Downhole pumping systems and intakes for same

An intake for a downhole pump includes an outer tubular member having a central axis. In addition, the intake includes an inner tubular member disposed within the outer tubular member. The inner tubular member is radially spaced from the outer tubular member to form an outer annular flow path radially positioned between the inner tubular member and the outer tubular member. Further, the intake includes a central shaft rotatably disposed within the inner tubular member. The central shaft is radially spaced from the inner tubular member to form an inner annular flow path radially positioned between the central shaft and the inner tubular member. Still further, the intake includes a plurality of inlet apertures extending radially through the outer tubular member and in fluid communication with the outer annular flow path. Each of the plurality of inlet apertures has a circumferential width W between 5% and 50% of a total circumference of the outer tubular member.

Not applicable.

BACKGROUND

The disclosure relates generally to downhole pumping systems and methods for lifting fluids from subterranean boreholes. More particularly, the disclosure relates to fluid intakes for downhole pumps used to lift fluids to the surface.

When producing hydrocarbons from a subterranean well, it is often necessary or at least desirable to install a pump (or multiple pumps) that lift fluids from the well to the surface. In many wells, the fluids that migrate into the well from the surrounding reservoir are multiphase or mixed phase, meaning the fluids include both gases and liquids. Such mixed phase fluids can present challenges to subterranean pumping systems.

BRIEF SUMMARY OF THE DISCLOSURE

Embodiments of intakes for downhole pumps are disclosed herein. In one exemplary embodiment, an intake for a downhole pump comprises an outer tubular member having a central axis. In addition, the intake comprises an inner tubular member disposed within the outer tubular member. The inner tubular member is radially spaced from the outer tubular member to form an outer annular flow path radially positioned between the inner tubular member and the outer tubular member. Further, the intake comprises a central shaft rotatably disposed within the inner tubular member. The central shaft is radially spaced from the inner tubular member to form an inner annular flow path radially positioned between the central shaft and the inner tubular member. Still further, the intake comprises a plurality of inlet apertures extending radially through the outer tubular member and in fluid communication with the outer annular flow path. Each of the plurality of inlet apertures has a circumferential width W that is between 5% and 50% of a total circumference of the outer tubular member.

Embodiments of downhole production systems are disclosed herein. In one exemplary embodiment, a downhole production system comprises a tubular string. In addition, the downhole production system comprises a pump coupled to the tubular string. Further, the downhole production system comprises an intake coupled to the pump. The intake is configured to receive fluid from a subterranean wellbore and route the fluid to the pump. The intake comprises an outer tubular member having a central axis. The intake also comprises an inner tubular member disposed within the outer tubular member. An outer annular flow path is radially disposed between the outer tubular member and the inner tubular member. The intake further comprises a central shaft rotatably disposed within the inner tubular member. An inner annular flow path is radially disposed between the inner tubular member and the central shaft. Still further, the intake comprises a plurality of inlet apertures extending radially through the outer tubular member to the outer annular flow path. Each inlet aperture includes an axial length L, a circumferential width W, and a length-to-width ratio of the axial length L to the circumferential width W. The length-to-width ratio of each inlet aperture is between 2.5 and 10.0.

Embodiments of intakes for downhole pumps are disclosed herein. In one exemplary embodiment, an intake for a downhole pump comprises an outer tubular member having a central axis, a first end, and a second end opposite the first end. In addition, the intake comprises an inner tubular member having a first end and a second end opposite the first end of the inner tubular member. The inner tubular member is coaxially disposed within the outer tubular member with the first end of the inner tubular member proximal the first end of the outer tubular member and distal the second end of the outer tubular member. Further, the intake comprises an outer annular flow path radially positioned between the outer tubular member and the inner tubular member. Still further, the intake comprises a central shaft coaxially disposed within the inner tubular member. The central shaft is configured to rotate relative to the outer tubular member and the inner tubular member. The intake also comprises an inner annular flow path radially positioned between the inner tubular member and the central shaft. The outer annular flow path and the inner annular flow path are in fluid communication at the second end of the inner tubular member. Moreover, the intake comprises a plurality of inlet apertures extending radially through the outer tubular member into the outer annular flow path. The plurality of inlet apertures are disposed more proximate the first end of the outer tubular member than the second end of the outer tubular member. The plurality of inlet apertures are arranged in a plurality of axially spaced rows such that each of the plurality of inlet apertures is circumferentially misaligned with each of the other inlet apertures about the central axis. Each inlet aperture includes an axial length L, a circumferential width W, and a length-to-width ratio of the axial length L to the circumferential width W that is between 2.5 and 10.0.

Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a particular axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to a particular axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Any reference to up or down in the description and the claims is made for purposes of clarity, with “up”, “upper”, “upwardly”, “uphole”, or “upstream” meaning toward the surface of the borehole and with “down”, “lower”, “downwardly”, “downhole”, or “downstream” meaning toward the terminal end of the borehole, regardless of the borehole orientation. As used herein, the terms “approximately,” “about,” “substantially,” “generally,” and the like mean within 10% (i.e., plus or minus 10%) of the recited value. Thus, for example, a recited angle of “about 80 degrees” refers to an angle ranging from 72 degrees to 88 degrees. Unless expressly stated otherwise, numerical ranges include the recited end points of the range as well as all points between the recited end points. Thus, for example, recited ranges of “about 10.0 to 20.0,” “from 10.0 to 20.0,” and “between 10.0 and 20.0” include end points 10.0 and 20.0, as well as all points therebetween.

As previously described, fluids produced from a subterranean formations often include both liquid and gas phases. Due to the presence of both liquids and gases, downhole pumps installed within the wellbore to lift the formation fluids to the surface can experience inefficiencies and even failures during operations. For example, in some instances, the pump may experience “gas lock,” which may occur when gas accumulates in a pumping section of the installed pump system. The accumulated gas (which may form a gas bubble) forms a blockage that interrupts the flow of liquids across the impeller of the pump. Interruption of liquid flow across the pump may result in a rapid increase in temperature of the pump, which may lead to damage or failure. Thus, it is desirable to separate the gases and liquids in the formation fluids prior to routing them to the pump inlet (e.g., upstream of the pump inlet). Embodiments disclosed herein are directed to production systems for installation in a subterranean wellbore that include pump intakes that facilitate gravity-based separation of all, most, or at least some of the gases from the liquids of the fluids produced from subterranean formations. Thus, through use of embodiments of the intakes disclosed herein, the damage and failures associated with gas lock of the associated downhole pumps may be avoided or at least reduced.

Referring now toFIG. 1, a wellbore10extends into a subterranean formation15to provide access to hydrocarbon fluids (e.g., oil, natural gas, etc.) contained within a reservoir in formation15. Wellbore10includes a casing11secured within formation15(e.g., with cement). Casing11defines a central throughbore or flow path12therein that extends from the surface (not shown). A plurality of perforations13extend through casing11into formation15to provide a plurality of flows paths for formation fluids (e.g., oil, natural gas, water, etc.) disposed within formation15to flow into throughbore12.

A production system or assembly50is disposed within throughbore12, thereby defining an annulus or annular region16radially positioned between production assembly50and casing11. Production assembly50includes a central or longitudinal axis55generally aligned with the central axis of casing11during operations (e.g., production assembly50is coaxially disposed within casing11). Moving axially downward, in this embodiment, production assembly50includes a downhole pump60, a gas separator30, an intake100, a seal20, a motor22, and a downhole sensor assembly24. Pump60may be an electrically drive submersible pump, in which case, production assembly50may be referred to as an electric submersible pump (ESP) assembly or system.

In this embodiment, pump60is axially uphole of each of separator30, intake100, seal20, motor22, and sensor assembly24. In addition, in this embodiment, gas separator30is immediately axially adjacent and downhole of pump60, intake100is immediately axially adjacent and downhole of separator30, seal20is immediately axially adjacent and downhole of intake100, motor22is immediately axially adjacent and downhole of seal20, and downhole sensor assembly24is immediately axially adjacent and downhole of motor22. However, it should be appreciated that the specific order and/or arrangement of the components (e.g., pump60, separator30, intake100, seal20, motor22, sensor assembly24, etc.) of production assembly50may be greatly varied. In addition, it should also be appreciated that the makeup of production assembly50may be varied in other embodiments. For example, in some embodiments, production assembly50may include one or more additional pumps (e.g., pump60), motors (e.g., motor22), or combinations thereof. As another example, in some embodiments, production assembly50may not include seal20, separator30, downhole sensor assembly24, or combinations thereof.

