CN-121994993-A - Carbon dioxide fracturing flowback carbon emission monitoring device and monitoring method

CN121994993ACN 121994993 ACN121994993 ACN 121994993ACN-121994993-A

Abstract

The invention discloses a carbon dioxide fracturing flowback carbon emission monitoring device and a monitoring method, and relates to the technical field of reservoir reformation and clean production in the oil and gas industry, wherein the monitoring device comprises a three-phase separator, a gas detection pretreatment module, a gas detection tank, a flow control valve and a data analyzer; the three-phase separator, the gas detection pretreatment module and the gas detection tank are sequentially connected through pipelines, and the gas detection tank is respectively connected with a flow control valve and a data analyzer. Carbon emission is monitored on carbon dioxide fracturing flowback, real-time carbon emission concentration in the fracturing fluid discharge process, real-time carbon emission in the fracturing fluid discharge process, accumulated carbon emission in each stage, carbon emission in the whole process and carbon emission distribution rule curves in the fracturing fluid discharge process are calculated, so that the distribution rule of carbon emission in the carbon dioxide fracturing site flowback process is mastered in time, and a more reasonable and efficient carbon dioxide trapping liquefaction process can be designed.

Inventors

WANG RONGHUA
TANG HONG
ZHANG RUI
WANG XIAOLI
WANG XIALING
LAN JIANPING
LI YANG
LIU HANJUN
ZOU YIWEI
YANG CHANGBIAO

Assignees

中国石油天然气集团有限公司
中国石油集团川庆钻探工程有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (15)

