Patent Application
20100313646
To obtain hydrocarbons, a drilling tool is driven into the ground surface to create a borehole through which the hydrocarbons are extracted. Typically, a drill string is suspended within the borehole. The drill string has a drill bit at a lower end of the drill string. The drill string extends from the surface to the drill bit. The drill string has a bottom hole assembly (BHA) located proximate to the drill bit.
Drilling operations typically require monitoring to determine the trajectory of the borehole. Measurements of drilling conditions, such as, for example, drift of the drill bit, inclination and azimuth, may be necessary for determination of the trajectory of the borehole, especially for directional drilling. As a further example, the measurements of drilling conditions may be information regarding the borehore and/or a formation surrounding the borehole. The BHA may have tools that may generate and/or may obtain the measurements. The measurements may be used to predict downhole conditions and make decisions concerning drilling operations. Such decisions may involve well planning, well targeting, well completions, operating levels, production rates and other operations and/or conditions. Moreover, the measurements are typically used to determine when to drill new wells, re-complete existing wells or alter wellbore production.
The measurements may be associated with a time that the measurements of drilling conditions are obtained. Typically, the tools have an internal timing mechanism synchronized with a computer located at the surface before the tools are used in the borehole. During use in the borehole, the tools obtain the measurements and associate the measurements with corresponding time data provided by the internal timing mechanism. The computer periodically calculates and records depths of the drill bit and associates a time with each depth of the drill bit. Thus, when the tools are retrieved from the borehole, the tools may transfer the measurements and the corresponding time data to the computer. The computer may use the time data to associate the measurements with corresponding depths of the drill bit. The computer may generate a log of the measurements as a function of the depth of the drill bit.
The above-described method of associating the depth of the drill bit with the measurements from tools retrieved from the borehole was acceptable for drilling that had relatively low rates of penetration, such as, for example, one hundred feet per hour or less. However, modern drilling operations may achieve rates of penetration over four hundred feet per-hour, such as, for example, approximately one thousand feet per hour, requiring analysis of the measurements while the tool is located in the borehole. In addition, the internal timing mechanism of the tool may experience drift relative to the computer located at the surface such that the time indicated by the internal timing mechanism may not match the time indicated by the computer. Drift of the internal timing mechanism varies for each tool and depends on time of use and temperature encountered. The drift causes inaccuracies in the log of the measurements as a function of the depth of the drill bit.
Technology for transmitting information within a borehole, known as telemetry technology, is used to transmit the measurements from the tools of the BHA to the surface for analysis while the tool is located in the borehole. However, the transmission of the measurements by a relatively slower telemetry technology may be hindered by the inclusion of the time data. Moreover, the telemetry technology may not have the capability to transmit the time data with the measurements. Instead of using time data transmitted from the tools, the computer located at the surface may calculate an estimated time to associate with the measurements received by the computer.
However, the estimated time is typically based on several assumptions that may render the estimated time inaccurate. For example, the estimated time may be based on assumptions regarding a rate of data acquisition for the tool, a data processing time for the tool, a data acquisition time for the telemetry system, a data processing time for the telemetry system, a data transmission time for the telemetry system, a data processing time for the computer and/or the like. These assumptions may vary in actual value and/or may be difficult to calculate. For example, the type of telemetry system used, an amount of data transmitted by the telemetry system and a depth of the tool from which the measurements are transmitted may cause a variance in the transmission time for the telemetry system that may render the estimated time inaccurate.
The present invention generally relates to a system and a method for associating time stamped measurement data with a corresponding wellbore depth. More specifically, the present invention relates to tools located in a wellbore that obtain the measurement data, and the measurement data is transmitted to the Earth's surface with time information. Wellbore depths may also be recorded as a function of time. As a result, the measurement data may be associated with the wellbore depth in which the measurement data was obtained based on the time information.
One or more of the tools may have a downhole clock and a surface terminal or other device may have a surface clock. The downhole clock and the surface clock may be synchronized. In an embodiment, the tools may determine a drift so that the tools may continue synchronization despite interruption of communication with the surface location by the telemetry system. A master tool may synchronize with a surface clock and/or may synchronize other tools with the surface clock. In another embodiment, the surface clock may synchronize with all tools directly or via the master tool or any combination there of.
Referring now to the drawings wherein like numerals refer to like parts,
A drilling fluid 20, such as, for example, mud, may be drawn from a reservoir 22 using a first fluid line 26 that may have one or more pumps 24. The pump 24 may direct the drilling fluid 20 through the drill string 14 and/or the drill bit 16. The drilling fluid 20 may travel through an annulus 28 that may be located between the drill string 14 and a wall of the borehole 30. A second fluid line 32 may extend from the annulus 28 to the reservoir 22 and/or may direct the drilling fluid 20 from the annulus 28 to the reservoir 22.