The various components of production assembly50(e.g., pump60, separator30, intake100, seal20, motor22, sensor assembly24, etc.) are supported and suspended within casing11by a tubular string70extending from the surface. Tubular string70defines a fluid flow path separate from the annulus16between casing11and string70that communicates with the surface. In general, tubular string70may comprise coiled tubing, braided line, threadably attached or flanged rigid tubulars, and/or any other suitable tubular member(s).

Separator30may be any suitable type of separator known in the art for separating liquid and gas phases of a mixed phase fluid. For example, in some embodiments, separator is a rotary gas separator. Seal20may comprise any suitable seal, sealing device, or seal assembly known in the art for preventing fluids from migrating from intake100into motor22during operations. Motor22may comprise any suitable motor or driver known in the art for providing power (e.g., rotary power) to drive pump60during operations. For example, in this embodiment, motor22comprises an electric motor that is energized by electric power delivered by a cable26extending from the surface. Downhole sensor assembly24may comprise any suitable arrangement or assembly known in the art for housing one or more sensors used to detect and/or measure various parameters of production assembly50and wellbore10. For example, in some embodiments, downhole sensor assembly24may include one or more sensors to detect and measure bottom hole pressure, bottom hole temperature, motor temperature, vibration, pump discharge pressure, etc.

In this embodiment, the formation fluids3entering throughbore12via perforations13include, among other things, gases (e.g., natural gas, carbon monoxide, hydrogen sulfide, air, carbon dioxide, etc.) and liquids (e.g., liquid oil, water, condensate, etc.). Because the gases within the formation fluids3can cause inefficiencies or even failures of pump60as described above (e.g., due to gas locking of pump60), it is advantageous to separate the gases and liquids in the formation fluids3so that only or mostly the liquid phase of the formation fluids3is routed to the pump60. Therefore, during pumping operations, intake100at least partially separates the liquid and gas phases of the formation fluids3migrating into casing11via perforations13. In particular, during production operations, formation fluids3pass through perforations13into casing11and then flow uphole through annulus16to intake100. As production fluids flow into annulus16, motor22is actuated via electrical power supplied by cable26extending to the surface to drive pump60and draw formation fluids3from annulus16into intake100via a plurality of intake apertures110. The mixed phase formation fluids3flow through intake100where they are separated (at least partially) into gas and liquid phases. Thereafter, the separated liquid phase (or substantially liquid phase) flows to gas separator30where any gas remaining in the separated liquid phase is further separated out of the liquid phase. Finally, the liquid phase of formation fluid3flows to pump60where it is pressurized and pumped to the surface via tubular string70. The separated gas phase5of the formation fluid3(e.g., the gases separated out of fluid3in both intake100and separator30) is emitted back into annulus16(e.g., via inlet apertures110) and flows uphole to the surface through annulus16.

In the manner described, during production operations, intake100separates the liquid and gaseous phases in the formation fluids3prior to any further separating of the liquid and gaseous phases by gas separator30. Thus, intake100performs an initial separation of the liquid and gas phases of formation fluids3. Accordingly, intake100may also be referred to herein as a “separator.” As previously described, in some embodiments gas separator30may not be included within production assembly50. Consequently, in such embodiments, intake100performs substantially all of the liquid and gas separation for formation fluid3prior to routing the separated liquid phase of formation fluid3to pump60as described above. The details regarding the structure (e.g., internal and external) of intake100are described in more detail below.

Referring now toFIGS. 2 and 3, intake100has a central axis coincident with axis55and includes a first or upper end100a,a second or lower end100bopposite upper end100a,a first or upper connector102at upper end100a,and a second or lower connector104at lower end100b.In addition, intake100includes an outer tubular member106, a first or upper adapter105, and a second or lower adapter107. Outer tubular member106is axially positioned between adapters105,107, upper adapter105extends axially from tubular member106to connector102, and lower adapter107extends axially from tubular member106to connector104. As best shown inFIG. 3, in this embodiment, upper adapter105is threadably attached to upper connector102and tubular member106, and lower adapter107is threadably attached to tubular member106and lower connector104.

Upper and lower connectors102,104are couple intake100to axially adjacent components within production assembly50(seeFIG. 1). As a result, upper and lower connectors102,104, respectively, may include one or more connection features (e.g., threads, flanges, etc.) to facilitate the connections with adjacent components of production assembly50. As best shown inFIG. 1, in this embodiment, upper connector102is connected to pump60and lower connector104is connected to seal20during operations.

