Multipath, multistage, erosion-resistant flow control valves have been developed that can sustain the extremely high pressure of deep oil wells. Fitting in the restricted available space and operating using limited power with a long lifetime are challenges for choke valves in the downhole environment of oil wells. These valves must control the flow rate from high-pressure oil reservoirs in the presence of fluids that have non-zero sand concentrations. This design consists of a digitized flow control valve with multipath and multistage pressure reduction structures. Specifically, the valve is configured as a set of parallel flow paths from the inlet to the outlet.

The flow control valve can be operated by a few actuators using an annular cam. The design solution allows the use of a single actuator or set of actuators for redundancy.
The choke valve controls the total flow rate by digitally opening different paths or different combinations of paths. Each path is controlled by a poppet cap valve operated in on/off states. To avoid erosion from sand in the oil and high-speed flow, the seal area of the poppet cap valve is located at a distance from the flow inlet away from the high-speed flow. The path is a multistate structure composed of a jet orifice and settling chamber pairs. The pressure drop of each stage and, therefore, the flow speed at the orifices for a set flow rate, is controlled by the number of stages. The paths have relatively small diameters (in centimeters), or cross-sections, and can be relatively long (in meters) for large numbers of stages and still fit in the strict annular space limit in the typical downhole region of an oil well. The actual inlet of the valve for the flow from the formation is located between the inner pipe and the casing pipe, whereas the outlet is positioned towards the inner pipe. The available space for this downhole valve is an annular cylinder between the inner pipe and the casing pipe.

This work was done by Xiaoqi Bao, Mircea Badescu, Stewart Sherrit, Jeffery L. Hall, and Yoseph Bar-Cohen of Caltech for NASA’s Jet Propulsion Laboratory.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

Technology Transfer at JPL
JPL
Mail Stop 321-123
4800 Oak Grove Drive
Pasadena, CA 91109-8099
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Refer to NPO-48980.

Topics:
Chokes Engine components Engine cylinders Engine mechanical components Engines Fittings Mechanical Components Mechanics Parts Powertrains Pressure Seals and gaskets Sensors and actuators Soils Valves
This Brief includes a Technical Support Package (TSP).
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Multipath, Multistage, Erosion-Resistive Valve for Downhole Flow Control

(reference NPO48980) is currently available for download from the TSP library.

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NASA Tech Briefs Magazine

This article first appeared in the February, 2016 issue of NASA Tech Briefs Magazine (Vol. 40 No. 2).

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Overview

The document presents a technical disclosure of a novel multipath, multistage erosion-resistive valve designed for downhole flow control in oil wells, developed by researchers at the Jet Propulsion Laboratory, California Institute of Technology. This valve addresses the challenges of controlling high-pressure flow from oil reservoirs, particularly in environments where fluids contain sand and other particulates.

The key features of the valve include:

  1. Multipath and Multistage Design: The valve consists of multiple parallel flow paths, each controlled by separate poppet cap valves that operate in an on/off manner. This digital flow control allows for precise regulation of the total flow rate by selectively opening different paths or combinations of paths.

  2. Erosion Resistance: The design incorporates high erosion tolerance, which is crucial for longevity in the presence of sand-laden fluids. The seal area of the poppet cap valve is strategically positioned away from high-speed flow to minimize erosion.

  3. Pressure Reduction Structures: The valve features multistage pressure reduction structures that limit the maximum flow speed, thereby reducing the risk of erosion from entrained particulates. Each stage consists of a jet orifice and a settling chamber, allowing for efficient energy dissipation and pressure drop.

  4. Compact Design: The valve is engineered to fit within the restricted annular space typical of downhole environments, making it suitable for deployment in oil wells where space is limited.

  5. Low Power Operation: The valve can be activated using a single actuator or multiple actuators, requiring low power, which is advantageous for downhole applications.

The document also highlights potential applications of this technology in NASA and other reimbursable projects that require high-pressure flow control, indicating its broader relevance beyond oil extraction.

In summary, this innovative valve design represents a significant advancement in flow control technology for oil wells, addressing critical issues such as erosion, space constraints, and power efficiency. The research was conducted under NASA's sponsorship, emphasizing its potential impact on both aerospace and commercial applications. The document serves as a technical support package, providing insights into the valve's functionality and its implications for future technological developments in fluid mechanics and flow control systems.