edit: Circuit example:
http://i.imgur.com/NWOwkgp.jpg
A few things:
1) Rotate the chem plant that produces sulfur so petroleum gas has a straight shot into the chemical plant. (This will save you a few pipe and look neater, that's all.)
2) Move the sulfur/sulfuric acid plants close together (one square apart) and use an inserter to directly feed the sulfur into the sulfuric acid plant. There's no need for belts here.
3) You probably don't need that much sulfuric acid storage. If you do or you're saving it for later, fine. If not, one storage tank is plenty.
4) Learn to love pipe-to-ground and use them wherever possible. They're more resource intensive than normal pipe but you'll thank me when you can run through your petroleum facility without needing to detour around pipes. Automating production of a couple hundred of the things won't take too long--four pipe assemblers feeding one pipe to ground assembler can pump them out rapidly. Then let your pipe assemblers output to storage for awhile so you have plenty of that, too.
5) Circuit production. These are really easy to mass produce in expandable lines, and that's good because you'll need a lot of each before you feel like you're properly exploiting the planet. With smaller scale production you can transfer directly between assemblers (eg, 3 copper coil -> 2 green circuit) but with large scale it's neater to output to conveyor belts so you can split things off.
Anyways, you wind up with parallel rows of: copper coil production, green circuits, red circuits, blue circuits. Each row feeds the next and sometimes the next row after that:
coil coil coil (output via belt to green and red circuit assemblers)
green (output via belt to red/blue circuit assemblers)
red (output via belt to blue circuit assemblers - a speed module 1 in each assembler will let red keep up with blue production
blue (output to storage - now we can make fancy pants stuff)
It's probably worth your while to create separate factories to make only green and red circuits because you're going to need a ton of them. Alternatively, when you feel you have enough blue processing units, remove the inserters and route the green/red circuits to storage.
6) Science production. Assuming you have logistic bots to go with that roboport, let your bots do all the work and move those labs elsewhere. One assembler each for red/green/blue science will supply five-ish labs (I *think* blue science will need a speed module) and five labs gets stuff researched in a reasonable amount of time. If that's not fast enough for you, blueprint the layout and double/triple your science production with the click of a button!
At minimum, it's usually easiest to keep science production separate from everything else, if only because you usually need to get science up and running RIGHT AWAY and later when you want to build a big production chain you have all this out of place stuff in your way. With bots and blueprints it's really, really easy to move at your whim.
7) You will need lubricant for express belts and electric engine units. Consider converting your heavy oil to lube instead of light oil.