Methods and systems for estimation of oil formation volume factor

Patent metadata

Field	Value
Publication number	US-11768191-B2
Application number	US-202117319857-A
Country	US
Kind code	B2
Filing date	May 13, 2021
Priority date	Nov 6, 2014
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

Embodiments of the disclosure can include systems, methods, and devices for determining saturation pressure of an uncontaminated fluid. A technique facilitates fluid analysis in situ at a downhole location. Downhole saturation pressure measurements and downhole OBM filtrate contamination of a contaminated fluid may be obtained and a relationship may be determined between the saturation pressure measurements and OBM filtrate contamination. The relationship may be extrapolated to zero OBM filtrate contamination to determine the saturation pressure of the uncontaminated fluid. According to an embodiment, a sample of oil is obtained at the downhole location from oil in a reservoir. A downhole sampling system is used to determine whether a sample has contamination and other selected characteristics of the sample. The data obtained may be processed to provide a formation volume factor of the oil.

First claim

What is claimed is:

1. A method for downhole fluid analysis, comprising:
deploying a sampling system downhole in a borehole located within a reservoir containing hydrocarbons;
using the sampling system to obtain contaminated fluid samples at a plurality of stations along the borehole, the contaminated fluid samples containing fluid and oil based mud (OBM) filtrate;
providing a processor with at least one property of the contaminated fluid samples;
analyzing each contaminated fluid sample in situ to determine saturation pressure and density of each contaminated fluid sample;
correcting for any oil based mud (OBM) filtrate;
determining the saturation pressure of each fluid of the contaminated fluid sample; and
further comprising determining a formation volume factor (FVF) of oil in the reservoir based on saturation pressure and density of the fluid.

2. The method as recited in claim 1 , wherein analyzing comprises using a contamination monitoring module of the sampling system.

3. The method as recited in claim 2 , wherein further analyzing comprises using a microfluidic measurement module.

4. The method as recited in claim 3 , wherein using the contamination monitoring module comprises using an optical spectroscopy sensor, a viscosity sensor, and a density sensor.

5. The method as recited in claim 4 , wherein using the microfluidic measurement module comprises placing each oil sample in a depressurization chamber.

6. The method as recited in claim 1 , wherein processing comprises determining variations in FVF as the pressure on the oil varies from an initial reservoir pressure to a bubble point pressure.

7. The method as recited in claim 1 , wherein further analyzing comprises incipient flashing of each contaminated fluid sample within the borehole.

8. A method, comprising:
obtaining a contaminated fluid sample from a reservoir at a downhole location in a borehole, the contaminated fluid sample containing fluid and oil based mud filtrate;
providing a processor with at least one property of the contaminated fluid sample; and
using a contamination monitoring module and sensors at the downhole location to obtain data on the fluid; and
processing the data obtained downhole to determine an FVF of oil in the reservoir.

9. The method as recited in claim 8 , wherein obtaining comprises obtaining a plurality of contaminated fluid samples at a plurality of stations along the borehole wherein the fluid is oil.

10. The method as recited in claim 8 , wherein using comprises using the sensors in the contamination monitoring module to determine optical spectroscopy, viscosity, and density of the oil.

11. The method as recited in claim 8 , wherein using comprises using the sensors to determine optical spectroscopy, viscosity, and density of the oil.

12. The method as recited in claim 8 , wherein using further comprises depressurizing the contaminated sample in a depressurization chamber to determine bubble point pressure.

13. The method as recited in claim 8 , wherein processing comprises processing the data at a downhole location.

14. The method as recited in claim 8 , wherein processing comprises using the FVF to determine original oil-in-place in a geological structure.

15. The method as recited in claim 8 , wherein processing comprises determining variations in the FVF from initial reservoir pressure to bubble point pressure.

16. A system, comprising:
a well string comprising a sampling system deployed downhole in a wellbore, the sampling system comprising a contamination monitoring module;
a processor configured to process the data; and
a non-transitory tangible machine-readable memory coupled to the processor, the non-transitory tangible machine-readable memory storing machine-readable instructions that when executed by the processor cause the processor to perform operations comprising:
measuring downhole saturation pressures of a contaminated fluid over a pumpout volume or a pumpout time, wherein the contaminated fluid comprises fluid and OBM filtrate;
determining a function for the measured saturation pressures based on the pumpout volume or pumpout time;
extrapolating the function to infinite pumpout volume or infinite pumpout time;
determining a saturation pressure for the fluid at the infinite pumping volume or infinite pumping time;

obtaining a saturation pressure of the fluid; and
processing the data obtained downhole to determine an FVF of oil in the reservoir.

17. The system as recited in claim 16 , wherein the downhole saturation pressure comprises bubble point pressures.

18. The system as recited in claim 16 , wherein the operations further comprise determining the FVF of the uncontaminated fluid based on the downhole saturation pressure and a density of the uncontaminated fluid.

Assignees

• Schlumberger Technology Corp

Inventors

• Jalali Younes
• Tonoue Ryota
• Chen Hua
• Harrison Christopher
• Kader Kamal
• Zuo Youxiang
• Gisolf Adriaan
• Ayan Cosan
• Toribio Michael Mallari
• Desai Chetankumar Natwarlal
• Mullins Oliver Clinton
• Sullivan Matthew T
• Smythe Elizabeth

Classifications

• G01N33/2823 Primary

  Raw oil, drilling fluid or polyphasic mixtures · CPC title

• E21B47/00

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title

• E21B47/06

  Measuring temperature or pressure · CPC title

• E21B49/005

  Testing the nature of borehole walls or the formation by using drilling mud or cutting data · CPC title

• E21B49/08

  Obtaining fluid samples or testing fluids, in boreholes or wells · CPC title