Surface Hydraulic Fracturing for Faster Block Cave Propagation
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Solution Overview
Problem
Conventional block cave mining methods face high upfront costs and long lead times due to complex ore bodies and logistical challenges, particularly in establishing or extending block cave mines, which are exacerbated by depth-related issues such as strength/stress ratios, material handling costs, and seismicity.
Innovation Solution
Hydraulic fracturing a rock mass from above-ground using a drill rig and hydraulic fracturing equipment to induce fractures, combined with non-metallic casings for drilled holes, allowing for larger and higher-powered drilling operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional hydraulic fracturing is performed from underground sub-levels, then the rock mass can be pre-conditioned for block cave mining, but the establishment costs and lead times are high due to complex logistics and depth-related issues
Solution Approach 1:
The patent inverts the conventional approach by drilling holes from the ground surface downward into the rock mass, rather than drilling from underground sub-levels. This surface-based drilling approach eliminates the need for complex underground drilling logistics, reduces establishment costs, and accelerates the timeline to production by allowing parallel drilling operations from the surface.
2Productivity
If larger diameter holes are drilled for hydraulic fracturing, then higher-powered drilling operations can be used to accelerate cave propagation, but the drilling equipment becomes more complex and costly
Solution Approach 1:
By inverting the drilling direction to operate from surface downward, the patent enables the use of larger diameter holes and higher-powered drilling equipment that would be impractical to deploy from underground locations. The surface-based approach provides unrestricted access to heavy drilling machinery, allowing faster cave propagation without the logistical constraints of underground operations.
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
Accelerates cave propagation, reduces rock mass quality, minimizes seismicity, and minimizes damage to downstream equipment, thereby reducing establishment costs and times.
Implementation Method 1
injecting a hydraulic fracturing fluid into the drilled holes from above-ground equipment... and inducing fractures in the rock mass
Data Source
AI summary
Methods of hydraulic fracturing a rock mass as part of a method of establishing a block cave mine or extending an existing block cave mine includes (a) drilling a plurality of holes downwardly into the rock mass using drill rig equipment positioned on the ground above a proposed or existing block cave mine; and (b) injecting a hydraulic fracturing fluid into the drilled holes from above-ground hydraulic fracturing equipment and inducing fractures in the rock mass. A hydraulic fracturing equipment installation located above-ground drills a plurality of holes downwardly into the rock mass and injects a hydraulic fracturing fluid into the drilled holes and induces fractures in the rock mass. A non-metallic casing for drilled holes is also disclosed.