阅读说明：本技术 地面浅井微地震采集实时监控系统及快速定位事件方法 (Ground shallow well micro-seismic acquisition real-time monitoring system and rapid event positioning method ) 是由 董健 李守才 姜宇东 袁昊 于 2018-08-28 设计创作，主要内容包括：本发明提供了一种地面浅井微地震采集实时监控系统及快速定位事件方法,属于地震勘探采集领域。该地面浅井微地震采集实时监控系统包括：检波点和云服务器；每个检波点分别赋予检波点号,每个检波点包括：一个检波器和与其连接的单点采集设备；所述检波器均埋设在地面浅井中,且均匀排布在水平井压裂段的两侧；所有单点采集设备通过无线方式与云服务器连接。利用本发明能够有效减少数据传输量,将数据传输效率提高90％以上,可在地面浅井微地震检测过程中快速对事件进行提取,提高数据采集处理的实时性,实时形成处理结果；本发明为油田动态监测提供一种有效的事件提取方式。(The invention provides a real-time monitoring system for micro-seismic acquisition of a shallow well on the ground and a rapid event positioning method, and belongs to the field of seismic exploration and acquisition. This ground shallow well microseism gathers real-time monitoring system includes: a wave detection point and a cloud server; each detection point is respectively assigned with a detection point number, and each detection point comprises: a detector and a single point acquisition device connected with the detector; the detectors are buried in a ground shallow well and are uniformly distributed on two sides of a fracturing section of the horizontal well; and all the single-point acquisition equipment is connected with the cloud server in a wireless mode. By using the method, the data transmission quantity can be effectively reduced, the data transmission efficiency is improved by more than 90%, the events can be quickly extracted in the ground shallow well micro-seismic detection process, the real-time performance of data acquisition and processing is improved, and the processing result is formed in real time; the invention provides an effective event extraction mode for oil field dynamic monitoring.)

1. The utility model provides a shallow well microseism of ground gathers real-time monitoring system which characterized in that: the surface shallow well micro-seismic acquisition real-time monitoring system comprises: a wave detection point and a cloud server;

each detection point is respectively assigned with a detection point number, and each detection point comprises: a detector and a single point acquisition device connected with the detector;

the detectors are buried in a ground shallow well and are uniformly distributed on two sides of a fracturing section of the horizontal well;

and all the single-point acquisition equipment is connected with the cloud server in a wireless mode.

2. The surface shallow well micro-seismic acquisition real-time monitoring system of claim 1, characterized in that: the system comprises n x 4+4 detectors, wherein n is an integer obtained by integrating the kilometer number/2 of a horizontal well fracturing section upwards;

n uniformly distributed points are sequentially arranged from the left end point to the right end point of the horizontal well fracturing section, the n uniformly distributed points averagely divide the horizontal well fracturing section into n-1 sections, and the length of each section is L;

making a straight line perpendicular to the horizontal well fracturing section through each point, and arranging 4 detectors on the straight line, wherein 2 detectors are positioned on the upper side of the horizontal well fracturing section, 2 detectors are positioned on the lower side of the horizontal well fracturing section, and the 4 detectors on the same straight line are symmetrically distributed on the upper side and the lower side of the horizontal well fracturing section;

the outer side of the left end point of the horizontal well fracturing section is provided with 2 detectors, and the 2 detectors are symmetrically distributed on the upper side and the lower side of the left end extension line of the horizontal well fracturing section;

the outer side of the right end point of the horizontal well fracturing section is provided with 2 detectors, and the 2 detectors are symmetrically distributed on the upper side and the lower side of the right end extension line of the horizontal well fracturing section.

3. The surface shallow well micro-seismic acquisition real-time monitoring system of claim 2, wherein: the distance between 2 detectors positioned outside the left end point of the horizontal well fracturing section, the distance between 2 detectors positioned outside the right end point of the horizontal well fracturing section and the distance between 2 adjacent detectors positioned on the same straight line vertical to the horizontal well fracturing section are all 1-2 kilometers;

the distance from the intersection point of the connecting line of the 2 detectors positioned outside the left end endpoint of the horizontal well fracturing section and the left end extension line of the horizontal well fracturing section to the left end endpoint of the horizontal well fracturing section is L;

and the distance from the intersection point of the connecting line of the 2 detectors positioned outside the right end point of the horizontal well fracturing section and the right end extension line of the horizontal well fracturing section to the right end point of the horizontal well fracturing section is L.

