Determination of scanning loops of capillary pressure and relative permeability curves and wettability distribution of rock samples

Patent metadata

Field	Value
Publication number	US-2020371011-A1
Application number	US-201916420923-A
Country	US
Kind code	A1
Filing date	May 23, 2019
Priority date	May 23, 2019
Publication date	Nov 26, 2020
Grant date	—

Abstract

A primary drainage process, a core aging process, a spontaneous water imbibition process, a forced water imbibition process, a spontaneous hydrocarbon imbibition process, and a secondary drainage process is conducted on a rock sample. For each of the primary drainage process, the spontaneous water imbibition process, the forced water imbibition process, the spontaneous hydrocarbon imbibition process, and the secondary drainage process, a pressure distribution and a fluid saturation distribution are measured across multiple locations along the rock sample. For each of the locations, the pressure distribution and the fluid saturation distribution are combined to produce a capillary pressure bounding curve and scanning loop for the rock sample, and a relative permeability bounding curve and scanning loop are determined at least based on the measured fluid saturation and pressure distributions at the respective location. A wettability distribution along the rock sample is determined based on the bounding curves and scanning loops.

First claim

What is claimed is:

1 . A method comprising:
conducting a primary drainage process on a rock sample; conducting a core aging process on the rock sample; conducting a spontaneous water imbibition process on the rock sample; conducting a forced water imbibition process on the rock sample; conducting a spontaneous hydrocarbon imbibition process on the rock sample; conducting a secondary drainage process on the rock sample; for each of the primary drainage process, the spontaneous water imbibition process, the forced water imbibition process, the spontaneous hydrocarbon imbibition process, and the secondary drainage process:
measuring a pressure distribution across a plurality of locations along a longitudinal length of the rock sample; and
measuring a fluid saturation distribution across the plurality of locations along the longitudinal length of the rock sample;
for each of the locations along the longitudinal length of the rock sample:
combining the pressure distribution and the fluid saturation distribution to produce a capillary pressure bounding curve and scanning loop for the rock sample at the respective location; and
determining a relative permeability bounding curve and scanning loop at least based on the measured fluid saturation distribution and pressure distribution at the respective location; and
determining a wettability distribution along the longitudinal length of the rock sample based on the capillary pressure bounding curves and scanning loops.

2 . The method of claim 1 , further comprising:
saturating the rock sample with a water stream; calibrating an imaging machine using the rock sample saturated with the water stream; and determining a permeability distribution across the plurality of locations along the longitudinal length of the rock sample based on the measured pressure distribution.

3 . The method of claim 1 , further comprising conducting a cleaning process on the rock sample, the cleaning process comprising:
a) flowing toluene through the rock sample; b) flowing methanol through the rock sample; and c) repeating and alternating between steps a) and b) until an effluent from the rock sample is visually clear.

4 . The method of claim 1 , further comprising:
saturating the rock sample with a hydrocarbon stream; and calibrating an imaging machine using the rock sample saturated with the hydrocarbon stream.

5 . The method of claim 1 , wherein each of the primary drainage process and the core aging process comprises:
flowing a hydrocarbon stream into a first end of the rock sample at a first hydrocarbon flow rate; and while flowing the hydrocarbon stream, flowing a water stream across a second end of the rock sample at a first water flow rate.

6 . The method of claim 5 , wherein the spontaneous water imbibition process comprises:
flowing the water stream across the second end of the rock sample at the first water flow rate; and while flowing the water stream, flowing the hydrocarbon stream into the first end of the rock sample at a second hydrocarbon flow rate.

7 . The method of claim 6 , wherein the spontaneous water imbibition process further comprises, while flowing the water stream and after flowing the hydrocarbon stream at the second hydrocarbon flow rate, decreasing the flow of the hydrocarbon stream into the first end of the rock sample.

8 . The method of claim 7 , wherein the spontaneous water imbibition process further comprises, while flowing the water stream, flowing the hydrocarbon stream across the first end of the rock sample.

9 . The method of claim 6 , wherein the forced water imbibition process comprises:
flowing the hydrocarbon stream across the first end of the rock sample at a third hydrocarbon flow rate; and while flowing the hydrocarbon stream, flowing the water stream into the second end of the rock sample at a second water flow rate.

10 . The method of claim 9 , wherein the forced water imbibition process further comprises, while flowing the hydrocarbon stream and after flowing the water stream at the second water flow rate, increasing the flow of the water stream into the second end of the rock sample.

11 . The method of claim 9 , wherein the spontaneous hydrocarbon imbibition process comprises:
flowing the hydrocarbon stream across the first end of the rock sample at the third hydrocarbon flow rate; and while flowing the hydrocarbon stream, flowing the water stream into the second end of the rock sample at a third water flow rate.

12 . The method of claim 11 , wherein the spontaneous hydrocarbon imbibition process further comprises, while flowing the hydrocarbon stream and after flowing the water stream at the third water flow rate, decreasing the flow of the water stream into the second end of the rock sample.

13 . The method of claim 12 , wherein the spontaneous hydrocarbon imbibition process further comprises, while flowing the hydrocarbon stream, flowing the water stream across the second end of the rock sample.

14 . The method of claim 9 , wherein the secondary drainage process comprises:
flowing the water stream across the second end of the rock sample at the first water flow rate; and while flowing the water stream, flowing the hydrocarbon stream into the first end of the rock sample at a fourth hydrocarbon flow rate.

15 . The method of claim 12 , wherein the secondary drainage process further comprises, while flowing the water stream and after flowing the hydrocarbon stream at the fourth hydrocarbon flow rate, increasing the flow of the hydrocarbon stream into the first end of the rock sample.

16 . The method of claim 1 , further comprising determining a correlation between an initial hydrocarbon saturation and a residual hydrocarbon saturation based on the measured fluid saturation distributions across the plurality of locations along the longitudinal length of the rock sample.

17 . The method of claim 1 , further comprising, for each of the locations (x) along the longitudinal length of the rock sample, determining a relative permeability of a water phase (K rw ) to be:

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Assignees

• Saudi Arabian Oil Co

Inventors

• Chen Quan
• Al Enezi Sultan Muhammad
• Al-Yousef Ali Abdallah

Classifications

• G01N33/241

  for hydrocarbon content · CPC title

• G01N33/246

  for water content · CPC title

• G01N15/0826 Primary

  and measuring fluid flow rate, i.e. permeation rate or pressure change · CPC title

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title