阅读说明：本技术 测井电缆长度校准方法 (Logging cable length calibration method ) 是由 张雷 芮学来 温金玉 冯伟 于 2019-11-07 设计创作，主要内容包括：本发明公开测井电缆长度校准方法,包括以下步骤：将多个套管通过接箍拼接在一起,并下入井中,测井电缆底部安装声波探管后下放至井中,采用测井仪将电缆进行下放并测井深,声波探管通过测井电缆连接地面的数据采集模块,数据采集模块连接数据处理显示模块。本发明的有益效果：电缆全程处于实际测井受力状态,使得校测结果既准确可靠又方便简单,能够实现测井深度与实际钻孔或地层深度的完美一致,为提高测井资料的地质应用效果奠定了坚实基础。(The invention discloses a method for calibrating the length of a logging cable, which comprises the following steps: a plurality of sleeves are spliced together through a coupling and enter a well, a sound wave exploring tube is installed at the bottom of a logging cable and then is placed into the well, the logging instrument is used for placing the cable and logging the depth of the well, the sound wave exploring tube is connected with a data acquisition module on the ground through the logging cable, and the data acquisition module is connected with a data processing and displaying module. The invention has the beneficial effects that: the whole process of the cable is in an actual logging stress state, so that the calibration and measurement result is accurate, reliable, convenient and simple, the logging depth can be perfectly consistent with the actual drilling depth or the actual stratum depth, and a solid foundation is laid for improving the geological application effect of logging data.)

1. The method for calibrating the length of the logging cable is characterized by comprising the following steps: splicing a plurality of sleeves together through a coupling, putting the sleeves into a well, arranging a sound wave probe at the bottom of a logging cable, then putting the logging cable into the well, putting the logging cable down by using a logging instrument and logging the depth of the well, connecting the sound wave probe with a data acquisition module on the ground through the logging cable, and connecting the data acquisition module with a data processing and displaying module; when the sound wave probe tube passes through the coupling, generating abnormity, selecting a section of depth, wherein the section of depth comprises a plurality of continuous casings, acquiring the depth of a casing coupling corresponding to a plurality of adjacent abnormal points, wherein the difference of the depths of the adjacent abnormal points is the depth of the casing, and adding the depths of the plurality of casings to obtain the sum of the depths of the section; and comparing the depth with the well depth measured by the logging cable, if the depth is the same as the well depth, calibrating the data, and if the data of the depth and the data of the well depth are deviated, acquiring the data by adopting the acoustic probe.

2. The method of claim 1, wherein a plurality of casing is encoded and measured prior to running the casing downhole, and wherein the plurality of measurements are averaged.

3. The method of claim 1, wherein the connections between individual casings are secured prior to running the casings downhole.

4. The method of claim 1, wherein a depth of 100 meters or more is selected for calibration.

5. The method of claim 1, wherein multiple depths are selected for multiple calibrations.

6. The method of claim 1, wherein the tool comprises a drum, a cable-arranging wheel, and a measuring wheel, the drum, the cable-arranging wheel, and the measuring wheel are spaced apart from each other, the logging cable is lowered into the well from the drum through the cable-arranging wheel and the measuring wheel, and the measuring wheel is provided with a counting device.

7. The method of claim 6, wherein a pinch roller is disposed at the bottom of the measuring wheel for pinching the logging cable.

8. The method for calibrating the length of the logging cable according to claim 1, wherein the data acquisition module is a surface acquisition instrument, and the data processing and displaying module is a computer.

Technical Field

The invention relates to a cable length calibration method, in particular to a novel method for calibrating the length of a logging cable.

Background

In a digital logging system of a coal field, depth data of a logging formal submission result is obtained by a depth measurement system shown in the following figure 1, and the data measured by the depth measurement system has a measurement error, wherein the error directly relates to whether important drilling parameters such as the depth of an underground coal rock stratum, a drilling inclination angle, an azimuth and the like are consistent with the actual stratum depth. Therefore, in the actual logging process, the logging depth data must be ensured to be accurate and consistent with the actual depth of the borehole (or the stratum).

However, in actual logging, the diameters of the measuring wheel and the cable are changed due to various reasons such as abrasion and mud skin adhesion, so that the measuring wheel and the cable cannot be perfectly matched, and a matching error between the counting depth of the instrument and the actual length of the cable is formed. This error must be accurately measured and calibrated by technical means in the well log data processing. This error in fit is always present with the logging process, usually due to wear of the measuring wheel and the cable and mud, mud and the like adhering to the cable during use.