One or more tools 10 may be associated with the BHA 21 and/or the drill string 14. The tools 10 may provide measurements regarding the borehole 30, a formation that may surround the borehole 30, the drill string 14 and/or any component of the drill string 14. For example, one or more of the tools 10 may be and/or may have a measurement-while-drilling (“MWD”) tool, a logging-while-drilling (“LWD”) tool, a strain measuring device, a torque measuring device, a temperature measuring device, a seismic tool, a resistivity tool, a direction measuring device, an inclination measuring device, a weight-on-bit measuring device, a vibration measuring device, a shock measuring device, a stick-slip measuring device, rotary steerable tool, sampling and testing tools, a drilling tool used to create the borehole 30 and/or the like.
In an embodiment, one or more of the tools 10 may be a wireline configurable tool, such as a tool commonly conveyed by wireline cable as known to one having ordinary skill in the art. In an embodiment, one or more of the tools 10 may be a well completion tool that may extract, may sample and/or may control reservoir fluid extracted from the reservoir. In an embodiment, one or more of the tools 10 may be a steering mechanism 50 that may control a direction of drilling, the rotation of the drill string 14, an inclination of the borehole 30 and/or an azimuth of the borehole 30. The present invention is not limited to a specific embodiment of the tools 10.
As shown in
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As shown in
An example of a mud pulse telemetry system 200 that may be used in the present invention is described in detail in U.S. Pat. No. 5,375,098 to Malone et al., herein incorporated by reference in its entirety. The present invention is not limited to a specific embodiment of the mud pulse telemetry system 200 and/or the MWD module 260. The mud pulse telemetry system 200 may be any system that may use the drilling fluid 20 to enable the tools 10 to communicate with the surface location 29 as known to one having ordinary skill in the art.
As discussed previously, the telemetry system 51 may be a hybrid telemetry system. For example, the telemetry system 51 may have the wired drill pipe 100 extending from the surface location 29 to a position within the borehole and the mud pulse telemetry system 200 extending from the position within the borehole 30 to the BHA 21. The present invention is not limited to a specific embodiment of the telemetry system 51. The telemetry system 51 may be any telemetry system that enables the tools 10 to communicate with the surface location 29 as known to one having ordinary skill in the art. The present invention is not limited to a specific number of telemetry systems, and the tools 10 may use any number of telemetry systems to communicate with the surface location 29. The surface location may also communicate with the tool 10 as required via downlink telemetry which can be any telemetry method, such as wired pipe, cable, electromagnetic and others. The uplink and the downlink telemetry may occur simultaneously.
As shown in
The terminal 62 may have a surface clock 65 that may clock 65 may have a circuit connected to an oscillator, such as, for example, a quartz crystal, as known to one having ordinary skill in the art. The surface clock 65 may increase the surface time tsurface incrementally by action of the oscillator. The surface clock 65 may be a real time clock that may indicate a time of a day. For example, if the surface clock 65 is a real time clock, the surface clock 65 may indicate a time ante meridiem (A.M.), a time post meridiem (P.M.), a military time that may use a twenty-four hour time frame and/or the like.
The surface clock 65 may be synchronized using GPS signals as known to one having ordinary skill in the art. For example, the surface clock 65 may have a GPS receiver. GPS satellites may be positioned in orbit around earth and may provide signals to the GPS receiver of the surface clock 65. The GPS receiver may use the signals provided by the GPS satellites to determine the surface time tsurface. The present invention is not limited to a specific embodiment of the surface clock 65, and the tool clock 65 may be any device capable of generating the surface time tsurface for the terminal 62 as known to one having ordinary skill in the art. The tools 10 may continuously synchronize with the surface clock 65 and/or the surface time tsurface as described in more detail hereafter. For example, the tools 10 may have an internal battery-powered clock, but may determine a time using the surface time tsurface transmitted from the surface clock 65 instead of the internal battery-powered clock as discussed in more detail hereafter.
As shown in
The tools 10 and the telemetry system 51 may communicate using the tool bus 90. The tool bus 90 may utilize a 250 kHz carrier frequency that may be modulated between 200 kHz and 300 kHz. In another embodiment, the communications methodology may be phase or amplitude modulation. The present invention should not be deemed as limited by the communications methodology used on the bus described herein. A person having ordinary skill in the art will appreciate other communications methodologies may be used within the spirit of the invention. The tool bus 90 may provide electrical power to the tools 10. The present invention is not limited to a specific embodiment of the tool bus 90, and the tool bus 90 may be any apparatus that may be used by the tools 10 and the telemetry system 51 to communicate with each other.
The telemetry system 51 may have an interface 56 that may be located in the borehole 30 and/or may be associated with the BHA 21. The tool bus 90 may connect the tools 10 to the interface 56. The interface 56 may operate as an interface between the telemetry system 51 and the tool bus 90 and/or the tools 10. The interface 56 may enable the tool bus 90 and/or the tools 10 to communicate with the telemetry system 51.
In an embodiment where the telemetry system 51 may be the mud pulse telemetry system 200, the interface 56 may be the MWD module 260. In an embodiment where the telemetry system 51 may be the wired drill pipe 100, the interface 56 may be a wired drill pipe interface sub (hereafter “the WDP interface”). The WDP interface may enable the tool bus 90 and/or the tools 10 to communicate with the wired drill pipe 100, and/or the MWD module 260 may enable the tool bus and/or the tools 10 to communicate with the mud pulse telemetry system 200.
