Abstract:
A method and apparatus for transferring data from a logging tool to a surface computer that involves attaching a stand-alone data dump device to the logging tool after the logging tool has gathered data about downhole parameters. After attaching the data dump device, data contained in a memory of the logging tool is copied to a memory of the data dump device. In one embodiment, once data copying between the logging tool and data dump device is complete, the data dump device is disconnected from the logging tool and connected to a surface computer which reads the data previously copied to the data dump device. A second embodiment of the data dump device has a radio frequency communication link between the surface computer and the data dump device to allow a wireless communication between the surface computer and the data dump device and/or logging tool.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Provisional Application titled “Logging Device Data Dump Probe” filed Dec. 21, 1999, Ser. No. 60/172,935. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED SEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to logging while drilling (LWD) technologies. More specifically, the invention relates to downloading data stored in the memory of LWD devices. More specifically still, the invention relates to a data dump probe that downloads data from LWD devices. 
     2. Background of the Invention 
     Modern petroleum drilling and production operations demand a great quantity of information related to parameters and conditions down hole. Such information typically includes characteristics of the formations traversed by the well bore, in addition to data relating to the size and configuration of the bore hole itself. The collection of information relating to characteristics of formations down hole is commonly referred to “logging.” Logging has been known in the industry for many years as a technique for providing information regarding the particular formation being drilled and can be performed by several methods. 
     One such logging method is convention wire-line logging. In wire-line logging a probe is lowered into the bore hole after some or all of the well has been drilled, and the probe is used to determine certain characteristics in the formations traversed by the bore hole or the bore hole itself. While wire-line logging is useful in assimilating information about down hole formations, before a wire-line logging tool can be run in the well bore, the drill string and bottom hole assembly must first be removed resulting in considerable cost and loss of drilling time for the driller (who typically is paying daily fees for the rental of equipment). 
     Because of the limitations associated with wire-line logging, there recently has been an increasing emphasis on the collection of data during the drilling process itself. By collecting data during the drilling process, without the necessity of removing the drilling assembly to insert a wire-line logging tool, data regarding the down hole formations can be collected more economically. Data collected during the drilling operation must either be relayed to the surface or stored until the logging device is brought back to the surface. Given the relatively slow data rates achievable in communicating from down hole logging and measuring devices to surface computers, storing the data collected may be the only option for the majority of data. 
     Several types of logging devices, or LWD tools, are used by the industry and each tool may require varying amounts of internal memory. For example, a “gamma” tool requires comparatively little memory; whereas, an acoustic or sonic tool may require a significant amount of memory, approaching 250 Megabytes, to have the capability to store all the information required during a drilling run. Other down hole tools may also include a resistivity tool, a caliper tool, and a directional tool. Information gathered by the directional tool is needed relatively real time with the drilling process, and therefore, the information gathered by a directional tool is generally sent from down hole to surface computers using known techniques such as by transmitting mud pulses to the surface at approximately a 1 Hz baud rate. 
     On a tool that stores data from a drilling run, some method must exist to extract the data stored in the tool. Currently, information obtained by a LWD tool is stored in memory within the tool itself until the logging tool is brought to the surface. Upon being lifted to the surface, the data is extracted. Referring to FIG. 1, there is depicted a prior art structure for downloading data stored in the memory of a logging tool. Shown in FIG. 1 is a drill string  10  which comprises a LWD tool  12  and drill bit  14 , a drilling table  16 , surface computer  18 , download cable  20  and connector  22 . 
     The LWD tool  12  is raised to the surface of the earth after a drilling run. Once the LWD tool  12  is raised slightly above the drill table  16 , an operator stretches download cable  20  to the LWD tool  12  and thereby couples the surface computer  18  to the LWD tool  12  via the connector  22 . While this operation seems relatively simple, several practical problems exist. 
