Multi-zone well completion system

Abstract

A multi-zone well completion system includes a casing surrounding an inner string, an annulus being formed between the inner string and the casing, and a dual-shrouded inflow control valve assembly. The assembly includes an upper outer ICV in fluid communication with the annulus and a lower inner ICV in fluid communication with the inner string. The dual-shrouded ICV assembly is configured to isolate a first hydrocarbon flow path located within the annulus from a second hydrocarbon flow path located within the inner string. The upper outer ICV is configured to independently control a first hydrocarbon flow through the first hydrocarbon flow path and the lower inner ICV is configured to independently control a second hydrocarbon flow through the second hydrocarbon flow path until they are commingled above the upper outer ICV.

Description

MULTI-ZONE WELL COMPLETION SYSTEMBACKGROUND

[0001] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0002] Certain reservoirs may require artificial lift methods such as the use of electrical submersible pumps (ESPs) to lift oil due to comparably low initial reservoir pressure and quick depletion. Currently, some well completions use a single zone frac-pack on a lower completion area with an ESP system in an upper completion area to lift the oil. This type of well completion may target, for example, a single sand only. In some situations, there may be multiple, smaller size shallow sands around the targeted sand which are not economical to target with a dedicated well completion for each.

[0003] It is now recognized that it would be beneficial to commingle and produce these multiple shallow sands together. Commingled production of multiple shallow sands would allow enhanced production rates from the well.SUMMARY OF THE DISCLOSURE

[0004] The present disclosure relates to a multi-zone intelligent well completion (IWC) system that can commingle and produce hydrocarbons from multiple sands or zones in a reservoir. The IWC system uses surface-controlled downhole inflow control valves (ICVs) that can remotely regulate the flow of hydrocarbons from each zone before they are lifted by an electrical submersible pump (ESP) system. The IWC system includes a dual-shrouded ICV assembly that isolates and controls the flow paths of the upper zone and the lower zones, and a dual-flow face receptacle assembly that interfaces the lower completion assembly with the upper completion assembly. The IWC system also includes a perforated pup joint that allows the commingled fluids from the zones to flow into the casing-tubing annulus and be lifted by the ESP system. The IWC system enables enhanced production rates, reservoir management capabilities, and maximized recovery from multiple shallow sands.BRIEF DESCRIPTION OF DRAWINGS

[0005] These and other objects, features and advantages of the present disclosure will become better understood with reference to the following description, appended claims and accompanying drawings, wherein:

[0006] Fig.l is a schematic of an example of an intelligent well completion system, in accordance with an embodiment of the disclosure;

[0007] Fig. 2 is a schematic of another example of an intelligent well completion system, in accordance with an embodiment of the disclosure;

[0008] Fig. 3 is a schematic depiction of hydrocarbon flow through the intelligent well completion system of Fig. 2, in accordance with an embodiment of the disclosure;

[0009] Figs. 4A-4D are example configurations of dual shrouded inflow control valve assemblies and intermediate interface assemblies used in the intelligent well completion systems of Figs. 1 and 2, in accordance with an embodiment of the disclosure;

[0010] Fig. 5 is a schematic of another example of an intelligent well completion system, in accordance with an embodiment of the disclosure;

[0011] Fig. 6 is a schematic depiction of hydrocarbon flow through the intelligent well completion system of Fig. 5, in accordance with an embodiment of the disclosure; and

[0012] Figs. 7A-7D are example configurations of dual shrouded inflow control valve assemblies and intermediate interface assemblies used in the intelligent well completion systems of Fig. 6, in accordance with an embodiment of the disclosure.DESCRIPTION OF THE INVENTION

[0013] As set forth above, commingled production of multiple shallow sands may allow enhanced production rates from wells. Disclosed herein are embodiments of a multiple-zone intelligent well completion (IWC) system to commingle and produce multiple sands together. Generally, a well completion with surface-controlled downhole inflow control valves (ICV) may be referred to as an intelligent well completion (IWC) system. The completion system embodiments of this disclosure may utilize downhole ICVs that provide remote downhole choking & shut-off capabilities from the surface, while also using an electrical submersible pump (ESP) system to assist with lifting oil. The disclosed embodiments couple the IWC with the ESP system together, and include flow paths within the wellbore system that allow hydrocarbon fluid from each sand to be remotely controlled (fully open, choking, and shut-off) by a dedicated ICV before being commingled together with fluid from other sands (which are also controlled by a dedicated ICV), and then lifted by the ESP system.

