A three-stage data processing method

Abstract

The application provides a three-section data processing method, which comprises the following steps: according to the time channel sequence of downhole data to be processed, processing time spectrum data corresponding to each time channel based on a first compression rule; when the time spectrum data corresponding to a certain time channel meets a second compression rule, processing time spectrum data corresponding to each time channel based on the second compression rule from the current time channel; and when the time spectrum data corresponding to a certain time channel meets a third compression rule, processing time spectrum data corresponding to each time channel based on the third compression rule from the current time channel. In the construction idea, the application customizes a new three-section data compression and packaging method according to the actual situation of the downhole logging instrument measurement curve, and the method can better adapt to the downhole logging instrument compared with the common compression algorithm in the prior art.

Description

Technical Field

[0001] This invention relates to the field of logging equipment technology after the casing of production wells in oil drilling, and more specifically, to a three-stage data processing method. Background Technology

[0002] With the development of logging technology, the number of downhole devices is gradually increasing, and the amount of downhole data that needs to be transmitted back to the surface is also increasing. In order to improve the efficiency of data transmission, data compression technology has been increasingly mentioned.

[0003] Data compression technology is a method that reduces the amount of data and storage space without losing the original data information, thereby improving the efficiency of transmission, storage, and processing. Alternatively, it can re-encode and organize the original signal data using a certain algorithm to reduce storage space and redundancy. A common data compression method encodes the input signal using an algorithm, resulting in a smaller bitstream that can replace the original signal. There are also decoding algorithms that can recover the signal from the output bitstream. The recovered signal is then compared to the original signal; if they completely match, this method is considered lossless compression.

[0004] Lossless compression algorithms typically achieve low compression ratios, generally between 1 / 2 and 1 / 5 of the original data volume. Based on their compression models, lossless compression can be broadly categorized into statistical compression algorithms and dictionary-based compression algorithms. Existing technologies commonly employ lossless compression methods such as Shannon-Fano coding, Huffman coding, run-length coding, and Lempel-Ziv-Welch encoding. While each of these methods has its own characteristics, they are not entirely suitable for downhole data output from downhole equipment.

[0005] To address the problems of existing technologies, this invention provides a simpler and more suitable three-stage data processing method for downhole data. Summary of the Invention

[0006] To achieve lossless data compression at the same level without employing statistical and dictionary compression algorithms, this invention provides a three-stage data processing method, comprising the following steps:

[0007] According to the time sequence of the downhole data to be processed, the time spectrum data corresponding to each time channel is processed sequentially based on the first compression rule;

[0008] If the time spectrum data corresponding to a certain time channel meets the second compression rule, then starting from the current time channel, the time spectrum data corresponding to each time channel will be processed sequentially based on the second compression rule.

[0009] If the time spectrum data corresponding to a certain time channel meets the third compression rule, then starting from the current time channel, the time spectrum data corresponding to each time channel will be processed sequentially based on the third compression rule.

[0010] According to one embodiment of the present invention, the downhole data to be processed is the voltage amplitude digital signal output by the receiving coil of a transient electromagnetic resistivity logging instrument when completing a logging curve measurement task within one acquisition cycle at a certain downhole depth measurement point. One acquisition cycle is evenly divided into multiple equal parts, each part being called a time channel. The time spectrum data is the voltage amplitude digital signal output by the receiving coil at a certain moment within each time channel. To balance the accuracy requirements of the logging task with the actual downhole storage capacity, the number of time channels is determined, which is 200-400.

[0011] According to an embodiment of the present invention, the method includes: if any bit in a specific bit interval of the current time spectrum data is a first preset value, then the first compression rule is satisfied; under the first compression rule, the current time spectrum data is determined to be compressible data; after removing the data in the specific bit interval of the current time spectrum data, the remaining data is stored in a first buffer.

[0012] According to an embodiment of the present invention, the method includes: if the specific bit range of the current time spectrum data contains both the first preset value and the second preset value, then the second compression rule is satisfied; under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored in the second buffer.

[0013] According to an embodiment of the present invention, the method includes: if any bit in the specific bit interval of the current time spectrum data is the second preset value, then the third compression rule is satisfied; under the third compression rule, the current time spectrum data is determined to be compressible data; after removing the data in the specific bit interval of the current time spectrum data, the remaining data is stored in a third buffer.

[0014] According to one embodiment of the present invention, the method comprises:

[0015] The data in the first buffer, the second buffer, and the third buffer are encapsulated as a whole to obtain encapsulated data corresponding to the downhole data to be processed;

[0016] The collected downhole temperature data, downhole magnetic positioning data, and downhole gamma data are processed and compiled into standardized data, which are then packaged to obtain downhole environment packaged data.

