WO2024066592A1

WO2024066592A1 - Test method and device for the adaptability of water-based completion fluid in crude oil containing hydrogen sulfide

Info

Publication number: WO2024066592A1
Application number: PCT/CN2023/104395
Authority: WO
Inventors: 刘会锋; 陈怀龙; 柴辉; 文光耀; 巴勒塔别克巴合达尔; 程维恒; 李万军; 顾亦新; 周海秋; 张玮
Original assignee: 中国石油天然气集团有限公司; 中国石油集团工程技术研究院有限公司; 中国石油国际勘探开发有限公司
Priority date: 2022-09-30
Filing date: 2023-06-30
Publication date: 2024-04-04
Also published as: CN117846542A

Abstract

The present invention provides a test method and device for the adaptability of a water-based completion fluid in crude oil containing hydrogen sulfide. The test method comprises: testing a completion fluid to be tested; pumping crude oil into a high-temperature and high-pressure reactor, and then introducing hydrogen sulfide gas until the crude oil is saturated with hydrogen sulfide; introducing the deoxygenated completion fluid to be tested into the reactor; heating the reactor to a set temperature and making adjustment to a set pressure, the set pressure being the fugacity of hydrogen sulfide; after a set reaction time is reached, performing pressure relief, and stopping heating; and performing comparison to obtain a change of the completion fluid before and after the reaction, and determining whether the completion fluid is adaptive to the crude oil containing hydrogen sulfide. The device comprises the high-temperature and high-pressure reactor, a hydrogen sulfide tank, a completion fluid introduction pipeline, a gas discharge pipeline, a pressure measurement apparatus and a temperature control apparatus. According to the test method provided by the present invention, interfacial reaction between a completion fluid and crude oil containing hydrogen sulfide in the stratum can be simulated when the completion fluid is in a well-kill state, and the adaptability of the water-based completion fluid in the crude oil containing hydrogen sulfide is accurately determined.

Description

A test method and device for the adaptability of water-based completion fluid in crude oil containing hydrogen sulfide

Technical Field

The invention relates to a method and equipment for testing the adaptability of a water-based completion fluid in crude oil containing hydrogen sulfide, and belongs to the technical field of petroleum engineering.

Background technique

Many reservoirs contain hydrogen sulfide in the crude oil, so the working fluid used in the completion process must take into account the requirements for hydrogen sulfide resistance. In particular, if the completion fluid reacts with hydrogen sulfide, it is easy to generate precipitation and block the wellbore or reservoir; more importantly, on the other hand, the density of the completion fluid may change, thereby causing well control risks. Therefore, the completion fluid used in oil and gas wells containing hydrogen sulfide needs to be tested for hydrogen sulfide resistance to ensure its stability in the wellbore environment containing hydrogen sulfide.

However, the experimental design of the reaction between completion fluid and crude oil containing hydrogen sulfide has always been a bottleneck problem in the industry. When the completion fluid is stationary in the wellbore, it mainly plays the role of well killing. Its reaction with crude oil containing hydrogen sulfide only occurs at the interface between the completion fluid and crude oil. Therefore, it is unreasonable to directly mix the completion fluid with crude oil for reaction. At the same time, hydrogen sulfide is a highly toxic gas, and the mixed reaction is prone to leakage, endangering the personal safety of the experimenters.

At present, the industry generally uses two methods to evaluate the hydrogen sulfide resistance of completion fluids: one is to first prepare a dilute solution of hydrogen sulfide (i.e., hydrosulfuric acid) and mix it with the completion fluid to test its hydrogen sulfide resistance; the other is to put the completion fluid in a high-temperature and high-pressure reactor and then pass hydrogen sulfide gas into the completion fluid to test its hydrogen sulfide resistance. Both methods cannot simulate the real interface reaction state and cannot simulate the actual concentration of hydrogen sulfide. Testing the hydrogen sulfide resistance of completion fluids has always been one of the problems that need to be solved in this field.

Summary of the invention

In order to solve the above technical problems, the purpose of the present invention is to provide a method and equipment for testing the adaptability of water-based completion fluid in crude oil containing hydrogen sulfide. The testing method provided by the present invention can simulate the interface reaction between the completion fluid and the crude oil containing hydrogen sulfide in the formation when the completion fluid is in a well-killing state, and accurately judge the adaptability of the water-based completion fluid in crude oil containing hydrogen sulfide.

