A. Minimum reservoir pressure calculation

Well model and skin-factor calculation

Well model was made in program “Perform” with parameters:

 

The properties of the fluid:
Oil density - 0.850 g/cm3,
Gas density - 0.7,
50% water cut,
Water density - 1.07
GOR - 37.8 m3 (r) / m3 (x),
Saturation pressure - 75 bar,

Formation parameters:
Reservoir Pressure - 280 atm,
Temperature - 95 ° C,
Gor. permability - 5 mD
The thickness of the reservoir - 7.5 m
turbulence i - 0
The radius of the well - 108 mm
The radius of the reservoir - 350 m,
Type of completion - Open face / without calculation
Data for the test wells - Qn = 3.5 m3/day at Rzab = 244.9 atm

Data on the construction of wells:
Stream type - Pipe,
The correlation hole - Hagedorn & Brown (1963) oil
Wellhead pressure - 12 bar,
The top. perforation interval - 2960 m,
Casing - The depth of 3000 m, OD 139.7 mm, ID 118.62 mm,
Tubing - the depth of 2950 m, OD 73.03 mm, ID 62.71 mm.

Well survey:

 

 

MD, м	TVD, м

 

According to given parameters skin-factor was given value 3.9:

 

Analysis of the conditions of well flowing before HF

a. Minimum reservoir pressure calculation

To calculate reservoir pressure, with which well still will be producing fluid and having current water cut (50%) different pressures were tried out in program “Perform” using special function “sensitivity analysis”. Obtained reservoir pressure equals 247,4 bar: