Degradable Ball Sealers for Offset Well Fluid Influx Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic fracturing in unconventional reservoirs leads to fracturing fluids or reservoir water flowing into adjacent producing wells, reducing hydrocarbon production rates and necessitating additional water disposal.
Innovation Solution
Incorporating degradable ball sealers or particles into offset wells before fracturing, using a carrier fluid to partially or fully seal perforations, maintaining pressure above reservoir pressure to prevent fluid influx during fracturing, and allowing degradation post-treatment to ensure unobstructed production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydraulic fracturing is performed in offset wells to open more rock for hydrocarbon production, then productivity of the reservoir is improved, but fracturing fluid flows into producing wells reducing hydrocarbon production rate
Solution Approach 1:
The patent applies preliminary action by injecting ball sealers into the producing well before the hydraulic fracturing treatment begins in the offset well. These ball sealers are carried by fluid into the wellbore and accumulate at the perforations, creating a barrier that prevents fracturing fluid from entering the producing well during the fracturing operation. This preliminary placement of the sealing barrier resolves the contradiction by protecting the producing well in advance while allowing the fracturing treatment to proceed.
Solution Approach 2:
The patent uses ball sealers as an intermediary substance that mediates between the fracturing operation in the offset well and the producing well. The ball sealers are introduced into the producing well and form a barrier at the perforations, acting as a mediator that blocks the harmful flow of fracturing fluid while allowing the producing well to continue its intended function. This intermediary barrier resolves the technical contradiction by preventing fluid ingress without stopping the fracturing treatment.
2Object-affected harmful factors
If ball sealers are injected into producing well to prevent fluid ingress, then fracturing fluid influx is prevented, but additional water injection and disposal is required
Solution Approach 1:
The patent employs ball sealers that are designed to be temporary, disposable barriers. These ball sealers are injected into the producing well, perform their sealing function during the fracturing treatment, and then degrade or are removed afterward. This approach uses cheap, short-lived objects that provide the necessary protection temporarily without requiring permanent infrastructure or long-term water management systems, thus reducing the overall water injection and disposal burden.
Solution Approach 2:
The patent utilizes parameter changes by selecting ball sealers with specific degradation characteristics. The ball sealers are chosen to degrade at controlled rates based on their material composition, allowing them to provide sealing during the fracturing operation and then naturally break down afterward. This parameter change from intact to degraded state eliminates the need for continuous water injection and disposal, resolving the contradiction between protection and substance loss.
3Object-affected harmful factors
If degradable ball sealers are used to seal perforations temporarily, then fluid influx is prevented during fracturing, but degradation time must be synchronized with treatment duration
Solution Approach 1:
The patent applies parameter changes by selecting ball sealers with specific degradation rates that can be controlled through their material composition. Different materials degrade at different rates, allowing the practitioner to choose sealers whose degradation timeline matches the expected duration of the fracturing treatment. This parameter control resolves the contradiction by ensuring the sealers remain intact during treatment and then degrade naturally afterward without requiring precise external control mechanisms.
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
Prevents fracturing fluid ingress into producing wells, maintaining higher hydrocarbon production rates and reducing water saturation, thus optimizing reservoir performance.
Implementation Method 1
degradable ball sealers or degradable particles, or both, together or separately, may be injected into well 20 in a carrier fluid such as water or a fracturing fluid. Injection of fluid into well 20 is continued and sufficient ball sealers or degradable particles are injected to provide partial or complete shut-off of all perforations 22 in well 20
Implementation Method 2
a slow injection rate will be continued in well 20 to maintain pressure at the perforations at least above estimated reservoir pressure around the well during the fracturing treatment, so as to ensure that flow into the well does not unseat a ball or backflow particles
Implementation Method 3
Ball sealers or particles 31 may degrade before being produced with production from well 20, or they may not be recovered if fully degraded
Data Source
AI summary
Method is provided for preventing fluid from entering a well, such as a producing well, during a hydraulic fracturing treatment in another well completed in the same reservoir. Degradable ball sealers or degradable particulate material is injected into the well and pressure is maintained in the well during the fracturing treatment to prevent influx of fluid.