[0014] In a first aspect of this disclosure and as shown in Figs. 1 and 2, an IWC system 10 (multi-zone well completion system 10) includes a multiple stage stacked frac-pack lower completion configuration that is used to produce hydrocarbons from multiple production zones. In these embodiments, the zones correspond to sands located at different subterranean locations and are depicted as including an “upper sand” or “upper zone,” a “middle sand” or “middle zone,” and a “lower sand” or “lower zone.” Although three zones are shown and described herein, the present embodiments may be applied to the production of hydrocarbons in other configurations, for example those including two production zones, or more than three production zones. Further, the use of “upper” or “above,” “lower” or “below,” and so forth, are intended to denote relative positions when the completion systems described herein are in place, with the longitudinal axis of the system being aligned generally with the depth direction of the subterranean formation in which it is located. Generally, the embodiments described herein enable isolation of at least one hydrocarbon flow produced from at least one production zone from at least one other hydrocarbon flow produced from at least one other production zone, while also enabling the control of these isolated flows until they are commingled before extraction from a well.

[0015] Figs. 1 and 2 differ in the isolation between the lower and middle zones. In particular, the completion system 10 of Fig. 1 may be used when there is a relatively small distance between the lower and middle zones, while the completion system 10 of Fig. 2 may be used when the distance is larger. The completion system of Fig. 2 includes a lower zone frac pack12 and flow control 14 located between the lower sand top and the middle sand bottom, while the completion system 10 of Fig. 1 includes a lower zone frac pack 12 and flow control 14 located between the middle sand top and the upper sand bottom. In other words, Fig. 1 includes two frac packs and flow controls while Fig. 2 includes three frac packs and flow controls.

[0016] In the completion systems of Fig. 1 and 2, there is a dual-flow Flow Loss Control Valve (FLCV 16) (labeled as XAFV in Figs. 1 and 2) installed between an upper zone frac-pack assembly 18 (UZ FP) and upper zone screens 20 which provides 3-way connection capability with an internal Polished Bore Receptacle (PBR) housing (see Fig. 4B) of a polished bore assembly (PBR) 22 on top or inside the dual-flow FLCV 16 to be interfaced with an intermediate isolation assembly 24 or to be directly interfaced with the upper completion assembly 26. As discussed in further detail below with respect to Figs. 4A and 4B, an inner string 28 is connected below the 3-way dual-flow FLCV 16 with a muleshoe & seals at bottom interfaced with a PBR housing of the middle zone frac-pack assembly.

[0017] Fig. 3 depicts the flow of hydrocarbons from the various zones through the completion system 10 of Fig. 1 (the flow is similar for Fig. 2). As shown in Fig. 3, the inner string 28 provides a flow path 40 allowing the hydrocarbon fluid from middle / lower sands flow. The hydrocarbon fluid from the upper sand will flow through an annulus flow path 42 between the frac-pack assembly / screens 20 and inner string 28 through the 3 -way dual-flow FLCV 16 (once it is trigged to open).

[0018] The interface between the upper completion assembly and the lower / middle completion assemblies of the IWC system 10, as well as details of the upper completion assembly, may be further appreciated with reference to Figs. 4A-4D. In particular, Figs. 4A and 4C are exploded views of embodiments of the upper completion assembly and interface with the lower / middle completion assemblies, while Figs. 4B and 4D are expanded views of the same.

[0019] In accordance with certain embodiments of this disclosure and as shown in Figs. 4A and 4B, to interface the stacked frac-pack lower completion assembly with the upper completion assembly properly and isolate the flow paths from upper sand and other sands (e.g., the rest of middle / low sands), the IWC systems of this disclosure use a Face Receptacle intermediate Isolation assembly (more generally, a “face receptacle assembly” 50) and a Dual Shrouded ICVs Assembly 52. The face receptacle assembly 50 includes a by-pass 3-way sub 54 connecting a landing head 56 to the long Outer polished bore receptacle (PBR) 58, and tothe long Inner PBR housing 60 inside. By-pass slots allow the annulus space of the 3 -way sub 54 to communicate with the inner larger space of the 3 -way sub at the ID change location.

