Well re-fracturing method

Patent metadata

Field	Value
Publication number	US-2016333680-A1
Application number	US-201514709849-A
Country	US
Kind code	A1
Filing date	May 12, 2015
Priority date	May 12, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

A method of re-treating a well with pre-existing fractures which includes: displacing a tool in a well, leaking off motive fluid to an open fracture zone passed by the tool to diminish the rate of displacement, and locating the open fracture zone above the tool.

First claim

What is claimed is:

1 . A method of re-fracturing a well with pre-existing fractures, comprising:
deploying into the well a tool connected to surface by a cable; pumping a motive fluid into the well at a flow rate effective to displace the tool in the well past one or more open fracture zones; leaking off the motive fluid into the one or more open fracture zones passed by the tool, to diminish a rate of displacement of the tool relative to a rate of the pumping the motive fluid into the well, and locate the one or more open fracture zones above the tool; and re-fracturing at least one of the one or more open fracture zones located above the tool.

2 . The method of claim 1 , further comprising tensioning the cable to selectively leak off the motive fluid into the one or more open fractures passed by the tool.

3 . The method of claim 1 , wherein the cable comprises a distributed measurement cable.

4 . The method of claim 1 , further comprising conducting a distributed measurement survey along a length of the cable as it is deployed into the well.

5 . The method of claim 1 , further comprising conducting a distributed measurement survey along a length of the cable in the well, wherein the surveyed measurement is selected from the group consisting of temperature, vibration data, strain data, and combinations thereof.

6 . The method of claim 1 , wherein the cable comprises a distributed measurement cable, and further comprising obtaining measurements from the cable to determine the location of the one or more open fractures located above the tool.

7 . The method of claim 1 , wherein the cable comprises a distributed measurement cable, and further comprising obtaining measurements from the cable to monitor execution of the re-fracturing.

8 . The method of claim 7 , wherein the measurements obtained comprise fluid flow rate versus depth during the re-fracturing to monitor fluid flow into the one or more open fracture zones located above the tool.

9 . The method of claim 8 , wherein the re-fracturing comprises diverting a re-fracturing treatment fluid by placing a plug in at least one of the one or more open fracture zones located above the tool, and wherein the measurement of the fluid flow rate versus depth indicates the effectiveness of the plug, and further comprising reinforcing the plug if the plug is indicated to be ineffective.

10 . The method of claim 1 , wherein the tool comprises an isolation device, a perforation tool, or a combination thereof.

11 . The method of claim 1 , comprising setting the tool at a target depth to isolate the one or more open fracture zones located above the tool for the re-fracturing, from a portion of the well below the tool.

12 . The method of claim 11 , comprising determining the target depth as a location where a total rate of the motive fluid leak-off into the one or more open fracture zones located above the tool matches the flow rate of the motive fluid pumped into the well, wherein the displacement of the tool is diminished substantially to zero.

13 . The method of claim 1 , further comprising logging the location of the one or more open fracture zones located above the tool from measurement of the rates of displacement of the tool and pumping the motive fluid into the well.

14 . A method of re-fracturing a well with a series of pre-existing open fracture zones, comprising:
(a) deploying into the well a first tool connected to surface by a cable; (b) pumping a motive fluid into the well to displace the first tool at a rate relative to a rate of the pumping of the motive fluid; (c) displacing the first tool past an open fracture zone to locate the open fracture zone above the first tool; (d) leaking off the motive fluid into the open fracture zone located above the first tool to diminish a rate of displacement of the tool relative to a rate of the pumping the motive fluid into the well; (e) plugging one or more of the open fracture zones located above the first tool to at least partially restore the rate of displacement of the first tool relative to the rate of the pumping the motive fluid into the well; (f) repeating the pumping (b), the displacement (c) and the leaking off (d) until the first tool reaches a first target depth; and (g) re-fracturing a portion of the well located above the first target depth.

15 . The method of claim 14 , wherein the cable gathers distributed measurement information to monitor any of (b), (c), (d), (e), (f), (g), or any combination thereof.

16 . The method of claim 14 , wherein the re-fracturing (g) introduces a fracturing fluid into one or more unplugged open fracture zones.

17 . The method of claim 14 , wherein the re-fracturing (g) comprises introducing a fracturing fluid and a diverter into the well to distribute the fracturing fluid into one or more of the pre-existing fracture zones, new fracture zones, or a combination thereof.

18 . The method of claim 17 , wherein the cable gathers distributed measurement information to monitor the distribution of the fracturing fluid.

19 . The method of claim 14 , further comprising repeating the plugging (e) and (f) a plurality of times until the first tool reaches the first target depth in the well.

20 . The method of claim 14 , wherein the first target depth is a toe of the well.

21 . The method of claim 14 , further comprising:
(h) optionally
1) repeating the plugging (e) and (f) a plurality of times until the first tool reaches the first target depth in the well, or
2) setting the first tool at the first target depth for re-fracturing (g) at least once above the first target depth, or
3) a combination thereof;
(i) pulling the first tool up the well to a second target depth; (j) setting the first tool at the second target depth to isolate a portion of the well above the second target depth from a portion of the well below the second target depth; and (k) re-fracturing in the portion of the well isolated above the second target depth.

22 . The method of claim 21 , wherein the second target depth is above an open fracture zone located between the first and second target depths.

23 . The method of claim 21 , further comprising:
(l) pulling the first tool up the well to a successively higher target depth; (m) setting the first tool at the successively higher depth to isolate a portion of the well above the successively higher target depth from a portion of the well below the successively higher target depth; and (n) re-fracturing in the portion of the well isolated above the successively higher target depth.

24 . The method of claim 23 , further comprising repeating (l), (m), and (n) at least once more.

25 . The method of claim 14 , further comprising:
(h) optionally
a. repeating the plugging (e) and (f) a plurality of times until the first tool reaches the first target depth in the well, or
b. setting the first tool at the first target depth for re-fracturing (g) at least once above the first target depth, or
c. a combination thereof;
(i) optionally disconnecting and retrieving the cable rom the first tool; (j) deploying a second tool into the well to a second target depth above the first target depth; (k) setting the second tool at the second target depth to isolate a portion of the well above the second target depth from a portion of the well below the second target depth; and (l) re-fracturing in the portion of the

Assignees

• Schlumberger Technology Corp

Inventors

• Richter Peter John
• Pena Gonzalez Alejandro Andres
• Lecerf Bruno
• Usoltsev Dmitriy

Classifications

• E21B43/26 Primary

  by forming crevices or fractures · CPC title

• E21B47/09

  Locating or determining the position of objects in boreholes or wells {, e.g. the position of an extending arm}; Identifying the free or blocked portions of pipes · CPC title

• E21B33/12

  Packers; Plugs (used for cementing E21B33/134, E21B33/16) · CPC title

• E21B43/14

  Obtaining from a multiple-zone well · CPC title

• E21B43/267

  reinforcing fractures by propping · CPC title