[0017] The encapsulated data and the downhole environment encapsulated data are combined into a single data stream and transmitted to the surface via a preset bus.

[0018] According to an embodiment of the present invention, when the time spectrum data is a 24-bit digital signal of voltage amplitude, the method includes:

[0019] If any of the high 8 bits of the current time spectrum data is 1, then the first compression rule is satisfied. Under the first compression rule, the current time spectrum data is determined to be compressible data. After removing the 1s from the high 8 bits of the current time spectrum data, the remaining data is stored in the first buffer in 2 bytes.

[0020] If the high 8 bits of the current time spectrum data contain both 1 and 0, then the second compression rule is satisfied. Under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored into the second buffer in 3 bytes.

[0021] If any of the high 8 bits of the current time spectrum data is 0, then the third compression rule is satisfied. Under the third compression rule, the current time spectrum data is determined to be compressible data. After removing the 0s from the high 8 bits of the current time spectrum data, the remaining data is stored in the third buffer in 2-byte blocks.

[0022] According to one embodiment of the present invention, the method comprises:

[0023] Determine the number of instruments to be deployed. If it is necessary to provide transient electromagnetic resistivity logging data at different depths simultaneously, at least two transient electromagnetic resistivity logging instruments, one for shallow exploration and one for deep exploration, must be deployed at the same time.

[0024] The logging curve measurement task is determined. If the two tasks of casing inspection and through-casing measurement need to be completed, a transient electromagnetic resistivity logging instrument shall provide at least 4 logging curves, namely the casing inspection and through-casing measurement curves received when the transmitting coil is emitted in the forward direction, and the casing inspection and through-casing measurement curves received when the transmitting coil is emitted in the reverse direction.

[0025] According to another aspect of the invention, a storage medium is also provided, which includes a series of instructions for performing the steps of the method described in any of the preceding claims.

[0026] According to another aspect of the present invention, a three-stage data processing apparatus is also provided, which performs the method as described in any of the preceding claims, the apparatus comprising:

[0027] The first compression rule module is used to process the time spectrum data corresponding to each time channel in sequence according to the time channel order of the downhole data to be processed, based on the first compression rule;

[0028] The second compression rule module is used to process the time spectrum data corresponding to each time channel sequentially based on the second compression rule, starting from the current time channel, when the time spectrum data corresponding to a certain time channel meets the second compression rule.

[0029] The third compression rule module is used to process the time spectrum data corresponding to each time channel sequentially based on the third compression rule, starting from the current time channel, when the time spectrum data corresponding to a certain time channel meets the third compression rule.

[0030] This invention provides a three-stage data processing method. In terms of its construction approach, this invention does not adopt the commonly used statistical or dictionary-based compression approaches in existing technologies. Instead, it tailors a new three-stage data compression and encapsulation method based on the actual conditions of downhole logging instrument measurement curves. Compared to common compression algorithms in existing technologies, this method is better adapted to downhole logging instruments. In terms of algorithm content, this invention does not require complex algorithmic processes, making it simpler and easier to implement than common compression algorithms in existing technologies. In terms of algorithm performance, this invention achieves lossless compression, and after decoding on the surface, it can accurately reconstruct the actual downhole measurement data.

[0031] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0032] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 A flowchart of a three-stage data processing method according to an embodiment of the present invention is shown;

[0034] Figure 2 The standard logging curve without compression is displayed;

[0035] Figure 3 A flowchart of a three-stage compression determination and storage method according to an embodiment of the present invention is shown;

[0036] Figure 4 A schematic diagram of a three-segment compression logging curve according to an embodiment of the present invention is shown;

[0037] Figure 5 A schematic diagram of a first compression rule according to an embodiment of the present invention is shown;

[0038] Figure 6 A schematic diagram of a second compression rule according to an embodiment of the present invention is shown;

[0039] Figure 7 A schematic diagram of a third compression rule according to an embodiment of the present invention is shown;

[0040] Figure 8 A schematic diagram of a three-segment data encapsulation method according to an embodiment of the present invention is shown.

[0041] In the accompanying drawings, the same parts use the same reference numerals. Also, the drawings are not drawn to scale. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0043] Figure 1 A flowchart of a three-stage data processing method according to an embodiment of the present invention is shown.

[0044] like Figure 1 As shown, in step S101, according to the time channel order of the downhole data to be processed, the time spectrum data corresponding to each time channel is processed sequentially based on the first compression rule.

