The initial reservoir pressure and temperature in the Lower

The initial reservoir pressure and temperature in the Lower Tuscaloosa reservoir of the East Fork Field were 5043 psig and 263 degree F. The bubble-point pressure of the 40 degree API oil plus 1110 scf/STB of gas produced from this field was measured as 3460 psig at 263 degree F. What type of reservoir fluid is in this reservoir? Is the reservoir oil saturated or undersaturated? How do you know? A field in north Louisiana discovered in 1953 and developed by 1956 had an initial producing gas-oil ratio of 2000 scf/STB. The stock-tank liquid was \"medium orange\" and had a gravity of 51.2 degree API. Classify this reservoir fluid. During the producing history of the field, the stock-tank liquid gravity steadily increased to 63 degree API, and the producing gas-oil ratio increased to a maximum of 29,000 scf/STB. Does this information confirm your classification? Why or why not?

Solution

3) According to the given conditions initial producing gas-oil ratio 1110 scf/STB is less than 2000 scf/STB and the stock tank gravity 40API is less than 45API. These are the basic characteristic of BLACK OIL.

Hence, the reservoir fluid type is BLACK OIL.

SInce the initial reservoir pressure 5043psig greater than the bubble point pressure 3460psig, the reservoir fluid is under saturated.