Geophysical exploration is an important part of the hydrocarbon recovery industry. Seismic and/or acoustic measurements and monitoring have long been viewed as a particularly effective means for measuring and monitoring the geophysical and reservoir environment downhole.
Commonly, seismic and/or acoustic information is gained from the wellbore either through a wireline tool in real time or in LWD more recently through processing and storage of received information at the downhole tool. In LWD a small subset of this information may be pulsed uphole, for example, with some delay in time due to limited bandwidth. The total recorded information is later brought to the surface for downloading and analysis. While wireline provides for a number of different functions in real time within the wellbore, the wireline itself occludes the flow passage within a string in which it is placed. Further, wireline measurements are acquired only after a well has been drilled to certain depth and therefore wireline is not effective to address the “while drilling” needs. Because of the occlusion, other wellbore operations are significantly hindered during a wireline testing process. Nevertheless wireline testing has been the gold standard for a substantial period of time where a borehole seismic and/or acoustic measurement is desired.
Where wireline is not the tool of choice, vibrations may be sent through the mud column or the drill string itself although compensation related to signal path velocity is required to determine the time value of the measurement. The method further suffers from having a limited bandwidth available. In such systems typically a seismic source would be located at the surface and transmit seismic energy in the downhole strata, which is recorded by sensors located downhole. The source does not need to be on the surface, however, as it maybe located downhole. Further, the source may be an acoustic source or noise created by a drill bit. This energy would then be measured at the sensor(s) either by a direct signal path or be reflected back to the sensors for the downhole measurement and stored there. In either event information is not rapidly obtained.
A seismic and/or acoustic while drilling configuration includes a high speed telemetry arrangement; at least one seismic and/or acoustic energy sensor in communication with the high speed telemetry arrangement; at least one seismic and/or acoustic energy source capable of producing at least one seismic and/or acoustic energy signal receivable by the at least one seismic and/or acoustic energy sensor.
A method for monitoring a wellbore while drilling includes measuring seismic and/or acoustic energy at a downhole location; transmitting a signal representative of the seismic and/or acoustic energy through a high-speed telemetry arrangement to a remote location.
A method for monitoring a formation while drilling includes stopping movement of the drill string; listening for sounds of the formation without running an additional tool; recommencing movement of the drill string.
A method for 4D monitoring a formation after drilling includes introducing into a seismic and/or acoustic while drilling configuration including a high speed telemetry arrangement; at least one seismic and/or acoustic energy sensor in communication with the high speed telemetry arrangement; at least one seismic and/or acoustic energy source capable of producing at least one seismic and/or acoustic energy signal receivable by the at least one seismic and/or acoustic energy sensor; initiating a seismic and/or acoustic signal from the seismic and/or acoustic source; and monitoring the signal over time.
A method for at least one of monitoring, adapting and operating in the wellbore while drilling includes introducing into a seismic and/or acoustic while drilling configuration including a high speed telemetry arrangement; at least one seismic and/or acoustic energy sensor in communication with the high speed telemetry arrangement; at least one seismic and/or acoustic energy source capable of producing at least one seismic and/or acoustic energy signal receivable by the at least one seismic and/or acoustic energy sensor; sending a signal over the high-speed telemetry arrangement to a sensor in the downhole environment; causing the sensor to deploy into contact with a target formation; measuring a parameter of the formation with the sensor; telemetering information measured by the sensor to a remote location.
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
Referring to
In addition to the foregoing, utilization of the configuration illustrated in
Another method disclosed herein is of stopping the drill string momentarily and listening to the formation over a period of time. Immediately following the listening, the drill string may be reactivated and drilling continued. Such a method provides a significant advantage of periodically listening to the wellbore sounds without having to run a wireline or remove any other well equipment. This reduces costs associated with the reduction of drilling activity that is inherent in the prior art. In other words, drilling is maximized while downtimes minimized.
In another aspect, the configuration and method taught herein enables the monitoring of geophysical and or reservoir properties such as gas caps, water floods, water legs, and other general changes in the reservoir. Mapping of these conditions over time provides valuable information about the health of the formation and about its potential future production capability. The ability to monitor these conditions over time is enabled by the configuration illustrated in
In yet another aspect, the conductor 14 and its high-speed telemetry capability also facilitates improved use of geophones. As one of ordinary skill in the art will clearly understand, geophones function best when in solid contact with the formation. Because drill bits are rotated, geophones depending therefrom in a radially outward direction tend to be damaged relatively easily. Geophones, therefore, are sometimes eschewed in favor of hydrophones, which do not require contact with the formation. Hydrophones are effective for their intended purpose of measuring pressure. It will be recognized, however, that geophones in some applications are more useful because, for example, in a particular situation, displacement of the formation is more relevant than the pressure of the formation. Conductor 14 is again beneficial to the operator in connection with the configuration of
The astute reader may notice from the foregoing paragraph that another capability is enabled by the configuration of
In another aspect, it is noted that because of the conductor 14, multiple sensors may be used in the downhole environment since signals may be piggybacked on one another on the conductor 14, and due to the speed with which conductor 14 can convey information, more sensors can over time be addressed and transmit information to the surface location. Moreover, because sensors may be distributed along the drill pipe 10, processes such as Q measurement may be affected more efficiently since the high frequency attenuation inherent in this measurement method can be measured more accurately over specific smaller distances over the length of the drill pipe.
While the invention has been described with reference to exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications will be appreciated by those skilled in the art to adapt a particular instrument, situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
The present application claims priority to U.S. Provisional Patent Application Ser. No. 60/968,799, filed Aug. 29, 2007, the entire contents of which are specifically incorporated herein by reference.
Number | Date | Country | |
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60968799 | Aug 2007 | US |