4. The system for real-time monitoring and controlling microseism acquisition of shallow wells on the ground according to any one of claims 1 to 3, wherein: the detector adopts a three-component detector;

the buried depth of all detectors is: 40-100 m;

the single point acquisition device comprises:

GPS: for providing GPS time when storing data;

an AD converter: converting the analog signal collected by the detector into a digital signal;

mass storage: the digital signal is used for storing the digital signal converted by the AD converter;

the 3G/4G wireless transmission module: the method is used for realizing data intercommunication between the detection point and the cloud server.

5. The method for rapidly positioning the event by using the ground shallow well micro-seismic acquisition real-time monitoring system as claimed in any one of claims 1 to 4, is characterized in that: the method comprises the following steps:

(1) initializing equipment of each wave detection point;

(2) monitoring environmental noise at each wave detection point to obtain an environmental noise value; defining an event starting value by using the environmental noise value;

(3) each wave detection point carries out data acquisition, whether the event is confirmed once is judged according to the initial value of the event, if so, the wave detection point sends an event confirmation message to a cloud server, and the event confirmation message comprises: UTC time value and detection point number; the event confirmation message is not repeatedly sent within R seconds after the event confirmation message is sent; then, turning to the step (4); if not, returning to the step (3);

(4) the cloud server records and analyzes all received event confirmation messages, judges whether the event is a microseism event, if so, the step (5) is carried out, and if not, the step (4) is carried out

(5) Triggering one-time micro-seismic event data recovery by the cloud server: the cloud server sends the earliest UTC time value received in P seconds to all the detection points;

(6) all the wave detection points transmit data collected in a collection time period with the earliest UTC time value as the starting time to a cloud server according to the earliest UTC time value transmitted by the cloud server:

(7) the cloud server combines the data sent by all the detection points: and (4) combining all data sent by the detection points into a standard SEGD file from small to large according to the detection point numbers.

6. The method of claim 5, wherein: the operation of the step (1) comprises the following steps:

after a wave detector and single-point acquisition equipment of each wave detection point are electrified and initialized, data acquisition and time calibration are carried out by means of GPS second pulse of the single-point acquisition equipment;

generating a file for storing data according to every 1 second of the GPS time;

the file name of the file is as follows: UTC time + detection point number.

7. The method of fast positioning events according to claim 6, characterized by: and (3) monitoring the environmental noise at each detection point in the step (2), wherein the operation of obtaining the environmental noise value comprises the following steps:

each detection point averages the values collected by all sampling points in the environment monitoring time period, and the average value is used as the environmental noise value of the detection point;

the operation of defining an event start value by using the ambient noise value in step (2) includes:

defining N times the ambient noise value as the event onset value.

8. The method of fast positioning events according to claim 7, characterized by: the data acquisition of each wave detection point in the step (3) is performed, and the operation of judging whether the event is confirmed for one time according to the event initial value comprises the following steps:

and each wave detection point carries out data acquisition, and when the wave detection point monitors that the acquired values of the continuous M sampling points are greater than the initial value of the event, the wave detection point is determined to be one-time event confirmation, otherwise, the wave detection point is determined not to be one-time event confirmation.

9. The method of fast positioning events according to claim 8, characterized by: the operation of determining whether the event is a micro-seismic event in the step (4) includes:

and judging whether the event confirmation messages sent by more than Q detection points are received within P seconds, if so, judging the micro-seismic event, and if not, judging the micro-seismic event not to be one micro-seismic event.

10. The method of fast positioning events according to claim 9, characterized by: the numerical value of the environment monitoring time period, the numerical value of the acquisition time period, the value of N, the value of M, the value of P, the value of Q and the value of R are all set by the cloud server;

the value of N is set according to the signal-to-noise ratio or the number of events;

and the value of P is set according to the burial depth of the detector, the wave group speed and the distance between two farthest detection points on a straight line parallel to the horizontal well fracturing section.

Technical Field

The invention belongs to the field of seismic exploration and acquisition, and particularly relates to a real-time monitoring system for micro seismic acquisition of a shallow well on the ground and a rapid event positioning method.

