Patent Application
20180149018
This disclosure relates generally to apparatus and methods for operating devices in wellbores using signal transmission by a transmitter in a drop device.
Wellbores are formed in subsurface formations for the production of hydrocarbons (oil and gas). Modern wells descend to great well depths, often more than 15,000 ft. Hydrocarbons are generally trapped in zones at various depths. A variety of sensors and tools are used to determine the location of such zones. A drilled wellbore at such a stage is referred to as open hole. To recover hydrocarbons, the wellbore is typically lined with a casing (serially connected metal tubulars) along the length of the wellbore to prevent collapse of the formation (rocks) into the wellbore. Such a wellbore is referred to as a cased wellbore. The zones bearing hydrocarbons are perforated through the casing to cause the hydrocarbons to flow from such zones to within of the casing. A string, such a work string or a completion string, containing a variety of devices or tools, is installed inside the casing or the open hole to controllably allow fluid containing hydrocarbons to move from the formation into the wellbore and to transport such fluid to the surface. The equipment on such as string is often referred to as the completion equipment. The completion equipment includes a variety of tools and devices, which may be electrically, hydraulically, electrically and/or mechanically operated, i.e. activated and/or deactivated to perform a variety of intended functions. Often a service string is conveyed into the completion string to operate devices in the work string. Service strings carrying a transmitter that transmits signals, such as light signals, in the wellbore to operate certain devices have been proposed. In one such system, a light source is mounted on a string to transfer data from sensors and memory located at the surface to a downhole device. Another system proposes a method of activating downhole tools using light signals transmitted via fiber-optic cables run inside a service string conveyed into the wellbore. Such systems require conveying a string in the wellbore or installation of communication links in the completion strings for operating various devices, which are very expensive and time consuming.
The disclosure herein provides apparatus and methods in which control signals or selected signals are generated in a wellbore by a transmitter carried by device traveling through the wellbore to operate one or more downhole devices.
In one aspect, an apparatus for operating a device in a wellbore is disclosed that in one non-limiting embodiment includes a drop device configured to be dropped into the wellbore that transmits a selected signal while the drop device is traveling in the wellbore, a control circuit in the wellbore that detects the transmitted selected signal and provides a control signal in response to the detected signal to operate the device in the wellbore.
In another aspect, a method of operating a device in a wellbore is disclosed that in one non-limiting embodiment includes: dropping a drop device in the wellbore that transmits a selected signal while the device is traveling in the wellbore; detecting by a detector in the wellbore the transmitted signal; and operating the device in the wellbore in response to the detected signal.
Examples of the more important features of certain embodiments and methods according to this disclosure have been summarized rather broadly in order that the 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 that will be described hereinafter and which will form the subject of the claims.
For a detailed understanding of the apparatus and methods disclosed herein, reference should be made to the accompanying drawing and the detailed description thereof, wherein:
In general, the disclosure herein provides apparatus and methods for operating (activating and/or deactivating) devices (also referred to herein as the target device or devices) disposed in a wellbore using signals such as light signals, acoustic signals and electromagnetic signals, without the use of strings conveyed into the wellbore or via links disposed or installed in the wellbore, such as conductors or fiber optic links. In one non-limiting embodiment, the apparatus includes a drop device, such as a drop ball, that is dropped from a surface location or from a tool located up hole from the device to be operated. The drop device may contain one or more transmitters or sources that transmit certain selected signals while the drop device is traveling in the wellbore. In one embodiment, a transmitter may include a light source, such as light emitting diodes (LEDs), an electromagnetic signal generator, an acoustic source, or another suitable signal generator. The transmitted signals may include one or more signals selected from a range of signals, such as signals having different frequencies, wavelength, etc. The apparatus may include a control circuit or control unit configured to detect the transmitted signals and provide one or more control signals to operate one or more target devices. A power unit may operate an associated device to be operated in response to the one or more control signals. In one embodiment, the control circuit includes a detector configured to detect the selected signals transmitted by the drop device. In the case of light signals, the receiver may include photodetectors to receive the transmitted light signals. A controller, such as a micro-processor based circuit, in the control circuit may be configured to process certain selected signals detected by the detector, such as signals corresponding to certain frequencies, and generate control signals to operate selected devices. In one non-limiting embodiment, when the drop device is proximate to or passes by the device to be operated, the detector in the control circuit detects or senses the transmitted signal that corresponds to or relates to its associated device to be operated and provides a control signal to a power unit associated with such device to operate the device. The controller in the control circuit may be programmed to generate the control signals to operate specific devices in response to the transmitted signals. A single drop device may be utilized to transmit a variety of signals to operate more than one device in the wellbore. Also, a common control circuit may be utilized to provide specific control signals (for example, signals having different wavelength or frequency for each device) corresponding to more than one device, or a separate receiver may be utilized for each device to be operated. In such cases, the drop device generates a specific signal for each device to be operated and the common receiver or separate receivers, as the case may be, provide corresponding control signals. In another embodiment, the same downhole device may be configured to perform different functions in response to different signals transmitted by the drop device. In the apparatus and methods described herein, the drop device does not need to contact a target device in order to convey the transmitted signal to its associated detector. Thus, the drop device may be sized to pass through the device to be operated without blocking the internal diameter of such a device. Also, in the case of light signals, the emitted light may be visible light or it may extend to other wavelengths on the electromagnetic spectrum, such as ultraviolet light or infrared light.
Still referring to
Thus, in aspects, to operate a device such as device 122, the drop device 200 is dropped from a surface location or a location in the wellbore above the device 122 into the work string 110, wherein the transmitters 202a-202n transmit control signals specific for device 122. The detector 132 detects such signals and the controller 134 sends control signals to the power unit 124 to cause it to operate the device 122. If another device, such as device 150, is also to be operated, the transmitters 202a-202n are configured to transmit signals corresponding to both devices 122 and 150. The control circuits 130 and/or 180, as the case may be, detect the signals corresponding to their associated device and send control signals to operate device 122 and device 150. In this manner, multiple devices may be operated or controlled by using a single drop device. The controllers in the control circuits 130 and/or 180 may be programmed to send control signals that are timed in a manner so as to operate various devices in any desired sequence and at any desired time. In this manner, a single drop device may be utilized to operate multiple devices in any desired sequence at any desired time regardless of their location (depth) in the wellbore.
The foregoing disclosure is directed to the certain exemplary embodiments and methods of apparatus and method for operating one or more devices in a wellbore. Various modifications to the apparatus and methods disclosed herein will be apparent to those skilled in the art. It is intended that all such modifications within the scope of the appended claims be embraced by the foregoing disclosure. The words “comprising” and “comprises” as used in the claims are to be interpreted to mean “including, but not limited to.” Also, the abstract is not to be used to limit the scope of the claims.