The interface 56 may have an internal timing mechanism 59. The internal timing mechanism 59 may be synchronized with the surface clock 65 of the terminal 62 before the telemetry system 51 and/or the interface 56 are used within the borehole 30. The internal timing mechanism 59 of the interface 56 may provide an interface time tinterface that may be based on and/or may correspond to the surface time tsurface. For example, the interface may have an oscillator, such as, for example, a quartz crystal, as known to one having ordinary skill in the art, for determining the interface time tinterface. The internal timing mechanism 59 of the interface 56 and the surface clock 65 may synchronize as described in more detail hereafter. The present invention is not limited to a specific embodiment of the interface 56 or the internal timing mechanism 59 of the interface 56. The internal timing mechanism may be any device that generates a time for the interface 56.
The tools 10 may have capabilities for measuring, processing and/or storing information. The tools 10 may have a sensor, such as, for example, a gauge, a temperature sensor, a pressure sensor, a flow rate measurement device, an oil/water/gas ratio measurement device, a scale detector, a vibration sensor, a sand detection sensor, a water detection sensor, a viscosity sensor, a density sensor, a bubble point sensor, a composition sensor, a resistivity array sensor, an acoustic sensor, a near infrared sensor, a gamma ray detector, internal and annulus pressure, formation pressure, inclination and azimuth sensors, a H2S detector, a CO2 detector and/or the like.
For example, the tools 10 may measure, may record and/or may transmit data acquired from and/or through the borehole 30 (hereinafter “the data”). The data may relate to the borehole 30 and/or the formation that may surround the borehole 30. For example, the data may relate to one or more characteristics of the formation and/or the borehole 30, such as, for example, a temperature, a pressure, a depth, a composition, a density and/or the like. The data may relate to one or more characteristics of the drill string 14, such as, for example, an amount of stretch, an amount of strain, an angle, a direction, a characteristic of fluid flowing through the drill string 14, a dog-leg severity and/or the like. For example, the data may indicate a trajectory of the borehole 30, a depth of the borehole 30, a caliper of the borehole 30 and/or the like. Further, the data may be and/or may indicate, for example, a location of the drill bit 16, an orientation of the drill bit 16, a weight applied to the drill bit 16, a rate of penetration, properties of an earth formation being drilled, properties of an earth formation and/or a hydrocarbon reservoir located proximate to the drill bit 16, fluid conditions, fluids collected and/or the like. Still further, the data may be, for example, resistivity measurements, neutron porosity measurements, azimuthal gamma ray measurements, density measurements, elemental capture spectroscopy measurements, neutron gamma density measurements that measure gamma rays generated from neutron formation interactions, sigma measurements and/or the like. The data may be and/or may indicate an inclination of the borehole 30 and/or an azimuth of the borehole 30, for example. The data may indicate annular pressure, three-axis shock and/or vibration, for example. The data may be measured and/or obtain at predetermined time intervals, at predetermined depths, at request by a user, command from the terminal, triggered based on event and/or the like. The present invention is not limited to a specific embodiment of the data.
As generally shown at step 201, the terminal 62 may determine surface times tsurface that may be provided by the surface clock 65 of the terminal 62. As generally shown at step 205, the interface 56, the tools 10 and/or the surface clock 65 may synchronize. For example, the internal timing mechanism 59 of the interface 56 may experience drift relative to the surface clock 65, and/or the surface clock may experience drift relative to the internal timing mechanism 59 of the interface 56. As a result of the drift of the internal timing mechanism 59 of the interface 56 and/or the surface clock 65, a time provided by the internal timing mechanism 59 at a specific time may not match a time provided by the surface clock 65 at the specific time. The drift of the internal timing mechanism of the interface 56 and/or the surface clock 65 may prevent the data from receiving accurate time information. Therefore, the interface 56 and/or the terminal 62 may periodically synchronize the internal timing mechanism 59 of the interface 56 and the surface clock 65.
As a further example, as generally shown in
The first clock 601 and/or the second clock 601 may experience drift relative to the surface clock 65, and/or the surface clock 65 may experience drift relative to the first clock 601 and/or the second clock 601. As a result of the drift of the first clock 601, the second clock 601 and/or the surface clock 65, a time provided by the first tool 501 and/or the second tool 502 at a specific time may not match a time provided by the surface clock 65 at the specific time. The drift of the first clock 601, the second clock 601 and/or the surface clock 65 may prevent the data from receiving accurate time information. Therefore, referring again to
The interface 56, the first tool 501, the second tool 502 and/or the terminal 62 may use any means known to one having ordinary skill in the art to synchronize the internal timing mechanism 59 of the interface 56, the first clock 601, the second clock 602 and/or the surface clock 65. For example, the internal timing mechanism 59 of the interface 56, the first clock 601, the second clock 602 and/or the surface clock 65 may synchronize using messages transmitted between the interface 56, the first tool 501, the second tool 502 and/or the terminal 62.
