CN-121827775-B - Fracturing method and device based on pulse gas-liquid combination, storage medium and equipment

CN121827775BCN 121827775 BCN121827775 BCN 121827775BCN-121827775-B

Abstract

The invention discloses a fracturing method and device based on pulse gas-liquid combination, a storage medium and equipment, relates to the technical field of coal seam exploitation, and mainly aims to solve the problem of low fracturing effectiveness of the traditional low-permeability coal seam. The method mainly comprises the steps of controlling a pulse gas generator to conduct gas fracturing on a target operation area in a three-stage independent ignition pulse mode according to gas fracturing control parameters adjusted through real-time feedback to form a main fracture network, identifying at least one fracturing weak response area and hydraulic fracturing control parameters of the fracturing weak response area according to real-time fracturing data formed by the main fracture network, controlling a jet device according to the hydraulic fracturing control parameters to conduct directional hydraulic fracturing on the fracturing weak response area to form a secondary fracture network, and controlling an injection allocation valve group to inject a supporting mixture into the main fracture network and the secondary fracture network after hydraulic fracturing on the fracturing weak response area is completed. The method is mainly used for fracturing the coal seam.

Inventors

ZHANG CHUANJIU
HOU PENG
LIU QUANSHENG
WU ZHIJUN
SUN LEI
LI PENG
LI XUANLIANG

Assignees

国能神东煤炭集团有限责任公司
中国神华能源股份有限公司神东煤炭分公司
武汉大学

Dates

Publication Date: 20260512
Application Date: 20260311

Claims (8)

