Patent Application
20120152562
1. Field of the Disclosure
The disclosure relates generally to an apparatus and method for control of fluid flow between subterranean formations and a production string in a wellbore.
2. Description of the Related Art
To form a wellbore or borehole in a formation, a drilling assembly (also referred to as the “bottom hole assembly” or the “BHA”) carrying a drill bit at its bottom end is conveyed downhole. The wellbore may be used to store fluids in the formation or obtain fluids from the formation, such as hydrocarbons. 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. One or more inflow control devices are placed in the wellbore to control the flow of fluids into the wellbore. These flow control devices and production zones are generally separated by packers. Fluid from each production zone entering the wellbore is drawn into a tubular that runs to the surface.
Horizontal wellbores often are completed with several inflow control devices placed spaced apart along the length of the horizontal section. Formation fluid often contains a layer of oil, a layer of water below the oil and a layer of gas above the oil. The horizontal wellbore is typically placed above the water layer. The boundary layers of oil, water and gas may not be even along the entire length of the horizontal well. Also, certain properties of the formation, such as porosity and permeability, may not be the same along the length of the well. Therefore, oil between the formation and the wellbore may not flow evenly through the various inflow control devices. For production wellbores, it is desirable to have a relatively even flow of the oil into the wellbore and also to inhibit the flow of water and gas through the inflow control devices. Passive inflow control devices are commonly used to control flow into the wellbore. Such inflow control devices are set at the surface for a specific flow rate and then installed in the production string, which is then conveyed and installed in the wellbore. Such pre-set passive flow control devices are not configured for downhole adjustments to alter a flow rate. To change the flow rate through such passive inflow control devices, the production string is pulled out to adjust or replace the flow control devices. Such methods are very expensive and time consuming.
In one aspect, an apparatus for controlling fluid flow between a formation and a tubular is provided, wherein the apparatus includes a retrievable communication device configured to be conveyed to a selected location in the tubular downhole. The apparatus also includes a control node configured to communicate with the retrievable communication device at the selected location, a flow control device coupled to and controlled by the control node and a sensor coupled to the control node, wherein the sensor and flow control device are downhole of the control node.
In another aspect, a method of controlling fluid flow between a wellbore and tubular is provided, wherein the method includes conveying a retrievable communication device downhole in the tubular to a selected location and communicating between the retrievable communication device and a control node at the selected location. The method also includes transmitting a first signal between the control node and a flow control device and transmitting a second signal between the control node and a sensor, wherein the sensor and flow control device are downhole of the control node.
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.
The advantages and further aspects of the disclosure will be readily appreciated by those of ordinary skill in the art as the same becomes 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 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.
Each production device 134 includes a downhole-adjustable flow control device 138 to govern one or more aspects of flow of one or more fluids from the production zones into the production string 120. The downhole-adjustable flow control device 138 may have a number of alternative structural features that provide selective operation and controlled fluid flow therethrough. In one embodiment, the downhole-adjustable flow control device 138 is in communication with a control node 160 configured to communicate signals to determine at least one downhole parameter and adjust a position of the flow control device 138. Thus, the control node 160 may adjust the flow rate and restriction for each flow control device 138 to control fluid production from each production zone 116. The control node 160 is also in communication with sensors 162 configured to determine a parameter of interest downhole, such as properties within the production string 129 and/or wellbore 110. The control node 160 may communicate with flow control devices 138 and sensors 162 using network 164, which may include wireless or wired devices. Wireless communication may be via radio frequency, 802.x protocol, Bluetooth or other suitable devices. Network 164 may also include a conductive wire or fiberoptic cable. The property of interest may be any desired property, including, but not limited to, position of flow control devices 138, flow rate, pressure, temperature, water or gas content in the fluid, resistivity, sound waves, nuclear magnetic resonance, chemical properties, physical properties and optical properties of a fluid downhole. Any suitable sensor may be used to determine the properties of interest, including, but not limited to a flow meter, pressure sensor, temperature sensor, resistivity sensor, acoustic sensor, and nuclear magnetic resonance sensor. Such sensors are known in the art and are thus not described in detail herein. As used herein, the term “fluid” or “fluids” includes liquids, gases, hydrocarbons, multi-phase fluids, mixtures of two of more fluids, water and fluids injected from the surface, such as water. Additionally, references to water should be construed to also include water-based fluids; e.g., brine or salt water. The flow control devices 138 are any suitable device capable of adjusting a flow rate while disposed downhole, wherein a position of the device corresponds to flow rates ranging from no flow (0% open) to open flow (100%) and any position in between (ranging from 0 to 100%).