In order to achieve the above object, the first aspect of the present invention provides a method for testing the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil, which comprises the following steps:

(1) testing the completion fluid to be tested, wherein the testing at least includes testing the basic properties of the completion fluid to be tested, and the basic properties testing of the completion fluid to be tested at least includes density testing;

(2) pumping crude oil into a high-temperature and high-pressure reactor, and then introducing hydrogen sulfide gas into the high-temperature and high-pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide;

(3) deoxygenating the completion fluid to be tested, and then introducing the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(4) heating the high-temperature and high-pressure reactor to a set temperature, adjusting its pressure to a set pressure, wherein the set pressure is the fugacity of hydrogen sulfide, and then keeping it stable; measuring the temperature and pressure of the high-temperature and high-pressure reactor at regular intervals, and if the temperature and/or pressure are different from the set temperature and/or set pressure, adjusting the temperature and/or pressure of the high-temperature and high-pressure reactor to make them the same as the set temperature and set pressure;

(5) After the set reaction time is reached, the pressure is released, the heating is stopped, the high temperature and high pressure reactor is cooled to room temperature, and the fluid therein is discharged;

(6) testing the completion fluid after the reaction, wherein the testing at least includes testing the basic properties of the completion fluid after the reaction, and the basic properties of the completion fluid after the reaction at least includes density testing;

(7) Based at least on the test result of the completion fluid to be tested obtained in step (1) and the test result of the completion fluid after reaction obtained in step (6), determine whether the completion fluid is suitable for use in crude oil containing hydrogen sulfide.

According to a specific embodiment of the present invention, preferably, the test method further comprises a preliminary screening after step (1), wherein the preliminary screening comprises:

(a)-1 Pump crude oil into a high temperature and high pressure reactor, and then introduce hydrogen sulfide gas into the high temperature and high pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide;

(a)-2 Deoxygenate the completion fluid to be tested, and then introduce the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(a)-3 Heat the high-temperature and high-pressure reactor to a set temperature, adjust its pressure to normal pressure as the set pressure, and then keep it stable; measure the temperature of the high-temperature and high-pressure reactor at regular intervals, and if the temperature is different from the set temperature, adjust the temperature of the high-temperature and high-pressure reactor to make it the same as the set temperature;

(a)-4 After reaching the set reaction time, stop heating, cool the high temperature and high pressure reactor to room temperature, and discharge the fluid therein;

(a)-5 testing the completion fluid after the reaction, wherein the testing at least includes testing the basic properties of the completion fluid after the reaction, and the basic properties of the completion fluid after the reaction at least includes density testing;

(a)-6 Preliminarily determine whether the completion fluid is suitable for crude oil containing hydrogen sulfide based at least on the test results of the completion fluid to be tested and the test results of the completion fluid after the reaction, and perform steps (2) to (7) on the completion fluid that is preliminarily determined to be suitable for crude oil containing hydrogen sulfide to finally determine whether the completion fluid is suitable for crude oil containing hydrogen sulfide.

Those skilled in the art should understand that since the above step (1) has already carried out basic performance testing on the completion fluid to be tested, it is not necessary to repeat the basic performance testing on the completion fluid to be tested during the preliminary screening process.

In the above method, preferably, in step (1), the basic property test of the completion fluid to be tested also includes one or a combination of pH value detection, viscosity detection, crystallization temperature detection and turbidity detection.

In the above method, preferably, in step (1), the detection of the completion fluid to be tested also includes detecting the ion content of the completion fluid to be tested.

In the above method, preferably, in step (2) and step (a)-1, the amount of crude oil pumped into the high temperature and high pressure reactor is 1000 to 3000 mL.

In the above method, preferably, in step (2) and step (a)-1, the time for introducing hydrogen sulfide gas is 1.5 to 2.5 hours, so that the crude oil is saturated with hydrogen sulfide, that is, the crude oil is dissolved with as much hydrogen sulfide as possible, while the influence of other residual gases in the reactor is eliminated to the greatest extent possible.

In the above method, preferably, step (2) and step (a)-1 further include: introducing carbon dioxide gas into the high temperature and high pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide and carbon dioxide. The time for introducing hydrogen sulfide gas and carbon dioxide gas can be 1.5 to 2.5 hours.

In the above method, in step (3) and step (a)-2, the deoxygenation method of the completion fluid to be tested can be a conventional completion fluid deoxygenation method in the art, preferably, the deoxygenation method can be activated carbon deoxygenation. The specific operation method of the activated carbon deoxygenation and the dosage ratio of the activated carbon and the completion fluid to be tested can be conventionally adjusted by those skilled in the art.

In the above method, preferably, in step (3) and step (a)-2, the amount of the deoxygenated completion fluid to be tested introduced into the high temperature and high pressure reactor is 1000-3000 mL.

