Combine the blood orange juice, sugar, and red wine vinegar in a small saucepan. Bring the mixture to a simmer over medium heat and cook until it thickens enough to coat the back of a spoon, about 8 minutes. Set the gastrique aside to cool slightly.
Heat a large skillet over medium heat and add the pancetta cubes. Cook them, stirring occasionally, until they turn golden and crisp. Remove the pancetta with a slotted spoon and drain it on a paper towel.
Pat the scallops dry with a paper towel and season both sides with salt and black pepper. Add the olive oil to the same skillet and increase the heat to medium-high.
Place the scallops in the hot skillet and sear them for 2 to 3 minutes per side until they develop a golden crust and are just cooked through. Remove them from the heat.
Thread three scallops onto each wooden skewer. Drizzle the blood orange gastrique over the scallops and scatter the crispy pancetta on top before serving.