[0045] In one embodiment, the downhole data to be processed is the voltage amplitude digital signal output by the receiving coil of a transient electromagnetic resistivity logging instrument when completing a logging curve measurement task at a certain downhole depth measurement point within one acquisition cycle. Here, one acquisition cycle is evenly divided into multiple equal parts, each part is called a time channel, and the time spectrum data is the voltage amplitude digital signal output by the receiving coil at a certain moment in each time channel.

[0046] In one embodiment, the transient electromagnetic resistivity logging instrument includes an A / D conversion unit that converts the analog voltage amplitude measurement of the receiving coil into a digital voltage amplitude signal. Furthermore, the time spectrum data is a 24-bit digital voltage amplitude signal in binary format.

[0047] It should be noted that time spectrum data with other bit depths can also be processed using the three-segment data processing method provided by this invention. This invention does not limit the number of bit depths in time spectrum data.

[0048] In step S101, if any bit in a specific bit interval of the current time spectrum data is a first preset value, then the first compression rule is satisfied. Under the first compression rule, the current time spectrum data is determined to be compressible data. After removing the data in the specific bit interval of the current time spectrum data, the remaining data is stored in the first buffer area.

[0049] like Figure 1 As shown, in step S102, when the time spectrum data corresponding to a certain time channel satisfies the second compression rule, the time spectrum data corresponding to each time channel is processed sequentially based on the second compression rule, starting from the current time channel.

[0050] In step S102, if the current time spectrum data contains both the first preset value and the second preset value within a specific bit range, then the second compression rule is satisfied. Under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored in the second buffer.

[0051] like Figure 1 As shown, in step S103, when the time spectrum data corresponding to a certain time channel satisfies the third compression rule, the time spectrum data corresponding to each time channel is processed sequentially based on the third compression rule, starting from the current time channel.

[0052] In step S103, if any bit in a specific bit range of the current time spectrum data is the second preset value, then the third compression rule is satisfied. Under the third compression rule, the current time spectrum data is determined to be compressible data. After removing the data in the specific bit range of the current time spectrum data, the remaining data is stored in the third buffer.

[0053] Through such Figure 1 The compression judgment and compression processing process shown can divide an uncompressed standard logging curve into three segments. The first segment is processed using the first compression rule, the middle segment using the second compression rule, and the last segment using the third compression rule. This can remove noise and other interference signals in the downhole data to be processed, and achieve lossless compression while ensuring data accuracy, thereby improving the efficiency of data transmission.

[0054] Figure 2 This displays an uncompressed standard logging curve obtained from a transient electromagnetic resistivity logging instrument.

[0055] like Figure 2 As shown, the horizontal axis represents the data acquisition time t, and one acquisition cycle for a certain downhole depth measurement point is t. n One acquisition cycle t n It is then evenly divided into n equal parts, each part being called a time channel. A time channel is the most basic unit of data acquisition time, such as t1, t2…t n.

[0056] In one embodiment, the number of time channels is determined by balancing the accuracy requirements of the logging task with the actual downhole storage capacity, wherein the number of time channels is 200-400. Specifically, a larger number of time channels indicates more dense data acquisition from the receiving coil, resulting in more data and a more realistic and accurate description of the logging curve. However, this also leads to a larger amount of data to be stored or transmitted, causing risks such as transmission system instability, data jamming, or code leakage. The need for more downhole storage space also increases the risk of excessively long instruments. Therefore, unilaterally pursuing a large number of time channels is not advisable. Under the premise of ensuring data acquisition accuracy, the appropriate range for the number of time channels is 200-400, preferably 200.

[0057] like Figure 2 As shown, the vertical axis represents the voltage amplitude V acquired during data acquisition. For the first time channel t1, the voltage amplitude acquired and output by the receiving coil of the transient electromagnetic resistivity logging instrument is labeled ε1. Correspondingly, for the second time channel t2, the voltage amplitude acquired and output by the receiving coil of the transient electromagnetic resistivity logging instrument is labeled ε2, ..., and so on for the nth time channel t... n The voltage amplitude acquired and output by the receiving coil of the transient electromagnetic resistivity logging instrument is denoted as ε. n .

[0058] from Figure 2 It can be seen that at the first time t1, the voltage amplitude ε1 collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is the largest. As time goes on, that is, as the time channel moves forward, the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument gradually decreases. In other words, the curve gradually decays from high to low. Ideally, the logging curve measured by the transient electromagnetic resistivity logging instrument is a monotonically decreasing curve within a period of one depth measurement point.

