Perforating Gun Pressure Charge Design for Transient Pressure Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Perforating wells with casing/carrier guns can create large transient pressure changes, damaging completion tools and causing other issues due to uneven pressure distribution along the wellbore, especially when partially loaded to target specific zones.

Innovation Solution

Deploying pressure charges with explosive material in non-perforation sections of the perforating gun string, which detonate to maintain pressure without creating perforations, using a jet-off part to arrest the formation of perforating jets and minimize transient pressure differentials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If perforating guns are partially loaded to perforate specific zones, then perforation precision is improved, but transient pressure changes increase causing damage to completion tools

Engineering Contradiction:

Improveperforation precisionVSAvoidtransient pressure changes

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by differentiating between perforating sections and non-perforating sections of the gun string. Pressure charges are specifically placed in non-perforating sections to generate pressure locally without creating perforations, while shaped charges are placed in perforating sections. This localized differentiation allows the system to achieve zone-specific perforation precision while simultaneously managing transient pressure changes in non-perforating zones.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If pressure charges are used in non-perforation regions, then transient pressure changes are reduced, but device complexity increases

Engineering Contradiction:

Improvetransient pressure changesVSAvoidgun string structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the functions of pressure generation and perforation into a unified gun string system. Pressure charges and shaped charges are integrated within the same carrier gun, allowing simultaneous pressure management and perforation operations. This combining approach reduces the need for separate devices while managing the complexity through functional integration.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The carrier gun structure serves multiple functions: it holds both pressure charges and shaped charges, provides structural support during deployment, and manages pressure distribution along the entire gun string. This multi-functionality reduces the need for additional specialized components, thereby managing device complexity while achieving the desired pressure control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Reliability

If shaped charges are detonated in perforating sections, then perforation effectiveness is improved, but pressure distribution becomes uneven along the gun string

Engineering Contradiction:

Improveperforation effectivenessVSAvoidpressure distribution

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary anti-action by placing pressure charges in non-perforating sections before the detonation sequence begins. These pressure charges pre-establish pressure support in sections that would otherwise experience pressure drops, counteracting the uneven pressure distribution that would result from shaped charge detonations alone. This preemptive pressure management maintains more uniform pressure distribution throughout the gun string.

Inventive Principle:

Principle #9Preliminary anti-action

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 approach ensures consistent pressure loading along the perforating gun, reducing the risk of damage to tools and formations by minimizing transient pressure differentials and preventing perforations in non-target zones, thus maintaining system integrity and preventing issues like sanded-in or stuck guns.

Implementation Method 1

Each pressure charge may comprise a casing with an explosive material disposed in the casing to create desired pressure effects

Methodology Applied

Scientific EffectDetonation: Detonation

Implementation Method 2

The components and structure of the pressure charge enable detonation and the corresponding increase in pressure within the gun string

Methodology Applied

Scientific EffectPressure increase: Pressure Increase

Implementation Method 3

a jet-off part positioned to arrest formation of a perforating jet

Methodology Applied

Scientific EffectJet arrest: Jet

Data Source

PatentUS11215040B2System and methodology for minimizing perforating gun shock loads

Publication Date: 2022.01.04 SCHLUMBERGER TECH CORP

AI summary

A technique facilitates perforating along specific regions of a wellbore without creating detrimental transient pressure changes along a perforating gun string. In non-perforation regions, pressure charges may be used to maintain pressure within the gun string without creating perforations through the surrounding casing and into the surrounding formation. Each pressure charge may comprise a casing with an explosive material disposed in the casing. However, the components and structure of the pressure charge enable detonation and the corresponding increase in pressure within the gun string without creating perforations.