Synchronization may be periodic such that the interface 56, the first tool 501, the second tool 502 and/or the terminal 62 messages synchronize at predetermined time intervals. A time interval for synchronization may be based on the drift. For example, the time interval may be one second if the drift may be relatively high. As a further example, the time interval may be one hour if the drift may be relatively low. In an embodiment, an accuracy of synchronization may be approximately one millisecond to approximately ten seconds. For example, synchronization of the internal timing mechanism 59 of the interface 56, the first clock 601, the second clock 602 and/or the surface clock 65 may cause times provided by the internal timing mechanism 59 of the interface 56, the first clock 601, the second clock 602 and/or the surface clock 65 to be within one millisecond of each other. The present invention is not limited to a specific embodiment of the time interval or the accuracy of synchronization.
As generally shown at step 210, the first tool 501 and/or the second tool 502 may obtain the data and/or may associate the data with a timestamp. The interface 56, the first tool 501 and/or the second tool 502 may transmit the data to the terminal 62 in association with the timestamp. The data and/or the timestamp may be transmitted to the terminal 62 using the telemetry system 51. The timestamp may be the time that the data was obtained, for example. In another example, when a range of data is acquired at a specific interval, the timestamp may be associated with any interval related to the acquisition time, such as an initial acquisition time of the range of data, a completed acquisition time of the range of data, or a time in between the initial acquisition time and the completed acquisition time for the range of data. If the data was transmitted from the first tool 501, the timestamp may be a time provided by the first clock 601. If the data was transmitted from the second tool 502, the timestamp may be a time provided by the second clock 602. In an embodiment, the timestamp may be a time provided by the internal timing mechanism 59 of the interface 56, such as, for example, if one or more of the tools 10 transmitting the data may not be capable of providing a time for the timestamp. The interface 59 may adjust the timestamp for the delay between the acquisition time and the time in which the timestamp is associated.
As generally shown at step 215, the terminal 62 may determine depths of the drill bit 15 and/or the drill string 14 at various times. For example, the terminal 62 may associate the depths with times provided by the surface clock 65. An example of a method for associating the depths with the various times that may be used in the present invention is described in detail in U.S. Patent App. Pub. No. 2009/0038392 to Alfred et al., herein incorporated by reference in its entirety. The present invention is not limited to a specific embodiment of the method for associating the depths with the various times. For example, each sensor may measure points that are known based on the BHA design, the depth can be calculated based on the measured bit depth, and the depths may then be associated with the time.
As generally shown at step 220, the terminal 62 may associate the appropriate depths with the data. For example, the terminal 62 may associate one of the sensor depths corresponding to a specific time with a portion of the sensor data corresponding to the specific time. The terminal 62 may receive the depths at a different rate than the terminal 62 may receive the data. For example, the terminal 62 may receive the depths at a rate of two Hz, ten Hz, 100 Hz, 1000 Hz, and/or the like. The present invention is not limited to a specific embodiment of a rate of receipt of the depths.
The terminal 62 may generate and/or may display a report, such as, for example, a depth log as known to one having ordinary skill in the art. The report may have and/or may display the data in association with the timestamps and/or the depths. For example, the report may display each of the depths in association with the corresponding portion of the data. In an embodiment, the report may be a log of the borehole, such as a record of the geological formations of the borehole.
In an embodiment, the surface clock 65 may be a master clock such that the first clock 601, the second clock 602 and/or the internal timing mechanism 59 of the interface 56 may be synchronized based on the time provided by the surface clock 65. Therefore, the first clock 601, the second clock 602 and/or the internal timing mechanism 59 of the interface 56 may be synchronized to compensate for the drift of the first clock 601, the second clock 602, the clocks of the other tools 10 and/or the internal timing mechanism 59 of the interface 56 relative to the surface clock 65. The present invention is not limited to a specific embodiment and/or location of the master clock. For example, the first clock 601 may be the master clock such that the second clock 602, the internal timing mechanism 59 of the interface 56 and/or the surface clock 65 may be synchronized to compensate for the drift of the second clock 602, the internal timing mechanism 59 of the interface 56 and/or the surface clock 65 relative to the first clock 601. All clocks in the drilling system from the surface clock 65 to the BHA, the other components in the drill string, repeaters (not shown), the interface 56 and/or the tool 10 may be synchronized. In case of wired drill pipe telemetry or other telemetry system that may have components with internal clocks, such as repeaters, these internal clocks may also be synchronized with the surface clock 65, especially if the components include a sensor and acquire data.
Receipt of the response from the terminal 62 by the interface 56 may indicate a round-trip transmittal time. The round-trip transmittal time may be the difference between the time the response was received by the interface 56 relative to the time the “ping” message was sent by the interface 56. The round-trip transmittal times associated with “ping” messages may be sent to the terminal 62 by the interface 56 and/or stored by the terminal 62 and/or the interface 56. The terminal 62 and/or the interface 56 may calculate an average round-trip time troundtrip based on the round-trip transmittal times associated with previous “ping” messages. The “ping” messages transmitted from the interface 56 to the terminal 62 may indicate the average round-trip time troundtrip of the previous “ping” messages. The interface 56 transmits the tdownhole to the terminal 62 at predetermined interval as previously described, and the terminal 62 synchronizes the time tsurface with the tdownhole. The time tsurface may be adjusted to account for the delay involved between the time the interface 56 actually transmits the time information to the terminal 62 and the time in which the terminal 62 receives the time information. This time difference may be significant in case of some types of telemetry like wired drill pipe, where there are repeaters in between. Until the next interface time tdownhole is received, the terminal will continue to increment the synchronized time tsurface with its internal clock. When the terminal 62 receives the next interface time tdownholer the terminal 62 will resynchronize tsurface.
