Perturbed In-Line Perforations for Lower-Pressure Fracture Initiation
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Solution Overview
Problem
Existing perforation technologies in the oil and gas industry face challenges in determining the optimal placement of perforations and achieving desired perforation geometry, leading to inefficiencies in hydraulic fracturing and reservoir connectivity.
Innovation Solution
The implementation of perturbed in-line perforations, where perforations are arranged along a longitudinal direction with varying azimuthal angles, allowing for transverse hydraulic fracture initiation at lower pressures and controlled fracture growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional perforation methods are used, then perforations can be created through casing and cement, but optimal placement and desired geometry are difficult to achieve
Solution Approach 1:
The perforation system segments the perforation creation process into multiple independent shaped charges arranged in a linear array. Each charge creates an individual perforation at a specific location and angle, allowing precise control over the overall perforation cluster geometry without requiring complex integrated tooling.
Solution Approach 2:
The system applies local quality by varying the azimuthal orientation of individual perforations within the cluster. Each perforation can be oriented at a different angle relative to the wellbore axis, creating a perturbed pattern that optimizes fracture initiation locally while maintaining overall cluster coherence.
2Stress or pressure
If traditional in-line perforations are used, then simple tool design is maintained, but transverse hydraulic fracture initiation at lower pressures is not achieved
Solution Approach 1:
The system introduces asymmetry by perturbing the azimuthal angles of perforations from a perfectly symmetric in-line arrangement. This asymmetric perturbation creates stress concentrations that favor transverse fracture initiation and reduces the pressure required for fracture initiation compared to symmetric configurations.
Solution Approach 2:
The system transitions from a one-dimensional in-line perforation arrangement to a three-dimensional perturbed configuration by introducing azimuthal angle variations. This dimensional enhancement allows the perforation cluster to initiate fractures in multiple directions and at lower pressures.
3Productivity
If perforations are placed without perturbation, then uniform distribution is achieved, but reservoir contact area and wellbore performance are limited
Solution Approach 1:
The system uses asymmetric perturbation of perforation azimuthal angles to enhance wellbore performance. The non-uniform angular distribution creates more effective stress orientations that improve fracture propagation into the reservoir, increasing productivity despite the irregular pattern.
Solution Approach 2:
The system changes the angular parameters of perforation orientation from uniform to perturbed values. By varying the azimuthal angles within a controlled range, the system optimizes fracture initiation and propagation characteristics to enhance reservoir drainage and wellbore performance.
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 enhances operational efficiency by facilitating fracture initiation and propagation at reduced hydraulic pressures, increasing reservoir contact area and wellbore performance.
Implementation Method 1
The shaped charges can be configured to focus the explosive energy in a specific direction and create perforations through the casing and cement, penetrating into the surrounding formation
Implementation Method 2
A perforating gun generally holds several explosive-shaped charges
Implementation Method 3
An abrasive jet perforating tool deploys high-pressure abrasive fluid jets to cut through the casing, cement and into the surrounding formations
Data Source
AI summary
A bottom hole assembly includes a downhole conveyance that is extendable from a terranean surface, through a wellbore, and to a subterranean formation; and a perforating tool configured to couple to the downhole conveyance and create a perforation cluster in the subterranean formation. The perforation cluster includes perforations arranged along a longitudinal direction of the wellbore. The perforations includes one or more first perforations extending along a first azimuthal direction, one or more second perforations extending along a second azimuthal direction at a first offset angle with respective to the first azimuthal direction, and one or more third perforations extending along a third azimuthal direction at a second offset angle with respective to the first azimuthal direction. The one or more second perforations and the one or more third perforations are alternative with each other along the longitudinal direction of the wellbore.