Perforating Gun With Segmented Explosive Charges
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Solution Overview
Problem
Current well perforating technologies face challenges such as fracture tortuosity, micro-annulus, and halo effect during hydraulic fracturing, which are complications that arise from the geometry and placement of perforation tunnels created by existing perforating guns.
Innovation Solution
The use of a perforating gun with strategically oriented explosive charges to create both wide and narrow perforation tunnels, where the narrow tunnels intersect with the wide tunnels at or beyond the endpoint of the wide tunnel, creating a fracture initiation area that mitigates these complications by encouraging fracture initiation away from the well and facilitating proppant placement and initial pressurization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional explosive charges are used to create perforation tunnels, then the formation can be perforated, but fracture tortuosity, micro-annulus, and halo effect occur
Solution Approach 1:
The explosive charge is divided into multiple segments or zones along the perforation tunnel, with each segment creating a specific tunnel geometry. This segmentation allows different portions of the charge to create wide tunnels near the wellbore and narrow tunnels at greater depths, preventing the formation of tortuous fractures and micro-annulus by distributing the explosive energy more effectively throughout the formation.
Solution Approach 2:
Different regions of the explosive charge are designed with different properties to create specific tunnel characteristics at different locations. The charge configuration varies locally to produce wide tunnels near the wellbore for initial pressurization and narrow tunnels deeper in the formation for fracture initiation, thereby eliminating the halo effect and improving overall fracturing reliability.
2Ease of operation
If wide perforation tunnels are created near the wellbore, then initial pressurization and proppant placement are facilitated, but fracture initiation may occur too close to the well causing complications
Solution Approach 1:
The explosive charge is segmented into distinct functional zones: a first portion creates wide tunnels near the wellbore for ease of pressurization and proppant placement, while a second portion creates narrow tunnels at greater depths to control fracture initiation location. This segmentation resolves the contradiction by assigning different tunnel geometry requirements to different spatial zones within the formation.
Solution Approach 2:
The solution transitions from considering only tunnel width to considering both tunnel width and depth as independent dimensions. Wide tunnels are created in the near-wellbore region while narrow tunnels are created at greater depths, using the depth dimension to control fracture initiation location away from the wellbore, thereby maintaining ease of operation while improving reliability.
3Reliability
If narrow perforation tunnels are created to extend deeper into the formation, then fracture initiation area is shifted away from the well, but the tunnels are narrower and may limit fluid flow
Solution Approach 1:
The explosive charge is divided into portions that create different tunnel widths at different depths. The first portion creates wide tunnels for adequate fluid flow capacity, while the second portion creates narrow tunnels that extend deeper into the formation to position the fracture initiation area away from the wellbore, thereby resolving the contradiction between tunnel width and initiation location.
Solution Approach 2:
Different local regions of the formation receive different tunnel geometries tailored to their specific functional requirements. The near-wellbore region receives wide tunnels to maximize fluid flow and proppant placement efficiency, while the deeper formation regions receive narrow tunnels to control fracture initiation location, optimizing both parameters simultaneously through spatially varying tunnel quality.
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
This configuration reduces the likelihood of fracture tortuosity, micro-annulus, and halo effect within the well, allowing for more effective hydraulic fracturing by shifting the fracture initiation area away from the well and enabling efficient proppant placement and formation pressurization.
Implementation Method 1
The perforating gun of the present invention contains a plurality of explosive charges capable of creating perforation tunnels in the well and the adjacent formation upon detonation
Data Source
AI summary
The present invention provides an apparatus for use in perforating a well having a plurality of explosive charges. Each explosive charge is adapted to generate a perforation tunnel in the formation adjacent to the well. In one embodiment, explosive charges are oriented to create perforation tunnels that converge at a location within the formation in order to create a fracture initiation plane capable of mitigating or avoiding hydraulic fracturing complications.