Buildcraft version: Buildcraft 7.1.22 for Minecraft 1.7.10
Forge version: 1.7.10 - 10.13.4.1614
Link to crashreport or log (on pastebin or gist, please don't put the entire log here) : There are no logs.
Singleplayer/multiplayer: Singleplayer

Additional information: I was mining some iron on my cave and then i fall into invisible petroleum.
Not using Optifine.

Can you try picking it up with a bucket to see what it is? (Or try in creative mode, whichever is easiest)

also can you provide a modlist (easiest is a debug crash, hold F3+c ingame for 10s and upload and link the crash)? if it is BC oil then another mod is most likely messing with it

The debug log is here: https://pastebin.com/SWGqbMAE

And i can pick up it with a bucket, and then drop it in another place but it is still invisible.

the picking up in a bucket was to confirm it is from buildcraft, can you check that the bucket is a bc oil bucket and not oil or anything else black from another mod?

It's from BC Energy.

does this heapen with just BC? if not then another mod is messing with the oil rendering somehow and you'll wana triage your mods to find the culpit then

this doesn't heapen with just BC installed so another mod must be messing with the rendering, try removing mods to see what mod is causing it to go invisible