The conventional calibration method:

step 1, on an open square, stopping a logging truck at one end of the square, measuring the length of 50 meters on the ground by using a steel ruler, and marking the two ends by using chalk;

step 2: pulling out the cable from a winch roller, measuring the cable by using a measuring mark on the land for 100 meters, and marking the two ends of the cable by using adhesive tapes;

and step 3: starting a winch pull-up cable, and setting a winch panel depth counter to zero when the first mark reaches the measuring wheel;

and 4, step 4: pulling the cable upwards continuously, wherein the cable is pulled backwards by manpower in the pulling process to keep the cable in a certain stress state so as to simulate the stress condition of the cable in the actual logging process in the borehole;

and 5: when the cable end mark reaches the same position of the measuring wheel, the winch stops running, records the number and calculates the length of the cable. The difference (positive or negative) between this value and 100 is the error between the actual length of the cable and the winch count length. This error value must be smoothed out during the log data processing to ensure that the depth of the log data is accurate.

The method for calibrating the length of the cable can be used for calibrating the length of the cable at any time and any place, but the defect is obvious, namely the cable is in a certain stress state by adopting manual pulling, the stress condition of the cable in the actual logging process cannot be completely simulated, and the cable is not in a stretched state when the cable is measured by a steel ruler on the ground, so that the cable calibration process has defects and large errors.

Furthermore, as in application No.: 201720510702.3, a novel logging cable length measuring device, discloses a novel logging cable length measuring device. Set up the counter base on the fixed bolster for location and fixed revolution counter, revolution counter upper portion has infrared emission and infrared receiver, is used for transmission and receiving infrared signal, utilizes the pulley rotation number of turns of revolution counter record, cable center to pulley center distance, can calculate the length that reachs the logging cable and transfer, and then the degree of depth of transferring of accurately confirming the probe. The utility model discloses a length measurement field is transferred to each item measuring instrument cable in mainly being applied to seismic underground fluid observation well. The technique still can not avoid the problem that wearing and tearing and attached mud skin lead to measurement error on measuring device and the cable.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to solve the problem that there is measuring error in the logging cable.

The invention solves the technical problems through the following technical means:

the method for calibrating the length of the logging cable comprises the following steps: splicing a plurality of sleeves together through a coupling, putting the sleeves into a well, arranging a sound wave probe at the bottom of a logging cable, then putting the logging cable into the well, putting the logging cable down by using a logging instrument and logging the depth of the well, connecting the sound wave probe with a data acquisition module on the ground through the logging cable, and connecting the data acquisition module with a data processing and displaying module; when the sound wave probe tube passes through the coupling, generating abnormity, selecting a section of depth, wherein the section of depth comprises a plurality of continuous casings, acquiring the depth of a casing coupling corresponding to a plurality of adjacent abnormal points, wherein the difference of the depths of the adjacent abnormal points is the depth of the casing, and adding the depths of the plurality of casings to obtain the sum of the depths of the section; and comparing the depth with the well depth measured by the logging cable, if the depth is the same as the well depth, calibrating the data, and if the data of the depth and the data of the well depth are deviated, acquiring the data by adopting the acoustic probe.

According to the invention, the lower end of the cable is connected with the acoustic probe, abnormal signals are generated at a coupling by the acoustic waves generated by the acoustic probe, the distance between the points of adjacent abnormal signals corresponds to the depth of a single casing, the length of the single casing is obtained, the sum of the adjacent single casings is compared with the well depth of the logging cable, and calibration is carried out; the whole process of the cable is in an actual logging stress state, so that the calibration and measurement result is accurate, reliable, convenient and simple, the logging depth can be perfectly consistent with the actual drilling depth or the actual stratum depth, and a solid foundation is laid for improving the geological application effect of logging data.

Preferably, a plurality of casings are encoded, measured and the plurality of measurements averaged prior to running the casing downhole. The length of the sleeve pipe must be measured accurately, and the calibration precision is improved.

Preferably, the connection between the casing and the casing is secured prior to running the casing downhole. In order to improve the accuracy of the calibration.

Preferably, a depth section of more than 100 meters is selected for calibration. In order to improve the accuracy of the calibration.

Preferably, multiple depths are selected for multiple calibrations. And selecting a plurality of depth sections for calibration work, so as to improve the calibration precision.

Preferably, the logging instrument comprises a winding drum, a cable arranging wheel and a measuring wheel which are arranged at intervals, the logging cable is placed into the well through the cable arranging wheel and the measuring wheel by the winding drum, and the measuring wheel is provided with a counting device.

Preferably, the bottom of the measuring wheel is provided with a pressing wheel used for pressing the logging cable.

Preferably, the data acquisition module is a ground acquisition instrument, and the data processing and displaying module is a computer.

The invention has the advantages that:

(1) according to the invention, the lower end of the cable is connected with the acoustic probe, abnormal signals are generated at a coupling by the acoustic waves generated by the acoustic probe, the distance between the points of adjacent abnormal signals corresponds to the depth of a single casing, the length of the single casing is obtained, the sum of the adjacent single casings is compared with the well depth of the logging cable, and calibration is carried out; the whole process of the cable is in an actual logging stress state, so that a calibration result is accurate, reliable, convenient and simple, the logging depth can be perfectly consistent with the actual drilling depth or the actual stratum depth, and a solid foundation is laid for improving the geological application effect of logging data;

(2) the calibration precision is improved by the preparation before measurement, such as measuring the length of the sleeve for multiple times, and stabilizing the connection between the sleeves;

(3) the calibration precision can also be improved by selecting a depth section of more than 100 meters for calibration and selecting multiple sections for calibration for multiple times.

