Perforating Bullet Assembly With Delayed Fracturing Charge
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Solution Overview
Problem
Existing wellbore perforating systems face challenges in effectively creating hydraulic communication passages and fracturing subterranean formations, as they often require extensive gun strings and may not efficiently direct pressure to isolate earth formations.
Innovation Solution
A charge device with a bullet assembly comprising a jacket filled with energetic material and a delay fuse, which is detonated to form a fracture in the formation, using expanding gases to direct pressure and optionally sealing the perforation to prevent backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional perforating systems use extensive gun strings to create hydraulic communication passages, then perforation coverage is improved, but device complexity and operation difficulty increase
Solution Approach 1:
The system segments the perforating function into multiple bullet assemblies that can be independently deployed. Each bullet assembly contains its own energetic material and delay fuse, allowing distributed perforation across the wellbore without requiring a single extensive gun string. This segmentation reduces the complexity of handling and deploying one long gun string while maintaining comprehensive perforation coverage.
Solution Approach 2:
The bullet assemblies are pre-loaded with energetic material and delay fuses before deployment. The delay fuse is pre-configured to ignite after a specific time delay, allowing the bullets to be deployed first and then automatically ignite their charges at the appropriate moment. This preliminary preparation simplifies the deployment process and reduces operational complexity during the actual perforating operation.
2Reliability
If traditional systems use cemented casing to hydraulically isolate earth formations, then formation isolation is improved, but the ability to efficiently direct pressure for fracturing is reduced
Solution Approach 1:
The bullet assembly acts as an intermediary device that bridges the wellbore and the formation. It creates a controlled pathway through the casing and cement sheath, allowing pressure to be efficiently directed into the formation for fracturing while maintaining isolation between formations. The perforation created by the bullet assembly serves as a controlled intermediary channel that overcomes the barrier effect of the cemented casing.
Solution Approach 2:
The system applies local quality by creating specific perforation zones at targeted locations rather than relying on uniform pressure distribution. The bullet assemblies are deployed to specific depths and orientations, creating localized pathways that efficiently direct pressure where needed for fracturing, while the cemented casing maintains overall formation isolation. This localized approach improves pressure direction efficiency without compromising formation isolation.
3Ease of manufacture
If perforating systems use simple bullet designs, then ease of manufacture is improved, but perforation efficiency and fracturing capability are reduced
Solution Approach 1:
The bullet assembly employs a nested structure where the delay fuse is contained within the jacket, and the energetic material is enclosed within the delay fuse assembly. This nested design consolidates multiple components into a compact unit that maintains perforation efficiency while simplifying manufacturing. The nested structure allows all critical components to be integrated into a single manufacturable unit rather than requiring assembly of separate complex parts.
Solution Approach 2:
The jacket is constructed from composite materials that combine structural integrity with the ability to contain and direct the energetic material reaction. This composite construction allows the jacket to serve multiple functions: containing the energetic material, directing the detonation wave, and maintaining structural integrity during deployment. The use of composite materials enables enhanced perforation efficiency without significantly increasing manufacturing complexity.
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 solution enables efficient fracturing of subterranean formations by generating pressure through the reaction of energetic materials, creating effective hydraulic communication passages and isolating earth formations, while minimizing backflow and enhancing perforation efficiency.
Implementation Method 1
A detonation wave is formed that directs the bullet assembly into the formation when the explosive in the housing is detonated
Implementation Method 2
The energetic material is reacted after the bullet assembly is launched a distance into the formation. Reacting the energetic material generates pressure within the formation to fracture the formation
Implementation Method 3
an end of the delay fuse is exposed to a detonation wave so that the delay fuse transfers the detonation wave to the energetic material for reacting the energetic material
Implementation Method 4
the seal ring provides a pressure barrier between the bullet assembly and an inner surface of the perforation
Data Source
AI summary
A method and device for fracturing a subterranean formation by projecting a bullet assembly into the formation and then reacting energetic material within the bullet assembly. The bullet assembly can be part of a charge device that is in a perforating gun. A delay fuse can be included so the energetic material reaction begins after the bullet assembly reaches the end of its travel in the formation.