Something I put together for my wife.
Cycles/BI combination.
600 samples HDR lighting
Do you mind explaining the shader? 
I came across the idea as part of a OSL shader blog post which used a script to generate the colors for the oil effect. Scripting is beyond me on a good day so I just started playing around with the sample node set up that was provided and plugged a Noise Texture into the Transparent BSDF to generate the colors. The Musgrave Texture produces the small deformities in the bubble surface while a wave displacement provides the larger distortions.
Thank you!