[0059] against Figure 2 The logging curve shown, without compression, stores the 24-bit voltage amplitude digital signal of each time channel in a 3-byte memory unit, simply denoted as "×××", indicating that each of the 24 bits in all three bytes may be 1 or 0; the high 8 bits are stored in one byte, the middle 8 bits are stored in one byte, and the low 8 bits are stored in one byte, each byte is represented by an "×", indicating that each of the 8 bits may be 1 or 0.

[0060] like Figure 2The positive decay logging curve shown typically has the largest time spectrum data in the first time channel (t1). In its corresponding 3-byte storage unit, the 8 bits of the high byte should be 11111111, which is denoted as "1". Any 1 bit of the 8 bits of the middle byte may be 1 or 0, which is denoted as "×". Any 1 bit of the 8 bits of the low byte may be 1 or 0, which is denoted as "×".

[0061] like Figure 2 As shown, the 24-bit voltage amplitude digital signal of the second time channel (t2) is smaller than the voltage amplitude of the first time channel. In its corresponding 3-byte storage unit, the 8 bits of the high byte are still 11111111, which is recorded as "1". Any 1 bit of the 8 bits of the middle byte may be 1 or 0, which is recorded as "×". Any 1 bit of the 8 bits of the low byte may be 1 or 0, which is recorded as "×".

[0062] As the number of time channels increases, the voltage amplitude received within a time channel gradually decreases. In the corresponding 3-byte storage unit, the 8 bits of the high byte will no longer be "1", and the low bits of the high 8 bits will begin to show 0, which is "×".

[0063] As the time channels continue to increase, the voltage amplitude received within each time channel gradually decreases. In the corresponding 3-byte storage unit, the 8 bits of the high byte will no longer contain 1s, becoming 00000000. The time spectrum data stored after this time channel will be recorded as "0" because the 8 bits of the high byte become 00000000. The high, medium, and low bytes can be represented as "0××".

[0064] In response to the actual curve shape of logging curves from transient electromagnetic resistivity logging instruments, this invention presents a novel three-segment data compression method that is better adapted to downhole logging instruments compared to common compression algorithms in existing technologies.

[0065] Figure 3 A flowchart of a three-stage compression determination and storage method according to an embodiment of the present invention is shown.

[0066] like Figure 3 As shown, 24-bit A / D data output by the transient electromagnetic resistivity logging instrument is collected in the order of time channels to define time channels and obtain time spectrum data (24-bit voltage amplitude digital signal) corresponding to the current time channel.

[0067] If any of the high 8 bits of the current time spectrum data is 1, then the first compression rule is satisfied. Under the first compression rule, the current time spectrum data is determined to be compressible data. After removing the 1s from the high 8 bits of the current time spectrum data, the remaining data is stored in the first buffer in 2 bytes.

[0068] If the high 8 bits of the current time spectrum data contain both 1 and 0, then the second compression rule is satisfied. Under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored into the second buffer in 3-byte blocks.

[0069] If any of the high 8 bits of the current time spectrum data is 0, then the third compression rule is satisfied. Under the third compression rule, the current time spectrum data is determined to be compressible data. After removing the 0s from the high 8 bits of the current time spectrum data, the remaining data is stored in the third buffer in 2 bytes.

[0070] If the defined time track has been completed, the time track is determined to be finished, indicating that the entire measurement curve of the transient electromagnetic resistivity logging instrument has been completely stored in the designated buffer in the predetermined format.

[0071] Figure 4 A schematic diagram of a three-segment compression logging curve according to an embodiment of the present invention is shown.

[0072] like Figure 4 As shown, based on the monotonically decreasing characteristic of the logging curve, there exists a time channel u. The time spectrum curves before the time channel u are all set to "1××". At the same time, there exists a time channel d. The time spectrum curves between the time channel u and the time channel d are set to "×××". The time spectrum curves after the time channel d are all set to "0××".

[0073] Adopting such Figure 3 The three-stage compression method shown describes the compression storage method for a single logging curve as follows: In the first to u time channels, the first compression rule is used, and the "1" in the high byte is removed in each time channel, leaving only the middle and low 2 bytes; in the u to d time channels, the second compression rule is used, and 3 bytes are stored in each time channel; in the d to n time channels, the third compression rule is used, and the "0" in the high byte is removed in each time channel, leaving only the middle and low 2 bytes.

[0074] Practice has shown that after implementing three-stage data compression, the data compression rate can reach 25-30%, which is lossless data compression.

[0075] Figure 5 , Figure 6 , Figure 7 A schematic diagram of a first compression rule, a second compression rule, and a third compression rule according to an embodiment of the present invention is shown.