Background

The surface shallow well micro-seismic acquisition is used as a novel acquisition technology, and has certain advantages: the detector is embedded in a shallow well on the ground, so that the attenuation of the surface layer to the weak microseism signals is effectively reduced, and the interference of environmental noise is avoided, thereby improving the energy and the signal-to-noise ratio of the weak microseism signals; the three-component detector is adopted for receiving, longitudinal and transverse wave signals can be received more completely, longitudinal and transverse wave fracturing micro-seismic information can be obtained and distinguished better through three-component synthesis and polarization analysis, and the improvement of positioning accuracy and data interpretation is facilitated. However, the application of the method has certain problems, mainly aiming at the real-time performance of fracturing, because the fracturing is sparsely arranged and the spacing distance is long, the use of wired transmission is difficult, the use of wireless transmission has the problems that the speed is seriously limited by the environment, the data volume is large (the time and the power consumption are large), and the like.

Disclosure of Invention

The invention aims to solve the problems in the prior art, provides a system for collecting and monitoring micro-earthquakes of a shallow well on the ground in real time and a method for quickly positioning events, and effectively solves the problem of the micro-earthquakes of the shallow well on the ground in practical application.

The invention is realized by the following technical scheme:

a system for real-time monitoring of surface shallow well microseismic acquisition, comprising: a wave detection point and a cloud server;

each detection point is respectively assigned with a detection point number, and each detection point comprises: a detector and a single point acquisition device connected with the detector;

the detectors are buried in a ground shallow well and are uniformly distributed on two sides of a fracturing section of the horizontal well;

and all the single-point acquisition equipment is connected with the cloud server in a wireless mode.

The system comprises n x 4+4 detectors, wherein n is an integer obtained by integrating the kilometer number/2 of a horizontal well fracturing section upwards;

n uniformly distributed points are sequentially arranged from the left end point to the right end point of the horizontal well fracturing section, the n uniformly distributed points averagely divide the horizontal well fracturing section into n-1 sections, and the length of each section is L;

making a straight line perpendicular to the horizontal well fracturing section through each point, and arranging 4 detectors on the straight line, wherein 2 detectors are positioned on the upper side of the horizontal well fracturing section, 2 detectors are positioned on the lower side of the horizontal well fracturing section, and the 4 detectors on the same straight line are symmetrically distributed on the upper side and the lower side of the horizontal well fracturing section;

the outer side of the left end point of the horizontal well fracturing section is provided with 2 detectors, and the 2 detectors are symmetrically distributed on the upper side and the lower side of the left end extension line of the horizontal well fracturing section;

the outer side of the right end point of the horizontal well fracturing section is provided with 2 detectors, and the 2 detectors are symmetrically distributed on the upper side and the lower side of the right end extension line of the horizontal well fracturing section.

The distance between 2 detectors positioned outside the left end point of the horizontal well fracturing section, the distance between 2 detectors positioned outside the right end point of the horizontal well fracturing section and the distance between 2 adjacent detectors positioned on the same straight line vertical to the horizontal well fracturing section are all 1-2 kilometers;

the distance from the intersection point of the connecting line of the 2 detectors positioned outside the left end endpoint of the horizontal well fracturing section and the left end extension line of the horizontal well fracturing section to the left end endpoint of the horizontal well fracturing section is L;

and the distance from the intersection point of the connecting line of the 2 detectors positioned outside the right end point of the horizontal well fracturing section and the right end extension line of the horizontal well fracturing section to the right end point of the horizontal well fracturing section is L.

The detector adopts a three-component detector;

the buried depth of all detectors is: 40-100 m;

the single point acquisition device comprises:

GPS: for providing GPS time when storing data;

an AD converter: converting the analog signal collected by the detector into a digital signal;

mass storage: the digital signal is used for storing the digital signal converted by the AD converter;

the 3G/4G wireless transmission module: the method is used for realizing data intercommunication between the detection point and the cloud server.

