Fusible alloy plug in flow control device

Abstract

A “passive” apparatus and method for isolating flow within a thermal wellbore wherein inflow apertures are plugged with a temporary fusible alloy plug that can be selectively removed by increasing the wellbore temperature.

Claims

1. A method for isolating flow within a wellbore comprising: a) obtaining a plurality of flow control devices, wherein each flow control device includes at least one aperture formed therein, wherein the aperture restricts hydraulic flow of fluids and wherein each flow control device includes an exclusion media to exclude formation particulates, b) inserting a temporary fusible alloy plug securely into said at least one aperture, wherein the temporary fusible alloy plug temporarily prevents flow through said at least one aperture, wherein the temporary fusible alloy plug is fabricated from any low melting temperature composition that is meltable at a melt temperature (T.sub.m), such that a first type of flow control device has a plug that melts at T.sub.m1 and a second type of flow control device has a plug that melts at T.sub.m2, which is higher than T.sub.m1; c) installing the plurality of flow control devices into the well; and d) increasing the reservoir temperature to T.sub.m1 to selectively remove said temporary fusible alloy plug from said first type of flow control device when inflow through said aperture is desired; and e) increasing the reservoir temperature to T.sub.m2 to selectively remove said temporary fusible alloy plug from said second type of flow control device when inflow through said aperture is desired.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:

(2) FIG. 1 is a schematic side view of an embodiment of the present invention.

(3) FIG. 2 is a schematic side view of an embodiment of the present invention.

(4) FIG. 3 is a list of fusible alloys available from Canada Metal (Quebec, CA).

(5) FIG. 4 shows additional alloys available from Reade Advanced Materials (R.I., USA).

DETAILED DESCRIPTION OF THE INVENTION

(6) The present disclosure describes a novel device for control flow in an oil reservior and methods of use thereof. Specifically, temporary fusible alloy plugs are used in flow control devices. The plug can be passively removed upon contact with high temperatures.

(7) The disclosure includes one or more of the following embodiments, in any combination:

(8) An apparatus for isolating flow within a wellbore comprising a flow control device with an exclusion media, wherein the flow control device includes at least one aperture formed therein, wherein the aperture restricts hydraulic flow, wherein the exclusion media limits the flow of formation materials; and a temporary fusible alloy plug securely installed into said at least one aperture, wherein the temporary fusible alloy plug can be passively removed upon thermal circulation or injection operations.

(9) An apparatus for isolating flow within a wellbore comprising a flow control device, wherein the flow control device includes at least one aperture formed therein, wherein the aperture restricts hydraulic flow; and a temporary fusible alloy plug securely installed into the aperture, wherein the temporary fusible alloy plug is fabricated from any low melting temperature composition comprising a meltable, removable material. The flow control device can also have exclusion media.

(10) The above apparatuses can have orifices, perforations, nozzles, capillaries, tubing and valves to restrict hydraulic flow. Additionally, exclusion media can include a perforated pipe, a slotted pipe, a screened pipe, meshed pipe, a sintered pipe, or any means that limits the inflow of particulates.

(11) A method for isolating flow within a wellbore comprising obtaining a flow control device, wherein the flow control device includes at least one aperture formed therein, wherein the flow control device includes an exclusion media, wherein the exclusion media limits the inflow of formation materials; inserting a temporary fusible alloy plug securely into the aperture, wherein the temporary fusible alloy plug temporarily prevents flow through the aperture, wherein the temporary fusible alloy plug is fabricated from any low melting temperature composition that is meltable at a T.sub.m; installing the flow device into the well; and increasing the reservoir temperature to T.sub.m and removing said temporary fusible alloy plug when inflow through said aperture is desired.

(12) A method for isolating flow within a wellbore comprising obtaining a flow control device, wherein the flow control device includes at least one aperture formed therein; inserting a temporary fusible alloy plug securely into the aperture, wherein the temporary fusible alloy plug temporarily prevents flow through the aperture, wherein the temporary fusible alloy plug; installing the flow device into the well; and injecting steam into said wellbore when it is desired to remove said temporary fusible alloy plug.

