The present invention relates generally to methods and apparatus for controlling the operation of downhole well tools from the surface, and particularly to a new and improved electronics packaging system for a downhole tool control system adapted for operation in harsh environments, involving high pressure and high temperature, such as those experienced by equipment in a downhole environment.
It has become commercially prudent to perform well service operations, such as formation testing and evaluation, in very deep wells using pressure controlled valve devices such as those taught by Upchurch, U.S. Pat. No. 4,796,699, which is hereby incorporated by reference.
Pressure controlled valve devices are valve structures that are operably responsive to command signals such as those from pressure pulses applied from surface to the fluid in the annulus, or from other wireless signals sent downhole such as acoustic signals or electromagnetic signals. Downhole electronics within the downhole tool must decode the incoming signals and provide the electrical stimulus to operate the tool in accordance with the received command.
In Upchurch, for example, a well testing tool is disclosed which is not totally mechanical in nature, and embodies a microelectronics package and a set of solenoids responsive to the microelectronics package for opening and/or closing a valve disposed in the tool. As such, the well testing tool of Upchurch is susceptible to damage in extreme, harsh conditions.
Recently, the search for hydrocarbons is leading to deeper wells having ever more extreme conditions related to, among other things, downhole pressure and temperature. While the electronics contained within the various downhole devices are typically protected from extreme pressure by being sealed within an atmospheric chamber. However, even when separated certain downhole environmental factors while sealed in an atmospheric chamber, the electronics are nevertheless exposed to the downhole temperatures.
Currently, conventional electronics are limited in operation to approximately 150° C./160° C. Traditionally, electronics are mounted on a Printed Circuit Board (PCB), which has a limited lifetime in a high-temperature (HT) environment (above 150° C.). Electronic components that may be available, which work at temperatures above approximately 150° C./160° C. generally fall into three major categories: (1) legacy ceramic components developed mostly for the military market that work at high temperature, (2) multi-chip modules (MCM) developed (or that can be developed) by end users and others using die known to work at high temperatures, and (3) a few very basic and very expensive silicon-on-insulator (SOI) components developed specifically for the market. A MCM may contain multiple integrated circuits, semiconductor dies, or other discrete components packaged onto a unifying substrate. Packaging multiple integrated circuits, semiconductor dies, or other components onto a unifying substrate may allow for the use of those circuits, dies, or components as a single component. For added reliability at high temperatures, it is preferable that all system electronics be comprised primarily of hermetically sealed MCMs. These MCMs will serve to eliminate or at least minimize interconnections between integrated circuits and circuit boards, an inherent weakness in high temperature applications.
To operate at substantially higher temperatures it is often necessary to create a special package using ceramic substrate technologies, to create a MCM, in which individual semiconductor component dies or integrated circuits, preferably without any individual plastic packaging, are placed on a ceramic substrate, the substrate serving as the conducting pathways analogous to a PCB in conventional electronics. Packaging integrated circuits within a MCM often employs a monolithic structure to interconnect two or more chips. The signal and electrical pads of the die are joined to their corresponding conducting pads on the ceramic substrate by methods such as aluminum wire bonding as is well known in the art. The many semiconductor dies are then usually surrounded by walls made from a material, such as Kovar, which are brazed to traces on the ceramic substrate to form a surrounding rectangular box. A lid, also made of a material, such as Kovar, is then placed over the four walls. The air is then evacuated from the interior of the box while simultaneously injecting an inert gas, such as nitrogen, into the interior of the box before brazing the seams of the lid in place to form a hermetically sealed enclosure for the semiconductor die.
As is well known in the art, this MCM assembly eliminates the need for packaging materials such as plastic to surround and hermetically seal each semiconductor die from the damaging effects of atmospheric corrosion and chemical reaction. Also eliminated is the repeated expansion and contradiction caused by extreme temperature acting on conventionally packaged semiconductors, where typical plastic packaging materials often possess thermal expansion coefficients that are significantly different than the encapsulated semiconductor die. This thermal mismatch of material properties can lead to a failure in the hermetic seal between the conventional package and the semiconductor die, leading to eventual failure in the operation of the semi-conductor component.