     On most drilling rigs, especially drilling platforms on the ocean, space is a commodity and therefore the surface computer may not, indeed most likely is not, close to the LWD tool  12 . Another consideration is the environment of the download process. Drilling rigs and drilling platforms, especially on the drilling table  16 , are generally explosive environments. Small sparks could create a fire or explosion. The computer may potentially create sparks, and thus may not be permitted on the rig floor. Consequently, the surface computer may be several floors and hundreds of feet from the drilling table  16 . Further, plugging an unplugging electrical connectors may created sparks in the potentially explosive environments and, for this additional reason, use of download cables  20  on or near the drilling table  16  have the added disadvantage of a potential fire or explosion hazard. 
     As one of ordinary skill in the art will realize, the information rate a cable may accurately transmit decreases as the length of the cable increases. This means, for the system described in FIG. 1, that as the surface computer is placed further from the logging tool, the download rate decreases and therefore the time required to download increases as the cable length increases. 
     An additional factor that decreases data download rates is electrical noise. A drilling rig has many pumps and motors associated with the drilling process which create significant electrical noise. Because the download cable  20  winds in and around the drilling rig to get to the surface computer, it becomes an antenna for receiving electrical noise. Electrical noise further decreases the data rate of the cable. Given all these conditions, the typical data rate for the cable  20  of the related art may be at or near 80 kilo-baud. 
     Further, with data rates associated with the related art methods of downloading information in the 80 kilo-baud range, downloading information from a memory intensive logging device, e.g. an acoustic probe, may take in excess of thirty minutes. Various techniques exist to insure that no data errors occur in the digital communication, but these techniques are not infallible. On occasion, a download may occur having errors that precipitate a second download of the same information, and possibly even a third, until the information is exchanged error free. In these instances when an error occurs and the process of downloading is repeated, significant rig time is lost to the download process. 
     As the demand for LWD data increases many companies have begun placing multiple logging devices in the drill string for measuring multiple parameters as part of the logging while drilling process. The problems experienced with the download cable  20  as described in reference to FIG. 1 increase substantially as the number of logging devices, with internal memories that require downloading on the surface, increase. Referring to FIG. 2, there is indicated one possible structure for downloading data contained in multiple logging devices. As indicated in the figure, the envisioned method is to have a breakout box  15  somewhere near the drilling table  16 , and from this breakout box having an individual download cable  20 A,  20 B,  20 C for each and every logging device in the drill string. Each download cable  20 A,  20 B,  20 C has its respective connector  22 A,  22 B,  22 C. Physically, this arrangement increases the hazards associated with downloading the information from a single logging device. That is, using this method to download the data from the logging devices requires multiple cables strewn about the drilling table  16 . The danger created by the download cables  20 A,  20 B,  20 C is increased by the fact that some of the logging devices  12  may be many feet in length and therefore the download cable  20 , when connected to an uppermost logging device, e.g.  12 A, would be draped either down to the drilling table  16  or to the breakout box  15  when a lower most logging device connector becomes accessible for connection thus creating tripping hazards. 
     Based on the foregoing, it would be desirable to have a method and device that eliminates the need for a download cable, and in the case of multiple logging devices, multiple download cables, and which further addresses the safety issues generally associated with downloading data from logging devices on a drilling rig or drilling platform. 
     BRIEF SUMMARY OF THE INVENTION 
     The problems noted above are solved in large part by a stand-alone data download device. In one embodiment, the data download device electrically couples to a LWD tool and downloads logging data stored in memory of the LWD tool to memory within the data download device. After the information is exchanged between the LWD tool and the data download device, the data download device can be de-coupled from the LWD tool and physically carried to a location near the surface computer where logging information, now contained in memory of the data download device, can be read by the surface computer. In the situation where multiple logging devices exist on the drill string, multiple data download devices could be used such that substantially simultaneous downloading could occur from the logging devices. 