A method for quickly positioning events by utilizing the system comprises the following steps:

(1) initializing equipment of each wave detection point;

(2) monitoring environmental noise at each wave detection point to obtain an environmental noise value; defining an event starting value by using the environmental noise value;

(3) each wave detection point carries out data acquisition, whether the event is confirmed once is judged according to the initial value of the event, if so, the wave detection point sends an event confirmation message to a cloud server, and the event confirmation message comprises: UTC time value and detection point number; the event confirmation message is not repeatedly sent within R seconds after the event confirmation message is sent; then, turning to the step (4); if not, returning to the step (3);

(4) the cloud server records and analyzes all received event confirmation messages, judges whether the event is a microseism event, if so, the step (5) is carried out, and if not, the step (4) is carried out

(5) Triggering one-time micro-seismic event data recovery by the cloud server: the cloud server sends the earliest UTC time value received in P seconds to all the detection points;

(6) all the wave detection points transmit data collected in a collection time period with the earliest UTC time value as the starting time to a cloud server according to the earliest UTC time value transmitted by the cloud server:

(7) the cloud server combines the data sent by all the detection points: and (4) combining all data sent by the detection points into a standard SEGD file from small to large according to the detection point numbers.

The operation of the step (1) comprises the following steps:

after a wave detector and single-point acquisition equipment of each wave detection point are electrified and initialized, data acquisition and time calibration are carried out by means of GPS second pulse of the single-point acquisition equipment;

generating a file for storing data according to every 1 second of the GPS time;

the file name of the file is as follows: UTC time + detection point number

And (3) monitoring the environmental noise at each detection point in the step (2), wherein the operation of obtaining the environmental noise value comprises the following steps:

each detection point averages the values collected by all sampling points in the environment monitoring time period, and the average value is used as the environmental noise value of the detection point;

the operation of defining an event start value by using the ambient noise value in step (2) includes:

defining N times the ambient noise value as the event onset value.

The data acquisition of each wave detection point in the step (3) is performed, and the operation of judging whether the event is confirmed for one time according to the event initial value comprises the following steps:

and each wave detection point carries out data acquisition, and when the wave detection point monitors that the acquired values of the continuous M sampling points are greater than the initial value of the event, the wave detection point is determined to be one-time event confirmation, otherwise, the wave detection point is determined not to be one-time event confirmation.

The operation of determining whether the event is a micro-seismic event in the step (4) includes:

and judging whether the event confirmation messages sent by more than Q detection points are received within P seconds, if so, judging the micro-seismic event, and if not, judging the micro-seismic event not to be one micro-seismic event.

The numerical value of the environment monitoring time period, the numerical value of the acquisition time period, the value of N, the value of M, the value of P, the value of Q and the value of R are all set by the cloud server;

the value of N is set according to the signal-to-noise ratio or the number of events;

and the value of P is set according to the burial depth of the detector, the wave group speed and the distance between two farthest detection points on a straight line parallel to the horizontal well fracturing section.

Compared with the prior art, the invention has the beneficial effects that:

by using the method, the data transmission quantity can be effectively reduced, the data transmission efficiency is improved by more than 90%, the events can be quickly extracted in the ground shallow well micro-seismic detection process, the real-time performance of data acquisition and processing is improved, and the processing result is formed in real time; the invention provides an effective event extraction mode for oil field dynamic monitoring.

Drawings

FIG. 1 is a horizontal well fracturing section wave detection point arrangement method;

FIG. 2 is a flow chart of shallow well microseismic event acquisition.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

different from conventional micro-seismic acquisition, the invention effectively reduces the data transmission amount (can reduce more than 90% of invalid data amount), improves the real-time performance of data acquisition and processing and provides an effective event extraction mode for oil field dynamic monitoring by designing the ground shallow well micro-seismic real-time monitoring system facing the horizontal well fracturing section and the rapid event positioning method.