1. The carbon dioxide fracturing flowback carbon emission monitoring device is characterized by comprising a three-phase separator (1), a gas detection pretreatment module, a gas detection tank, a flow control valve (17) and a data analyzer (16); The three-phase separator (1), the gas detection pretreatment module and the gas detection pool are sequentially connected through pipelines, the three-phase separator (1) is used for carrying out three-phase separation on carbon dioxide fracturing flowback materials, the gas detection pretreatment module is used for carrying out filtration and drying pretreatment on the gas materials after three-phase separation, and the gas detection pool is used for carrying out gas detection on the gas materials after pretreatment; the gas detection tank is respectively connected with a flow control valve (17) and a data analyzer (16), the flow control valve (17) is used for controlling the discharged material flow after the gas detection tank detects, and the data analyzer (16) is used for carrying out carbon emission monitoring according to the gas detection data and the discharged material flow data.
2. The carbon dioxide fracturing flowback carbon emission monitoring device according to claim 1, wherein the three-phase separator (1) utilizes the gravity and relative density difference of materials in fracturing flowback fluid to realize three-phase separation, and comprises a feed inlet, a gas-liquid separation chamber, a gas-phase outlet, a liquid-phase outlet and a solid-phase outlet, wherein separated liquid is discharged through the liquid-phase outlet after being metered by a flowmeter, separated solids are discharged through the solid-phase outlet, and separated gas enters a gas detection pretreatment module through a gas sampling air inlet (3) connected with the gas-phase outlet.
3. The carbon dioxide fracturing flowback carbon emission monitoring device according to claim 1, wherein the three-phase separator (1), the gas detection pretreatment module, the gas detection tank, the flow control valve (17) and the data analyzer (16) are all fixed in a box body, a gas sampling air inlet (3), an air outlet, a standard air inlet, a power interface and a signal input interface are arranged on the box body, a touch display screen is arranged on a panel of the box body, and the touch display screen is electrically connected with the data analyzer (16); A pressure reducing valve (2) is arranged on a pipeline between the three-phase separator (1) and the gas sampling air inlet (3).
4. A carbon dioxide fracturing flowback carbon emission monitoring device as in claim 3, wherein the gas detection pretreatment module comprises a pressure regulating valve (4), a water vapor separator (5), a triple filter (6), a vacuum filter (7) and a dryer (8) which are sequentially connected, wherein the inlet of the pressure regulating valve (4) is connected with the gas sampling air inlet (3), the water vapor separator (5), the triple filter (6) and the vacuum filter (7) are connected with a peristaltic drainage pump (9) and a stainless steel water washing tank (10), and the outlet of the dryer (8) is connected with the inlet of the gas detection pretreatment module and is provided with a constant pressure valve (11) on a connecting pipe.
5. The carbon dioxide fracturing flowback carbon emission monitoring device according to claim 1, wherein a carbon dioxide methane two-in-one gas detection sensor (12), a temperature sensor (13), a pressure sensor (14) and a constant temperature module (15) are arranged in the gas detection tank, the two-in-one gas detection sensor (12) is electrically connected with the data analyzer (16), a flow control valve (17) and an exhaust pump (18) are arranged on an outlet pipeline of the gas detection tank, and the flow control valve (17) is electrically connected with the data analyzer (16).
6. The carbon dioxide fracturing flowback carbon emission monitoring method is characterized by comprising the following steps of: S001, carrying out three-phase separation on the carbon dioxide fracturing flowback mixture by utilizing a three-phase separator (1), and carrying out pressure reduction treatment on fracturing flowback gas after three-phase separation; s002, carrying out dust removal, water removal and oil removal pretreatment on the fracturing return exhaust after the pressure reduction treatment by utilizing a gas detection pretreatment module; s003, regulating the pressure of the pretreated fracturing return exhaust to normal pressure through a constant pressure valve (11); s004, conveying the fracturing return exhaust gas subjected to pressure regulation to normal pressure into a gas detection tank, and collecting gas concentration change data in the fracturing return exhaust gas in real time by a two-in-one gas detection sensor (12) in the gas detection tank, wherein a constant temperature module (15) controls the temperature of the fracturing return exhaust gas; S005, calculating the real-time carbon emission concentration in the fracturing fluid discharge process by utilizing the gas concentration change data; S006, calculating real-time carbon emission, accumulated carbon emission in each stage and carbon emission in the whole process in the fracturing and drainage process by combining real-time flow data of a flow control valve (17) and gas concentration change data of a two-in-one gas detection sensor (12); S007, drawing a carbon emission distribution rule curve in the fracturing fluid discharge process by utilizing the real-time carbon emission concentration in the fracturing fluid discharge process, the real-time carbon emission in the fracturing fluid discharge process and the accumulated carbon emission in each stage.
7. The carbon dioxide fracturing flowback carbon emission monitoring method of claim 6, wherein in the step S001, a decompression valve (2) connected with an outlet of a three-phase separator (1) is utilized to decompress the carbon dioxide fracturing flowback gas after three-phase separation, the decompression valve (2) stably controls the flow of the fracturing flowback gas, and the output pressure is regulated within the regulation range of 0-0.4Mpa.
8. The carbon dioxide fracturing flowback carbon emission monitoring method of claim 6, wherein in the step S002, the fracturing flowback gas is filtered by a water vapor separator (5), a triple filter (6) and a vacuum filter (7), filtered water is discharged by a peristaltic drainage pump (9), oil contamination impurities in the fracturing flowback gas are removed by a stainless steel water washing tank (10), and finally the fracturing flowback gas is dried by a dryer (8).