Referring again toFIGS. 2 and 3, outer tubular member106includes a first or upper end106a,a second or lower end106bopposite upper end106a,a radially outer cylindrical surface106cextending axially from end106ato end106b,and a radially inner cylindrical surface106dextending axially from end106ato end106b.Upper end106ais threadably attached to upper adapter105and lower end106bis threadably attached to lower adapter107.

Referring now toFIG. 3, intake100also includes an inner tubular member120coaxially disposed within outer tubular member106. Inner tubular member120includes a first or upper end120a,a second or lower end120bopposite upper end120a,a radially outer cylindrical surface120cextending axially from end120ato end120b,and a radially inner cylindrical surface120dextending axially from end120ato end120b.Upper end120ais proximal upper end106aof outer tubular member106, and lower end120bis proximal lower end106bof outer tubular member106. Inner tubular member120has an outer diameter that is less than the inner diameter of outer tubular member106, and thus, an annulus or annular flow path112is radially disposed between tubular members106,120. Annular flow path112extends axially from upper ends120a,106ato lower ends106b,120b.Upper end120aof inner tubular member120is threadably attached to upper adapter105and lower end120bis engaged with and radially supported by a connection profile (discussed below) within lower adapter107.

Referring still toFIG. 3, a central shaft150extends axially through intake100. In particular, central shaft150extends axially through upper connector102, upper adapter105, inner tubular member120, lower adapter107, and lower connector104. An annulus or annular flow path114is radially disposed between shaft150and inner tubular member120. In this embodiment, central shaft150is operatively coupled (e.g., either directly or indirectly) to motor22and pump60(e.g., shaft150may be coupled either directly or indirectly to other shafts rotatably disposed within pump60and motor22). During operations, central shaft150is driven by motor22to rotate in direction101, which in turn drives pump60(e.g., drives rotation of one or more impellers within pump60). However, it should be appreciated that in some embodiments motor22may drive shaft150to rotate in a direction opposite direction101. As one having ordinary skill in the art will appreciate, the choice of the rotational direction of shaft150is typically driven by the design of pump60. Central shaft150may also be coupled (e.g., directly or indirectly) to other components disposed within production system50(e.g., at one or both of the ends of driveshaft150) so that the operation of motor22may further cause actuation of those other components as well via central shaft150.

Referring now toFIG. 2, each of the plurality of inlet apertures110are disposed along outer tubular member106in a region or position more proximate upper end106athan lower end106b.In this particular embodiment, all of the inlet apertures110are disposed on the upper half (or uphole half) of outer tubular member106. In addition, apertures110are arranged in a plurality of axially spaced, circumferentially oriented rows. For example, in this embodiment, apertures110are arranged in four axially-spaced rows111a,111b,111c,111d;each row111a,111b,111c,111dincluding two circumferentially-spaced apertures110therein. Although each row111a,111b,111c,111dincludes two apertures110in this embodiment, in other embodiments, each row (e.g., each row111a,111b,111c,111d) may include one or more apertures (e.g., apertures110). For example, in some embodiments, intake apertures110are arranged in eight axially spaced, circumferentially oriented rows with one aperture110in each row, and with each aperture110being circumferentially-spaced approximately 45° from the aperture(s)110in each of the immediately axially adjacent row(s). In the embodiment shown inFIGS. 2 and 3, each row111a,111b,111c.111dincludes two apertures110that radially oppose one another about axis55(i.e., for each row111a,111b,111c,111d,there are two apertures110circumferentially-spaced approximately 180° apart). In addition, it should be appreciated that in this embodiment each aperture110is circumferentially or angularly spaced from each of the other apertures110such that none of the apertures110are circumferentially or angularly aligned along outer tubular member106with respect to axis55. In other words, apertures110are circumferentially misaligned with one another such that none of the apertures110are disposed directly axially above or below any of the other apertures110. In this embodiment, each aperture110is circumferentially or angularly spaced approximately 45° from each of the immediately circumferentially adjacent aperture(s)110. However, it should be appreciated that in some embodiments, apertures110are not circumferentially or angularly misaligned such that at least some of the apertures are disposed axially above or below others of the apertures110.

