those are minor and a turtle that size would most likely survive. and that sure looks like claw marks/damage from foreign objects.

check your tank, maybe the turtle hits sharp objects (edge of filters/skimmers) or something. and your substrate (gravel) is definitely too rough for piggies.

standard treatment procedure for injuries on softshell turtles that i usually implement are just the usage of aquarium salt and raised temperatures (85-86 degrees f)

no substrate (bare bottom) works fine for most keepers.

raise temperature of course use heater (with thermostat better)

anyway, those gravels would likely only cause injuries to the plastron (unless that piggy swims upside down) so there must be something else in the tank.