Patent Application
20110180267
1. Field of the Disclosure
The disclosure relates generally to gas lift apparatus for use in wells.
2. Description of the Related Art
Hydrocarbons such as oil and gas are recovered from a subterranean formation using a well or wellbore drilled into the formation. In some cases the wellbore is completed by placing a casing along the wellbore length and perforating the casing adjacent each production zone (hydrocarbon-bearing zone) to extract fluids (such as oil and gas) from the associated a production zone. In other cases, the wellbore may be open-hole, i.e. no casing. A production string is placed in the wellbore. The wellbore includes a tubing (also referred to as base pipe) and a number of flow control devices that enable the formation fluid to enter into the production tubing. In some cases, the downhole pressure is not adequate to lift the formation fluid in the wellbore to the surface. In such cases, artificial lift mechanisms are often used to lift the formation fluid to the surface. In one such mechanism gas is injected from the surface through tubing run in the wellbore to a selected location in the wellbore. The gas reduces the density of the formation fluid and the downhole pressure, thus causing fluid to be lifted to the surface. The valve is usually placed in a pocket in a side mandrel. The gas lift valves are typically operated by the pressure of the injected gas. Such valves utilize mechanical components such as springs to control the valve position. Such mechanically-set valves are generally imprecise and can result excessive introduction of the injected gas to the selected locations.
The present disclosure provides an improved gas lift valve and methods of using and making the valve that address at least some of the deficiencies of commercially available gas lift valves.
In one aspect, a downhole-adjustable flow control device is provided that in one embodiment includes an inflow control device with a flow-through region configured to receive formation fluid at an inflow region and discharge the received fluid at an outflow region. The inflow control device also includes a setting device configured to adjust the flow of the fluid through the flow-through region to a selected level, the setting device including a coupling member configured to be coupled to an external latching device adapted to move the coupling member to cause the setting device to alter the flow of the fluid to a desired level.
In another aspect, an apparatus for controlling flow is disclosed that in one embodiment may include a passive inflow control device configured to receive fluid from a formation and discharge the received fluid to an outflow region, a setting device configured to adjust flow of the fluid through the inflow control device, the setting device including a coupling member and a latching device configured to couple to the coupling member to operate the setting device to adjust the flow of the fluid through the inflow control device.
Examples of the more important features of the disclosure have been summarized rather broadly in order that detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto.
Advantages and additional aspects of the disclosure will be readily appreciated by those of ordinary skill in the art as the same become better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference characters designate like or similar elements throughout the several figures of the drawing, and wherein:
The present disclosure relates to apparatus and methods for controlling flow of formation fluids in a well. The present disclosure provides certain exemplary drawings to describe certain embodiments of the apparatus and methods that are to be considered exemplification of the principles described herein and are not intended to limit the concepts and disclosure to the illustrated and described embodiments.
The flow control system 102 includes the flow control device 112 configured to detect wireless command signals from a control unit 120. The control unit 120 includes a transmitter 122 and surface controller 124. The surface controller 124 may be a computing device that includes a processor 126, memory 128 and computer program 130 configured to run on the processor 126. An input device 132, such as a touch screen, keyboard and/or mouse, and display 134 may be used to operate and program the surface controller 124. A power supply 135 may include a battery to provide power to components of the control unit 120. In an embodiment, an operator at the surface may use software such as the computer program 130 on the control unit 120 to control the position of the flow control device 112, thereby adjusting the amount of gas that flows into the base pipe 110 to enhance the flow of formation fluid to the surface. The control unit 120 and transmitter 122 may transmit a wireless command signal 136 that includes commands from the computer program 130 to control the flow position of the flow control device 112. The flow control device 112 may receive the wireless signal 138 using a sensor or other device suitable for the various forms of wireless communication. In one embodiment, the flow control device 112 may have a plurality of flow positions, wherein each of the positions enables a range of gas flow rates (from open to closed) into the base pipe 110. Formation fluid 140 flows from the production zone through the casing 108 and into the base pipe 110. The formation fluid 140 then mixes with the gas in a mixing region 142 to enhance flow of the mixture toward the surface 144. In an aspect, the wellbore may include isolation packers 146 configured to restrict and enable formation fluid flow into selected portions of the wellbore 106 and casing 108.
In one embodiment, the flow control system 102 enables improved extraction of hydrocarbons from the formation by wirelessly communicating with the downhole flow control device 112. The surface controller 124 issues a command to the flow control device 112 using transmitter 122 to send the command using a wireless signal 136, 138. The flow control device 112 receives the wireless command signal 138 and processes the signal to determine a selected position for the flow control device 112. The selected position of the device will enable a selected amount of gas to flow into the base pipe 110. As depicted, the gas is injected into the wellbore 106 by the supply system 118 and is routed to the flow control device 112 by flowing along an annulus or within lines in the annulus. The gas is mixed with the formation fluid 140 within the base pipe 110 to improve flow of the formation fluid to the surface 144. The control unit 120 and flow control device 112 may use mud pulses, radio, wireless networks (802.11) or any combination thereof to wirelessly communicate. In other embodiments, cables may be used to communicate with downhole flow control devices. Cables may be costly to place in the wellbore and may require repair after wear and tear over time. The remote wireless command of the flow control device 112 from the surface enables improved control over the mixing process while improving reliability for the flow control system 102.
In an aspect, the flow control device 200 is configured to receive a wireless command signal via the sensor 210. A surface controller and transmitter may emit the wireless signal as one of, but not limited to: acoustic signals, pressure pulses through fluid in the wellbore; vibration signals and radio signals. Therefore, the sensor 210 may be any suitable device to detect the selected wireless signal, such as an accelerometer configured to sense vibration. In an embodiment, the sensor 210 is powered by the battery/controller 208 to sense the wireless command signal. In addition, upon detecting a wireless command signal, the battery/controller 208 may transition from an inactive state to an active state. The inactive state may also be referred to as a sleep or power saving state. The battery/controller 208 is “awakened” to an active state by receiving a command signal, it may process the signal. The battery/controller 208 processes the received signal and sends the corresponding control signal to the motor 206, causing movement of the flow control mechanism 204 to a selected position. After moving the flow control mechanism 204 to the desired position, the rate of gas flow may be determined via a sensor or measurement device located within or near the flow control device 200 to ensure a stable inflow of gas. In an embodiment, the battery/controller 208 may return to an inactive state (“sleep”) after the gas flow is stabilized and/or a specified period of time (e.g., 1-10 minutes) elapses during which no new command signal is received. For example, if the gas flow into the base pipe is stable and a signal with instructions to implement a gas flow position change have not been received for three minutes, the battery/controller 208 will transition to the inactive mode.
The battery/controller 208 may consist of any suitable power source or chemical-based battery to supply electrical power to the motor 206 and sensor 210. In an aspect, the battery is a suitable durable and robust power source capable of extended life and repeated charging. Further, the battery/controller 208 may include a processor, memory and suitable software or firmware to control operation of the motor 206, wherein the movement of the motor 206 corresponds to various positions of the flow control device 204. The motor 206 may be any suitable electric motor and mechanism configured to actuate movement of the flow control device 204. The flow control device 204 may include any suitable mechanism, such as a ball valve, bonnet valve, disc valve, spring valve or any combination thereof, configured to translate movement from the motor 206 to an opening or closing of a flow path.
