I'm going to try this when I get home, but I was curious if anyone has tried this. Most op amps are rated for ~ +15V to -15V. What would happen if I used +30V to -30V, but never amplified above the +15V to -15V range. Overall, I am looking to reduce power supply complexity. This is for just for testing, not production.
You will damage the opamp, possibly destroy it. Absolute maximum ratings will probably say +/- 18 V, beyond which they'll note that damage may occur. Since you'll not be exceeding the maximum by a few volts, but by 24 V no less, I have little hopes of your opamp surviving.
This is one of the many ways to make a magic smoke generator.
Ones made in this manner are extremely reliable and consistent in making magic smoke.
Why would you?
Reducing the power supplies to the correct limits may take as little as 4 resistors.
(Two per rail, in a divider that is "stiff" compared to op amp current.
BUT no matter what is required to provide power supplies in spec , that is what is required.