In some embodiments, apertures110are arranged in rows (e.g., rows111a,111b,111c,111d) such that apertures110are generally evenly circumferentially-spaced about axis55(e.g., such as the embodiment ofFIGS. 2 and 3). However, in other embodiments, apertures110may not be evenly or uniformly circumferentially-spaced about axis55. Regardless of whether apertures110are evenly or not evenly circumferentially-spaced about axis55, in some embodiments, it is desirable to space apertures110about the entire circumference of outer tubular member120. Without being limited to this or any other theory, the complete (or nearly complete) coverage for inlet apertures110about the circumference of outer tubular member120of intake100allows fluid flowing through all circumferential portions or regions of annulus16to communicate with at least one of the inlet apertures110during production operations.

In this embodiment, each aperture110is shaped as an elongate, axially extending, rectangular slot having an axial length (measured parallel to axis55) that is greater than its width (measured circumferentially about outer tubular member106). However, it should be appreciated that apertures110may have other shapes in other embodiments. For example, in other embodiments, apertures110are formed as ovals (e.g., ovals or ellipses elongated in a direction parallel with axis55), squares, circles, triangular, zig-zags, curved/arcuate holes, etc. As shown inFIG. 2, each inlet aperture110includes an axial length L110and a circumferential width W110. In this embodiment the ratio of length L110to width W110(i.e., L110/W110) for each aperture110is between about 2.5 and 10.0, preferably between about 5.0 and 8.0, and more preferably equal to about 6.67. Without being limited to this or any other theory, the exemplary length-to-width ratios above provide an optimum size for inlet aperture110so that formation fluids (e.g., formation fluid3shown inFIG. 1) may flow into intake100from annulus16via apertures110without substantially disrupting or impeding the flow of separated gases (e.g., gases5shown inFIG. 1) back into annulus16from intake100via apertures110and vice-versa. The performance of intake100is further enhanced when intake apertures110are spaced as described above (i.e., evenly circumferentially-spaced about axis55and/or spaced so that each aperture110is not circumferentially aligned with any of the other aperture110).

In at least some embodiments, the circumferential width W110(or the widest circumferential width) of each aperture110is between 5% and 50% of the entire circumference of radially outer cylindrical surface106cof outer tubular member106. This may be true regardless of the particular shape of apertures110(e.g., rectangular, circular, elliptical, irregular, etc.). In this embodiment, the circumferential width W110of each inlet aperture110is approximately 12% of the entire circumference of radially outer cylindrical surface106cof outer tubular member106. Without being limited to this or any other theory, by placing the circumferential width W110of apertures110between 5% and 50% of the entire circumference of radially outer cylindrical surface106c,there is a sufficient amount of tubular wall along outer tubular member106circumferentially adjacent apertures110to help create a “quiet” area within annular flow path112that is shielded from the turbulent flow within annulus16. As will be described in more detail below, the creation of these so called “quiet” areas within annular flow path112further promotes separation of the gases (e.g., gases5) from formation fluids3during operations. The formation of these quiet areas may also further be facilitated by the spacing and general arrangement of apertures110as discussed below.

As previously described, annulus112is radially disposed between tubular members106,120, and annulus114is radially disposed between shaft150and inner tubular member120. The radial spacing between outer tubular member106and inner tubular member120, and the radial spacing between inner tubular member120and central shaft150are maintained by a plurality of spacer assemblies160axially spaced from one another in a region axially between upper ends106a,120aand lower ends106b,120b.

Referring now toFIG. 4, one spacer assembly160is shown, it being understood that each of the spacer assemblies160is the same. In this embodiment, each spacer assembly160includes a plurality of uniformly circumferentially-spaced outer spacers162radially positioned between tubular members106,120and an inner spacer member164radially positioned between shaft150and inner tubular member120. Inner spacer member164includes an annular hub166disposed about shaft150and a plurality of uniformly circumferentially-spaced inner spacers168extending radially from hub166to inner tubular member120. Inner spacers168extend radially outward from hub166such that when hub166is coaxially disposed within inner tubular member120, each of the inner spacers168engages inner surface120dof inner tubular member120to center inner spacer member164relative to axis55. In this embodiment, four outer spacers162are evenly circumferentially-spaced spaced 90° apart and four inner spacers168are evenly circumferentially-spaced 90° apart. However, it should be appreciated that the number and arrangement of inner spacers168may be varied in other embodiments (e.g., there may be more or less than four spacers168that may or may not be evenly circumferentially-spaced about axis55in other embodiments).