1. The fracturing method based on pulse gas-liquid combination is characterized by comprising the following steps of: According to the gas fracturing control parameters which are fed back and adjusted in real time, controlling a pulse gas generator to carry out gas fracturing on a target operation area in a three-stage independent ignition pulse mode so as to form a main fracture network in the target operation area; Identifying at least one fracturing weak response zone and hydraulic fracturing control parameters of the fracturing weak response zone according to real-time fracturing data after the formation of the main fracture network, controlling a jet device by using the hydraulic fracturing control parameters, and carrying out directional hydraulic fracturing on the fracturing weak response zone so as to form a secondary fracture network on the basis of the main fracture network; After hydraulic fracturing of the fracturing weak response zone is completed, a propping mixture is injected into the main fracture network and the secondary fracture network by controlling a distribution injection valve group so as to complete fracturing of the target operation zone; The gas fracturing control parameters adjusted according to real-time feedback control the pulse gas generator to perform gas fracturing on a target operation area in a three-stage independent ignition pulse mode, and the gas fracturing control parameters comprise: In the gas fracturing process, microseismic parameters and acoustic parameters are collected in real time, the gas fracturing control parameters are calculated and updated in real time according to the microseismic parameters and the acoustic parameters, and the pulse gas generator is controlled to perform gas fracturing on the target operation area according to the updated gas fracturing control parameters; the gas fracturing control parameters comprise primary ignition pressure, secondary ignition pressure, tertiary pressure maintaining time, secondary ignition time sequence interval and secondary and tertiary ignition time sequence interval, the microseismic parameters comprise microseismic event frequency and microseismic magnitude, the sound wave parameters comprise sound wave signal continuity and sound wave intensity, and the calculation process of the gas fracturing control parameters comprises the following steps: The method comprises the steps of calculating to obtain primary ignition pressure according to the frequency of the microseismic event and the microseismic level, calculating to obtain secondary ignition pressure according to the sound wave intensity, calculating to obtain tertiary pressure maintaining time according to the sound wave signal continuity, calculating a secondary ignition time sequence interval according to the frequency of the microseismic event, and calculating a secondary ignition time sequence interval according to the sound wave signal continuity.
2. The method of claim 1, wherein the identifying at least one frac weakly responsive zone and hydraulic frac control parameters for the frac weakly responsive zone based on real-time frac data after formation of the primary fracture network comprises: Identifying a target geological condition corresponding to the real-time fracturing data from a fracturing parameter reference library through a K neighbor matching model, and extracting target reference fracturing parameters under the target geological condition, wherein the real-time fracturing data comprise real-time fracturing parameters corresponding to a plurality of monitoring areas; calculating the deviation value of any parameter item in the real-time fracturing parameters and the corresponding parameter item in the target reference fracturing parameters aiming at each monitoring area, and determining the crack development state of the monitoring area according to the deviation value continuously monitored in a preset historical period, wherein the crack development state comprises good crack development, no effective crack and poor crack development; Determining a fracturing weak response zone according to a monitoring zone without effective cracks or poor crack development, and determining the coordinates of the fracturing weak response zone according to the coordinate extremum of all microseismic events in the fracturing weak response zone; and calculating real-time jet flow control parameters of the fracturing weak response zone according to the real-time fracturing parameters in the fracturing weak response zone, and generating hydraulic fracturing control parameters according to the coordinates of the fracturing weak response zone and the real-time jet flow control parameters.
3. The method of claim 2, wherein determining the crack development status of the monitored area from the deviation values continuously monitored over a preset historical period of time comprises: Counting the number of parameter items with deviation values larger than corresponding deviation threshold values in the preset history period for each monitoring area; if the number of the parameter items is larger than a first preset number threshold, determining that the crack development state of the monitoring area is free of effective cracks; if the number of the parameter items is smaller than or equal to the first preset number threshold value and larger than the second preset number threshold value, determining that the crack development state of the monitoring area is crack dysplasia; And if the number is smaller than or equal to a second preset number threshold, determining that the crack development state of the monitoring area is good in crack development.
4. The method of claim 2, wherein the real-time fracturing parameters include sonic intensity and microseismic event frequency; the calculating the real-time jet flow control parameters of the fracturing weak response zone according to the real-time fracturing parameters in the fracturing weak response zone comprises the following steps: Calculating a sound wave intensity difference value between a preset sound wave intensity blind area threshold value and the sound wave intensity, calculating a cavitation jet pressure compensation value according to the sound wave intensity difference value, and correcting the current cavitation jet pressure according to the cavitation jet pressure compensation value to obtain corrected cavitation jet pressure; Calculating a frequency difference value between a preset microseismic event frequency blind area threshold value and a microseismic event frequency, calculating according to the frequency difference value to obtain a cavitation jet frequency compensation value, and correcting the current cavitation jet frequency according to the cavitation jet frequency compensation value to obtain a corrected cavitation jet frequency; And generating real-time jet control parameters according to the corrected cavitation jet pressure and the corrected cavitation jet frequency.
5. The method of any one of claims 1-4, wherein the injecting a propping mixture into the primary and secondary fracture networks by controlling a set of injection allocation valves to complete fracturing of the target operational zone comprises: acquiring real-time fracture morphology data after hydraulic fracturing of the fracturing weak response zone is completed; Matching a propping mixture ratio from a propping injection combination database according to a target geological condition and the real-time fracture morphology data, and determining control parameters of each valve body in the propping injection valve group according to the propping mixture ratio; The supporting mixture comprises gas, sand-carrying fluid containing propping agent and surfactant, wherein each valve body in the injection allocation valve group is used for controlling injection amounts of the high-pressure gas supply assembly, the high-pressure water pump, the sand mixing assembly and the chemical additive injection pump respectively.
6. A fracturing device based on pulse gas-liquid recombination, the device being configured to perform operations corresponding to the fracturing method based on pulse gas-liquid recombination according to claim 1, comprising: The pulse gas generator control module is used for controlling the pulse gas generator to carry out gas fracturing on a target operation area in a three-level independent ignition pulse mode according to the gas fracturing control parameters which are fed back and adjusted in real time so as to form a main fracture network in the target operation area; The jet device control module is used for identifying at least one fracturing weak response area and hydraulic fracturing control parameters of the fracturing weak response area according to real-time fracturing data after the formation of the main fracture network, controlling the jet device by the hydraulic fracturing control parameters, and carrying out directional hydraulic fracturing on the fracturing weak response area so as to form a secondary fracture network on the basis of the main fracture network; And the injection allocation valve group control module is used for injecting a propping mixture into the main fracture network and the secondary fracture network through controlling the injection allocation valve group after hydraulic fracturing of the fracturing weak response area is completed, so as to complete fracturing of the target operation area.
7. A storage medium having stored therein at least one executable instruction for causing a processor to perform operations corresponding to the pulse gas-liquid composite based fracturing method of any one of claims 1-5.
8. The fracturing equipment based on pulse gas-liquid combination is characterized by comprising a multi-source monitoring sensor, a pulse gas generator, a jet device, a injection allocation valve group, a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface are in communication with each other through the communication bus; The memory is configured to store at least one executable instruction that causes the processor to perform operations corresponding to the fracturing method based on pulsed gas-liquid recombination of any one of claims 1-5.