[0020] Some embodiments, as shown in Figs. 4C and 4D, may differ from the embodiment of Figs. 4A and 4B in that the interface seals are located on the dual-flow face receptacle assembly (shown as 50’) while the PBRs are located on the dual-shrouded ICVs assembly (shown as 52’). More specifically, the dual-shrouded ICVs assembly 52’ of Figs. 4C and 4D includes a PBR at the inner diameter (ID) side of outer shroud 62 and another PBR on the outer diameter (OD) side of the inner string 28. The dual-flow face receptacle assembly 50’ includes an outer receptacle with seals 64 and an inner receptacle with seals 66. Thus, as described in further detail below, the IWC system of the embodiment of Figs. 4C and 4D includes a dual-shrouded ICVs assembly 52 having an outer string ID-PBR and an inner string OD-PBR, and a 3 -way dual-flow dual-seals face receptacle assembly.

[0021] In still further embodiments, there may be a mixture of these two embodiments utilized. For instance, in one embodiment, the dual-shrouded ICVs assembly may include inner string seals but an outer string ID PBR, while the face receptacle assembly includes an inner PBR and an outer receptacle with seals. In another embodiment, the dual-shrouded ICVs assembly may include an inner string OD-PBR and outer string inverted seals, while the face receptacle assembly includes an inner receptacle with seals and an outer PBR. In all the embodiments, therefore, it is contemplated that the interface between the dual-shrouded ICVs assembly and the face receptacle assembly includes at least two seal-polished bore receptacle interfaces, each sealing different respective annular regions from one another to allow for flow isolation between the upper zone and the lower and middle zones. Further description will be made with reference to the embodiment of Figs. 4A and 4B, but it should be noted that the arrangement of polished bore surfaces and seals may be switched in various embodiments.

[0022] In the embodiment of Figs. 4A and 4B, the inner string 28 is connected below the Inner Polished Bore Receptable (PBR) housing 60 at the bottom of the intermediate isolation assembly with muleshoe & seals 68 at bottom. An outer string is connected below the Outer PBR 58 with muleshoe & seals 70 at bottom. The landing head of the isolation assembly allows the outer shroud 62 (with invert seals at ID side) of the Dual Shrouded ICVs Assembly 52 (in upper completion assembly) to readily form a sealed interface with the long Outer PBR 58 (polished face on the OD) below and isolate the flow path for upper sand flow. The long Inner PBR housing 60 at the inner side of the intermediate isolation assembly provides another seal interface to allow the inner string (with muleshoe & seals) of the Dual Shrouded ICVsAssembly 52 (in upper completion assembly) to readily stab in and isolate flow paths between the upper sand flow and the remaining lower sands flow.

[0023] To assemble the IWC system 10, the intermediate isolation assembly 24 is stabbed into the upper zone frac-pack 18 of the lower completion system and is landed, while its bottom inner string with muleshoe & seals 68 will stab into the internal PBR housing of the dual-flow FLCV 16 (on top or inside the dual-flow FLCV). The outer string of the isolation assembly with muleshoe & seals 70 will stab into the upper frac-pack pack sealbore to seal-off the MCS sleeve. In this way, the inner string of the intermediate isolation assembly 24 continues to provide a flow path allowing the hydrocarbon fluid from middle / lower sands flow, and the annulus space between the inner and outer strings of the intermediate isolation assembly continues to provide the flow path allowing the hydrocarbon fluid from the upper sand flow.

[0024] To allow for remote downhole control (fully-open / choking / shut-off) of the zonal production of the upper sand and the lower sands (middle / lower sands), the IWC system includes the Dual Shrouded ICV Assembly 52. An inner shroud 72 isolates a combined flow path to allow a lower-inner ICV 74 to control flow from the middle and lower sands (see, e.g., Fig. 3). The outer shroud 62 isolates the upper sand flow path to allow an upper-outer ICV 76 to control flow from the upper sand (see, e.g., Fig. 3).