As discussed previously, the terminal 62 may determine depths of the drill bit 15 and/or various sensor measure points in the drill string 14. As generally shown at step 305, the terminal 62 may associate the depths with times. The terminal 62 may associate the depth data with time tsurface which may be synchronized with the time tdownholer, such as from the interface 56. For example, the first depth is associated with the first surface time t1surface and the second depth is associated with the second surface time t2surface and so on. In yet another example, the terminal 62 may determine a first depth after receiving the first downhole time tdownhole from the interface 56. The terminal 62 may not associate the first depth with the current time provided by the surface clock 65. Instead, the time tsurface to associate with the first depth may be based on the average round-trip time troundtrip and the first downhole time tdownhole that may be provided by the message from the interface 56.
As generally shown at step 310, the tools 10 may obtain or acquire data and associate the time when the data was acquired using an internal clock of the tools 10. Data associated with timestamp may be stored in internal memory of the tools 10. As generally shown at step 315, the interface 56 may transmit a first data request that may request the first set of data from the tools 10. The interface 56 may transmit the first data request to the tools 10 using the tool bus 90. The interface 56 may transmit the first data request at a second downhole time tdownhole. The terminal 62 may direct that the interface 56 transmit the first data request, and/or the first data request may be one of a plurality of data requests transmitted from the interface 56 periodically at predetermined time intervals. The first data request may indicate which of the tools 10 may be intended to respond to the first data request.
As generally shown at step 320, the tools 10 may determine a lapse time delta-t based on a time the tools 10 transmit the data. The lapse time delta-t may be the difference between when the data was obtained and the time the tools 10 transmit the data. For example, the tools 10 may have an oscillator, such as, for example, a quartz crystal, as known to one having ordinary skill in the art, for determining the lapse time delta-t.
One or more of the tools 10 may not be capable of determining a current time but may be capable of determining the lapse time delta-t using the oscillator. For example, one or more of the tools 10 may not be capable of determining the current time because one or more of the tools 10 may not have an internal battery-powered clock. The tools 10 that may not have an internal battery-powered clock may be reset and/or may lose power after receiving the most recent downhole time tdownhole transmitted by the interface 56. However, oscillations of the oscillator may indicate the lapse time delta-t. Therefore, the tools 10 that may not be capable of determining the current time may associate the data with the lapse time delta-t. Further, one or more of the tools 10 may be capable of determining the current time using an internal battery-powered clock. The tools 10 that may be capable of determining the current time may associate the data with the lapse time delta-t and/or may not associate the data with the current time provided by the internal battery-powered clock.
As generally shown at step 325, the tools 10 specified by the data request may transmit the data in association with the lapse time delta-t to the interface 56 using the tool bus 90. For example, the tools 10 may transmit a first encoded message that may encode the data in association with the lapse time delta-t. The tools 10 may transmit the first encoded message to the interface 56 using the tool bus 90. In yet another embodiment, the tools 10 can push the data with timestamp or delta-t, send data to interface either at a predetermined time interval or as they are acquired.
The interface 56 may receive the data in association with the lapse time delta-t from the tools 10 using the tool bus 90. For example, the interface 56 may receive the data in association with the lapse time delta-t using the first encoded message. As generally shown at step 330, the interface 56 may assign a first timestamp to the data. The first timestamp may be the result of subtraction of the lapse time delta-t from the second downhole time tdownhole. In another embodiment, if the timestamp was received from the tools 10, the interface 56 may use the timestamp without adjustment. For example, the interface 56 may assign the timestamp to the data substantially at the time the interface 56 receives the data. As generally shown at step 335, the telemetry system 51 may transmit the data in association with the first timestamp from the interface 56 to the terminal 62. For example, the telemetry system 51 may transmit a second encoded message from the interface 56 to the terminal 62. The second encoded message may encode the data and the first timestamp.
As generally shown at step 340, the terminal 62 may associate one of the depths with the data received in response to the first data request. The terminal 62 may associate one of the depths with the data received in response to the first data request based on synchronization of the times with the internal timing mechanism 59 of the interface 56. The terminal 62 may associate one of the depths with the data received in response to the first data request using the first timestamp and the depth associated with a time corresponding to the first timestamp. For example, a specific pressure measurement associated with a specific time and a specific depth associated with the specific time may indicate that the specific pressure measurement may be associated with the specific depth. A data request by a terminal model is described above, but a person having ordinary skill in the art will appreciate that other models may be used, such as a data push model where the data may be sent by the interface 56 and/or tools to the terminal 62 without a specific request. The present invention should not be limited by the specific method of data transmission scheme described above. Any known techniques of data transmission could be used.