In the above method, preferably, the amount of crude oil pumped into the high-temperature and high-pressure reactor is the same as the amount of the deoxygenated completion fluid to be tested introduced into the high-temperature and high-pressure reactor.

In the above method, preferably, in step (4), the fugacity of hydrogen sulfide is calculated according to the following formula (1):

In formula (1), is the fugacity of hydrogen sulfide, in MPa; is the partial pressure of hydrogen sulfide, in MPa; is the fugacity coefficient.

The partial pressure of hydrogen sulfide is the partial pressure of hydrogen sulfide in the crude oil containing hydrogen sulfide. The specific calculation method is conventional in the art. Generally speaking, it is obtained by multiplying the total system pressure (that is, the formation pressure of the crude oil containing hydrogen sulfide) by the molar fraction of hydrogen sulfide in the gas phase. The calculation can also be performed using conventional methods in the art. For example, the calculation can be performed according to the formula for calculating the fugacity coefficient of components in a mixture obtained by combining the SRK equation with the one-parameter van der Waals mixing rule disclosed on pages 6 to 8 of "Improvement of the SRK equation and its application in phase equilibrium calculations" (Luo Mingjian, master's thesis of Tianjin University, December 2005), that is, formula (2-34).

In the above method, preferably, in step (4) and step (a)-3, the set temperature is the crude oil temperature of the completion fluid working formation to be tested, and more preferably can be 80-120°C.

In the above method, preferably, in step (4), the temperature and pressure of the high temperature and high pressure reactor are measured every 60 to 80 hours.

In the above method, preferably, in step (a)-3, the temperature of the high temperature and high pressure reactor is measured once every 24 to 80 hours. More preferably, the temperature of the high temperature and high pressure reactor is measured once every 60 to 80 hours.

In the above method, preferably, in step (4), the temperature of the high-temperature and high-pressure reactor is adjusted by the intensity of heating, and the pressure of the high-temperature and high-pressure reactor is adjusted by passing hydrogen sulfide gas. Among them, more preferably, when the measured pressure of the high-temperature and high-pressure reactor is lower than the set pressure by more than 0.5MPa, hydrogen sulfide gas is passed into the high-temperature and high-pressure reactor to supplement the pressure to the set pressure. More preferably, when the pressure is adjusted, the flow rate of the hydrogen sulfide gas is less than 10mm/min, and the flow rate is 150-250mL/min (especially preferably 200mL/min). Alternatively, if step (2) also includes: passing carbon dioxide gas into the high-temperature and high-pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide and carbon dioxide, the pressure of the high-temperature and high-pressure reactor can be adjusted by passing hydrogen sulfide gas and carbon dioxide gas. Preferably, the flow rates of hydrogen sulfide gas and carbon dioxide gas are both less than 10mm/min, and the flow rates are both 150-250mL/min (more preferably 200mL/min). When replenishing the pressure, the gas flow rate and flow rate specified in the present application are used to avoid disturbance and flow shock at the outlet of the gas in the reactor, thereby avoiding convection at the interface between the crude oil and the completion fluid.

In the above method, preferably, in step (a)-3, the temperature of the high temperature and high pressure reactor is adjusted by the intensity of heating.

In the above method, preferably, in step (5), the set reaction time is 6-8 days.

In the above method, preferably, in step (a)-4, the set reaction time is 1 day to 2 months. More preferably, the set reaction time is 1 month to 2 months.

In the above method, preferably, in step (6) and step (a)-5, the basic performance test of the completion fluid after the reaction also includes one or a combination of pH value detection, viscosity detection, crystallization temperature detection and turbidity detection.

In the above method, preferably, in step (6) and step (a)-5, the detection of the completion fluid after the reaction also includes detecting the ion content of the completion fluid after the reaction.

In the above method, preferably, in step (7), judging whether the completion fluid is suitable for crude oil containing hydrogen sulfide includes the following manner: if the density change of the completion fluid before and after the reaction is greater than 0.2SG or there is obvious precipitation in the completion fluid after the reaction, then the completion fluid is not suitable for crude oil containing hydrogen sulfide. More preferably, the obvious precipitation is the amount of precipitation after passing through a filter screen of 300 to 400 mesh (more preferably 400 mesh) of 100g/1000mL (the amount of completion fluid after the reaction) or more. Wherein, SG (specific gravity) is the ratio of the density of the completion fluid to the density of water under the conditions of standard atmospheric pressure and 3.98°C.