     In another embodiment of the invention the data download device includes a radio frequency (RF) transmitter/receiver and the surface computer likewise has a RF transmitter/receiver. Therefore, the data download device and the surface computer could communicate while the data download device is electrically coupled to the logging device. In this embodiment it is envisioned that the RF link is used for either relaying data extracted from the logging device, or, is used as a control and monitoring feature whereby the surface computer initiates and monitors downloads between the LWD tool and the data download device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a detailed description of the preferred embodiment of this invention, reference will now be made to the accompanying drawings in which: 
     FIG. 1 shows a prior art drilling assembly including a logging device; 
     FIG. 2 shows a configuration for downloading information from multiple logging devices; 
     FIG. 3 shows a side view of one embodiment of the data download device; 
     FIG. 4 shows a block diagram of the internal components of the data download device; 
     FIG. 5 shows use of the invention in a drill string with a single logging device; 
     FIG. 6 depicts a data dump probe coupled to a surface computer; and 
     FIG. 7 shows use of the invention in a drill string assembly having multiple logging devices. 
     FIG. 8 shows use of the invention in combination with a central interface module. 
    
    
     NOTATION AND NOMENCLATURE 
     Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, different companies may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but limited to . . . .” Also, the term “coupled” or “couples” in the electrical context is intended to mean either an direct or indirect electrical connection. 
     CATALOG OF ELEMENTS 
     As a aide to correlating the terms of the claims to the exemplary drawings, the following catalog of elements is provided: 
       10  drill string 
       12  LWD tool 
       14  drill bit 
       15  breakout box 
       16  drilling table 
       18  surface computer 
       20  download cable 
       22  connector 
       110  drill string 
       112  LWD tool 
       114  drill bit 
       116  drilling table 
       118  surface computer 
       130  data download device 
       132  logging device connector 
       134  surface computer connector 
       136  enclosure 
       138  radio frequency antenna 
       140  dump probe memory 
       142  processor 
       144  input/output logic 
       146  RF link 
       148  central interface module 
       150  CIM memory 
       152  CIM connector 
       154  surface computer download cable 
       156  surface computer RF link 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIG. 3, an exemplary embodiment of a data download device  130  is described. The data download device  130 , also referred to herein as a dump probe, has many components including two electrical connectors—logging device connector  132  and surface computer connector  134 . Logging device connector  132  is used to both physically connect the data download device  130  to a logging device, as well as to couple the two devices to facilitate data exchange. Connector  134  allows data download device  130  to couple to surface computer  118  (not shown in FIG. 3, see FIG. 6) to allow data exchange between those two devices. FIG. 5 shows data download device  130  physically connected to a logging device  112 . 
     Referring still FIG. 3, enclosure  136  houses the data dump probe  130 . It is within enclosure  136  that the electronic circuits and components necessary to copy data from a LWD tool  112  to memory within the data dump probe  130  reside. Enclosure  136  could be made of any suitable material; however, as indicated generally in the figures, enclosure  136  not only houses the electronics required for the data dump device but also physically supports the components of the data dump device when attached to a LWD tool  112 . For this reason, the enclosure  136  could be made of steel or resilient plastic. The data dump probe  130  may be used in explosive environments and for this reason the enclosure  136  may be made from brass such that if it was dropped it would not spark. 
     Logging device connector  132  is designed to physically couple with a complimentary connector on the LWD tool  112 . This connector could be any suitable connector for making the electrical connection and supporting the dump probe  130 . FIG. 3 also shows surface computer connector  134 . As the name implies, it is through this connector  134  that the electronic components of the dump probe  130  couple to a surface computer such that data downloaded from a LWD tool to the dump probe  130  can be furthered transferred from the memory of the data dump probe to the surface computer  118 . Connector  134  is shown to have a cap and keeper chain; however, these are not required elements. Inasmuch as the data dump probe  130  may be used in a relatively dirty and explosive environment, the cap on connector  134  may serve a dual purpose. The first purpose would be to keep drill cuttings, drilling fluid, grease and other foreign substances out of the electrical connections housed under the cap. Secondly, in an explosive environment, to be rated as intrinsically safe, a device must not emit energy above a threshold amount during operation and this energy limit may be in the milli-Joule range. Therefore, the cap over connector  134  acts as a shield to limit the amount of energy, if any, that may be released by exposed electrical connectors within the connector  134 . 