[0076] Three-segment data compression can be understood as dividing the entire logging curve into three parts: the front segment, the middle segment, and the rear segment. In the front and middle segments, the useful signal in the signal is stronger, while the noise and other interference signals are weaker. The useful signal in the signal is the main contributor, so the front and middle segment signals play a major role in the accuracy of data extraction and data analysis.

[0077] For the front end, the signal is strongest. Each time channel acquires a 24-bit digital signal of voltage amplitude, with each of the high 8 bits being 1, i.e., 11111111. The values ​​of the middle 8 bits and the low 8 bits are both in the range of 11111111 to 00000000.

[0078] At this point, the high 8 bits (1201) are determined to be in "1" format, while the middle 8 bits and low 8 bits are determined to be in "×" format. Based on the first compression rule, the high 8 bits of the time spectrum data for this time channel are removed, and the data is stored in the designated buffer in a 2-byte format ("1××"). Figure 5 As shown.

[0079] For the middle section, the signal is stronger. Each time channel acquires a 24-bit digital signal of voltage amplitude. The value range of the high 8 bits is 11111110~00000001, while the value range of the middle 8 bits and the low 8 bits is still 11111111~00000000.

[0080] At this point, the high 8 bits (1204), middle 8 bits, and low 8 bits are all determined to be in "×" format. Based on the second compression rule, the time spectrum data of this time channel is stored in the designated buffer in the format of "×××" (3 bytes). Figure 6 As shown.

[0081] For the latter part, the signal is weaker, and the high 8 bits of the time spectrum data collected in each time channel are 00000000.

[0082] At this point, the high 8 bits are determined to be in "0" format, while the middle 8 bits and low 8 bits are still determined to be in "×" format. Based on the third compression rule, the high 8 bits of the time spectrum data for this time channel are removed, and the data is stored in the designated buffer in the format of "0××" (2 bytes). Figure 7 As shown.

[0083] In the latter part, the useful signal in the signal gradually weakens, while noise and other interference signals become the main contributors. Therefore, eliminating meaningless 0 bytes has no impact on the measurement accuracy of transient electromagnetic resistivity logging instruments.

[0084] Figure 8 A schematic diagram of a three-segment data encapsulation method according to an embodiment of the present invention is shown.

[0085] For a transient electromagnetic resistivity logging curve, this invention provides a data encapsulation method, which is used in conjunction with a three-segment data compression and storage method. Specifically, the data in the first, second, and third buffers are encapsulated as a whole to obtain encapsulated data corresponding to the downhole data to be processed. The acquired downhole temperature data, downhole magnetic positioning data, and downhole gamma data are processed and compiled into standardized data, which is then encapsulated to obtain downhole environment encapsulated data. The encapsulated data and the downhole environment encapsulated data are merged into a single data stream and transmitted to the surface via a preset bus.

[0086] In one embodiment, before conducting formal logging, the number of instruments to be run downhole and the logging curve measurement tasks need to be determined based on logging requirements. In one embodiment, if it is necessary to provide transient electromagnetic resistivity logging data at different detection depths simultaneously, at least two transient electromagnetic resistivity logging instruments, one for shallow detection and one for deep detection, must be run down simultaneously. Furthermore, if it is necessary to complete both casing flaw detection and through-casing measurement tasks, then one transient electromagnetic resistivity logging instrument needs to complete at least four logging curve measurement tasks, that is, provide four logging curves, namely the casing flaw detection ε received when the transmitting coil is forward-facing. s and the through-sleeve measurement curve ζ s ε of the sleeve flaw detection received when the transmitting coil transmits in reverse s 'and the casing measurement curve ζ s Furthermore, a suitable acquisition cycle for the logging depth measurement point is set. Within this acquisition cycle, each transient electromagnetic resistivity logging instrument completes a full-time channel measurement of four transient electromagnetic resistivity curves.

[0087] In one embodiment, for shallow-depth transient electromagnetic resistivity logging instruments, four transient electromagnetic resistivity logging curves with shallow depths are generated, namely ε s and ε s ',ζ s and ζ s ', where ε s and ζ s The curves for sleeve flaw detection and through-sleeve measurement received when the transmitting coil is transmitting in the forward direction are ε. s 'and ζ s 'The curves of sleeve flaw detection and through-sleeve measurement received when the transmitting coil transmits in reverse.'

[0088] In one embodiment, for deep-penetrating transient electromagnetic resistivity logging instruments, four transient electromagnetic resistivity logging curves with varying depths are also generated, labeled ε. d and ε d ',ζ d and ζ d '.

