The invention relates to apparatus and methods for autonomously controlling fluid flow through a system using a fluid diode. More specifically, the invention relates to using a fluid diode defined by an orifice having a high resistance side and a low resistance side.
Some wellbore servicing tools provide a plurality of fluid flow paths between the interior of the wellbore servicing tool and the wellbore. However, fluid transfer through such a plurality of fluid flow paths may occur in an undesirable and/or non-homogeneous manner. The variation in fluid transfer through the plurality of fluid flow paths may be attributable to variances in the fluid conditions of an associated hydrocarbon formation and/or may be attributable to operational conditions of the wellbore servicing tool, such as a fluid flow path being unintentionally restricted by particulate matter.
The invention provides apparatus and methods for autonomously controlling fluid flow in a subterranean well, and in particular for providing a fluid diode to create a relatively high resistance to fluid flow in one direction and a relatively low resistance to fluid flowing in the opposite direction. The diode is positioned in a fluid passageway and has opposing high resistance and low resistance entries. The low resistance entry providing a relatively low resistance to fluid flowing into the diode through the low resistance entry. The high resistance entry providing a relatively high resistance to fluid flowing into the diode through the high resistance entry. In a preferred embodiment, the high resistance entry has a concave, annular surface surrounding an orifice and the low resistance entry has a substantially conical surface. The entries can have a common orifice. In one embodiment, the concave, annular surface of the high resistance entry extends longitudinally beyond the plane of the orifice. That is, a portion of a fluid flowing through the diode from the high resistance side will flow longitudinally past, but not through, the orifice, before being turned by the concave, annular surface. In a preferred embodiment, the fluid will flow in eddies adjacent the concave, annular surface.
The apparatus and method can be used in conjunction with other autonomous flow control systems, including those having flow control assemblies and vortex assemblies. The invention can be used in production, injection and other servicing operations of a subterranean wellbore. The invention can be positioned to provide relatively higher resistance to fluid flow as it moves towards or away from the surface.
For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
It should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. Where this is not the case and a term is being used to indicate a required orientation, the Specification will state or make such clear. “Uphole,” “downhole” are used to indicate location or direction in relation to the surface, where uphole indicates relative position or movement towards the surface along the wellbore and downhole indicates relative position or movement further away from the surface along the wellbore, regardless of the wellbore orientation (unless otherwise made clear).
While the making and using of various embodiments of the present invention are discussed in detail below, a practitioner of the art will appreciate that the present invention provides applicable inventive concepts which can be embodied in a variety of specific contexts. The specific embodiments discussed herein are illustrative of specific ways to make and use the invention and do not limit the scope of the present invention.
Positioned within wellbore 12 and extending from the surface is a tubing string 22. Tubing string 22 provides a conduit for fluids to travel from formation 20 upstream to the surface. Positioned within tubing string 22 in the various production intervals adjacent to formation 20 are a plurality of autonomous fluid control systems 25 and a plurality of production tubing sections 24. At either end of each production tubing section 24 is a packer 26 that provides a fluid seal between tubing string 22 and the wall of wellbore 12. The space in-between each pair of adjacent packers 26 defines a production interval.
In the illustrated embodiment, each of the production tubing sections 24 includes sand control capability. Sand control screen elements or filter media associated with production tubing sections 24 are designed to allow fluids to flow therethrough but prevent particulate matter of sufficient size from flowing therethrough.
The fluid flowing into the production tubing section typically comprises more than one fluid component. Typical components are natural gas, oil, water, steam or carbon dioxide. Steam and carbon dioxide are commonly used as injection fluids to drive the hydrocarbon towards the production tubular, whereas natural gas, oil and water are typically found in situ in the formation.
The invention provides a method and apparatus for use of a fluid diode in a passageway to provide a relatively high resistance to fluid flow through a passageway in one direction while providing a relatively low resistance to fluid flow in the opposite direction. It is envisioned that such relative restriction of fluid flow can be used in any operation where fluid flow is desired in one direction and undesired in the opposite direction. For example, during production of hydrocarbons from the wellbore, fluid typically flows from the wellbore, into the tubing string, and thence uphole towards the surface. However, if flow is reversed for some reason, a fluid diode, or series of diodes, will restrict flow in the reverse direction. The diodes can be used similarly in injection operations to restrict fluid flow uphole. Persons of skill in the art will recognize other uses where restriction of flow in one direction is preferable.
