Oil Fields
Main Oil Pipeline
This stretches throughout the level and acts as a temporary perimeter - you can take out the individual sections in order to cut across it. Just make sure that you do so well in advance, as they take a few seconds to explode and clear completely.
Green Drum Compound
This compound contains a number of explosive elements - so try not to get caught up in them when they go off. In addition to the large containers, there are a number of smaller drums surrounding them. Wait until there are a number of enemies neraby, then start taking the drums out to cause a chain reaction - with your vehicle hopefully emerging intact form the wreckage!
Oil Canisters
There are lots of these in the level - behind the main refinery, surreounding the refinery on the hill and behind the green container compund. Shoot the tank a few time to dismount it, then watch as it rolls around the arena. As soon as it comes in contact with a vehicle, it explodes, so set a few of them free at the same time, jsut to be sure!
Larger vehicles are particularly prone being hit as they'll have trouble getting out of the way in time. High-avoidance vehicles on the other hand fare much better, they can usually zig zag in and out of the with ease.
Oil Towers
Take these towers out, then, when the fire dies down, a large gusher of oil fires into the air. These a much like the jets in Hoover Dam, just drive into them and you'll be launhced skyward without taking damage. Again, smaller vehicles can make the most of this, usually gaining enough height to cross one or more pipelines
Oil Refinery (on Hill)
This is the highest point in the level and as such, a great vantage point to lauch mortars/missiles from. Unfortunately, it's also surrounded by explosive components and be careful to keep an eye on enemies sneaking up the backroad to take you by surprise!
Main Oil Refinery
There's a road running straight through this refinery which provides good cover from homing attacks. The buildings nearby can withstand a good deal of punishment before they're destroyed and there's usualyy a powerup or two...