     One of the primary purposes of the data dump probe  130  is to copy logging data from a LWD tool  112 . More specifically, one function is to copy data stored in a memory of a LWD tool  112  to a data dump probe memory  140 . Referring to FIG. 4 there is indicated a block diagram of one configuration of the data dump probe  130 . In the preferred embodiment of FIG. 4, the dump probe  30  includes a processor  42  which controls copying of data from the LWD tool  112 . The data dump probe may also verify that data in data dump probe matches data in the LWD tool. Processor  142  preferably couples to read only memory (ROM)  148  which contains programs executed by the processor  142  to complete necessary operations. Further, processor  142  couples to memory  140  in which data copied from the LWD tool  112  is placed for storage until the data can be sent to a surface computer  118 . To facilitate communication to and from the LWD tool, processor  142  couples to an input/output logic  144 . Input/output logic  144  provides necessary signal amplification and may further facilitate implementing the protocol for data communication used between the data dump device  130  and the LWD tool  112 . For example, the protocol with which the data dump device  130  and the LWD tool  112  communicate could be RS-232, RS-485, or some other non-standard or proprietary communication protocol. 
     As one skilled in the art will appreciate, memory  140  requires sufficient capacity to store data from even the most memory intensive LWD tool. Given the current state of the art in LWD tools, the data dump probe  130  may need as much as a gigabyte of memory. This memory capacity requirement may increase as the volume of information stored in LWD tools increases. This memory may comprise any suitable type of memory, for instance, some type of NAND FLASH memory, or possibly a plurality of PCMCIA memory cards may be used to withstand the harsh environments encountered at the rig site. If using PCMCIA type memory, or any memory that may be physically disconnected from the data dump probe  130 , it is possible to move the data stored in the data dump probe  130  to the surface computer  118  by moving the memory physically from the data dump probe  130  and placing it in a receiving device such that the surface computer  118  can read the data directly. 
     One of ordinary skill in the art will appreciate that many possible configurations of electrical components could be used to complete the task of downloading information from a LWD tool  112  to the data dump device  130  with the respective protocol used. The electronics could be as unsophisticated as a microcontroller, in which case the ROM, input/output logic, and possibly the memory could all reside on a single component. Likewise, the electronics in the data dump probe  130  could be implemented as a full-scale microprocessor. As the speed and capabilities of the internal processor increase, capabilities for data manipulation within the data dump probe increase. 
     Part of the significant advantage of the data dump probe  130 , over a long connector cable  20  of the prior art, is that the data dump probe  130  is relatively close to the LWD tool  112 . Therefore, the connection between the data dump probe  130  and the LWD tool  112  is relatively short. Indeed, given the relatively small size of the data dump probe  130 , it may be possible to place the electronics and memory of the data dump probe  130  within feet or even inches of the electronics and memory of the LWD tool  112 . Given this relatively short distance, higher data rates over the desired protocol are achievable. However, higher data rates are not the only advantage of this invention, but the advantages may also include fewer cables on the drilling rig, increased ability to monitor the download process, and easier implementation of downloading data with or without increased data transfer rates. 
     Further, given the possibly explosive environment in which the data dump probe  130  may be used, other methods of coupling the data dump probe  130  to the LWD tool  112  may be advantageous. For example, some form of optical or fiber optic connection, or possible even magnetic coupling may be used. These methods of coupling reduce the likelihood of sparks associated with typical conductor to conductor coupling. 