9. The carbon dioxide fracturing flowback carbon emission monitoring method is characterized in that in the step S004, concentration values, real-time temperature and pressure values of carbon dioxide and methane gas in fracturing flowback gas are detected in real time by a two-in-one gas detection sensor (12), a temperature sensor (13) and a pressure sensor (14) in a gas detection tank, and the whole process of fracturing flowback gas is heated by a constant temperature module (15) in the gas detection tank.
10. The carbon dioxide fracturing flowback carbon emission monitoring method is characterized in that in the step S005-S007, calculation is carried out through acquired real-time flowback concentration of carbon dioxide gas, real-time emission concentration of methane gas and real-time flow data in a flow control valve (17), a real-time carbon emission concentration, real-time carbon emission amount and accumulated carbon emission amount change curve of each stage are drawn, and the carbon emission change trend and distribution rule of the whole carbon emission process of the carbon dioxide fracturing flowback are visualized.
11. The carbon dioxide fracturing flowback carbon emission monitoring method of claim 6, wherein the step S005 comprises the steps that a data analyzer (16) obtains real-time concentration values of carbon dioxide flowback gas and methane exhaust gas at different stages in the fracturing fluid discharge process, and the data analyzer (16) obtains real-time carbon emission concentrations at different moments in the whole fracturing fluid discharge process by adding volume fractions of two exhaust gases through the real-time gas concentration values at different stages.
12. The carbon dioxide fracturing flowback carbon emission monitoring method of claim 11, wherein the step S005 comprises: C T ＝C 1T +C 2T Wherein C T is the real-time carbon emission concentration at the moment T, C 1T is the real-time carbon dioxide gas flowback concentration at the moment T, C 2T is the real-time methane gas emission concentration at the moment T, the flowback materials are carbon dioxide gas and fracturing flowback fluid at the early stage of fracturing fluid discharge, C 2T is 0 and C T ＝C 1T when no methane gas is emitted, the flowback materials are carbon dioxide gas, methane gas and fracturing flowback fluid at the middle stage of fracturing fluid discharge, C 1T 、C 2T is not 0 and C T ＝C 1T +C 2T when the flowback materials are carbon dioxide gas and methane gas at the later stage of fracturing fluid discharge, and C 1T 、C 2T is not 0 and C T ＝C 1T +C 2T when the flowback materials are carbon dioxide gas and methane gas.
13. The carbon dioxide fracturing flow-back carbon emission monitoring method of claim 6, wherein in step S006, a data analyzer (16) obtains real-time concentration values of carbon dioxide flow-back gas and methane emission gas in different stages of the fracturing fluid-discharge process, calculates real-time carbon emission in the fracturing fluid-discharge process by using the real-time gas concentration values in different stages and combining real-time flow data in a flow control valve (17), and further calculates accumulated carbon emission in each stage and carbon emission in the whole fracturing fluid-discharge process.
14. The carbon dioxide fracturing flowback carbon emission monitoring method of claim 13, wherein step S006 comprises: N T ＝C 1T ×Q T ×q P T ＝C 2T ×Q T ×g S T ＝N T +P T ×2.75 S w ＝S e +S m +S l Wherein S T is the real-time carbon emission amount of the fracturing flowback process at a moment T, N T is the real-time carbon emission amount of the carbon dioxide gas at the moment T, P T is the real-time carbon emission amount of the methane gas at the moment T, C 1T is the real-time flowback concentration of the carbon dioxide gas at the moment T, C 2T is the real-time emission concentration of the methane gas at the moment T, Q T is the real-time flow data in a flow control valve at the moment T, Q is the density of the carbon dioxide gas at normal temperature, g is the density of the methane gas at normal temperature, S e is the accumulated carbon emission amount at the early stage of fracturing flowback, N ei is the collected by a two-in-one gas detection sensor at the early stage, And the value of the real-time return displacement of the ith carbon dioxide calculated in the later stage is acquired by a two-in-one gas detection sensor in the earlier stage, And the total number of the real-time carbon dioxide flow back discharge values calculated in the later stage is t e which is the time required by finishing data detection and acquisition in the earlier stage, S m is the medium-term accumulated carbon discharge amount in fracturing fluid discharge, N mi is the acquisition of a medium-term two-in-one gas detection sensor, And the P mi is the real-time return displacement value of the ith carbon dioxide calculated in the later stage, which is acquired by a two-in-one gas detection sensor in the middle stage, the real-time discharge quantity value of the ith methane calculated in the later stage, and b is the acquired by the two-in-one gas detection sensor in the middle stage, And the total number of the real-time carbon dioxide flow back discharge values calculated in the later stage is t m which is the time required by finishing data detection and acquisition in the middle stage, S l is the accumulated carbon discharge amount in the later stage of fracturing fluid discharge, N li is the acquisition of a two-in-one gas detection sensor in the later stage, And the real-time carbon dioxide return discharge value calculated by the later stage is the real-time methane discharge value calculated by the later stage and acquired by the later stage two-in-one gas detection sensor, P li is the real-time carbon dioxide return discharge value calculated by the later stage, c is the total number of the real-time carbon dioxide return discharge values calculated by the later stage and acquired by the later stage, t l is the time required for finishing data detection and acquisition at the later stage, and S w is the carbon discharge of the whole fracturing fluid discharge process.
15. The carbon dioxide fracturing flow-back carbon emission monitoring method of claim 6, wherein in the step S007, a data analyzer (16) uses the real-time carbon emission concentration of the fracturing fluid discharge process calculated in the step S005 to obtain a relation chart of real-time carbon emission concentration and fracturing fluid discharge time, and uses the real-time carbon emission of the fracturing fluid discharge process calculated in the step S006 to accumulate the carbon emission in each stage to obtain the relation charts of real-time carbon emission and fracturing fluid discharge time and carbon emission of the stage process and different fracturing fluid discharge stages.