(13) The apertures can be an orifice, a perforation, a nozzle, a capillary, tubing, a valve or combinations thereof. Furthermore, the exclusion media can include a perforated pipe, a slotted pipe, a screened pipe, meshed pipe, a sintered pipe, or any means that limits the inflow of particulates.

(14) An improved flow control device (“FCD”) for a wellbore, said FCD having apertures for selective inflow of fluids, the improvement comprising blocking said apertures with temporary fusible alloy plugs which melt at a temperature T.sub.m, which is higher than the normal reservoir temperatures.

(15) Referring to FIGS. 1 and 2, a portion of a wellbore 12 may be completed with a flow control liner 22. The flow control liner includes a string of pipe joints 16 incorporating one or more flow control device(s) (FCD) 14 and an exclusion media 24, which limits the flow of sand grains and reservoir particulates into the liner. Each flow control device 14 may include at least one aperture, which restricts hydraulic flow. The aperture may be orifices, perforations, nozzles, capillaries, tubes, and/or valves. The exclusion media 24 may be a perforated pipe, a slotted pipe, a screened pipe, meshed pipe, a sintered pipe, or any means that limits the flow of formation materials, such as sand or other particulate filtration media. While the exclusion media is depicted in FIGS. 1 and 2, the operator can determine whether use of the exclusion media is necessary.

(16) Prior to installation of the flow control liner into the wellbore, temporary fusible alloy plugs 20 may be securely installed in the apertures of each FCD. The temporary fusible alloy plug enables the liner to be installed while circulating fluids through the inside of the liner, out the toe end of the liner and back through the annulus outside the liner without allowing the fluid to pass through the plugged FCD restrictors. This protects the exclusion media from being plugged with fine particles contained in the circulating fluids.

(17) Alternatively, the plugged flow control devices 14 allow the liner to be floated, thereby, reducing effective normal side loads. The ability to float the liner further reduces torque and drag forces allowing the liner to be run in shallower true vertical depths with longer lateral intervals.

(18) The fusible alloy plug composition is preferably non-toxic and non-damaging to the wellbore or the inflow control device. Furthermore, the temporary fusible alloy plug may be removed from the inflow control device with steam circulation. The fusible alloy plug may be fabricated from any low melting temperature composition that is meltable, for effective removal during normal steam circulation or injection operations. These low melting temperature compositions may include but are not limited to bismuth, lead, tin, cadmium, indium, solder or other alloys.

(19) In one aspect, the fusible alloy plug can include a biodegradable material that can be effectively removed when exposed to a set of predetermined thermal conditions. The thermal conditions can include normal or ‘thermal’ wellbore operating conditions of increased temperature during the completion or production operations. In other words, no special chemicals, acids, sources of radiation, abrasive particles, pressure, etc. need to be introduced into the wellbore or carried within the downhole tool itself to initiate the removal of the fusible plug, which will automatically be removed by pre-determined thermal wellbore conditions.

(20) It may be possible to use different melting points of the plugs so that they may be selectively removed to further allocate the flow distribution control of the liner system. For example, some joints of the liner may employ temporary fusible alloy plugs that require increased temperature removal prior to other plugs that can be opened at even higher temperature thermal operations. This concept would allow initiating flow at some point in the liner system prior to opening up primary flow throughout the liner system. This may have advantages for selectively opening specific sections after installation to allow circulation prior to initiating final overall thermal operations.

(21) In the event the operator installs the inflow control device containing the fusible alloy plugs into the wellbore, annular fluids can be circulated from the wellbore into the annulus 18 prior to the completion from newly drilled thermal wells in order to recover drilling fluids, minimize the volumes of the fluids for disposal and further minimizing flow cleanup time. Additionally, preventing drilling fluid flow through the inflow control device during filling or circulating should ensure limited premature solid plugging of the sand exclusion media.

(22) The “passive” flow control apparatus described herein does not require moving parts, mechanical or hydraulic intervention, thus providing significant advantages over that of non-passive systems.

(23) Exemplary low melting alloys are shown in Table 1 below. Preferred allows are solid at typical reservoir temperatures, but melt on steam or other heating of the reservoir. Preferred melt temperatures are >100° C., >150° C., >200° C., but <300° C., or <250° C., but there may be some variability based on reservoir location and conditions. For example, Athabasca oil sands are typically at 7-11° C., and thus lower melt temperature alloys can be used. In contrast, the Texas reservoir at San Miguel is at about 35° C. (95° F.).