As generally shown at step 350, steps 301-340 may be repeated. For example, a second set of data may be obtained using a second data request. A second timestamp may be associated with the second set of data. Thus, a second depth may be associated with the second set of data. Any number of data requests may be transmitted and any number of sets of data may be obtained. Any number of timestamps or depths may be associated with the data. The present invention is not limited to a specific number of the data requests, the sets of data, the timestamps or the depths.
As generally shown at step 345, the terminal 62 may generate and/or may display a report, such as, for example, the depth log known to one having ordinary skill in the art. The report may have and/or may display the data in association with the timestamps and/or the depths. For example, the report may display the first set of data in association with the first depth and/or the second set of data in association with the second depth. The report may have and/or may display any number of the sets of data, the timestamps or the depths. As generally shown at step 345, steps 301-340 may be repeated. For example, additional reports may be generated and/or displayed subsequent to the report. The present invention is not limited to a specific number of reports.
As generally shown at step 401, the terminal 62 may determine surface times tsurface that may be provided by the surface clock 65 of the terminal 62. As generally shown at step 430, the terminal 62 may periodically transmit a message to the interface 56 using the telemetry system 51. The message may indicate a surface time tsurface that may be provided by the surface clock 65 of the terminal 62. For example, the message may be a “ping” message that may indicate the surface time tsurface and/or may request a response from the interface 56. As generally shown at step 435, the interface 56 may transmit the response to the “ping” message to the terminal 62. For example, the interface 56 may transmit the response substantially simultaneous to receipt of the message.
As generally shown at step 440, the terminal 62 may determine a round-trip transmittal time Trt based on receipt of the response from the interface 56. The round-trip transmittal time may be the difference between the time the response was received by the terminal 62 relative to the time the “ping” message was sent by the terminal 62. For example, if the “ping” message was transmitted by the terminal 62 at a first time t1 and the response was received by the terminal 62 at a second time t2, the round-trip transmittal time may be calculated by subtracting the first time t1 from the second time t2.
The round-trip transmittal times associated with “ping” messages may be monitored and/or stored by the terminal 62. As generally shown at step 445, the terminal 62 may calculate an average round-trip time AvgTrt based on the round-trip transmittal times associated with previous “ping” messages. The “ping” messages transmitted from the terminal 62 to the interface 56 may indicate the average round-trip time AvgTrt of the previous “ping” messages. The terminal 62 may transmit the “ping” messages to the interface 56 periodically. For example, the terminal 62 may determine if a predetermined time interval for the next “ping” message may have lapsed as generally shown at step 450. If the predetermined time interval has lapsed, the terminal 62 may send the next “ping” message as generally shown at step 430. The present invention should not be limited by the specific method of calculating the round-trip time. For example, the time synchronization method advantageously may represent the average round-trip time and eliminate the noisy samples. Any known signal processing techniques could be used. The averaging time window can be a moving window or a finite time period with alternating window. The time period can be decided based on the time where the system changes the round-trip time significantly. This time period can be variable as system requires. It can be adjusted manually or automatically.
As generally shown at step 405, the terminal 62 may transmit the surface time tsurface and/or the average round-trip time AvgTrt to the interface 56 and/or the tools 10 using the telemetry system 51. For example, the tools 10 may receive the surface time tsurface and/or the average round-trip time AvgTrt from the interface 56 using the tool bus 90 as generally shown at step 410. The “ping” message sent to the interface 56 may have the surface time tsurface and/or the average round-trip time AvgTrt. The interface 56 and/or the tools 10 may determine a current time based on the surface time tsurface and/or the average round-trip time AvgTrt. For example, the current time tcurrent may be calculated by adding half of the average round-trip time AvgTrt to the surface time tsurface provided by the message from the terminal. For example, tcurrent=tsurface+½(AvgTrt). The interface 56 may synchronize its clock with the current time and may continually update its internal clock as shown in 415. The interface 56 may transmit the current time tcurrent to the tools 10 using the tool bus 90. The tools 10 may use the time tcurrent to synchronize its clock and may continually update its internal clock time. In another embodiment, the interface 56 or one of the tools 10 can be the source of the master clock for synchronization.
As generally shown at step 420, the tools 10 may obtain the data and/or may associate the updated current time with the data. The tools 10 may associate the data and/or sets of data with a timestamp based on the current time tcurrent. The tools 10 may transmit the data in association with the current time tcurrent to the interface 56 using the tool bus 90 and/or to the terminal 62 using telemetry system 51.
One or more of the tools 10 may not be capable of determining time internally. For example, one or more of the tools 10 may not be capable of determining time internally because one or more of the tools 10 may not have an internal battery-powered clock. The tools 10 that may not have an internal battery-powered clock may be reset and/or may lose power. However, the tools 10 that may not be capable of determining time internally may associate the data with the updated current time tcurrent. For example, the tools 10 may receive the current time tcurrent from the interface 56 at regular interval. Alternatively, the tools may determine the current time tcurrent based on transmittal of the average round-trip time troundtrip and/or the surface time tsurface to the tools 10 from the interface 56.
