Expandable Sleeves for Hydraulic Stimulation Zone Isolation
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Solution Overview
Problem
Current hydraulic fracking methods for horizontal wells face challenges such as lengthy cementing operations, limited control over fracture initiation and propagation, and risks associated with expandable sleeves sagging under pressure, leading to inefficient gas or petroleum extraction.
Innovation Solution
A method involving a conduit with expandable tubular sleeves positioned along its external face, where fluid is injected under pressure to expand the sleeves tightly against the well casing, allowing for targeted and controlled hydraulic stimulation by creating a confined space for each stimulation area, enabling precise fracking and re-fracking operations with perfect sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If expandable sleeves are used to isolate stimulation areas, then fracture initiation and propagation can be controlled, but the sleeves may sag under pressure reducing reliability
Solution Approach 1:
The wellbore is divided into multiple isolated stimulation zones using expandable sleeves that can be independently controlled. Each sleeve creates a sealed segment between packers, allowing precise control over where fractures initiate and propagate along the horizontal well, while maintaining structural integrity through the segmentation of pressure zones.
2Reliability
If cementing operations are performed in horizontal wells, then isolation between zones is achieved, but the operation becomes lengthy and difficult
Solution Approach 1:
The patent replaces the complex chemical cementing process with a mechanical isolation system using expandable sleeves and packers. The sleeves are mechanically expanded against the wellbore wall to create seals, eliminating the need for lengthy cementing operations while achieving reliable zone isolation through pure mechanical means.
3Ease of operation
If sliding sleeves are activated by balls launched from surface, then stimulation areas can be accessed, but the number of stimulated areas is limited
Solution Approach 1:
The system transitions from static sliding sleeves to dynamically expandable sleeves that can be activated on-demand. The expandable sleeves remain collapsed during deployment and are only expanded when a specific stimulation zone needs to be accessed, allowing multiple stimulation areas to be serviced by the same physical device through dynamic reconfiguration.
4Device complexity
If the same stimulation pressure is applied throughout the well, then simplicity is maintained, but control over specific fracture areas is lost
Solution Approach 1:
The pressure system is segmented into independent zones by the expandable sleeves, allowing each stimulation area to receive controlled pressure independently. While the overall system maintains simplicity through uniform pressure application from a single pump, the segmented isolation enables precise control over which specific areas experience fracture pressures, combining simplicity with precision.
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 method allows for highly targeted and efficient fracking and re-fracking operations, increasing fracture penetration and developing new fracture networks, thereby optimizing production while minimizing costs and maintaining tight sealing between fracked areas and surrounding rock.
Implementation Method 1
injecting a fluid into said conduit under a first pre-determined pressure, this first pressure being sufficient to prompt the expansion of the said sleeves towards the wall of the casing so they get applied against this wall in a tightly sealed way
Data Source
AI summary
A method for hydraulic stimulation of rock of a borehole of a well having an internal casing. The method includes positioning a conduit in the casing, the conduit having along its external face expandable tubular sleeves, fixedly linked to the conduit, and at least one aperture before each sleeve placing the internal space of the conduit into communication with the space demarcated by the conduit and each sleeve. A fluid is injected into the conduit under a first pre-determined pressure, which is sufficient to expand the sleeves. For each of the areas of the wall of the well to be stimulated, the method includes: plugging the conduit downstream from a first area to be stimulated; perforating the wall of the conduit and, at least in certain cases, perforating the casing at the first area to be stimulated; and injecting a fluid into the conduit under a second stimulation pressure.