In the above method, preferably, in step (7), it is determined whether the completion fluid is suitable for use in a well containing hydrogen sulfide. The oil further includes the following manner: if the pH value of the completion fluid to be tested is above 2, or if the viscosity of the completion fluid before and after the reaction changes by more than 10 mPa.s, or if the crystallization temperature of the completion fluid before and after the reaction changes by more than 5°C, or if the turbidity of the completion fluid before and after the reaction changes by more than 10 NTU, then the completion fluid is not suitable for crude oil containing hydrogen sulfide.

In the above method, preferably, in step (7), judging whether the completion fluid is suitable for crude oil containing hydrogen sulfide further includes the following manner: if the change in the main ion content of the completion fluid before and after the reaction is greater than 0.05 kg/L, the completion fluid is not suitable for crude oil containing hydrogen sulfide. The main ions include calcium ions, zinc ions, etc., which are mainly derived from inorganic salts commonly used in completion fluids.

In the above method, in step (7), if the density change of the completion fluid before and after the reaction is less than 0.2SG and there is no obvious precipitation in the completion fluid after the reaction, and if the pH value, viscosity, crystallization temperature, turbidity and ion content of the completion fluid before and after the reaction are also tested, then they all do not meet the above-mentioned index conditions for completion fluid not suitable for hydrogen sulfide crude oil, then the completion fluid is suitable for hydrogen sulfide crude oil.

In the above method, preferably, in step (a)-6, the preliminary judgment of whether the completion fluid is suitable for crude oil containing hydrogen sulfide includes the following manner: if the density change of the completion fluid before and after the reaction is greater than 0.2SG or there is obvious precipitation in the completion fluid after the reaction, the completion fluid is not suitable for crude oil containing hydrogen sulfide; if the density change of the completion fluid before and after the reaction is less than 0.2SG and there is no obvious precipitation in the completion fluid after the reaction, it is preliminarily judged that the completion fluid is suitable for crude oil containing hydrogen sulfide. More preferably, the obvious precipitation is the amount of precipitation after passing through a filter screen of 300 to 400 mesh (more preferably 400 mesh) of 100g/1000mL (the amount of completion fluid after the reaction) or more. The completion fluid that is suitable for crude oil containing hydrogen sulfide after preliminary screening is subjected to the above steps (2) to (7) to finally judge whether the completion fluid is suitable for crude oil containing hydrogen sulfide.

In the above method, preferably, in step (a)-6, the preliminary judgment of whether the completion fluid is suitable for crude oil containing hydrogen sulfide further includes the following manner: if the pH value of the completion fluid to be tested is above 2, or if the viscosity of the completion fluid before and after the reaction changes by more than 10 mPa.s, or if the crystallization temperature of the completion fluid before and after the reaction changes by more than 5°C, or if the turbidity of the completion fluid before and after the reaction changes by more than 10 NTU, then the completion fluid is not suitable for crude oil containing hydrogen sulfide.

In the above method, preferably, in step (a)-6, the preliminary judgment on whether the completion fluid is suitable for crude oil containing hydrogen sulfide further includes the following manner: if the change in the main ion content of the completion fluid before and after the reaction is greater than 0.05 kg/L, the completion fluid is not suitable for crude oil containing hydrogen sulfide.

In the above method, in step (a)-6, during the preliminary screening process, if the pH value, viscosity, crystallization temperature, turbidity, and ion content of the completion fluid before and after the reaction are also tested, then if they all do not meet the above-mentioned index conditions for completion fluid that is not suitable for hydrogen sulfide-containing crude oil, then it is preliminarily determined that the completion fluid is suitable for hydrogen sulfide-containing crude oil.

In the above method, preferably, step (a)-6 also includes: for the completion fluid that is initially judged to be unsuitable for crude oil containing hydrogen sulfide, steps (2) to (7) may also be performed to finally judge whether the completion fluid is suitable for crude oil containing hydrogen sulfide.

The test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil provided by the present invention is a test method for the hydrogen sulfide resistance of water-based completion fluid for oil and gas wells, which can simulate the interface reaction between the completion fluid and the hydrogen sulfide-containing crude oil in the formation when the completion fluid is in a well-killing state, and accurately judge the adaptability of the water-based completion fluid in the hydrogen sulfide-containing crude oil. The method has at least the following groundbreaking advances:

(1) The present invention uses the fugacity of hydrogen sulfide in crude oil under a specific temperature and pressure environment to simulate the experimental pressure conditions. On the one hand, it is more realistic and effective (fugacity represents the effective pressure of an actual gas in chemical thermodynamics); on the other hand, it is lower than the value of partial pressure, which is easier to implement in the laboratory than using partial pressure to simulate the experimental pressure, and has less experimental risks.