[0089] In summary, if it is necessary to simultaneously provide transient electromagnetic resistivity logging data at different depths and to complete both casing flaw detection and through-casing measurement, then the following tasks are required: shallow exploration co-excitation time spectrum curves ε with formation resistivity signals as the main feature. s and the time spectrum curve ζ, which is mainly characterized by the bushing signal. s The time spectrum curve ε of shallow probe reverse excitation, characterized primarily by formation resistivity signals. s 'and the time spectrum curve ζ, which is mainly characterized by the bushing signal' s '; The time spectrum curve ε of deep exploration co-excitation with formation resistivity signal as the main feature.' d and the time spectrum curve ζ, which is mainly characterized by the bushing signal. d The time spectrum curve ε of deep-penetration reverse excitation, characterized primarily by formation resistivity signals. d 'and the time spectrum curve ζ, which is mainly characterized by the bushing signal' d There are a total of 8 curve data.

[0090] To save time, this invention integrates the data streams from two transient electromagnetic resistivity logging instruments into a single data stream for transmission to the surface. Therefore, to transmit or store information for a single downhole depth measurement point, at least eight time-spectrum curves from two transient electromagnetic resistivity logging instruments must be transmitted or stored.

[0091] like Figure 8 As shown, the downhole data to be processed generated by any transient electromagnetic resistivity logging instrument belongs to the curve ζ. s According to the first compression rule, the data in the first segment needs to be compressed. After removing the high-order byte "1" and compressing, it is sent to the first buffer for data encapsulation; this belongs to the curve ζ. s According to the second compression rule, the middle segment of data is not compressed and is directly sent to the second buffer for data encapsulation; this belongs to the curve ζ. s According to the third compression rule, the data in the latter part needs to be compressed. After removing the high-order byte "0" and compressing, it is sent to the third buffer for data encapsulation, and then the curve ζ is processed. s All the data is encapsulated as a whole to form Encapsulated Data 1.

[0092] like Figure 8 As shown, at the same time, the downhole data to be processed generated by any set of transient electromagnetic resistivity logging instruments belongs to the curve ε s According to the first compression rule, the preceding data needs to be compressed. After removing the high-order byte "1" and compressing, it is sent for data encapsulation; this belongs to curve ε. s According to the second compression rule, the middle section of data is not compressed and is directly sent for data encapsulation; this belongs to the curve ε. sAccording to the third compression rule, the data in the latter part needs to be compressed. After removing the high-order byte "0" and compressing, it is sent for data encapsulation, and then the curve ε is calculated. s All the data also needs to be encapsulated as a whole to form Encapsulated Data 2.

[0093] like Figure 8 As shown, similarly, for any set of transient electromagnetic resistivity logging instruments, the downhole data to be processed belongs to the curve ζ. s 'and curve ε s The data is also compressed in three stages and encapsulated as a whole, forming encapsulated data 3 and encapsulated data 4.

[0094] like Figure 8 As shown, the collected temperature, magnetic positioning, and gamma parameters are processed and compiled into standardized data. This data is not compressed and is directly encapsulated into encapsulated 0 data.

[0095] Simultaneously, four logging data curves collected from a depth measurement point of another transient electromagnetic resistivity logging instrument were encapsulated and labeled as data encapsulation 5 to data encapsulation 8.

[0096] Data from four shallow-detection transient electromagnetic resistivity logging curves and four deep-detection transient electromagnetic resistivity logging curves were encapsulated and labeled as data encapsulations 1 to 8. These data encapsulations 1 to 8 were further encapsulated to form a single data stream. Data was sent to the transmission module via the CAN bus according to the data stream pattern. The CAN bus divided the measurement data of the data stream into 450 to 600 standard frames according to the CAN bus format. Simultaneously, the collected temperature, magnetic positioning, and gamma parameters were processed, compiled into standardized data, encapsulated into data encapsulation 0, and incorporated into the CAN data stream.

[0097] The collected temperature, magnetic positioning, and gamma parameters provide logging depth correspondence for the transient electromagnetic resistivity downhole instrument logging data, display the casing coupling position inside the casing well, and provide gamma measurement data inside the casing. Since the gamma curves measured before and after the casing are not affected by the casing, by comparing the measured gamma curve inside the casing with the gamma curve before the casing, the depth correspondence can be further established. At the same time, a one-to-one correspondence relationship can be established between the casing and the formation outside the casing.

