Patent ID: 11913333
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 0:
1. A computer implemented method for determining three-phase saturation of a subsurface reservoir from data measurements of a well in the reservoir during production, the method comprising:
obtaining a surface production rate of oil, a surface production rate of water, and a surface production rate of gas from the well;
obtaining a static bottomhole pressure at a datum depth in the well;
determining a productivity index for each of a plurality of perforated cells associated with the well;
setting an initial well fractional flow, the initial well fractional flow comprising an initial well fractional flow of oil, an initial well fractional flow of gas, and an initial well fractional flow of water;
setting an initial bottomhole pressure for each of the plurality of perforated cells associated with the well;
determining, using the well fractional flow, a cell fractional flow of oil, a cell fractional flow of gas, and a cell fractional flow of water for each of the plurality of perforated cells;
determining, using the static bottomhole pressure, a cell bubble point pressure for each of the plurality of perforated cells;
determining, using the cell bubble point pressure for each of the plurality of perforated cells, a pressure-volume-temperature (PVT) property for each of the plurality of perforated cells;
determining, using the PVT property for each of the plurality of perforated cells, an oil density, a gas density, and a water density for each of the plurality of perforated cells;
determining, using the oil density, the gas density, and the water density for each of the plurality of perforated cells and the cell fractional flow of oil, the cell fractional flow of gas, and the cell fractional flow of water for each of the plurality of perforated cells, an average oil density, an average gas density, and an average water density for each of the plurality of perforated cells;
determining, using the PVT property for each of the plurality of perforated cells and the cell fractional flow of oil, the cell fractional flow of gas, and the cell fractional flow of water for each of the plurality of perforated cells, a PVT property for the well;
determining, using the PVT property for the well, a total production rate for the well at reservoir conditions, the total production rate comprising a total production rate of oil, a total production rate of gas, and a total production rate of water;
determining, using the total production rate for the well and the PVT property for the well, a new well fractional flow of oil, a new well fractional flow of gas, and a new well fractional flow of water;
using the new well fractional flow of oil, the new well fractional flow of gas, and the new well fractional flow of water, to determine the three-phase saturation of the subsurface reservoir, wherein the three-phase saturation comprises an oil saturation, a gas saturation, and a water saturation;
identifying a drilling site using the three-phase saturation; and
drilling a well based on the identification.