Description

Fracturing method and device based on pulse gas-liquid combination, storage medium and equipment Technical Field The invention relates to the technical field of coal mining, in particular to a fracturing method and device based on pulse gas-liquid combination, a storage medium and equipment. Background Most coal seams in coal mines in China have the characteristics of low permeability, high gas content and complex geological structure, and particularly the soft low-permeability coal seams are extremely low in original air permeability coefficient, so that the conventional drilling pre-extraction gas effect is poor, the period is long, and the safe and efficient production of the coal mines and the recovery of coal seam gas resources are seriously restricted. Currently, existing methods for increasing the permeability of coal seams mainly include hydraulic fracturing and gas phase fracturing. However, the two methods have better application effects of only penetrating the coal seam in the hard. For soft, hypotonic and heterogeneous coal beds, pure water is directly used for fracturing, water lock is easy to generate, the soft coal is greatly damaged, and the problems of single fractured crack and low fracturing effectiveness and poor permeability improvement effect can be caused by directly using pure gas for fracturing. The existing coal bed fracturing generally adopts a construction mode based on a static geological model and an empirical pumping curve, and the injection process is mainly regulated by depending on macroscopic indexes of total ground flow and total pressure. Because the underground coal bed has obvious heterogeneity, the dynamic fracture characteristics of the coal and rock cannot be sensed and responded in real time, the pumping program is matched with the actual requirements of the stratum and is not aligned, and the problems of inaccurate adjustment of fracturing parameters and insufficient injection pressure and flow control precision exist. Disclosure of Invention In view of the above, the invention provides a fracturing method and device based on pulse gas-liquid combination, a storage medium and equipment, and mainly aims to solve the problem of low fracturing effectiveness of the traditional low permeability coal seam. According to one aspect of the invention, there is provided a fracturing method based on pulsed gas-liquid recombination, comprising: According to the gas fracturing control parameters which are fed back and adjusted in real time, controlling a pulse gas generator to carry out gas fracturing on a target operation area in a three-stage independent ignition pulse mode so as to form a main fracture network in the target operation area; Identifying at least one fracturing weak response zone and hydraulic fracturing control parameters of the fracturing weak response zone according to real-time fracturing data after the formation of the main fracture network, controlling a jet device by using the hydraulic fracturing control parameters, and carrying out directional hydraulic fracturing on the fracturing weak response zone so as to form a secondary fracture network on the basis of the main fracture network; After hydraulic fracturing of the frac weakly responsive zone is completed, a propping mixture is injected into the primary and secondary fracture networks by controlling a set of injection allocation valves to complete fracturing of the target operating zone. Further, the controlling the pulse gas generator to perform gas fracturing on the target operation area in a three-stage independent ignition pulse mode according to the gas fracturing control parameters adjusted by real-time feedback includes: controlling a pulse gas generator to perform gas fracturing on the target operation area according to the initialized gas fracturing control parameters; and in the gas fracturing process, acquiring microseismic parameters and acoustic parameters in real time, calculating and updating the gas fracturing control parameters in real time according to the microseismic parameters and the acoustic parameters, and controlling a pulse gas generator to perform gas fracturing on a target operation area according to the updated gas fracturing control parameters. Further, the gas fracturing control parameters comprise primary ignition pressure, secondary ignition pressure, tertiary pressure maintaining time, secondary ignition time sequence interval and secondary and tertiary ignition time sequence interval, wherein the microseismic parameters comprise microseismic event frequency and microseismic magnitude, and the acoustic parameters comprise acoustic signal continuity and acoustic wave intensity; The calculation process of the gas fracturing control parameters comprises the following steps: Calculating to obtain primary ignition pressure according to the frequency of the microseismic events and the microseismic level; calculating to obtain secondary ignition pressure according to the s