     Referring again to FIG. 3, a radio frequency (RF) antenna  138  preferably attaches to enclosure  136 . This antenna  138 , in combination with another antenna and RF link  146  coupled to the surface computer  118  (see FIG.  5 ), permit RF communication between the data dump device  130  and the surface computer  118 . Therefore, the data dump device  130  and the surface computer  118  could communicate while the data dump device is coupled to the logging device. The radio frequency link is used for either relaying data extracting from the logging device, or may be used as a control and monitoring feature whereby the surface computer initiates and monitors downloads between the LWD tool and the data download device. 
     In a drilling operation, one or more logging devices  112  preferable are included as part of the drill string  110 . These logging devices, as well as drill bit  114 , are lowered into a bore hole and the drilling operation begins. As the drilling operation proceeds, each logging device performs its respective logging function. For example, the logging devices may perform acoustic, nuclear or gamma formation measurements. After a certain amount of drilling, the drill string may be raised to the surface to change drill bits, or possibly even a dedicated lift to download information from the logging devices. Assuming the drill string has multiple logging devices, as the first logging device is raised to be positioned slightly above the drilling table  116 , a first data download device  130 A is connected to a connection port on the first logging device. The drill string is further raised until the connection port for the second logging device is slightly above the drilling table. A second data download device  130 B is connected to the second logging device. The drill string is raised again and a third data download device  130 C is attached. This sequential raising and connecting is repeated until each logging device has connected to it a data download device  130 . 
     It is possible to configure a series of LWD tools for use on a drill string such that each LWD tool need not have an individual receptacle for electrical connection. Referring to FIG. 8 there is shown a drill string  110  having two LWD tools  112 A and  112 B and further showing a central interface module (CIM)  148  coupled to each logging device  112 A and  112 B. In this embodiment, the central interface module gathers data collected by each logging device  112 A and  112 B and stores it in a memory  150  in the CIM  148 . Copying data from the logging device memories to the CIM memory  150  could be done either substantially simultaneously with the gathering of data down hole, or could be transferred during raising the drill strings to the surface. Upon being raised to the surface, connector  152  of the CIM  148  would be available to connect to a data dump device  130 . In this way, a single dump device  130  could download data from multiple logging devices. One of ordinary skill in this art will realize that a drill string  110  may have any combination of LWD tools and therefore it may be possible that one or more stand alone tools, e.g. an acoustic tool, could be placed in a drill string with multiple LWD tools that could attach to a CIM module. In this configuration, multiple data download devices  130  could be used to download data from the LWD tools: a dedicated download device  130  for each memory intensive LWD tool; and a dedicated download device  130  could be used for each CIM module in any combination in the drill string. 
     When data downloads are completed, the sequence of attaching the multiple data download devices is reversed and each device is removed as the drill string is lowered back into the bore hole. After removing each data download device, all devices are physically transported to a location at or near the surface computer  118  where each data download device  130  is coupled to the surface computer so the logging data contained therein can be transferred to the surface computer  118  for analysis. 
     The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will be apparent to those skilled in the art once the above disclosure is fully appreciated. For example, it may be that each data download device has a relatively simple user interface on one face of the enclosure  136 . From this user interface, an operator connecting the data download device to a particular LWD tool would enter the type device to which the data download device is being attached and start the process through keystrokes. Likewise, it has been disclosed that the data download device  130  is physically supported by logging device connector  132 . It would be within the contemplation of this invention that the LWD tool connector  132  not support the weight of the data download device  130 , but rather, the device could be strapped, or possibly held in place by magnets, on an outer wall of a LWD tool. If such was the case, a short cable could run from the electrical components of the data download device  130  to the LWD tool connector  132 . Further, many possible embodiments for the electrical components necessary to facilitate transferring data from memory in the LWD tool to a memory in the data download device exist. These embodiments could range from anything as simple as a low-end microcontroller that merely initiates the data transfer, to a full-scale microprocessor which could actually process, to some extent, the data as it transfers between the logging device and the data download device, and all would be within the contemplation of this invention. Finally, while dedicated logging device connectors and surface computer connectors have been described, the functionality may be combined into the same connector. It is intended that the following claims be interrupted to embrace all such variations and modifications.