Annular fracturing service tool system

Abstract

An annular fracturing device and method for perforating and annular fracturing multiple zones of a wellbore on a single trip, the annular fracturing device being connected to coiled tubing. The annular fracturing device may include a locating device connected beneath a packing device used to hydraulically isolate a portion of the wellbore. The packing device may be releasably connected to an abrasive perforating device, such as a sand jetting sub. The sand jetting sub may be connected to the bottom of coiled tubing, which is used to run the annular fracturing device into the well bore and to supply the sand jetting sub with abrasive material to perforate the wellbore. The coiled tubing may also supply the sand jetting sub with fluid to circulate out of the sand jetting sub during the fracturing process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows one embodiment of an annular fracturing device on the end of coiled tubing 10 above a first zone of interest 100 that has previously been perforated and fractured.

FIG. 2 shows the annular fracturing device of FIG. 1 beginning to perforate the well at a new zone of interest.

FIG. 3 is shows the sand jetting sub 30 of the annular fracturing device moved below the perforations 200 prior to fracturing the new zone of interest.

FIG. 4 is a cross-section view of collar locator 60 positioned within a collar 70 of the well casing.

While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Illustrative embodiments of the invention are described below as they might be employed in the method of perforating and annular fracturing a wellbore with an annular fracturing device connected to the bottom of coiled tubing that allows for multiple zones to be abrasively perforated and fractured in a single trip into the well. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the are having the benefit of this disclosure.

Further aspects and advantages of the various embodiments of the invention will become apparent from consideration of the following description and drawings.

FIG. 1 shows one embodiment of the annular fracturing device of the present disclosure that includes a collar locator 60, a retrievable bridge plug 50, a yo-yo disconnect tool 40, and a sand jetting sub 30. The collar locator 60 is connected beneath the retrievable bridge plug 50 and is used to determine when the assembly is within a particular zone of interest in the well based on collars 70 located in the well casing 20. Although the embodiment of FIG. 1 includes a collar locator, this device may be one of a various number of downhole devices used to determine the location of a downhole assembly within a wellbore. After being properly positioned, the retrievable bridge plug 50 is then set to hydraulically isolate the zone of interest. A cup type retrievable bridge plug may be preferred in this application as a cup type retrievable bridge plug may be set by using differential pressure from either above or below the plug. Also a cup type retrievable bridge plug may be ideal for this application because the plug may be released by merely pulling up with the coiled tubing. Although the embodiment of FIG. 1 includes a retrievable bridge plug, one of ordinary skill in the art having this disclosure would appreciate a number of different packing devices that may be run and set with coiled tubing which may be used with the annular fracturing device to isolate a zone within the wellbore.

Once the retrievable bridge plug 50 has been set, the sand jetting sub 30 may be released from the bridge plug 50. In one embodiment, a yo-yo disconnect tool 40 is used to releasably connect the sand jetting sub 30 to the bridge plug 50. A yo-yo disconnect tool 40 may be ideal for this application because it releases the sand jetting sub 30 simply by picking up on the coiled tubing 10, but a different releasable connector may be used with the annular fracturing device as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure.

After the sand jetting sub 30 has been released from the bridge plug 50, the sand jetting sub 30 is moved up the casing 20 to the location within the zone of interest that is to be perforated as shown in FIG. 2. Once the sand jetting sub 30 is positioned at the proper location, an abrasive laden fluid may be pumped at a high pressure down the coiled tubing 10 and through the jetting ports 35 on the exterior of the sand jetting sub 30. For example, 20/40 Ottowa sand may be pumped through the sand jetting sub 30 to perforate 200 the casing 20 at the desired location as shown in FIG. 2. Using 20/40 Ottowa sand pumped through the sand jetting sub 30 may perforate the casing at the zone of interest in as little as twenty minutes. The configuration of the jetting ports 35 of the sand jetting sub 30 may be varied to change the number and locations of perforations created by the sand jetting sub 30. The configuration of the individual jetting ports 35 may also be changed to modify the cutting power of the sand jetting sub 30.

After the casing or tubular has been perforated, the coiled tubing is run down the casing 20 until the sand jetting sub 30 is located below the perforations 200 in the zone of interest. Alternatively, the sand jetting sub 30 may be move up the wellbore to a location that has a larger diameter than the zone of interest. The sand jetting sub 30 is moved away from the perforations 200 to provide a sufficient annular flow path to allow stimulation of the perforations 200. Fracturing fluid may then be pumped down the annulus 15 between coiled tubing 10 and the casing 20. Fracturing fluid is pumped down at a high pressure in an attempt to propagate the perforations 200 in the zone of interest into fractures 300 in the formation as shown in FIG. 3. The set bridge plug 50 isolates the zone and aids in allowing the high pressure fracturing fluid to propagate the fractures in the formation. Fluid may be pumped down the coiled tubing 10 and circulated out of the jetting ports 35 while fracturing fluid is being pumped down the annulus 15. The fluid circulated out of the jetting ports 35 may help to prevent proppant located in the fracturing fluid from accumulating on the jetting sub 30 or downhole on the disconnect tool 40 and the bridge plug 50.

After the zone of interest has been stimulated, the sand jetting sub 30 may then be re-connected to the yo-yo disconnect tool 40 and the bridge plug may be deactivated allowing the pressure in the zone of interest to equalize with the well pressure below. The annular fracturing device may then be positioned in the next zone of interest using the collar locator 60. Once properly position in the new location, the bridge plug 50 may again be set hydraulically isolating the new zone of interest. After the bridge plug 50 is set, the yo-yo disconnect tool 40 releases the sand jetting sub 30 which is moved up to perforate the casing 20 in a designated location. The configuration of this annular fracturing device allows multiple zones of a well to be perforated and fractured in a single trip. FIG. 4 is a cross section of the collar locator 60 positioned within a collar 70 of the well casing 20. As discussed above, the collar locator 60 allows the coiled tubing operator to position the annular fracturing device within a desired zone of the wellbore.