As shown inFIG. 3, a pair of securing members161(e.g., bolts, rivets, screws, pins, etc.) are inserted radially through each aligned pair of outer spacers162and inner spacers168to thereby secure each pair of the spacers162,168both to one another and to inner tubular member120. As a result, each of the securing members161extend radially through the wall of inner tubular member120(i.e., through cylindrical surfaces120c,120d).

An annular bearing169is radially positioned between and engages hub166and shaft150. During operations, central shaft150is received through bearing169within throughbore167such that bearing169supports rotation of shaft150about axis55relative to spacer member164, spacers162,168, and tubular members106,120. Bearing169is depicted only schematically inFIG. 4as a matter of convenience; however, it should be appreciated that bearing169may, in some embodiments, include a pair of bearing races and one or more bearing elements (e.g., balls) to facilitate the relative rotation of central shaft150and inner spacer member164. In other embodiments, bearing169may more simply comprise a bushing or cylindrical sleeve (i.e., bearing169may not include any relatively moving parts or components). Thus, bearing member164may comprise any suitable bearing known in the art for simultaneously supporting radial loads while allowing relative rotation between central shaft150and inner spacer member164.

Referring again toFIG. 4, spacers162,168maintain the radial spacing of tubular member106,120and shaft150, while simultaneously allowing fluid (e.g., formation fluid3) to flow axially along annular flow paths112,114across assemblies160. Specifically, a plurality of inner flow ports or openings161are defined between each pair of circumferentially adjacent inner spacers168, and a plurality of outer flow ports or openings163are defined between each pair of circumferentially adjacent outer spacers162. Inner flow ports161allow fluid communication along annular flow path114axially across spacer assemblies160, and outer flow ports163allow fluid communication along annular flow path112axially across spacer assemblies160. Because spacers162,168maintain radial spacing between tubular members102,120, and shaft150and help to support rotational movement of shaft150, spacers162,168may be referred to herein as “bearings.”

Referring now toFIG. 5, lower end120bof inner tubular member120is radially supported by a lower support profile170disposed within lower adapter member107. Support profile170includes a plurality uniformly circumferentially-spaced, radially extending engagement members172. A plurality of flow ports or openings174are circumferentially disposed between each pair of adjacent engagement members172. Flow ports174allow axial fluid flow along annular flow path112across support profile170. In this embodiment, four engagement members172spaced 90° apart from one another about axis55, and thus, there are four flow ports174spaced 90° apart from one another about axis55.

Referring now toFIGS. 1-3, during production operations, formation fluids3flow into throughbore12of casing11via perforations13and then into inlet apertures110of intake100as previously described. Motor22is powered via electricity provided by cable26to drive rotation of central shaft150about axis55in direction101(FIG. 3) within intake100. In some embodiments, lower end100bof intake100is positioned vertically lower than upper end100aof intake100such that the formation fluids3flow axially toward lower end100bwithin annular flow path112upon entering at inlet apertures110under the force of gravity. In addition, the relatively lower pressure within annular flow passage112compared to the pressure within annulus16also facilitates the flow of fluid3into apertures110, down annular flow passage112and toward inner annular flow passage114. Due to differences in densities, the gases and liquids within formation fluids3separate within annular flow path112under the force of gravity so that the liquids continue to flow/fall toward lower end100bwhile at least some of the gases5within formation fluid3migrate back upward toward upper end100aand out apertures110. As a result, apertures110function as an entrance point or inlet for formation fluids3(liquids and gases) and as an exit point or outlet for separated gases5during production operations.

Without being limited to this or any other theory, because inlet apertures110are arranged such that none of the apertures110are circumferentially aligned with one another with respect to axis55, and because apertures110are sized to include the length-to-width ratios discussed above (i.e., L110/W110), the annular volume of liquid (e.g., the liquid of formation fluid3) available to enter into intake100from annulus16is maximized. In addition, without being limited to this or any other theory, due at least in part to the sizing and arrangement of inlet apertures110described above, gas (e.g., gases5) exiting intake100via inlet apertures110impart minimal resistance and/or interference for formation fluids3flowing into the intake100and flow path112. More specifically, the relationship between aperture110size (e.g., L110/W110) and aperture110alignment (e.g., the arrangement of apertures110within rows111a,111b,111c,111d,discussed above) minimizes friction inhibiting either the entrance of formation fluid3into intake100(including both liquid and gas) through apertures110or the exiting of gas5into annulus16through apertures110. In addition, without being limited to this or any other theory, the circumferential misalignment of apertures110over length Lihelps to minimize the exposure of formation fluid3within annular flow passage112to the turbulent flow in annulus16, thereby contributing to the creation of the “quiet areas” within annular flow path112as described above. As a result, gravity separation of the gas phase5of formation fluid3may occur in these relatively sheltered and “quiet” areas within annular flow passage112, along the length of intake100carrying inlet apertures110(e.g., inlet length Lidiscussed supra). Additional gravity separation may then occur as the fluid3flows through annular flow passage below or downstream of inlet apertures110(e.g., sump length Lsdiscussed supra). It should also be appreciated that the circumferential width W110of inlet apertures (e.g., a width W110being between and including 5% and 50% of the total circumference of outer tubular member106) also contributes and/or facilitates the formation of the so-called quiet areas within annular flow path112as previously described.

