Requesting Supervision and Visit

[Hanyuye]

Hi GC'ers,

This is my second application season. I'm applying to graduate programs in Applied Math and Petroleum Engineering.

I graduated with a BA in English in several years ago and now returning to my roots, thus taking advanced undergrad math courses.

The main point is, I relished in Electrical Engineering shop class during high school and I want to engage in engineering again. Specifically in petroleum engineering, drilling and reservoir modeling/simulation. I love being in the field and the applied physics/math/geology/earth science of petroleum engineering is fascinating ever since I met one last summer.

I've emailed a few graduate directors of PE schools and some of them have said that I contact professors to request them to supervise me while I take remedial courses as an graduate student (that's if get in the first place). Do I ask professors now before application season, during, or after?

How do I approach this? I feel very clueless about requesting professors to supervise me while I'm a math major and having them deem me worthy.