Systems and Methods For Formation Fluid Sampling

Patent metadata

Field	Value
Publication number	US-2016130940-A1
Application number	US-201414534813-A
Country	US
Kind code	A1
Filing date	Nov 6, 2014
Priority date	Nov 6, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

Embodiments of the disclosure can include systems and methods for formation fluid sampling. In one embodiment, a method can include monitoring a relationship between a first characteristic of a formation fluid extracted from a formation and a second characteristic of the formation fluid extracted from the formation, determining, based at least in part on the monitoring, that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation, and determining a reservoir fluid breakthrough based at least in part on the identification of the linear trend, wherein the reservoir fluid breakthrough is indicative of virgin reservoir fluid entering a sampling tool.

First claim

What is claimed is:

1 . A method comprising:
monitoring a relationship between a first characteristic of a formation fluid extracted from a formation and a second characteristic of the formation fluid extracted from the formation; determining, based at least in part on the monitoring, that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation; and determining a reservoir fluid breakthrough based at least in part on the identification of the linear trend, wherein the reservoir fluid breakthrough is indicative of virgin reservoir fluid entering a sampling tool.

2 . The method of claim 1 , wherein the sampling tool comprises a focused sampling tool comprising a sample flowline and a guard flowline, and wherein the method further comprises:
in response to identifying the reservoir fluid breakthrough, operating the sampling tool in a split-flow configuration such that a portion of the formation fluid is directed into the sample flowline and a portion of the formation fluid is directed into the guard flowline.

3 . The method of claim 2 , wherein the sample flowline is configured to provide a conduit for a flow of formation fluid extracted from the formation, wherein the guard flowline is configured to provide a conduit for flow of formation fluid extracted from the formation, and wherein the sampling tool comprises:
a sample pump configured to generate the flow of formation fluid through the sample flowline; and a guard pump configured to generate the flow of formation fluid through the guard flowline; and
wherein operating the sampling tool in the split-flow configuration comprises:
simultaneously operating both of the sample pump and the guard pump to generate the flow of formation fluid through the sample flowline and the guard flowline.

4 . The method of claim 2 , further comprising:
monitoring a contamination level of the formation fluid directed into the sample flowline; determining that the contamination level of the formation fluid directed into the sample flowline falls below a contamination threshold; and in response to determining that the contamination level of the formation fluid directed into the sample flowline falls below the contamination threshold, sampling the formation fluid directed into the sample flowline.

5 . The method of claim 4 , wherein sampling the formation fluid directed into the sample flowline comprises acquiring a sample of the formation fluid directed into the sample flowline, and wherein the method further comprises:
determining one or more characteristics of virgin formation fluid of the formation based at least in part on the sample.

6 . The method of claim 1 , wherein the method further comprises:
in response to identifying the reservoir fluid breakthrough:
identifying an interval that begins and ends after the reservoir fluid breakthrough;
identifying a set of optical density data that corresponds to the identified interval;
conducting a normalization procedure using the set of optical density data that corresponds to the identified interval; and
estimating a contamination level of the formation fluid based at least in part on the results of the normalization procedure.

7 . The method of claim 1 , wherein the first characteristic comprises a fluid density and wherein the second characteristic comprises an optical density.

8 . The method of claim 1 , wherein the first characteristic comprises a first optical density corresponding to optical measurements using a first wavelength of light, and the second characteristic comprises a second optical density corresponding to optical measurements using a second wavelength of light.

9 . The method of claim 1 , wherein the first characteristic comprises fluid conductivity and the second characteristic comprises fluid density.

10 . The method of claim 1 , wherein the reservoir fluid comprises oil.

11 . The method of claim 1 , wherein the reservoir fluid comprises water.

12 . The method of claim 1 , wherein the linear trend comprises a build-up trend or a build-down trend.

13 . The method of claim 1 , wherein determining that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation comprises:
determining that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation across at least a threshold period of time.

14 . The method of claim 1 , wherein determining that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation comprises:
determining that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation across at least a threshold volume of pumping.

15 . The method of claim 1 , wherein monitoring a relationship between a first characteristic of a formation fluid extracted from a formation and a second characteristic of the formation fluid extracted from the formation comprises:
acquiring downhole data; and identifying, in real-time, the relationship between a first characteristic of a formation fluid extracted from a formation and a second characteristic of the formation fluid extracted from the formation using the downhole data; and displaying, in real-time in a graphical user interface, a cross-plot of the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid.

16 . A non-transitory computer-readable storage medium comprising computer-executable instructions that are executable by one or more processors to cause:
monitoring a relationship between a first characteristic of a formation fluid extracted from a formation and a second characteristic of the formation fluid extracted from the formation; determining, based at least in part on the monitoring, that a linear trend is exhibited by the relationship between the first characteristic of the formation fluid extracted from the formation and the second characteristic of the formation fluid extracted from the formation; and determining a reservoir fluid breakthrough based at least in part on the identification of the linear trend, wherein the reservoir fluid breakthrough is indicative of virgin reservoir fluid entering a sampling tool.

17 . The medium of claim 16 , wherein the sampling tool comprises a focused sampling tool comprising a sample flowline and a guard flowline, and wherein the method further comprises:
in response to identifying the reservoir fluid breakthrough, operating the sampling tool in a split-flow configuration such that a portion of the formation fluid is directed into the sample flowline and a portion of the formation fluid is directed into the guard flowline.

18 . The medium of claim 16 , wherein the first characteristic comprises an optical density of the formation fluid.

19 . The medium of claim 16 , wherein the first characteristic comprises an

Assignees

• Schlumberger Technology Corp

Inventors

• Hsu Kai
• Gisolf Adriaan
• Zuo Youxiang
• Chang Yong
• Barbosa Beatriz E

Classifications

• E21B49/003 Primary

  by analysing drilling variables or conditions (E21B49/005 takes precedence; systems specially adapted for monitoring a plurality of drilling variables or conditions E21B44/00) · CPC title

• E21B49/10 Primary

  using side-wall fluid samplers or testers · CPC title

• E21B47/00

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

• E21B49/081 Primary

  with down-hole means for trapping a fluid sample (E21B49/10 takes precedence) · CPC title

• E21B49/088

  combined with sampling · CPC title