Upon reaching the lower end120bof inner housing member120, the formation fluids3in annular flowpath112, which include a reduced concentration of gas5, pass through ports174in support profile170(seeFIG. 5) and then flow upward in annular flow path114within inner tubular member120. Upon exiting annular flow path114the formation fluids3are directed through upper end100aof intake100and then and into gas separator3to further reduce the concentration or amount of gases5within fluids3prior to ultimately routing fluid into pump60(seeFIG. 1). Thereafter, pump60pressurizes the now mostly (or possibly only) liquid formation fluid3and then further induces fluid3to flow to the surface through one or more defined flow paths (e.g., the at least one flow path defined with tubular string70). During these operations, the formation fluids3and/or gases5flowing through annular flow paths112,114are able to bypass spacer assemblies160via the flow ports163,161, respectively, disposed therein (seeFIG. 4) as previously described.

In some embodiments most (if not all) of the gases5separate out of the formation fluids3as the formation fluids3flow axially downward within annular flow path112toward lower end120bof inner tubular member, mostly (if not only) liquid advances into annular flow path114and then ultimately on to pump60. In these embodiments, production assembly50may not include the additional gas separator30described above. However, in other embodiments, if the flow rate of formation fluid3through intake100and/or the gas concentration within the formation fluid3is high (i.e., above some threshold), some amount of gas5may flow through annular flow path112into inner annular flow path114and out through upper end100a.In these embodiments, intake100at least reduces (potentially significantly) the amount or concentration of gases5flowing to pump60. In addition, in these embodiments, the inclusion of the additional gas separator30further reduces the amount of gases5within formation fluid3(potentially removing all gases5in some instances); however, pre-separating out at least a portion of the gases5with intake100may help to increase the efficiency and overall performance of separator30during operations.

Regardless of whether intake100is operated with or without gas separator30, through use of intake100the chances that gas5will accumulate at the inlet of pump60in sufficient amounts to cause gas lock of pump60is reduced. In addition, due to the relatively long length that the formation fluids3must travel to reach annular flow path114, the lower portion (e.g., the portion extending axially from lower end120btoward inlet apertures110) of annular flow path112forms a sump for collecting liquids that will eventually flow into annular flow path114and pump60. Without being limited to this or any other theory, the sump in annular flow path112creates a reservoir of liquid that helps ensure that the flow of liquid to pump60will not be totally interrupted or lost, even in the event that a large gas bubble is advanced into annular flow path112. Therefore, intake100may also improve the performance and longevity of pump60in formations that produce substantially slugged flow (i.e., the formation produces fluids in alternating slugs of liquid and gas). As shown inFIG. 2, intake100includes a total length L100measured axially between ends100a,100b.In addition, the length of intake100that corresponds with inlet apertures110is shown as an inlet length LiinFIG. 2. Further, the length of intake100that corresponds with the sump (i.e., the length from the axially lower end of the axially lowest aperture110to the lower end100bof intake100) is shown as a sump length LsinFIG. 3. In this embodiment, the inlet length Liis approximately between 25% and 75% of the total length L100, and the sump length Lsis approximately between 25% and 75% of the total length L100.

In the manner described, through use of an intake (e.g., intake100), in accordance with the embodiments disclosed herein, upstream of a pump (e.g., pump60) in a production assembly50disposed within a subterranean wellbore, failures resulting from flowing gases to the pump may be avoided or at least reduced. Accordingly, through use of intake in accordance with the embodiments herein, the operational life of such pumps may be increased, which thereby reduces the overall costs for producing hydrocarbons from a subterranean well via such an artificial lift system.