Systems and methods for in-situ measurements of mixed formation fluids

Patent metadata

Field	Value
Publication number	US-10132164-B2
Application number	US-201514975698-A
Country	US
Kind code	B2
Filing date	Dec 18, 2015
Priority date	Dec 18, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Systems and methods for obtaining in-situ measurements of mixed formation fluids are provided. A downhole acquisition tool may move to a first station in a wellbore in a geological formation to collect a sample of first formation fluid from the first station. The downhole acquisition tool may move to a second station in the wellbore and a sample of second formation fluid may be collected. A proportion of the first formation fluid and the second formation fluid may be mixed within the downhole acquisition tool in-situ while the downhole acquisition tool is within the wellbore to obtain a formation fluid mixture. The formation fluid mixture may be passed into a fluid testing component of the downhole acquisition tool while the downhole acquisition tool is in the wellbore to measure fluid properties of the formation fluid mixture in-situ.

First claim

The invention claimed is:

1. A method comprising:
moving a downhole acquisition tool to a first station in a wellbore in a geological formation;
collecting a sample of first formation fluid from the first station using the downhole acquisition tool;
moving the downhole acquisition tool to a second station in the wellbore;
collecting a sample of second formation fluid from the second station using the downhole acquisition tool;
mixing a proportion of the first formation fluid and the second formation fluid within the downhole acquisition tool in-situ while the downhole acquisition tool is within the wellbore to obtain a formation fluid mixture; and
passing the formation fluid mixture into a fluid testing component of the downhole acquisition tool while the downhole acquisition tool is in the wellbore to measure fluid properties of the formation fluid mixture in-situ.

2. The method of claim 1 , wherein:
the first station is at a first depth in the wellbore where the first formation fluid derives substantially from a first fluid zone;
the second station is at a second depth in the wellbore where the formation fluid derives substantially from a second fluid zone; and
the first fluid zone and the second fluid zone are substantially hydraulically isolated from one another in the geological formation.

3. The method of claim 1 , wherein:
the sample of the first formation fluid is collected into a first sample chamber;
the sample of the second formation fluid is collected into a second sample chamber; and
the first formation fluid and the second formation fluid are mixed in-situ including by:
transferring a first portion of the first formation fluid from the first sample chamber into a third sample chamber; and
transferring a second portion of the second formation fluid from the second sample chamber into the third sample chamber to obtain the formation fluid mixture.

4. The method of claim 3 , wherein a volume of the first portion and a volume of the second portion are substantially equal, thereby producing approximately a 1:1 mixture of the first formation fluid and the second formation fluid in the formation fluid mixture.

5. The method of claim 3 , wherein a volume of the first portion and a volume of the second portion are substantially unequal, thereby producing a mixture of the first formation fluid and the second formation fluid in the formation fluid mixture that is not 1:1 in proportion.

6. The method of claim 3 , wherein the first formation fluid and the second formation fluid are mixed in-situ including by transferring the formation fluid mixture from the third sample chamber into a fourth sample chamber to further mix the formation fluid mixture.

7. The method of claim 6 , wherein the first formation fluid and the second formation fluid are mixed in-situ including by transferring the formation fluid mixture from the fourth sample chamber back into the third sample chamber to even further mix the formation fluid mixture.

8. The method of claim 1 , wherein:
the sample of the first formation fluid is collected into a first sample chamber;
the sample of the second formation fluid is collected into a second sample chamber; and
the first formation fluid and the second formation fluid are mixed in-situ including by forcing the first formation fluid out of the first sample chamber while simultaneously forcing the second formation fluid out of the second sample chamber, thereby causing the first formation fluid and the second formation fluid to mix in a flowline of the downhole acquisition tool to obtain the formation fluid mixture.

9. The method of claim 8 , wherein the first formation fluid is forced out of the first sample chamber at a first flowrate and the second formation fluid is forced out of the second sample chamber at a second flowrate, wherein the flowrates are approximately equal.

10. The method of claim 8 , wherein the first formation fluid is forced out of the first sample chamber using a force fluid from a first pump and wherein the second formation fluid is forced out of the second sample chamber using the force fluid from the same first pump.

11. The method of claim 8 , wherein the first formation fluid is forced out of the first sample chamber using a force fluid from a first pump and wherein the second formation fluid is forced out of the second sample chamber using a force fluid from a second pump not in fluid communication with the first pump.

12. The method of claim 11 , wherein:
the first formation fluid is forced out of the first sample chamber at a first flowrate that is substantially equal to a force fluid flowrate from the first pump; and
the second formation fluid is forced out of the second sample chamber at a second flowrate that is substantially equal to a force fluid flowrate from the second pump;
wherein the first flowrate and the second flowrate are unequal, thereby causing a proportion of the formation fluid mixture to be controllable by a proportion of the first flowrate and the second flowrate.

13. The method of claim 1 , wherein:
the sample of the first formation fluid is initially collected into a first sample chamber; and
the sample of the second formation fluid is initially collected into the same first sample chamber, thereby causing the first formation fluid and the second formation fluid to mix inside the first sample chamber to obtain the formation fluid mixture.

14. A downhole acquisition tool configured to be placed in a wellbore in a geological formation and perform in-situ fluid testing of a formation fluid mixture that includes first formation fluid from a first station in the wellbore and second formation fluid from a second station in the wellbore, the downhole acquisition tool comprising:
a first flowline;
a second flowline;
a comingle valve configured to selectively permit or deny fluid communication between the first flowline and the second flowline;
a probe configured to draw formation fluid in from outside the downhole acquisition tool onto the first flowline via an interval valve disposed between the first flowline and the probe;
a first sample chamber having a first front volume attached to a first location on the first flowline and a first back volume attached to a first location on the second flowline, wherein the first front volume and the first back volume are separated from one another by a first separating piston such that as an amount of fluid that is held by the first front volume changes, an amount of fluid that is held by the first back volume changes in an equal but opposite way;
a second sample chamber having a second front volume attached to a second location on the first flowline and a second back volume attached to a second location on the second flowline, wherein the second location on the first flowline is beneath the first location on the first flowline and the second location on the second flowline is beneath the first location on the second flowline, and wherein the second front volume and the second back volume are separated from one another by a second separating piston such that as an amount of fluid that is held by the second front volume changes, an amount of fluid that is held by the second back volume changes in an equal but opposite way;
a first pump configured to pump fluid up or down the first flowline, wherein the first pump is attached to the first flowline at a third location on the first flowline, wherein the third location is beneath the first location on the first flowline and the second location on the first flowline; and
a pressure-volume-temperature tester disposed along the first flowline;
wherein:
the firs

Assignees

• Schlumberger Technology Corp

Inventors

• Dumont Hadrien
• Harrison Christopher
• Zuo Youxiang
• Babin Christopher Albert
• Agarwal Abhishek
• Gisolf Adriaan

Classifications

• E21B49/081

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

• E21B49/10 Primary

  using side-wall fluid samplers or testers · CPC title