RE:RE:RE:O&G companies take noteFirst off, the vast majority of the injection gas will be Methane, the main componant of Natural gas. I'm sure they will not purchase propane for injection but it will be a component of the natural gas injection, meaning they are receiving the NG before it is treated through a de-propanizer. Propane is worth too much to inject.
The production of 1400 bbls/day of oil is just that, oil. It is the same as saying 1400 bopd. There may be no water production (I don't know but normally in a misible flood there is not water) and associated gas will be separated and re-injected, so will not be in the final production numbers.
In a formation such as this, the NG is injected in higher parts of the reservoir and the oil produced in the lower parts. There is very little increased gas production until enough oil production has occured allowing the gas blanket to break through. At that time high gas production wells will be shut in until it is no longer economic, at which time the field will be produced as a gas reservoir with high liquids cut.
Think of a keg of beer (which I do all the time). Air or CO2 is injected into the top of the keg forcing the beer up to the tap. When the air starts coming out of the tap, the keg is effectivly empty but still has all the air or CO2 in it which could be produced through the tap with a spray of beer but isn't as it is not any value. In the reservoir the NG has value though.