(24) Particularly preferred alloys are chemically stable to water, oil, bitumen, and the various additives that may be present, and avoid the use of toxic heavy metals, such as lead and mercury. As mentioned above, different temperature melting plugs can be used at different positions along the wellbore, lower melt temperature (T.sub.m) plugs melting first.

(25) TABLE-US-00001 TABLE 1 EXEMPLARY FUSIBLE ALLOYS Common Composition in weight-percent ° C. Eutectic Name Bi 100 271.5 (yes) Bi 32.5, In 51.0, Sn 16.5 60.5 yes Field's metal Bi 40.3, Pb 22.2, In 17.2, Sn 10.7, Cd 41.5 yes 8.1, Tl 1.1 Bi 40.63, Pb 22.1, In 18.1, Sn 10.65, Cd 46.5 8.2 Bi 49.5, Pb 27.3, Sn 13.1, Cd 10.1 70.9 yes Lipowitz's alloy Bi 50, Lead 30, Sn 20, Impurities 92 no Onions' Fusible Alloy Bi 50.0, Pb 25.0, Sn 12.5, Cd 12.5 71 no Wood's metal Bi 50.0, Pb 28.0, Sn 22.0 109 no Rose's metal Bi 50.0, Pb 31.2, Sn 18.8 97 no Newton's metal Bi 52.5, Pb 32.0, Sn 15.5 95 yes Bi 56.5, Pb 43.5 125 yes Bi 58, Sn 42 139 yes Cs 100 28.6 (yes) Cs 73.71, K 22.14, Na 4.14 −78.2 yes Cs 77.0, K 23.0 −37.5 Ga 100 29.8 (yes) Ga 61, In 25, Sn 13, Zn 1 8.5 yes Ga 62.5, In 21.5, Sn 16.0 10.7 yes Ga 68.5, In 21.5, Sn 10 −19 no Galinstan Ga 69.8, In 17.6, Sn 12.5 10.8 no Ga 75.5, In 24.5 15.7 yes Hg 100 −38.8 (yes) Hg 91.5, Tl 8.5 −58 yes used in low readings thermo- meters In 100 157 (yes) In 66.3, Bi 33.7 72 yes K 76.7, Na 23.3 −12.7 yes K 78.0, Na 22.0 −11 no NaK Sn 62.3, Pb 37.7 183 yes Sn 63.0, Pb 37.0 183 no Eutectic solder Sn 91.0, Zn 9.0 198 yes Sn 92.0, Zn 8.0 199 no Tin foil Zn 100 419.5 (yes)

(26) A wide variety of fusible alloys are commercially available. FIG. 3 provides a list of fusible alloys available from Canada Metal with a wide range of melt temperatures, and a few more from Reade Advanced Materials are found in FIG. 4.

(27) Although the systems and processes described herein have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the invention as defined by the following claims. Those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described herein. It is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims while the description, abstract and drawings are not to be used to limit the scope of the invention. The invention is specifically intended to be as broad as the claims below and their equivalents.

(28) All references cited herein are expressly incorporated by reference in their entireties for all purposes. The discussion of any reference is not an admission that it is prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. Incorporated references are listed again here for convenience:

(29) U.S. Pat. No. 7,409,999 Downhole inflow control device with shut-off feature

(30) U.S. Pat. No. 8,276,670 Downhole dissolvable plug

(31) U.S. Pat. No. 5,479,986 Temporary plug system

(32) U.S. Pat. No. 5,607,017 Dissolvable well plug

(33) U.S. Pat. No. 5,685,372 Temporary plug system

(34) U.S. Pat. No. 5,765,641 Bidirectional disappearing plug

(35) U.S. Pat. No. 6,220,350 High strength water soluble plug

(36) U.S. Pat. No. 7,380,600 Degradable material assisted diversion or isolation

(37) US20130075112 Wellbore Flow Control Devices Comprising Coupled Flow Regulating Assemblies and Methods for Use Thereof

(38) U.S. Pat. No. 7,673,678 Flow control device with a permeable membrane