Perforating Apparatus with Segmented Load Path for Deeper Penetration
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Solution Overview
Problem
Conventional perforating guns for high pressure and high temperature wellbores require thick carrier gun bodies to withstand loads, which reduces perforation depth and increases the risk of cracks and tool failure, while also limiting the size of shaped-charges and penetration efficiency.
Innovation Solution
A perforating apparatus with a charge-carrier that supports shaped-charges within an exterior tubular, where the charge-carrier bears axial loads and the exterior tubular, often made of lighter materials, handles radial loads, allowing for thinner walls and enhanced perforation performance without increased wall thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the carrier gun body wall thickness is increased to withstand high pressure and high temperature loads, then the strength and reliability of the perforating gun are improved, but the available volume for shaped-charges is reduced and the penetration depth into the formation is limited
Solution Approach 1:
The invention divides the load-bearing function into two separate components: the exterior tubular carries radial pressure loads, while the charge-carrier supports axial loads. This segmentation allows each component to be optimized for its specific function, enabling the charge-carrier to have thinner walls since it only needs to bear axial loads during gun string conveyance, thereby increasing the available volume for shaped-charges while maintaining overall structural strength.
Solution Approach 2:
The invention introduces a dual-load-path architecture that separates radial and axial load bearing functions into different spatial dimensions and structural elements. The exterior tubular handles radial compression from wellbore pressure, while the charge-carrier handles axial tensile and compressive loads during deployment. This dimensional separation of load paths resolves the contradiction by allowing the charge-carrier walls to be thinner without compromising overall gun body strength.
2Reliability
If the carrier gun body wall thickness is increased to prevent tool failure in high pressure wellbores, then the reliability is improved, but the penetration depth of perforations into the formation is reduced
Solution Approach 1:
By segmenting the load-bearing functions between the exterior tubular (radial loads) and charge-carrier (axial loads), the invention enables the use of thinner charge-carrier walls. This segmentation maintains reliability under high pressure conditions while reducing the barrier thickness that explosive jets must penetrate, thereby increasing perforation depth into the formation.
Solution Approach 2:
The invention applies different structural qualities to different parts of the system: the exterior tubular is designed with sufficient thickness to withstand radial pressure differentials, while the charge-carrier is designed with thinner walls optimized for axial load bearing. This local differentiation of structural properties allows the system to achieve both high reliability and deep penetration without requiring uniformly thick walls throughout.
3Strength
If the carrier gun body is designed with thick walls to withstand high pressure loads, then the strength is improved, but the available volume within the carrier gun body is reduced which necessitates the use of smaller shaped-charges
Solution Approach 1:
The invention segments the load-bearing responsibilities between two components: the exterior tubular handles radial pressure loads, allowing the charge-carrier to use thinner walls for axial load support only. This segmentation increases the internal volume of the charge-carrier, enabling the use of larger shaped-charges with greater explosive content, which improves perforation effectiveness.
Solution Approach 2:
The invention changes the structural parameters of the charge-carrier by reducing wall thickness through the dual-load-path design. This parameter change increases the internal volume available for shaped-charges, allowing larger charge sizes to be used within the same outer diameter constraints, thereby improving the quantity and potency of explosive material that can be deployed.
4Length of stationary object
If the carrier gun body wall thickness is reduced to increase perforation depth, then the penetration depth is improved, but the strength of the perforating gun is reduced
Solution Approach 1:
The invention segments the strength requirements into two separate components: the exterior tubular provides radial strength to withstand wellbore pressure, while the charge-carrier provides axial strength during deployment. This segmentation allows the charge-carrier walls to be reduced in thickness to enhance perforation depth without compromising overall gun body strength, as the exterior tubular compensates for the reduced axial load-bearing capacity.
5Productivity
If scallops are added to the hollow carrier gun body to reduce resistance and increase penetration depth, then the perforation performance is improved, but the spatial distribution of scallops must correspond to the shaped-charges which increases device complexity
Solution Approach 1:
The invention extracts the load-bearing and structural functions from the charge-carrier by introducing a separate exterior tubular. This extraction eliminates the need for complex scallop features in the charge-carrier, as the exterior tubular assumes the role of providing structural integrity. The charge-carrier can then be simplified to focus solely on supporting and positioning shaped-charges, reducing device complexity while maintaining perforation efficiency.
Solution Approach 2:
The invention applies different structural qualities to different components: the exterior tubular is designed with features optimized for pressure containment, while the charge-carrier is designed with features optimized for charge support and positioning. This local differentiation allows the charge-carrier to be simpler in design without compromising perforation performance, as the exterior tubular provides the necessary structural features.
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 apparatus achieves deeper and more efficient perforations in high pressure and high temperature wellbores by distributing loads effectively, reducing the risk of tool failure and maintaining performance across multiple uses.
Implementation Method 1
a plurality of shaped-charges supported by the charge-carrier and positioned within the exterior tubular such that, upon detonation, the shaped-charges perforate the exterior tubular
Implementation Method 2
A detonating cord that is used to detonate the shaped-charges is positioned adjacent to the rear of the shaped-charges
Data Source
AI summary
A perforating apparatus for a gun string is presented. The apparatus experiences an axial load and potentially a radial load during use. A central charge-carrier supports shaped-charges and substantially bears the axial load on the apparatus during use. The charge-carrier is positioned within an exterior sleeve and the plurality of shaped-charges, upon detonation, perforate the exterior sleeve. The exterior sleeve does not bear a substantial portion of the axial load on the apparatus and can therefore be thinner and cheaper than in prior art assemblies. An annular space can be defined between the charge-carrier and exterior sleeve. The exterior tubular can bear the radial load due to differential pressure in one embodiment. Alternately, the apparatus includes radial support members extending between the charge-carrier and sleeve for transmitting radial load to the charge-carrier. Alternately, the sleeve and charge-carrier abut one another along a substantial portion of the length of the charge-carrier.