Drawings

FIG. 1 is a schematic diagram of a method for calibrating a length of a logging cable according to an embodiment of the invention;

figure 2 is a plot of casing depth versus acoustic wave.

Reference numbers in the figures: the device comprises a logging instrument 1, a measuring wheel 11, a toothed belt 12, a pressing wheel 13, a logging cable 14, a cable arranging wheel 15 and a winding drum 16;

a sound wave probe 2, a sleeve 3 and a coupling 31.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the logging instrument 1 includes a winding drum 16, a cable arranging wheel 15 and a measuring wheel 11 which are arranged at intervals, a pressing wheel 13 for pressing a logging cable 14 is arranged at the bottom of the measuring wheel 11, the logging cable 14 is placed into a well after passing through the cable arranging wheel 15 and the measuring wheel 11 by the winding drum 16, a counting device such as a photoelectric encoder is arranged on the measuring wheel 11, if the circumference of the measuring wheel is 0.5m, during the moving process of the logging cable 14, the logging cable 14 drives the measuring wheel 11 to rotate due to the effect of the pressing wheel 13, so that the length of the logging cable 14 can be measured. The photoelectric encoder can record the number of turns of the measuring wheel and send a signal to an instrument which can display the length, for example, the instrument panel counts for 0.5 meter when the measuring wheel 11 rotates for one turn, and the instrument panel counts for 1 meter when the measuring wheel 11 rotates for another turn. In this embodiment, the bottom of the logging cable 14 is provided with the sonic probe 2. This embodiment only shows a logging tool capable of measuring the depth of a well, and other logging devices may be used.

The method for calibrating the length of the logging cable by adopting the device comprises the following steps: before the casing 3 goes into the well, a plurality of casings 3 are coded and measured, a plurality of measured values are averaged, the length of the casing 3 must be measured accurately, the calibration precision is improved, and the required connection between the casing 3 and the casing 3 is stable before the casing 3 goes into the well.

The method comprises the following steps that a plurality of casings 3 are spliced together through a coupling 31 and are placed in a well, a sound wave probe 2 is installed at the end of a logging cable 14 and then is placed in the well for logging, the sound wave probe 2 is connected with a data acquisition and processing module on the ground, in the process of placing the logging cable, the sound wave probe 2 connects data with the data acquisition module on the ground through the logging cable in real time, the data acquisition module is connected with a data processing and displaying module, and the data processing and displaying module can establish a two-dimensional relation graph of a change curve graph and depth of sound waves through logging software and can visually display the condition of the sound waves; the data acquisition module can be a ground acquisition instrument, the data processing and displaying module can be a computer, the data processing and displaying module can be processed through logging software in the computer, the displaying device can be a display screen of the computer, and the technical personnel in the field can select and use instruments and software in the prior art.

When the sound wave probe 2 passes through the casing coupling 31, the sound wave time difference is obviously increased (abnormal), and the sound wave curves of other parts in the casing 2 are kept smooth; acquiring the depths of a plurality of adjacent abnormal points corresponding to the casing coupling 31, wherein the difference between the depths of the adjacent abnormal points is the depth of the casing, and adding the depths of the plurality of casings to obtain the sum of the depths of the section; and comparing the depth with the well depth measured by the logging cable, if the depth is the same as the well depth, calibrating the data, and if the data of the depth and the data of the well depth are deviated, acquiring the data by adopting the acoustic probe.

As shown in fig. 2, the total depth of the casing 2 is 436.85m, a depth of the lowest section is selected, the depth of the section comprises three continuous single casings, the section generates 3 peaks (i.e. abnormal points), and the depths corresponding to the depths are 427.5m, 419m and 410.75m, respectively, so that the difference between the depths of the adjacent abnormal points is the depth of the single casing: 8.25m, 8.5m and 9.35m respectively, and the total length of the section is 26.10 m; 26.10m was compared to the well depth measured by the wireline.

Errors are generated at deeper positions, and it is more appropriate to select a depth section of more than 100 meters for calibration.

Or selecting multiple sections of depths and carrying out multiple times of calibration. And selecting a plurality of depth sections for calibration work, so as to improve the calibration precision.

According to the invention, the lower end of a logging cable 14 is connected with an acoustic probe 2, abnormal signals are generated at a coupling 31 by acoustic waves generated by the acoustic probe 2, the distance between the points of adjacent abnormal signals corresponds to the depth of a single casing, the length of the single casing is obtained, the sum of the adjacent single casings is compared with the well depth of the logging cable, and calibration is carried out; the whole course of the logging cable 14 is in an actual logging stress state, so that the calibration and measurement result is accurate, reliable, convenient and simple, the logging depth can be perfectly consistent with the actual drilling depth or the actual stratum depth, and a solid foundation is laid for improving the geological application effect of logging data.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.