[0098] The transmission module transmits the CAN data stream to the surface via the AMI bus in AMI mode, forming an AMI data stream. This AMI data stream is received by the surface decompression unit, which decompresses it according to a compression algorithm, restoring it to a standard format of lossless data for interpretation and display. This results in formation, wellbore, or casing information that is easily readable or identifiable by drilling or logging engineers. Practice shows that the three-stage compression algorithm reduces the total transmission time of the CAN mode data stream from 120ms to no more than 90ms, and the total transmission time of the AMI mode data stream from 400ms to no more than 300ms.

[0099] Due to the implementation of data compression, the transmission time of AMI is significantly reduced. If three-stage data compression is used, the transmission time of AMI for a depth measurement point is no more than 300ms, the data compression rate can reach 25-30%, and the data loss rate is 100%.

[0100] For example Figure 2 The uncompressed standard logging curve shown contains at least 200 time channels, each with a 24-bit voltage amplitude digital signal. If each 24-bit voltage amplitude digital signal is allocated a 3-byte storage unit, then the storage capacity of one logging curve is at least 600 bytes. Accordingly, the storage capacity of 8 time spectrum curves is at least 4800 bytes. If a three-segment compression is used, the total capacity is no more than 3600 bytes.

[0101] This invention compresses eight logging curves from downhole near-field and far-field transient electromagnetic resistivity logging instruments. While maintaining the measurement accuracy of the downhole logging instruments, it reduces the amount of downhole logging data uploaded and improves the transmission capacity of the transmission channel. Implemented in production wells, this lossless data compression increases the speed of downhole data upload, reduces the pressure on the communication channel, and improves logging timeliness, providing technical support for data interpretation and map production.

[0102] The three-stage data processing method provided by this invention can also be used in conjunction with a computer-readable storage medium. The storage medium stores a computer program, and executing the computer program runs the three-stage data processing method. The computer program can execute computer instructions, which include computer program code. The computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc.

[0103] Computer-readable storage media can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0104] It should be noted that the contents of computer-readable storage media may be appropriately added to or subtracted from the contents according to the requirements of legislation and patent practice in a jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media may not include electrical carrier signals and telecommunication signals.

[0105] Furthermore, this invention also provides a three-stage data processing device that executes a three-stage data processing method, comprising: a first compression rule module, a second compression rule module, and a third compression rule module. The first compression rule module is used to process the time spectrum data corresponding to each time channel sequentially according to the time channel order of the downhole data to be processed, based on the first compression rule. The second compression rule module is used to process the time spectrum data corresponding to each time channel sequentially, starting from the current time channel, based on the second compression rule, if the time spectrum data corresponding to a certain time channel satisfies the second compression rule. The third compression rule module is used to process the time spectrum data corresponding to each time channel sequentially, starting from the current time channel, based on the third compression rule, if the time spectrum data corresponding to a certain time channel satisfies the third compression rule.

[0106] In summary, this invention provides a three-stage data processing method. In terms of its construction approach, this invention does not adopt the statistical-based or dictionary-based compression approaches commonly used in existing technologies. Instead, it tailors a new three-stage data compression and encapsulation method based on the actual conditions of downhole logging instrument measurement curves. Compared to common compression algorithms in existing technologies, this method is better adapted to downhole logging instruments. Regarding the algorithm content, this invention does not require complex algorithmic processes, making it simpler and easier to implement than common compression algorithms in existing technologies. In terms of algorithm performance, this invention achieves lossless compression, and after decoding on the surface, it can accurately reconstruct the actual downhole measurement data.

[0107] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should be extended to equivalent substitutions of these features as understood by those skilled in the art. It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0108] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0109] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0110] Certain terms are used throughout this application to refer to specific system components. As those skilled in the art will recognize, the same components may often be referred to by different names, and therefore this application is not intended to distinguish those components that differ only in name and not in function. In this application, the terms “comprise,” “include,” and “have” are used in an open-ended manner and should therefore be interpreted as meaning “including, but not limited to…”. Furthermore, the terms “substantially,” “materially,” or “approximately” as used herein refer to industry-accepted tolerances for the corresponding terms. The term “coupling,” as may be used herein, includes direct coupling and indirect coupling via additional components, elements, circuits, or modules, wherein, for indirect coupling, the intermediate component, element, circuit, or module does not alter the information of the signal but may adjust its current level, voltage level, and / or power level. Inferred coupling (e.g., one element is inferredly coupled to another element) includes direct and indirect coupling between two elements in the same manner as “coupling.”