In addition to active digital semi-conductor components, very often passive devices such as resistors, capacitors, inductors, etc. are needed to form a complete functioning circuit. These passive components often require a different connection technology than do semiconductor dies. An example is soldering of gold plated contacts for passive components versus aluminum wire-bonding of active semiconductor dies. The different attachment and bonding technologies used on active versus passive components can be a source of adverse physical or chemical reactions which can lead to reliability problems over time. For example out-gassing of trace chemicals from one process could adversely affect components using another process. The potential for this type of subtle chemical or physical reaction increases as the temperature increases, and therefore the available activation energy, such as is the case in more extreme downhole conditions.
Therefore, a need exists to maintain high reliability of electronic circuits in downhole tools destined for use in extreme high temperature environments and to avoid the potential for mixing component types which require different and incompatible bonding or attachment technologies within the same sealed enclosure.
It is therefore desirable to provide a well tool control system and method for performing well service operations in harsh conditions, such as high pressure and high temperature.
Certain embodiments of the present invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
Specific embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Further, in the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the embodiments disclosed herein may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
The terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as “including,” “comprising,” “having,” “containing,” or “involving,” and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited.
Moreover, in this description the terms “up” and “down”; “upward” and downward”; “upstream” and “downstream”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly described some embodiments of the invention. However, when applied to apparatus and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
The present invention is particularly applicable to testing and/or production installations such as are used in oil and gas wells or the like.
A packer 18 is positioned on the tubing 14 and can be actuated to seal the borehole around the tubing 14 at the region of interest. Various pieces of downhole test equipment (collectively, downhole tool(s) 20) are connected to the tubing 14 above or below the packer 18. Such downhole tool(s) 20 may be referred to herein as one or more downhole equipment and may include, but is not limited to: additional packers; tester valves; circulation valves; downhole chokes; firing heads; TCP (tubing conveyed perforator) gun drop subs; samplers; pressure gauges; downhole flow meters; downhole fluid analyzers; and the like.
In the embodiment of
In order to support acoustic signal transmission along the tubing 14 between the downhole location and the surface, a series of the acoustic modems 25Mi−1 and 25M, etc. may be positioned along the tubing 14. The acoustic modem 25M, for example, operates to receive an acoustic signal generated in the tubing 14 by the acoustic modem 25Mi−1 and to amplify and retransmit the signal for further propagation along the tubing 14. The number and spacing of the acoustic modems 25Mi−1 and 25M will depend on the particular installation selected, for example on the distance that the signal must travel. A typical spacing between the acoustic modems 25Mi−1, 25M, and 25Mi+1 is around 1,000 ft, but may be much more or much less in order to accommodate all possible testing tool configurations. Thus an acoustic signal can be passed between the surface and the downhole location in a series of short hops.
The role of a repeater is to detect an incoming signal, to decode it, to interpret it and to subsequently rebroadcast it if required. In some implementations, the repeater does not decode the signal but merely amplifies the signal (and the noise). In this case the repeater is acting as a simple signal booster. However, this is not the preferred implementation selected for wireless telemetry systems of the present invention.
The acoustic modems 25M, 25Mi−1, and 25Mi+1 will either listen continuously for any incoming signal or may listen from time to time.