One or more of the tools 10 may be capable of determining time internally. For example, the tools 10 that may be capable of determining time internally may have an internal battery-powered clock. The tools 10 that may be capable of determining time internally may associate the data with the updated current time tcurrent transmitted from the interface 56. The tools 10 that may be capable of determining time internally may determine the current time tcurrent based on the average round-trip time AvgTrt and/or the surface time tsurface that may be transmitted from the interface 56. The tools 10 that may be capable of determining time internally may not associate the data with time determined internally, such as, for example, time provided by the internal battery-powered clock.
As discussed previously, the terminal 62 may determine depths of the drill bit 15 and/or the drill string 14 at various times as generally shown at step 460. Knowing the design of the BHA and the drill string, depths of each measurement sensors can be calculated for a given time. For example, the terminal 62 may associate the depths with times provided by the surface clock 65. The present invention is not limited to a specific embodiment of the method for associating the depths with the various times.
As generally shown at step 425, the terminal 62 may associate the depths with the data. For example, the terminal 62 may associate one of the depths corresponding to a specific time with a portion of the data corresponding to the specific time. The terminal 62 may generate and/or may display the depth log that may have and/or may display the data in association with the times and/or the depths. For example, the report may display each of the depths in association with the corresponding portion of the data.
As generally shown in
As generally shown at step 515, the tools 10 may obtain the data and/or may associate an acquisition time tacq, tools 10 internal clock time, with the data. The tools may associate the data with a timestamp based on the acquisition time tacq. The tools 10 may determine the acquisition time tacq internally. For example, the tools 10 may have an internal battery-powered clock, and/or the internal battery-powered clock may provide the acquisition time tacq. The tools 10 may store the obtained data and the associated time stamp in its internal memory.
The terminal 62 and/or the interface 56 may transmit a first data request that may request a first set of the data from the tools 10. The interface 56 may transmit the first data request to the tools 10 using the tool bus 90. The terminal 62 may direct that the interface 56 transmit the first data request, and/or the first data request may be one of a plurality of data requests transmitted from the interface 56 periodically at predetermined time intervals. The first data request may indicate which of the tools 10 may be intended to respond to the first data request. For example, the first data request may be a packet that has a header that may specify one or more of the tools 10 from which the data is requested. In another embodiment, data may be pushed by tools 10 to the interface 56 using tool bus 90 or to the terminal 62 using the telemetry 51. Communicating data over bus or network is well known to the skill in the art and should not be considered as limiting the present invention.
As generally shown at step 520, the tools 10 specified by the first data request may transmit the first set of the data in association with a lapse time delta-t to the interface 56 using the tool bus 90. The lapse time delta-t may be the difference between when the first set of the data was obtained tacq and a time tsend when the tools 10 transmit the first set of the data. The tools 10 may determine the lapse time delta-t=tsend−tacq. For example, the tools 10 may have an oscillator, such as, for example, a quartz crystal, as known to one having ordinary skill in the art, for determining the lapse time delta-t. For example, the lapse time delta-t may be calculated by subtracting the acquisition time tacq from the time tsend when the data is transmitted by the tools 10.
For example, the tools 10 may transmit a first encoded message that may encode the first set of the data in association with the lapse time delta-t. The lapse time delta-t may be encoded by a smaller encoded message relative to a message encoding the current time, and/or communication of the lapse time delta-t may require less bandwidth relative to communication of the current time. In this method of transmitting delta-t with the data from tools 10, the tools 10 may not synchronize their own clocks with the interface 56 and/or the terminal clock or the tools 10 may not require battery backed up real time clock. The tools 10 may transmit the first encoded message to the interface 56 using the tool bus 90. The present invention is not limited to a specific embodiment of the first encoded message.
As generally shown at step 525, the interface 56 may receive the first set of the data in association with the lapse time delta-t from the tools 10 using the tool bus 90. The interface 56 may associate the first set of the data and/or the lapse time delta-t with a data receipt time treceipt determined by the interface 56. For example, the data receipt time treceipt may be the most recent current time tcurrent determined by the interface 56 when the first set of the data is received. The most recent current time tcurrent may be based on the surface time tsurface and/or the average round-trip time troundtrip transmitted in the most recent message from the terminal 62. The telemetry system 51 may transmit a second encoded message from the interface 56 to the terminal 62. The second encoded message may encode the first set of the data, the lapse time delta-t and/or the data receipt time treceipt determined by the interface 56. For example, the interface 56 may generate the second encoded message by adding a coding segment to the first encoded message. The coding segment added to the first encoded message may encode the data receipt time treceipt determined by the interface 56. For example, a remainder of the second encoded message may be substantially similar to the first encoded message.
As generally shown at step 530, the terminal 62 may determine the first timestamp for the first set of the data. A value of the first timestamp may be calculated by subtracting the lapse time delta-t from the data receipt time treceipt transmitted from the interface 56 with the first set of the data. For example, the lapse time delta-t and/or the data receipt time treceipt may be encoded by the second encoded message. In another embodiment, the interface 56 may compute the timestamp by subtracting the lapse time delta-t from the data receipt time treceipt and send it to the terminal 62, such as in the encoded message.
