Additive Manufacturing of Dissolvable Downhole Tools and Materials

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The hydraulic fracturing of horizontal wellbores is an important process in Alberta's oil sands industry. The process requires a technique to seal previously fractured zones and to direct the flow to the next fracture stage, through a process known as "plug and perf", in which frac plugs are employed to isolate lower zones of the wellbore and perforation charges are employed to open the next zone for fracturing. Different down hole tools are used for this process and these tools are conventionally removed after their use by drilling or milling them out of wellbore. These drillout (or millout) and cleanup operations are time consuming and expensive. A number of innovations in this area have resulted into design and manufacturing of degradable metallic downhole tools using the principle of galvanic corrosion to eliminate the need for drillout (or millout) and cleanup operations. These tools dissolve in the well bore, thereby eliminating the need for expensive drillouts. Currently these tools are manufactured by powder metallurgy (chemical vapor deposition, and homogeneous mixing) to fabricate these tools. This results into challenges related to complex powder metallurgy process for material design and a complex manufacturing process and associated supply chain for manufacturing the dissolvable tools. The current process also limits the choice of materials and their mechanical properties. This research proposal aims to improve the design of dissolvable downhole tools by investigating appropriate material selection and additive manufacturing (AM) process. The research will look at Powder bed fusion (PBF) additive manufacturing technique as well as hybrid 3D printing and casting to develop parts with mechanical properties significantly higher than those achieved by conventional fabrication methods. This technique will also allows to make parts with complex geometry, leading to improved and controlled dissolving performance.