RE: Watercut13 Jul 2020 01:34
CaptainSwag,
Someone on my wavelength.
"if i have my rose tinted glasses on i have always assumed/hoped the water cut will get worse as it starts emptying out and will eventually run dry(ish). but i am no oilie."
My understanding is:
Scenario 1: For conventional wells (e.g. oil reservoir with an aquifer):-
Yes, water cut will increase very slowly overtime as oil reserves are removed. The current productivity indexes are 205 stb/d/psi and 190 stb/d/psi for well 6 and 7z respectively. Overtime, as oil (and water) is removed from the well, the pressure decreases in the well (to the point where Hurricane may have to inject water into the well, to increase the pressure). As more and more water is injected, the water cut will increase.
Scenario 2: For Hurricane's case, assuming perched water:
As oil is extracted, water (from the perched water reserve) fills the "space" created by the extraction of oil due to the pressure difference between oil reserve and the perched water reserve. Therefore, water cut increases much quicker. At some point, the pressure between oil reserve and perched water reserve is likely to reach equilibrium (stopping water moving into the oil reserve). Following this, as production continues, more and more water is removed from the oil reserve --> therefore reducing the water cut quickly to "normal levels"
"normal levels" being scenario 1 above.
Slift.