As discussed previously, the terminal 62 may determine depths of the drill bit 15 and/or the drill string 14 at various times as generally shown at step 460. For example, the terminal 62 may associate the depths with times provided by the surface clock 65. The present invention is not limited to a specific embodiment of the method for associating the depths with the various times.
As generally shown at step 535, the terminal 62 may associate the depths with the data. For example, the terminal 62 may associate one of the depths with the first set of the data, and/or the terminal 62 may associate a different one of the depths with a second set of the data obtained at a different time relative to the first set of the data. The terminal 62 may generate and/or may display the depth log that may have and/or may display the data in association with the times and/or the depths.
As generally shown at step 603, the interface 56, the tools 10 and/or the surface clock 65 may synchronize before the telemetry system 51 and/or the tools 10 are used within the borehole 30. As generally shown at step 605, the interface 56 and/or one of the tools 10 that may be a master tool may periodically synchronize with the surface clock 65. As discussed previously, the internal timing mechanism 59 of the interface 56 may experience drift relative to the surface clock 65, and/or internal clocks of the tools 10 may experience drift relative to the surface clock 65. As a result of the drift of the internal timing mechanism 59 of the interface 56 and/or the internal clocks of the tools 10, a time provided by the internal timing mechanism 59 and/or the internal clocks of the tools 10 at a specific time may not match a time provided by the surface clock 65 at the specific time. The drift of the internal timing mechanism 59 of the interface 56 and/or the internal clocks of the tools 10 may prevent the interface and/or the tools 10, respectively, from providing accurate time information for the data. Therefore, the interface 56 and/or a master tool may periodically synchronize the internal timing mechanism 59 of the interface 56 and/or the internal clock of the master tool, respectively, with the surface clock 65.
The interface 56 and/or the master tool may use any means known to one having ordinary skill in the art to synchronize the internal timing mechanism 59 of the interface 56 and/or the internal clock of the master tool with the surface clock 65. For example, the internal timing mechanism 59 of the interface 56 and/or the clock of the master tool may be synchronized with the surface clock 65 using messages transmitted from the terminal 62.
As generally shown at step 610, the interface 56 and/or the master tool may synchronize the internal clocks of the tools 10 with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool. The interface 56 and/or the master tool may use any means known to one having ordinary skill in the art to synchronize the internal clocks of the tools with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool. For example, the internal clocks of the tools may be synchronized with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool using messages transmitted to the tools 10.
As generally shown at step 615, the interface 56 and/or the master tool may determine a rate of drift. The drift may be a function of time elapsed since the interface 56 and/or the tools 10 were synchronized with the surface clock 65. The rate of drift may be any value or calculation that may be used to determine the drift of the internal timing mechanism 59 of the interface 56 and/or the internal clock of the master tool as known to one having ordinary skill in the art. The rate of drift may be any value or calculation that may be used to synchronize the internal timing mechanism 59 of the interface 56 and/or the internal clock of the master tool as known to one having ordinary skill in the art. The present invention is not limited to a specific embodiment of calculating the rate of drift.
As generally shown at step 620, the interface 56 and/or the master tool may determine if communication using the telemetry system 51 may be prevented and/or may be hindered. For example, if the telemetry system 51 may be the wired drill pipe 100, adjacent joints of the WDP joints 110 the wired drill pipe may be separated. If the communication using the telemetry system 51 may be prevented and/or may be hindered, the interface 56 and/or the master tool may continuously estimate the surface clock timing using the rate of drift calculated before the communication using the telemetry system 51 was prevented and/or was hindered as generally shown at step 625. The interface 56 and/or the master tool may synchronize the internal clocks of the tools 10 with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool. For example, messages transmitted to the tools may synchronize the internal clocks of the tools 10 with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool.
As generally shown at step 630, the tools 501 may obtain the data and/or may associate the data with a timestamp. The timestamp may be based on synchronization of the internal clocks of the tools 10 with the internal timing mechanism 29 of the interface 59 and/or the internal clock of the master tool. Thus, the data may be associated with timestamps synchronized with the surface clock 65 despite interruption of the communication using the telemetry system 51. The tools 10 may store the data for transmission to the terminal 62 in association with the timestamps when communication using the telemetry system 51 is re-established.
As generally shown at step 635, the tools 10 may transmit the data to the terminal 62 in association with the timestamps. As discussed previously, the terminal 62 may determine depths of the drill bit 15 and/or the drill string 14 and/or associated sensors at various times as generally shown at step 640. For example, the terminal 62 may associate the depths with times provided by the surface clock 65. The present invention is not limited to a specific embodiment of the method for associating the depths with the various times.
As generally shown at step 645, the terminal 62 may associate the depths with the data. For example, the terminal 62 may associate one of the depths with the data. The terminal 62 may generate and/or may display the log that may have and/or may display the data in association with the times and/or the depths.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those having ordinary skill in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the claims.
This application claims priority from U.S. Patent Application Ser. No. 61/186,111, filed on Jun. 11, 2009, entitled “System and Method for Associating Measurements from a Wellbore with a Time and Depths,” which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61186111 | Jun 2009 | US |