Still referring to
The retrievable communication device 154 may be any device configured to wirelessly communicate with control node 160 downhole. An exemplary retrievable communication device 154 includes an inductive coupling 154a. The inductive coupling 154a communicates with an inductive coupling 160a in control node 160. The inductive couplings 154a and 160a are configured to communicate a variety of signals, including commands for downhole devices, signals corresponding to sensed parameters, power provided to downhole devices and other signals.
Exemplary signals or commands sent to the downhole devices include adjustments to an inflow rate of formation fluid through one or more flow control device 138, wherein the inflow rate is determined by a position of the device. Flow rates may be manipulated based on desired production at a given time as well as characteristics of the formation and formation fluid, which may be known or determined by sensors 162 and 202. Thus, the sensors 162 and 202 communicate signals corresponding to sensed or determined downhole parameters to the retrievable communication device 154 via network 164, optional processing unit 203 and inductive couplings 154a and 160a. In addition, signals may be communicated from sensors 162 and 202 to retrievable communication device 154, wherein the signals correspond to determined downhole parameters. The determined parameters include flow rate, temperature, pressure, pH and other suitable sensors related to formation fluids and/or downhole conditions. Thus, the determined parameters from sensors 162 and 202 are transmitted, via inductive couplings 160a and 154a, to the retrievable communication device 154, wherein the device 154 and controller 170 use the parameters to operate downhole devices, such as flow control devices 138. For example, referring to the components at position 200b, a decrease in a flow rate of formation fluid 204 is sensed by sensor 202, wherein the flow rate is an input for the retrievable communication device 154 and controller 170, which then determine a substantially open or increased flow position for flow control device 138. Further, a sensed flow rate at position 200a is also an input for the device 154 and controller 170, wherein an increased flow rate at position 200a leads to a restriction or reduced flow of flow control device at 200a. Thus, the retrievable communication device 154 is conveyed downhole to adjust flow rates and balance a flow across the production string 120 to improve production.
In addition, the retrievable communication device 154 and control node 160 provide communication of power signals via inductive couplings 154a and 160a. For example, the power sources 201 may be rechargeable batteries used to power operation of flow control devices 138 and sensors 162, 202. The retrievable communication device 154 may transmit power signals, via inductive couplings 154a, 160a, control node 160 and network 164, to recharge power sources 201. In another embodiment without power sources 164, the retrievable communication device 154 provides power to operate flow control devices 138 and sensors 162, 202 when the device 154 is inductively coupled to control node 160. Thus, after and retrievable communication device 154 have adjusted and communicated with flow control devices 138 and sensors 162, 202, the conveying member 155 pulls the tool 150 and retrievable communication device 154 uphole. Accordingly, in the embodiment, the downhole devices are only powered when coupled to the retrievable communication device 154 and are only adjusted when the device 154 is conveyed downhole. The illustrated production system 100 (
The inductive couplings 154a and 160a include suitable electrical components and devices, such as conductors, in a selected configuration to provide communication between retrievable communication device 154 and control node 160 without a physical connection. Further, the inductive coupling between 154a and 160a is configured to pass through fluids flowing through production string 120. In an embodiment, inductive coupling 160a includes an outer coil that is a solenoid wound inductive coil located in the control node 160. The outer coil is in electric communication with processor unit 203 and other electronics in or proximate control node 160. The inductive coupling 154a includes an inner coil that is a solenoid wound inductive coil located in the retrievable communication device 154. In embodiments, the radial distance between the outer coil of inductive coupling 160a and the inner coil of inductive coupling 154a in a selected axial position of the production string 120 will vary with the rotational orientation of the tool 150 with respect to the production string 120. In addition, electronic signatures, such as RFID devices, may be used to orient the tool 150 and retrievable communication device 154 in the desired location within production string 120. In other embodiments, the rotational position of the tool 150 and retrievable communication device 154 do not affect the inductive coupling with control node 160 once the axial positions of the components are properly aligned.