The invention mainly aims at the process of acquiring the micro seismic data of the ground shallow well of the fracturing section of the horizontal well, the geophone adopts three components, the buried depth is 40-100m, the geophone consists of (n x 4+4) demodulator probes, and n is the kilometer number of the fracturing section of the horizontal well/2 and is rounded upwards. Taking a section of horizontal well fracturing section shown in fig. 1 as an example, n in fig. 1 is 5, and 5 uniformly distributed points divide the horizontal well fracturing section into 4 sections. In figure 1, 24 detection points are arranged, the detection point numbers assigned to the detection points are 1-24 respectively, wherein the detection points 1 and 2 are positioned outside the left end endpoint of the horizontal well fracturing section, are symmetrically distributed on the upper and lower sides of the left end extension line of the horizontal well fracturing section, the detection points 23 and 24 are positioned outside the right end endpoint of the horizontal well fracturing section, are symmetrically distributed on the upper and lower sides of the right end extension line of the horizontal well fracturing section, the detection points 3, 4, 5 and 6 are positioned on a straight line perpendicular to the left end endpoint (namely, a first point), and are symmetrically distributed on the upper and lower sides of the horizontal well fracturing section, the detection points 7, 8, 9 and 10 are positioned on a straight line perpendicular to a second point, and are symmetrically distributed on the upper and lower sides of the horizontal well fracturing section, the detection points 11, 12, 13 and 14 are positioned on a straight line perpendicular to a third point, and are symmetrically distributed on the upper and lower sides of the horizontal well fracturing section, And the lower two sides are provided with No. 15, 16, 17 and 18 wave detection points which are positioned on a straight line vertical to the fourth point and are symmetrically distributed on the upper and lower two sides of the horizontal well fracturing section, and the No. 19, 20, 21 and 22 wave detection points are positioned on a straight line vertical to a right end point (namely, a fifth point) and are symmetrically distributed on the upper and lower two sides of the horizontal well fracturing section.

When the geophone layout is designed, the entire layout can cover the entire fracturing section as far as possible, and the geophone points are evenly distributed on two sides of the fracturing section. The spacing between each detector point is 1-2 km. Each wave detection point is provided with a single-point acquisition device, the acquisition device adopts the existing acquisition device and a 3G/4G wireless transmission module, the acquisition device has the functions of GPS, AD conversion, large-capacity storage and 3G/4G wireless transmission, and all the wave detection points are controlled by a cloud server through wireless communication.

As shown in fig. 2, after the power-on initialization of the demodulator probe device, data acquisition and time calibration are performed by means of GPS second pulse, and all data storage is performed in a second unit file according to GPS (UTC + demodulator probe number combined into a file name), that is, data in a 1-second time period of each GPS time forms a file, and the name of the file is UTC time + demodulator probe number.

And automatically analyzing the environmental noise of the wave detection point for 30s (the parameter is reset through the cloud server) before the collection is started, and averaging the numerical values of all sampling points (determined according to the sampling rate of the wave detector) in 30s, wherein the numerical value is the environmental noise of the wave detection point. When the subsequent sampling value of the detection point exceeds N times of the environmental noise (the parameter can be reset through the cloud server), the subsequent sampling value is defined as an event starting value, and a specific value is determined according to a specific signal-to-noise ratio (the value can be set to be larger when the signal-to-noise ratio is higher, and can be set to be smaller when the signal-to-noise ratio is lower, and the subsequent sampling value can be adjusted according to the number of events, and if the number of events is too small, the value can be reduced to obtain more possible small signal events. When the wave detection point monitors that the numerical value of 3 continuous sampling points (the parameter is reset through the cloud server) is greater than the initial numerical value of the event, the wave detection point determines an event confirmation, and sends an event confirmation message to the cloud server, wherein the event confirmation message comprises: the UTC time value + the detection point number are not repeatedly sent within 3s (the parameter can be reset through the cloud server) after the event confirmation message is sent once. The cloud server records and analyzes all received UTC time values and the detection point number, if 1S (the parameter can be reset through the cloud server), the time is mainly set according to the burial depth of the detector, the wave group speed (mainly referring to the average speed from a fractured stratum to a detector buried stratum, both P-wave and S-wave are considered), the farthest distance of the detection point (the distance between two detection points which are farthest away from each other on a straight line parallel to a horizontal well fracture section), the maximum value of the time is theoretically more than 3 (the parameter can be reset through the cloud server) event confirmation messages sent by the detection points in the shortest distance of the detection point divided by the speed with the smaller speed value in the P-wave and the S-wave), the cloud server determines the time as a micro-seismic event, triggers one-seismic event data recovery, sends the earliest UTC time value in the time period to all the detection points, and transmitting the 5s acquisition data with the time value as the starting time (the parameter can be reset by the cloud server) to the cloud server by all the wave detection points according to the UTC time value.

The above-described embodiment is only one embodiment of the present invention, and it will be apparent to those skilled in the art that various modifications and variations can be easily made based on the application and principle of the present invention disclosed in the present application, and the present invention is not limited to the method described in the above-described embodiment of the present invention, so that the above-described embodiment is only preferred, and not restrictive.