Description

Carbon dioxide fracturing flowback carbon emission monitoring device and monitoring method Technical Field The invention relates to the technical field of clean production for reservoir reformation in the oil and gas industry, in particular to a carbon dioxide fracturing flowback carbon emission monitoring device and a monitoring method. Background Along with the proposal of the 'double carbon' target, the carbon dioxide fracturing is rapidly and comprehensively developed in each large oil field due to the advantages of 'carbon utilization' and 'carbon emission reduction', and simultaneously the emission amount of the carbon dioxide in the back flow after fracturing is greatly increased. Therefore, the carbon emission monitoring device and the monitoring method for the carbon dioxide fracturing flowback process are necessary to be researched, and the distribution rule of the carbon emission in the carbon dioxide fracturing site flowback process is mastered in time. Based on the method, a more reasonable and efficient carbon dioxide capturing and liquefying process is designed, and recycling of the back-flow carbon dioxide after pressure is realized. The carbon emission can be reduced, carbon closed-loop management of carbon dioxide fracturing can be realized while the cost of carbon dioxide fracturing operation is reduced, and a foundation is laid for carbon emission reduction capability authentication of carbon dioxide fracturing. Therefore, there is a need for a carbon dioxide fracturing flowback carbon emission monitoring device and a monitoring method for monitoring carbon dioxide fracturing flowback. Disclosure of Invention In order to overcome the defects in the prior art, the invention discloses a carbon dioxide fracturing flowback carbon emission monitoring device and a carbon dioxide fracturing flowback carbon emission monitoring method, which are used for monitoring carbon dioxide fracturing flowback carbon emission. In order to achieve the above purpose, the present invention adopts the technical scheme that: the carbon dioxide fracturing flowback carbon emission monitoring device comprises a three-phase separator, a gas detection pretreatment module, a gas detection tank, a flow control valve and a data analyzer; The three-phase separator is used for carrying out three-phase separation on the carbon dioxide fracturing flowback materials, the gas detection pretreatment module is used for carrying out filtration and drying pretreatment on the gas materials after three-phase separation, and the gas detection pond is used for carrying out gas detection on the pretreated gas materials; The gas detection pond is connected with flow control valve and data analysis appearance respectively, flow control valve is used for controlling the discharge material flow after the gas detection pond detects, data analysis appearance is used for carrying out carbon emission monitoring according to gas detection data and discharge material flow data. Preferably, the three-phase separator realizes three-phase separation by utilizing the gravity and relative density difference of materials in the fracturing flowback fluid, and comprises a feed inlet, a gas-liquid separation chamber, a gas phase outlet, a liquid phase outlet and a solid phase outlet, wherein separated liquid is discharged through the liquid phase outlet after being metered by a flowmeter, separated solids are discharged through the solid phase outlet, and separated gas enters the gas detection pretreatment module through a gas sampling air inlet connected with the gas phase outlet. Preferably, the three-phase separator, the gas detection pretreatment module, the gas detection tank, the flow control valve and the data analyzer are all fixed in a box body, a gas sampling air inlet, an air outlet, a gas marking inlet, a power interface and a signal input interface are arranged on the box body, a touch display screen is arranged on a panel of the box body, and the touch display screen is electrically connected with the data analyzer. Preferably, a pressure reducing valve is arranged on a pipeline between the three-phase separator and the gas sampling air inlet. Preferably, the gas detection pretreatment module comprises a pressure regulating valve, a water vapor separator, a triple filter, a vacuum filter and a dryer which are sequentially connected, wherein an inlet of the pressure regulating valve is connected with the gas sampling air inlet, the water vapor separator, the triple filter and the vacuum filter are all connected with a peristaltic drainage pump and a stainless steel water washing tank, an outlet of the dryer is connected with an inlet of the gas detection pretreatment module, and a constant pressure valve is arranged on a connecting pipeline. Preferably, a carbon dioxide methane two-in-one gas detection sensor, a temperature sensor, a pressure sensor and a constant temperature module are arranged in the gas detection tank, the two-in-one gas