$65 Isometric Complex Crude Oil Processing Plant Low-poly 3D model by OlegShuldiakov. Available on CGTrader with 52000 polys and 62000 vertices. Check it out on CGHub.
OBJ (OBJ, filesize: 52.1 MB), FBX (Autodesk FBX, filesize: 24.3 MB), MAX (Autodesk 3ds Max, filesize: 41.7 MB), MA (Autodesk Maya, filesize: 37.8 MB)