[0025] The inner string seal s / mule shoe 73 of the Dual Shrouded ICVs Assembly 52 stab into the long inner PBR housing 60 of the Dual Polished Faces Receptacle intermediate isolation assembly 50, to provide an isolated flow path from inner string of lower / intermediate completion which is the flow path of lower sand / sands, allowing the hydrocarbon fluids from middle / lower sands to flow up and be controlled by the lower-inner ICV 74. The outer shroud 62 of the Dual Shrouded ICVs Assembly 52 with invert seals at ID side receives the landing head interface 56 and seals with the long outer polished face receptacle 58 of the Dual Polished Faces Receptacle intermediate isolation assembly 50, to provide a flow path for the upper sand hydrocarbon which is isolated from the annulus flow of lower / intermediate completion, allowing the hydrocarbon fluids from upper sand to flow up and be controlled by the upperouter ICV 76, as shown in Fig. 3.

[0026] As also shown in Fig. 3, the fluids from the upper, middle, and lower sands are commingled at a perforated pup joint 78 after the flows are remotely controlled (fully- open / choking / shut-off) by upper-outer ICV 76 and lower-inner ICV 74 separately. That is, the upper-outer ICV 76 controls the hydrocarbon flow from the upper sand (e.g., a firsthydrocarbon flow), while the lower-inner ICV 74 controls the flow from the middle and lower sands (e.g., second and third hydrocarbon flows), and the hydrocarbon flows from all the sands are then commingled at the perforated pup joint.

[0027] More specifically, the commingled fluids from the sands / zones are lifted by ESPs 80 from the casing-tubing annulus after being controlled by the ICVs. In the embodiments of this disclosure, the IWC system includes a Y-check ESP system 82 with an ESP packer 84 above which allows through tubing intervention to by-pass the ESPs 80. In accordance with these embodiments, the perforated tubing / pup joint 78 is located between the Dual Shrouded ICVs Assembly 52 and a lower ESP support 86 to allow commingled fluids (after being controlled by the ICVs) to flow through this perforated pup / tubing 78 into casing-tubing annulus.

[0028] Various aspects of the invention, including the dual-shrouded ICVs assembly 52, may be applied to other configurations, an example of which is shown in Figs. 5-7. More specifically, Fig. 5 is a schematic representation of an embodiment of the dual-shroud intelligent well completion system 10 having a single trip multiple zone (STMZ) lower completion assembly 88 configuration. The IWC system of Figs. 5-7 includes both the dualshrouded ICV assembly 52 and the 3-way dual flow dual-polished face receptacle assembly 50, as shown more particularly in Figs. 7A and 7B. The 3-way dual flow dual-polished face receptacle assembly 50 includes the dual-flow FLCV 16 and a fluid loss ball valve (FLBV) 90, also known as a fluid loss isolation barrier valve (FLIBV) as noted above. As with the description of Figs. 4A-4D, a combination of different PBRs and seal locations are contemplated - as may be appreciated when comparing Figs. 7A and 7B with Figs. 7C and 7D.

[0029] The isolation of flow paths accomplished in this embodiment may be further appreciated with reference to Fig. 6, which shows the flow of fluids from the lower and middle sands (zones) being separately introduced into the completion system, but being commingled approximately at the location of the production tube where the middle sand flow is introduced. As shown in Fig. 6, the flow from the upper sand (zone) is isolated from the commingled middle and lower zone flows until the upper zone flow commingles with them after the upper zone flow flows through the upper inflow control valve (ICV) 76 and into the perforated pup joint 78 where the commingling occurs.

[0030] This flow isolation, and proper interfacing between the STMZ lower completion system 88 and the upper completion system may be accomplished using the Dual-Flow Dual-Polished- Face Receptacle intermediate Isolation assembly 50, which may be most easily seen withreference to Figs. 7A and 7B. As depicted in Figs. 7A and 7B, the dual-flow dual-polished- face receptacle intermediate isolation assembly includes the 3-way connection dual-flow fluid loss control valve (DF-FLCV) 16 with the internal polished bore receptacle (PBR) housing 60 to connect the long outer polished face receptable 58 with the landing head 56 above, to connect a large outer diameter (OD) shroud 92 below, and to connect with a FLB V 90 inside.

