get_all_mining_drills.lua

function find_all_entity(entity_name)
  local surface = game.surfaces['nauvis']
  local entities = {}
  for chunk in surface.get_chunks() do
    local chunk_area = {lefttop = {x = chunk.x*32, y = chunk.y*32}, rightbottom = {x = chunk.x*32+32, y = chunk.y*32+32}}
    local chunk_entities = surface.find_entities_filtered({area = chunk_area, name = entity_name})
    for i = 1, #chunk_entities do
      entities[#entities + 1] = chunk_entities[i]
    end
  end
  return entities
end

print(serpent.dump(find_all_entity('mining-drill')))