How can I mix petroleum and natural gas in Modelica/SystemModeler?

I am trying to simulate petroleum gas lift like in the image below:
enter image description here

Here, gas will be injected through the valve and mix with oil. The problem is that Modelica always gives an error when the medium in one component differs from the medium in the other. I am not sure how to make them mix together.

I would like to mix natural gas with petroleum and be able to control the gas injection rate to control the production of petroleum. Any ideas on how to make gas and petroleum mix in Modelica/ SystemModeler?

Thanks

I tried this, but I can't mix different media:

enter image description here

You have to define a new Medium model that describes the behavior of the mixture of gas and petroleum. It's a very tricky problem that you want to model. I suggest to do some research first to find literature describing this phenomenon in 1D in order to find a way how to describe it in Modelica.