Although various embodiments have been shown and described, the invention is not so limited and will be understood to include all such modifications and variations as would be apparent to one skilled in the art.

Claims

1. An annular fracturing device for use with coiled tubing, the device comprising: a packing device, wherein the packing device may be actuated to isolate a portion of a wellbore;a locating device to determine the position of the annular fracturing device within the wellbore;a sand jetting sub having at least one fluid port on the exterior, wherein the sand jetting sub is connectable to an end of coiled tubing and the at least one fluid port of the sand jetting sub is in fluid communication with the coiled tubing; anda connecting device connected above the packing device, wherein the connecting device is releasably connected beneath the sand-jetting sub.

2. The device of claim 1, wherein the locating device is connected beneath the packing device.

3. The device of claim 2, wherein the locating device comprises a collar locator.

4. The device of claim 1, wherein the locating device is a part of the packing device.

5. The device of claim 1, wherein the connecting device is a yo-yo disconnect tool.

6. The device of claim 1, wherein the packing device is a retrievable bridge plug.

7. The device of claim 6, wherein the retrievable bridge plug is a cup type retrievable bridge plug.

8. The device of claim 1, wherein the packing device is a mechanically or hydraulically set packer.

9. A method of annular fracturing a zone within a wellbore, the method comprising the steps of: running a downhole assembly into the wellbore on the bottom end of coiled tubing, the downhole assembly comprising, a sand jetting sub in fluid communication with the coiled tubing, a releasable connector attached beneath the sand jetting sub, a retrievable packing device connected beneath the releasable connector, and a collar locator connected beneath the retrievable packing device;locating the packing device below the zone of interest within the wellbore;setting the retrievable packing device below the zone of interest;releasing the releasable connector from the sand jetting sub;moving the sand jetting sub up the wellbore to the zone of interest, wherein the sand jetting sub has at least one exterior port in fluid communication with the coiled tubing;pumping abrasive material down the coiled tubing and through the exterior port of the sand jetting sub to perforate the wellbore at the zone of interest;moving the sand jetting sub to provide an annular flow path to the wellbore perforations; andpumping fracturing fluid down the annulus between the wellbore and the coiled tubing.

10. The method of claim 9, wherein the sand jetting sub is moved above the wellbore perforations into a portion of the wellbore having a larger diameter than the zone of interest.

11. The method of claim 9, wherein the sand jetting sub is moved below the wellbore perforations.

12. The method of claim 11 further comprising pumping fluid down the coiled tubing and through the exterior port of the sand jetting sub while pumping fracturing fluid down the annulus between the wellbore and the coiled tubing.

13. The method of claim 9, wherein the releasable connector is a yo-yo disconnect tool.

14. The method of claim 9, wherein the packing device is a retrievable bridge plug.

15. The method of claim 14, wherein the retrievable bridge plug is a cup type retrievable bridge plug.

16. The method of claim 9, wherein the packing device is a mechanically or hydraulically set packer.

17. An apparatus for use on coiled tubing in annular fracturing, the apparatus comprising: means for hydraulically isolating a portion of a wellbore;means for locating a specified location of the wellbore;means for abrasively perforating a portion of the wellbore, the means for abrasively perforating being connected to coiled tubing and being releasably connected above the means for hydraulically isolating a portion of a wellbore; andmeans for selectively releasing the means for abrasively perforating from above the means for hydraulically isolating a portion of the wellbore.

18. The apparatus of claim 17, wherein the means for locating a specified location of the wellbore is connected beneath the means for hydraulically isolating a portion of the wellbore.

19. The apparatus of claim 17, wherein the means for locating a specified location of the wellbore is a part of the means for hydraulically isolating a portion of the wellbore.

20. The apparatus of claim 17, wherein the means for hydraulically isolating a portion of a wellbore is actuated by differential pressure.

21. The apparatus of claim 17, wherein the means for hydraulically isolating a portion of the wellbore is mechanically or hydraulically actuated.

22. The apparatus of claim 17, wherein the releasing means releases due to pulling up on the coiled tubing.

23. A method of annular fracturing a zone in a well tubular within a wellbore, the method comprising the steps of: running a downhole assembly into the well tubular on the bottom end of coiled tubing, the downhole assembly comprising, a sand jetting sub in fluid communication with the coiled tubing, a releasable connector attached beneath the sand jetting sub, a retrievable packing device connected beneath the releasable connector, and a collar locator connected beneath the retrievable packing device;locating the packing device below the zone of interest within the well tubular;setting the retrievable packing device below the zone of interest;releasing the releasable connector from the sand jetting sub;moving the sand jetting sub up the well tubular to the zone of interest, wherein the sand jetting sub has at least one exterior port in fluid communication with the coiled tubing;pumping abrasive material down the coiled tubing and through the exterior port of the sand jetting sub to perforate the well tubular and the wellbore at the zone of interest;moving the sand jetting sub to provide an annular flow path to the well tubular and wellbore perforations; andpumping fracturing fluid down the annulus between the well tubular and the coiled tubing.

24. The method of claim 23, wherein the sand jetting sub is moved above the well tubular and wellbore perforations into a portion of the wellbore having a larger diameter than the well tubular.

25. The method of claim 23, wherein the sand jetting sub is moved below the well tubular perforations.

26. The method of claim 25 further comprising pumping fluid down the coiled tubing and through the exterior port of the sand jetting sub while pumping fracturing fluid down the annulus between the well tubular and the coiled tubing