Dissolving Material Flow Control Device
A flow control device formed of a tubular housing having a circumferential wall and a central passage. A plurality of flow apertures are formed through a section of the circumferential wall and a dissolvable material is positioned to block flow through the flow apertures. A closing sleeve capable of moving into a position to block flow through the flow apertures is also positioned within the housing.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 62/157,834 filed May 6, 2015, which is incorporated by reference herein in its entirety.
BACKGROUND OF INVENTIONIn the oil and gas completions industry, a tubular string position within the wellbore will have various devices (often generically called “valves”) for controlling the flow of fluid between the interior and exterior of the tubular string. One common form for such valves is a “sliding sleeve” valve, where an outer tubular member has a series of apertures and a concentric internal tubular sleeve is shifted to uncover the apertures (i.e., “open” the valve) or to cover the apertures (i.e., “close” the valve). Often, this sleeve is shifted between its open and closed position by a tool which is run into the wellbore (e.g., on coiled tubing) and which engages a profile on the internal surface of the sleeve.
Obviously, each trip running a tool in and out of the wellbore is a time consuming and costly action. Therefore, the oil and gas industry is always seeking more efficient ways to selectively open communication between the interior of the tubular string and the producing formation through which the wellbore extends.
The embodiment of the flow control device 1 seen in
The dissolving material may be any number of materials including, but not limited to, dissolvable metals such as magnesium, aluminum (including alloys thereof), dissolvable polymeric materials, or other dissolvable polymers. Magnesium (Mg), either in elemental form or as an alloy, can serve as one preferred base material for dissolvable material 34. For example, the dissolvable material 34 could be Mg alloys that combine other electrochemically active metals, including binary Mg—Zn, Mg—Al and Mg—Mn alloys, as well as tertiary Mg—Zn—Y and Mg—Al—X alloys, where X includes Zn, Mn, Si, Ca or Y, or a combination thereof. These Mg—Al—X alloys may include, by weight, up to about 85% Mg, up to about 15% Al and up to about 5% X. These electrochemically active metals, including Mg, Al, Mn or Zn, or combinations thereof, may also include a rare earth element or combination of rare earth elements. As used herein, rare earth elements include Sc, Y, La, Ce, Pr, Nd, Fe, or Er, or a combination thereof. Where present, a rare earth element or combinations of rare earth elements may be present, by weight, in an amount of about 5% or less. As a specific example, TervAlloy™ available from Terves, Inc. of Euclid, Ohio is a magnesium and aluminum nanocomposite disintegrating material designed to disintegrate (turn to powder) based on exposure to a controlled fluid (e.g., an electrolyte), or an electrical or thermal stimuli. TervAlloy™ will disintegrate into very fine grained particles after a specified time in response to a controlled environmental stimulus. A wide range of solvents may be employed as long as they are capable of reducing the dissolving material without excessive corrosion of downhole tubulars and equipment. As nonlimiting examples, the solvent could be brines formed from NaCl, CaCl, NaBr, CaBr, caesium formates, sodium formates, etc. Likewise, the solvent could be any number of acids including various concentrations of hydrofluoric acid, hydrochloric acid, sulfuric acid, acetic acid, and other acids commonly used in the downhole environment. In one embodiment, the dissolvable material such as the above TervAlloy™ may be coated with a polymer that is unaffected by acids and brines found in the downhole environment where the material is to be used. When it is desired to remove the dissolvable material, a solvent effective against the polymer (e.g., hydrofluoric acid) is circulated to remove the polymer coating, thus exposing the TervAlloy™ existing brines that will ultimately degrade it. The brine may be latent brine or additional brine which is circulated downhole.
Adjacent to the section 6 of apertures 10 is the closing sleeve 20. Closing sleeve 20 is a slidable sleeve having an outer diameter slightly smaller than the inner diameter of section 6 such that closing sleeve 20 travels into section 6. Although a portion of the sleeve length is shown removed in the
Although the
In many contemplated uses, the flow control device seen in
As one example of a contemplated use, a tubular string incorporating a series of flow control devices 1 will be run into the wellbore such that the flow control devices are positioned at the wellbore locations where communication exterior to the string is desired. At this point, the dissolvable material is intact in the flow apertures (or the dissolving sleeves are in place) and the closing sleeves (i.e., nondissolving permanent sleeves) are in the open position. Various downhole operations requiring an increase of fluid pressure internal to the tubular string may be carried out; for example, setting pressure activated packers incorporated into the string, or circulating while running in the hole without need of an inner string. In one example, the pressure is within the central passage of the flow control device is increased in the range of about 7,500 to 15,000 about p.s.i. (or any sub-range therebetween).
It will be understood that when the dissolvable material is in place in the flow apertures, there are no flow paths through the circumferential wall of the tubular housing, i.e., no flow paths from outside the tubular housing into the central passage (or from the central passage to the outside of the tubular housing). The absence of flow paths is not only in portion of the central passage in the immediate area of the flow apertures, but also portions of the central passage extending above or below the tubular housing along the tubular string.
As suggested above, there are certain embodiments where the step of initially positioning the flow control device in the wellbore includes running the flow control device into the wellbore without a service tool (or any other type of inner tubular member) being positioned within the central passage of the flow control device's tubular housing. These embodiments could be employed to carry out operations such as a single trip standalone screen application where the production assembly and sandface assembly are run and installed in a single trip using the dissolvable material as a barrier to flow. This arrangement enables circulation of filter cake removal fluids, packer corrosion inhibitor fluids, and aides in fluid loss control while removing the BOP's and installing the wellhead. Further, packers may be set without the need of running a plug or any other isolation device by applying pressure against the dissolvable material prior to its degradation phase permitting activation of any downhole hydraulic device in the completion assembly as required.
