We still don't know there is an ongoing oil drill carried out by Vietnam or not. But there is one by Malaysia.
Last year, China sent the ship to Vietnam water as a tit for tat. https://twitter.com/DzungLeVN/status/1249934801848553472

Updated by anh @duandang https://twitter.com/duandang/status/1249993302352392192

As we predicted, Malaysia oil exploration activities could be the target for China's harassment. https://twitter.com/duandang/status/1250235057635086337