The acoustic wireless signals, conveying commands or messages, propagate in the transmission medium (the tubing 14) in an omni-directional fashion, that is to say up and down. It is not necessary for the acoustic modem 25Mi+1 to know whether the acoustic signal is coming from the acoustic modem 25M above or an acoustic modem 25Mi+2 (not shown) below. The direction of the acoustic message is preferably embedded in the acoustic message itself. Each acoustic message contains several network addresses: the address of the acoustic modem 25Mi−1, 25M or 25Mi+1 originating the acoustic message and the address of the acoustic modem 25Mi−1, 25M or 25Mi+1 that is the destination. Based on the addresses embedded in the acoustic messages, the acoustic modem 25Mi−1 or 25M functioning as a repeater will interpret the acoustic message and construct a new message with updated information regarding the acoustic modem 25Mi−1, 25M or 25Mi+1 that originated the acoustic message and the destination addresses. Acoustic messages will be transmitted from acoustic modem 25Mi−1 to 25M and may be slightly modified to include new network addresses.
The acoustic modem 25Mi−2 is provided at surface, such as at or near the well-head equipment 16 which provides a connection between the tubing 14 and a data cable or wireless connection 28 to a control system 30 that can receive data from the downhole tool(s) 20 and provide control signals for its operation.
In the embodiment of
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Disposed within the at least one cavity 50A on the first side 52 of the substrate 40 may be at least one or more of the first type component 44. The first type component 44 may comprise multiple components requiring similar attachment or bonding technologies which may be placed together within the at least one cavity 50. For instance, the first type component 44 may be any one of a number of active components. Active components often rely on a source of energy, often from a DC circuit, and may be able to introduce power into a circuit although such ability is not required. Active components may include, but are not limited to, transistors, tunnel diodes, semiconductor dies, integrated circuits, optoelectrical devices, piezoelectric devices, or any other such component known in the art. Active components may often employ wire bonding connection technologies, such as aluminum wire bonding of a semiconductor die. In the example depicted in
The second type component 46 may be disposed on the second side 54 of the substrate 40 within the cavity 50C defined by the housing 38. The second type component 46 may comprise multiple components requiring similar attachment or bonding technologies which may be placed together within the void 48, but remaining separate from the first type component 44 sealed within the cavity 50A. For instance, the second type component 46 may be any one of a number of passive components. Passive components may be defined as components which cannot introduce net energy into the circuit to which the passive component is connected. Passive components often rely only on the power available from the circuit to which they are connected. Passive components may include, but are not limited to, resistors, capacitors, inductors, transformers, or any other such component known in the art. The second type component 46 is connected to the substrate 40, preferably using a connection technology which is different from the manner in which the first type component 44 is connected to the substrate 40. For example, the second type component 46 may be connected to the substrate 40 using soldering techniques rather than aluminum wire bonding as described above and may be employed in connecting the first type component 44 to the substrate 40. For example, the second type component 46 may be connected to the substrate 40 utilizing techniques for soldering gold plated contacts.
In other words, techniques for connecting the first type component 44 and the second type component 46 to the substrate 40 may comprise differing component elements and differing connection technologies, such as wire bonding or soldering of gold plated contacts. The differing connection technologies often employed with active components, which may act as the first type component 44, and passive components, which may act as the second type component 46, may be a source of adverse physical or chemical reaction. The adverse physical or chemical reactions which may result from close proximity of differing connection technologies may have deleterious effect on the components and the reliability of the electronics package 34 and the downhole tool 20 in which the electronics package 34 is disposed. The first type component 44 and the second type component 46 are preferably sealed within the cavities 50A and 50C to limit the deleterious effect of combining differing connection technologies, creating separate nonreactive atmospheres within the housing 38.
The housing 38 can be provided in a variety of different manners having various shapes and sizes. In the example shown, the housing 38 is shown having a rectangular cross-section and may be provided with at least one wall 56 and at least one connector 58. As shown in the embodiment of
The housing 38, in the embodiment shown in
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Although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of the present invention. Accordingly, such modifications are intended to be included within the scope of the present invention as defined in the claims.
The present patent application claims priority under 35 U.S.C. §119 to the provisional patent application identified by U.S. Ser. No. 61/544,178 filed on Oct. 6, 2011, the entire content of which is hereby incorporated herein by reference.
Number | Date | Country | |
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61544178 | Oct 2011 | US |