[0111] The phrase "an embodiment" or "an embodiment" used in this specification means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, the phrase "an embodiment" or "an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0112] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

[0113] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in form and detail of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A three-stage data processing method, characterized in that, The method includes the following steps: According to the time sequence of the downhole data to be processed, the time spectrum data corresponding to each time channel is processed sequentially based on the first compression rule. If any bit in a specific bit interval of the current time spectrum data is a first preset value, then the first compression rule is satisfied. Under the first compression rule, the current time spectrum data is determined to be compressible data. After removing the data in the specific bit interval of the current time spectrum data, the remaining data is stored in the first buffer. When the time spectrum data corresponding to a certain time channel meets the second compression rule, the time spectrum data corresponding to each time channel is processed sequentially based on the second compression rule, starting from the current time channel. If the specific bit range of the current time spectrum data contains both the first preset value and the second preset value, the second compression rule is met. Under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored in the second buffer. When the time spectrum data corresponding to a certain time channel satisfies the third compression rule, starting from the current time channel, the time spectrum data corresponding to each time channel is processed sequentially based on the third compression rule. If any bit in the specific bit interval of the current time spectrum data is the second preset value, then the third compression rule is satisfied. Under the third compression rule, the current time spectrum data is determined to be compressible data. After removing the data in the specific bit interval of the current time spectrum data, the remaining data is stored in the third buffer.

2. The three-stage data processing method as described in claim 1, characterized in that, The downhole data to be processed is the digital signal of voltage amplitude output by the receiving coil of the transient electromagnetic resistivity logging instrument when completing a logging curve measurement task at a certain downhole depth measurement point within one acquisition cycle. One acquisition cycle is evenly divided into multiple equal parts, each part is called a time channel. The time spectrum data is the digital signal of voltage amplitude output by the receiving coil at a certain moment in each time channel. To balance the accuracy requirements of the logging task and the actual downhole storage capacity, the number of time channels is determined, which is 200-400.

3. The three-stage data processing method as described in claim 1, characterized in that, The method includes: The data in the first buffer, the second buffer, and the third buffer are encapsulated as a whole to obtain encapsulated data corresponding to the downhole data to be processed; The collected downhole temperature data, downhole magnetic positioning data, and downhole gamma data are processed and compiled into standardized data, which are then packaged to obtain downhole environment packaged data. The encapsulated data corresponding to the downhole data to be processed and the downhole environment encapsulated data are merged into a single data stream and transmitted to the surface via a preset bus.

4. The three-stage data processing method as described in claim 1, characterized in that, When the time spectrum data is a 24-bit digital signal of voltage amplitude, the method includes: If any of the high 8 bits of the current time spectrum data is 1, then the first compression rule is satisfied. Under the first compression rule, the current time spectrum data is determined to be compressible data. After removing the 1s from the high 8 bits of the current time spectrum data, the remaining data is stored in the first buffer in 2 bytes. If the high 8 bits of the current time spectrum data contain both 1 and 0, then the second compression rule is satisfied. Under the second compression rule, the current time spectrum data is determined to be incompressible data, and the current time spectrum data is directly stored into the second buffer in 3 bytes. If any of the high 8 bits of the current time spectrum data is 0, then the third compression rule is satisfied. Under the third compression rule, the current time spectrum data is determined to be compressible data. After removing the 0s from the high 8 bits of the current time spectrum data, the remaining data is stored in the third buffer in 2-byte blocks.

5. A three-stage data processing method as described in any one of claims 1-4, characterized in that, The method includes: Determine the number of instruments to be deployed. If it is necessary to provide transient electromagnetic resistivity logging data at different depths simultaneously, at least two transient electromagnetic resistivity logging instruments, one for shallow exploration and one for deep exploration, must be deployed at the same time. The logging curve measurement task is determined. If the two tasks of casing inspection and through-casing measurement need to be completed, a transient electromagnetic resistivity logging instrument shall provide at least 4 logging curves, namely the casing inspection and through-casing measurement curves received when the transmitting coil is emitted in the forward direction, and the casing inspection and through-casing measurement curves received when the transmitting coil is emitted in the reverse direction.

6. A storage medium, characterized in that, It includes a series of instructions for performing the method steps as described in any one of claims 1-5.

7. A three-stage data processing device, characterized in that, The apparatus for performing the method as described in any one of claims 1-5 comprises: The first compression rule module is used to process the time spectrum data corresponding to each time channel in sequence according to the time channel order of the downhole data to be processed, based on the first compression rule; The second compression rule module is used to process the time spectrum data corresponding to each time channel sequentially based on the second compression rule, starting from the current time channel, when the time spectrum data corresponding to a certain time channel meets the second compression rule. The third compression rule module is used to process the time spectrum data corresponding to each time channel sequentially based on the third compression rule, starting from the current time channel, when the time spectrum data corresponding to a certain time channel meets the third compression rule.

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