[0031] The landing head 56 of the intermediate isolation assembly allows the outer shroud 92 (with invert seals at ID side) of the Dual Shrouded ICVs Assembly 52 (in the upper completion assembly) to readily join into a seal interface with the long outer polished face receptacle 58 (polished face on the OD) below and isolate the flow path for upper sand (zone) flow (see, e.g., Fig. 6). The large OD shroud 92 connected below the 3-way dual-flow FLCV 16 will cover the FIBV 90 and isolate an annulus flow path between the shroud inner diameter (ID) and FLBV outer diameter (OD).

[0032] An outer string with muleshoe & seals 94 at bottom is connected below the large OD shroud 92. A long inner string extends over the whole lower completion system and is connected below the FLBV 90 with sliding sleeve shifters at bottom and isolation seals space out between zones to isolate each sand. As shown in Figs. 5 and 6, sliding sleeves 100 (depicted as sliding sleeve doors 100 A and 100B in Fig. 5) may be installed onto the inner string 28 between zones to give open / shut-off capability per the through-tubing intervention solutions such as slickline / e-line.

[0033] The inner PBR housing 60 of the 3 -way dual-flow FLCV 90 provides another sealinterface to allow the inner string (with muleshoe & seals) of the Dual Shrouded ICVs Assembly 52 (in upper completion assembly) to easily stab in and isolate flow paths between the upper sand flow and the rest of the lower sands flow. Once the intermediate isolation assembly trips in hole stabbed into the STMZ lower completion system 88 and landed, the sliding sleeve shifters at the bottom of the inner string assembly will shift all the frac / production sleeves open with the space out seals engaged into the PBR of each zone’s isolation packer & MCS sealbore to isolate each zone, the outer string with muleshoe & seals will stab into the upper frac-pack packer & MCS sealbore to seal-off the upper zone MCS sleeve. In this way, the inner string of the intermediate isolation assembly provides a flow path allowing the hydrocarbon fluid from the middle / lower sands (zones) to flow through the sliding sleeves on the inner string, while the annulus space between the inner and outer strings of the intermediate isolation assembly provides the flow path allowing the hydrocarbon fluid from upper sand flow.

[0034] To allow remote control (fully-open / choking / shut-off) of the downhole zonal production of the upper sand and the remaining lower sands (middle / lower sands), the embodiment of Figs. 5-7 includes an embodiment of the dual shrouded ICV assembly 52 to be run with an upper completion trip. Referring to the dual shrouded ICV assembly 52, as can be best seen in Figs. 6 and 7A-7D, an inner shroud 72 isolates the lower and middle zone flow path from a flow path of the upper zone. This also allows the lower-inner ICV 74 to control the flow in from the lower and middle zones via an inner string 102 with muleshoe & seals 104 at the bottom. The outer shroud 62 of the dual shrouded ICV assembly 52 isolates the upper zone flow path to allow the upper-outer ICV 76 to control flow in from the upper zone via the inverted seals 106 at the ID side of outer shroud bottom (which seal against the outer polished face receptacle 58 of the intermediate completion assembly). As shown in Fig. 6, the fluids from the upper / middle / lower sands (zones) will be commingled at the location of upper-outer ICV 76 after being remotely controlled (fully-open / choking / shut-off) by the upper-outer ICV 76 and the lower-inner ICV 74 separately.

[0035] As shown in Fig. 5, the Y-check ESP system 82 with the ESP packer 84 above allows commingled fluids from the shallow sands to be lifted by the ESP pumps 80 from the casingtubing annulus after being controlled by the ICVs. This also allows through tubing intervention to by-pass ESP pumps. The perforated tubing / pup joint 78 (see Fig. 7B) between the dual shrouded ICVs 52 assembly and the lower ESP pump support 86 allows commingled fluids (after controlled by ICVs) to flow through this perforated pup / tubing into casing-tubing annulus.

