I like the #35, but I like the shape of #29 or #27 for the graphic a bit better. Can you remove the blue from the oil drop? Water is bad news in my business.
I am starting to think I'd like to see something other than an oil drop. If I do choose one, it will be yours, but I am hoping to see something a bit more sophisticated for my audience. My audience is 40 year old business people, and I need the logo to reflect intelligence, sophistication and rocks. Can you try to do something with rock layers?
by the way, your design #49 is my favourite of the oil drops. If I do decide to pick that style of logo you are the winner. I am hoping to see a few more designs from you yet still. Google "3D geological diagrams" to understand what I am still hoping to see in my logo.