When it is desired to establish communication outside the tubular string, a dissolving agent may be circulated into contact with the dissolving material for sufficient duration to remove or to sufficiently weaken the dissolving material within the flow apertures. For example, this may be achieved at the end of a gravel or frac pack using the inner service tool string on a multi-zone, single trip application; or it can be achieved using a smaller workstring run on a separate trip to circulate the solvent (dissolution fluid). This may involve a single solvent or more than one (e.g., one solvent to remove a protective coating and another to dissolve the underlying material) and thus involve separate trips to spot the different solvents. Once this is accomplished, fluid communication will be opened with the environment exterior to the tubular string. When the well operator desires to close off this fluid path, a closing tool is run downhole to engage and shift the closing sleeve into the closed position.
In operation, the tubular string is lowered into the wellbore until the packers 60 are positioned above and below the producing interval. As suggested in
Although
Claims
1-28. (canceled)
29. A flow control device comprising:
- a. a tubular housing having a circumferential wall and a central passage;
- b. a plurality of flow apertures formed through a section of the circumferential wall;
- c. a dissolvable material positioned to block flow through the flow apertures; and
- d. a closing sleeve capable of moving into a position to block flow through the flow apertures.
30. The flow control device of claim 29, wherein the dissolvable material is formed within the flow apertures.
31. The flow control device of claim 29, wherein the dissolvable material forms a dissolvable sleeve positioned to the interior of the circumferential wall.
32. The flow control device of claim 29, wherein the dissolvable sleeve has a sleeve wall with a thickness ranging between about ⅛ inch and about 1 inch.
33. The flow control device of claim 29, wherein the closing sleeve has an internal profile engageable by a service tool inserted into the housing's central passage.
34. The flow control device of claim 33, wherein the closing sleeve includes a holding collet for holding the closing sleeve in a closed position.
35. The flow control device of claim 34, wherein the tubular housing has an internal closing profile shaped to be engaged by fingers on the closing collet.
36. The flow control device of claim 35, wherein the fingers of the closing collet are configured to disengage from the closing profile when force is applied to the closing sleeve by a service tool moving within the tubular housing's central passage.
37. The flow control device of claim 29, wherein a sleeve seal is position on either side of a section of the circumferential wall having the flow apertures such that the sleeve seals engage the closing sleeve when the closing sleeve blocks the flow apertures.
38. The flow control device of claim 31, wherein the dissolvable sleeve is positioned to block the closing sleeve prior to it dissolving.
39. The flow control device of claim 38, wherein a screen encloses the tubular housing.
40. The flow control device of claim 38, wherein the dissolvable material is a magnesium and aluminum nanocomposite disintegrating material.
41. A method of selectively establishing a fluid communication between the interior and exterior of a tubular string positioned within a wellbore, the method comprising the steps of:
- a. positioning within a wellbore a flow control device comprising: i. a tubular housing having a circumferential wall and a central passage; ii. a plurality of flow apertures formed through a section of the circumferential wall; iii. a dissolvable material positioned to block flow through the flow apertures; and iv. a closing sleeve capable of moving into a position to block flow through the flow apertures; v. wherein the flow control device is run into the wellbore without a further tubular string or service tool being positioned within the central passage of the tubular housing
- b. performing at least one downhole operation by increasing pressure in the tubular string while the dissolvable material blocks flow through the flow apertures;
- c. dissolving the dissolvable material and thereby establishing fluid communication between an interior and exterior of the tubular string; and
- d. wherein the central passage extends above the tubular housing along the tubular string and prior to the dissolving of the dissolvable material, there is no flow path through the circumferential wall from outside the tubular housing into the central passage.
42. The method of claim 41, wherein the step of increasing the pressure includes increasing the pressure in the range of about 7,500 to about 15,000 p.s.i.
43. The method of claim 41, wherein a screen encloses the tubular housing.
44. The method of claim 41, wherein the flow control device is position within a production interval of the wellbore and discrete screen sections are positioned above and below the flow control device within the production interval.
45. A method of carrying out completion operations within a wellbore having at least one producing interval, the method comprising the steps of:
- a. positioning within the producing interval a tubular string including a flow control device and at least one screen joint above or below the flow control device, the flow control device comprising: i. a tubular housing having a circumferential wall and a central passage; ii. a plurality of flow apertures formed through a section of the circumferential wall; iii. a dissolvable material positioned to block flow through the flow apertures; and iv. a closing sleeve capable of moving into a position to block flow through the flow apertures; v. wherein the positioning of the tubular string is carried out without a further tubular member being positioned within the central passage of the flow control device;
- b. after step (a), circulating fluids through the central passage and back up an annulus of the wellbore; and
- c. after step (b), increasing pressure within the central passage in order to set packers and isolate the annulus along the producing interval.
46. The method of claim 45, wherein at least one screen joint is positioned above the flow control device and at least one screen joint is positioned below the flow control device.
47. The method of claim 45, further comprising, before the step of setting the packers, spotting a solvent to the dissolvable material in the wellbore along the producing interval.
Type: Application
Filed: May 5, 2016
Publication Date: Nov 10, 2016
Inventors: Eddie Glenn Bowen (Porter, TX), Anthony Thomas (Houston, TX)
Application Number: 15/147,417