[0036] Technical effects of the invention include downhole remote control and fully- open / choking & shut-off capabilities from surface on each sand / zone, coupling with the ESP system to lift oil. Commingled production of multiple shallow sands maximizes the well initial production rate. The downhole fully-open / choking & shut-off capabilities for each sand / zone provides reservoir management capabilities to allocate zonal production & manage zonal depletion of each sand, shut-off the highest water production sand to allow other sands continue producing, and shut-off the highly depleted sand to avoid crossflow, thereby maximizing recovery.

[0037] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of example embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustrationpurposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

CLAIMS1. A multi-zone well completion system, comprising: a casing positioned within a well and in which fractures are formed to allow hydrocarbons to enter the multi-zone well completion system from a surrounding subterranean formation; an upper completion assembly surrounded by the casing; and a dual-shrouded inflow control valve (ICV) assembly of the upper completion assembly comprising: an upper outer ICV in fluid communication with a first hydrocarbon flow path; a lower inner ICV in fluid communication with a second hydrocarbon flow path; an outer shroud shrouding the upper outer ICV and isolating an upper extent of the first hydrocarbon flow path from the casing; and an inner shroud shrouding the lower inner ICV and isolating the upper extent of the first hydrocarbon flow path from an upper extent of the second hydrocarbon flow path.

2. The multi-zone well completion system of claim 1, wherein the upper outer ICV is configured to independently control a first hydrocarbon flow through the first hydrocarbon flow path and the lower inner ICV is configured to independently control a second hydrocarbon flow through the second hydrocarbon flow path until they are commingled above the upper outer ICV.

3. The multi-zone well completion system of claim 1, comprising a perforated pup joint of the upper completion assembly and positioned above the upper outer ICV and above the outer shroud, wherein the first hydrocarbon flow path and the second hydrocarbon flow path converge at the perforated pup joint to form a commingled hydrocarbon flow path.

4. The multi-zone well completion system of claim 3, comprising: an annulus space located between the casing and the perforated pup joint; andan electrical submersible pump (ESP) system located above the perforated pup joint, wherein the commingled hydrocarbon flow path extends from the perforated pup joint, into the annulus space, and to the ESP system, and wherein the ESP system is a tubing by-pass ESP system configured to lift hydrocarbon fluids through the multi-zone well completion system.

5. The multi-zone well completion system of claim 1, comprising a face receptacle assembly connecting a lower completion assembly of the multi-zone well completion system with the upper completion assembly.

6. The multi-zone well completion system of claim 5, wherein the face receptacle assembly comprises an inner receptacle configured to interface with the inner shroud and an outer receptacle configured to interface with the outer shroud.

7. The multi-zone well completion system of claim 6, wherein the face receptacle assembly comprises a by-pass 3-way sub connecting the inner receptacle to the outer receptacle.

8. The multi -zone well completion system of claim 7, wherein the face receptacle assembly interfaces with a flow loss control valve of an inner string of the multi-zone well completion system to form a portion of the second hydrocarbon flow path, and interfaces with an upper frac-pack sealbore to form a portion of the first hydrocarbon flow path.

9. The multi-zone well completion system of claim 8, comprising a multiple stage stacked frac-pack lower completion configuration that is used to produce hydrocarbons from multiple production zones, wherein the multiple production zones correspond to sands located at different subterranean depths, and wherein the multiple production zones comprise at least an upper sand from which the first hydrocarbon flow is produced and a lower sand from which at least a portion of the second hydrocarbon flow is produced.

10. The multi-zone well completion system of claim 1, wherein the first hydrocarbon flow path extends from an upper screen of the multi-zone well completion system, through an annulus between the upper screen and the inner string of the multi-zone well completion system, and through the upper outer ICV.

11. The multi-zone well completion system of claim 1 or 10, wherein the second hydrocarbon flow path extends from a lower screen, through the inner string, and through the lower inner ICV.

12. The multi-zone well completion system of claim 1, wherein the second hydrocarbon flow path combines hydrocarbon flows from multiple fracture regions located below a first fracture region, extends through the inner string, and to through the lower inner ICV.

Images