The fluid diode 100 has a high resistance entry 104 and a low resistance entry 106. The low resistance entry 104, in the preferred embodiment shown, has a substantially conical surface 108 narrowing from a large diameter end 110 to a small diameter end 112 and terminating at an orifice 114. The substantially conical surface is preferably manufactured such that it is, in fact, conical; however, the surface can instead vary from truly conical, such as made of a plurality of flat surfaces arranged to provide a cone-like narrowing. The high resistance entry 106 narrows from a large diameter end 116 to a small diameter end 118 and terminates at an orifice 114. In the preferred embodiment shown, the orifice 114 for the high and low resistance ends is coincident. In other embodiments, the orifices can be separate. The orifice 114, high resistance entry 106 and low resistance entry 104 are preferably centered on the longitudinal axis 103 of the passageway 102. The orifice 114 lies in a plane 115. Preferably the plane 115 is normal to the longitudinal axis 103.
The high resistance entry 106 preferably includes a concave surface 120. The concave surface 120 is annular, extending around the orifice 114. In a preferred embodiment, as seen in
In use, fluid F can flow either direction through the diode 100. When fluid flows into the diode through the low resistance entry 104, as indicated by the solid arrow in
The following data is exemplary in nature and generated from computer modeling of a diode similar to that in
In a preferred embodiment, fluid diodes 100 are arranged in series, such that the fluid flow passes through a plurality of diodes. For example, two diodes 100 are seen downstream of the vortex assembly 80 in
The diode explained herein can be used in conjunction with the various flow control systems, assemblies and devices described in the incorporated references as will be understood by those of skill in the art.
Descriptions of fluid flow control using autonomous flow control devices and their application can be found in the following U.S. patents and patent applications, each of which are hereby incorporated herein in their entirety for all purposes: U.S. patent application Ser. No. 12/635,612, entitled “Fluid Flow Control Device,” to Schultz, filed Dec. 10, 2009; U.S. patent application Ser. No. 12/770,568, entitled “Method and Apparatus for Controlling Fluid Flow Using Movable Flow Diverter Assembly,” to Dykstra, filed Apr. 29, 2010; U.S. patent application Ser. No. 12/700,685, entitled “Method and Apparatus for Autonomous Downhole Fluid Selection With Pathway Dependent Resistance System,” to Dykstra, filed Feb. 4, 2010; U.S. patent application Ser. No. 12/791,993, entitled “Flow Path Control Based on Fluid Characteristics to Thereby Variably Resist Flow in a Subterranean Well,” to Dykstra, filed Jun. 2, 2010; U.S. patent application Ser. No. 12/792,095, entitled “Alternating Flow Resistance Increases and Decreases for Propagating Pressure Pulses in a Subterranean Well,” to Fripp, filed Jun. 2, 2010; U.S. patent application Ser. No. 12/792,117, entitled “Variable Flow Resistance System for Use in a Subterranean Well,” to Fripp, filed Jun. 2, 2010; U.S. patent application Ser. No. 12/792,146, entitled “Variable Flow Resistance System With Circulation Inducing Structure Therein to Variably Resist Flow in a Subterranean Well,” to Dykstra, filed Jun. 2, 2010; U.S. patent application Ser. No. 12/879,846, entitled “Series Configured Variable Flow Restrictors For Use In A Subterranean Well,” to Dykstra, filed Sep. 10, 2010; U.S. patent application Ser. No. 12/869,836, entitled “Variable Flow Restrictor For Use In A Subterranean Well,” to Holderman, filed Aug. 27, 2010; U.S. patent application Ser. No. 12/958,625, entitled “A Device For Directing The Flow Of A Fluid Using A Pressure Switch,” to Dykstra, filed Dec. 2, 2010; U.S. patent application Ser. No. 12/974,212, entitled “An Exit Assembly With a Fluid Director for Inducing and Impeding Rotational Flow of a Fluid,” to Dykstra, filed Dec. 21, 2010; U.S. patent application Ser. No. 12/983,144, entitled “Cross-Flow Fluidic Oscillators for use with a Subterranean Well,” to Schultz, filed Dec. 31, 2010; U.S. patent application Ser. No. 12/966,772, entitled “Downhole Fluid Flow Control System and Method Having Direction Dependent Flow Resistance,” to Jean-Marc Lopez, filed Dec. 13, 2010; U.S. patent application Ser. No. 12/983,153, entitled “Fluidic Oscillators For Use With A Subterranean Well (includes vortex),” to Schultz, filed Dec. 31, 2010; U.S. patent application Ser. No. 13/084,025, entitled “Active Control for the Autonomous Valve,” to Fripp, filed Apr. 11, 2011; U.S. Patent Application Ser. No. 61/473,700, entitled “Moving Fluid Selectors for the Autonomous Valve,” to Fripp, filed Apr. 8, 2011; U.S. Patent Application Ser. No. 61/473,699, entitled “Sticky Switch for the Autonomous Valve,” to Fripp, filed Apr. 8, 2011; and U.S. patent application Ser. No. 13/100,006, entitled “Centrifugal Fluid Separator,” to Fripp, filed May 3, 2011.
While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.