Flexible Jacket for Unconsolidated Sand Core Stress Simulation
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Solution Overview
Problem
Current methods for testing well perforators are inadequate for unconsolidated sandstones as they cannot simulate in-situ stress and pore pressure conditions, limiting the extension of well performance improvements to these types of reservoirs.
Innovation Solution
An apparatus is developed to construct a target core from unconsolidated sand, applying confining stress using a flexible jacket and support core, allowing for simulated downhole conditions and flow performance testing of perforations made in the target core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If API Section I tests are used to assess charge penetration performance in concrete targets under surface conditions, then penetration depth can be measured simply, but the results are misleading for selecting charges for rocks with different properties under in-situ conditions
Solution Approach 1:
The patent introduces an intermediary device - a flexible jacket - that mediates between the unconsolidated sand and the confining stress application. This jacket allows the simulation of in-situ stress conditions while maintaining the ability to test unconsolidated sand, bridging the gap between simple testing and accurate results
Solution Approach 2:
The patent changes the testing parameters by transitioning from surface conditions to simulated in-situ conditions. By applying confining stress through the flexible jacket to reach target effective stresses between 1,000-20,000 psi, the testing parameters are adjusted to match actual downhole environments, making charge selection accurate for specific reservoir conditions
2Reliability
If API Section IV procedures are used to assess perforation inflow performance under simulated in-situ stress conditions, then well productivity data can be obtained, but the procedures cannot be applied to unconsolidated sandstones due to inability to simulate in-situ stress and pore pressure conditions
Solution Approach 1:
The patent employs a flexible jacket (flexible shell) to contain the unconsolidated sand and transmit confining stress. This flexible shell enables the simulation of in-situ stress conditions that were previously impossible with unconsolidated sand, allowing API Section IV procedures to be applied to this material type
Solution Approach 2:
The flexible jacket acts as an intermediary that allows pore pressure to be applied to the unconsolidated sand while maintaining structural integrity. This intermediary enables the simulation of both in-situ stress and pore pressure conditions simultaneously, making the testing applicable to unconsolidated sandstones
3Adaptability or versatility
If unconsolidated sand is used as the target material, then testing can be performed on actual reservoir material, but the sand cannot maintain structural integrity under simulated downhole conditions without the flexible jacket
Solution Approach 1:
The flexible jacket provides the necessary structural support to unconsolidated sand, allowing it to maintain integrity under simulated downhole conditions. The jacket contains the sand while transmitting the confining stress, enabling the use of actual reservoir material without compromising structural stability
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
Enables the collection of data on penetration and inflow performance of shaped charges under simulated in-situ conditions, enabling the extension of well performance improvements to unconsolidated sandstone reservoirs.
Implementation Method 1
A flexible jacket is operable to receive the support core and apply a confining stress to the support core. The support core is operable to transmit at least a portion of the confining stress to the unconsolidated sand, thereby forming the target core from the unconsolidated sand.
Implementation Method 2
a shaped charge operable to form a perforation in the target core under the simulated downhole conditions
Implementation Method 3
detonation of the shaped charge to form a perforation in the target core
Data Source
AI summary
An apparatus for constructing a target core to enable testing at simulated wellbore conditions. The apparatus includes a support core having a target core receiving region. A flexible jacket is operable to receive the support core and apply a confining stress to the support core. A quantity of unconsolidated sand is disposed within the target core receiving region of the support core. The support core is operable to transmit at least a portion of the confining stress to the unconsolidated sand, thereby forming the target core. The apparatus simulates downhole conditions such that flow tests may be performed on the target core before and after perforating the target core.