired fluid production zones from the rest of the well, maintaining or restoring production by creating a robust barrier that prevents fluid flow, even in cases where existing barriers have lost integrity, thereby optimizing well production and preventing water or gas coning.
Implementation Method 1
pumping a fluidized plugging material down the string and out into the pipe body, and thereby also into the annulus via the perforations in the pipe body
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method for zone isolation in a subterranean well (1) is described, the well (1) being provided with a pipe body (211) at least in a portion, characterized by the method including: (A) providing a plug (25) over a longitudinal section (L1) of the well (1), the plug (25) covering substantially the entire cross section (T1) of the well (1) at least in a portion of the longitudinal section (L1), so that the plug (1) fills the inside of a pipe body (211) and an annulus (5) between the outside of the pipe body (211) and a surrounding well body (7).