Alternating Acid and Proppant Injection for Horizontal Well Fracturing
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Solution Overview
Problem
Creating multiple fractures in highly deviated or horizontal wells with open hole completions is challenging due to the lack of effective zonal isolation, which limits the creation of additional fractures along the wellbore.
Innovation Solution
A method involving alternating pressurized acid fracturing fluid and proppant-loaded fluid injections to create and sustain multiple fractures along the wellbore, where the proppant blocks the existing fracture, allowing the acid to initiate new fractures at different locations, thereby maintaining continuous pumping and preventing zonal isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional hydraulic fracturing is used in highly deviated or horizontal wells with open hole completions, then a single fracture can be created, but multiple fractures cannot be effectively created due to lack of zonal isolation
Solution Approach 1:
The treatment process is segmented into alternating cycles of acid fracturing fluid injection and proppant slurry injection. Each cycle creates or extends a fracture and then blocks it with proppant, enabling sequential creation of multiple fractures along the wellbore without requiring zonal isolation equipment.
Solution Approach 2:
The method employs periodic alternation between acid fracturing fluid and proppant slurry injection. This periodic action allows the system to create a fracture, block it, then move to the next location to create another fracture, repeating the cycle to generate multiple fractures along the horizontal or highly deviated wellbore.
2Productivity
If proppant is injected to block the fracture, then the existing fracture is blocked allowing new fracture initiation, but continuous fluid flow into the original fracture is prevented
Solution Approach 1:
Proppant material serves as an intermediary that selectively blocks the original fracture while allowing the acid fracturing fluid to initiate new fractures at different locations. The proppant acts as a temporary barrier that redirects fluid pressure to create additional fracture pathways for hydrocarbon production.
Solution Approach 2:
The method converts the harmful effect of fluid flow blockage into a beneficial outcome by intentionally using proppant to block the original fracture. This blockage prevents fluid from continuing down the same pathway and instead directs energy to create new fractures, ultimately increasing overall productivity through multiple fracture zones.
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 effectively generates multiple fractures connected along the wellbore, enhancing hydrocarbon production by creating a conductivity channel filled with proppant, which increases the flow communication between the fractures and the wellbore, overcoming the limitations of conventional fracturing techniques.
Implementation Method 1
The acid functions to dissolve formation materials forming the walls of the fracture, thus increasing the width and permeability thereof
Implementation Method 2
Granular proppant material, such as sand, ceramic beads, or other materials, is generally injected with the later portion of the fracturing fluid to hold the fracture(s) open after the pressures are released
Implementation Method 3
Hydraulic fracturing consists of injecting viscous fluids (usually shear thinning, non-Newtonian gels or emulsions) into a formation at such high pressures and rates that the reservoir rock fails and forms a plane, typically vertical, fracture
Data Source
AI summary
A method of creating multiple fractures in a well traversing a formation is described using pressurized fluids in a highly deviated or horizontal section of the well at a pressure above the fracturing pressure of the formation, wherein for creating a fracture the pressurized fluid is alternated between an acid fracturing fluid and a proppant loaded fluid, such that the proppant blocks the flow of pressurized fluid into a fracture created during a previous step of the method and the subsequently pressurized acid fracturing fluid creates a new fracture at a location along the highly deviated or horizontal section different from the location of the previously created fracture.