Experiments on hydrogen sulfide in the petroleum industry all assume that hydrogen sulfide is in gaseous state, and the pressure of hydrogen sulfide is obtained by multiplying the total system pressure by the mole fraction of hydrogen sulfide in the gas phase. The industry standard NACE TM0177: Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking in H ₂ S Environments also recommends using the partial pressure of hydrogen sulfide in gas to simulate the corrosive environment containing hydrogen sulfide - mixing hydrogen sulfide with nitrogen or carbon dioxide to reach the required partial pressure, and then passing the mixed gas into the reaction solution.

In the reaction between hydrogen sulfide in a dissolved state and completion fluid involved in the present invention, the above-mentioned simulation experiment using partial pressure is unreasonable, because the chemical reactivity of hydrogen sulfide is much lower than that in a gas state. If partial pressure is used to characterize, the reactivity of hydrogen sulfide is estimated to be too high (especially under high temperature and high pressure conditions), which does not conform to the actual situation; and if the pressure of the reaction environment is too high, it is also difficult to simulate under laboratory conditions. Therefore, the present invention creatively uses fugacity to characterize the chemical reactivity of hydrogen sulfide in a dissolved state.

(2) The present invention utilizes the density difference and gravity differentiation between water-based completion fluid and crude oil to simulate the interfacial reaction between completion fluid and crude oil containing hydrogen sulfide. Crude oil is first placed in a reactor, and then hydrogen sulfide is introduced to saturation, and then the deoxygenated completion fluid is pumped into the reactor. Due to its high density, the completion fluid will gather below the crude oil containing hydrogen sulfide, thereby ensuring that hydrogen sulfide reacts with the completion fluid only through mass transfer to the crude oil interface during the reaction.

In the oil industry, when testing the reaction between hydrogen sulfide and the fluid entering the well, the method of directly introducing hydrogen sulfide gas into the liquid phase is often used. However, this is far from simulating the contact reaction between crude oil containing hydrogen sulfide and the fluid entering the well. When this method is used to carry out the experiment of the present invention, the problem of the measured reaction rate being much higher than the actual reaction rate will definitely occur. This is because the reaction rate between crude oil dissolved with hydrogen sulfide and completion fluid depends on two processes: one is convection, and the other is mass transfer. Therefore, how to simulate the reaction process controlled by mass transfer is crucial. In the application scenario involved in the present invention, the completion fluid and crude oil are both stationary, and hydrogen sulfide is also in a dissolved, stationary liquid phase. There is no convection, and only mass transfer affects the reaction rate. In the present invention, the crude oil is first saturated with hydrogen sulfide, and then it is contacted with the completion fluid in a stationary state for reaction. It can completely simulate the working state of completion fluid, which is an innovative progress in the industry.

In addition, in the present invention, the order of introducing each fluid is also crucial. If the completion fluid is introduced first and then the crude oil, the crude oil cannot be saturated with hydrogen sulfide, and it cannot be guaranteed that the completion fluid and hydrogen sulfide do not undergo convection reaction. The method of the present invention is to first introduce crude oil, saturate hydrogen sulfide, and then introduce the completion fluid; the static state is maintained during the entire reaction process, and the mass transfer reaction of the interface is truly simulated.

(3) The present invention ensures constant experimental pressure conditions during the entire reaction process by compensating the pressure. During the experimental reaction, if the system pressure drop is detected to be greater than 0.5 MPa, hydrogen sulfide gas is introduced to compensate the pressure to ensure that the pressure value during the entire reaction process is equal to the set fugacity value.

The second aspect of the present invention provides a testing device for the adaptability of a water-based completion fluid in a hydrogen sulfide-containing crude oil, the device being used to implement the above-mentioned testing method for the adaptability of a water-based completion fluid in a hydrogen sulfide-containing crude oil, the device comprising at least: a high-temperature and high-pressure reactor, a hydrogen sulfide tank, a completion fluid inlet pipeline, a gas outlet pipeline, a pressure measuring device, and a temperature control device; the temperature control device comprising a heating unit, a temperature measuring unit, and a regulating unit;

Wherein, the hydrogen sulfide tank is connected to the high-temperature and high-pressure reactor through a pipeline; the completion fluid inlet pipeline is connected to the high-temperature and high-pressure reactor; the gas exhaust pipeline is connected to the high-temperature and high-pressure reactor; the pressure measuring device is arranged on the gas exhaust pipeline through a tee; the heating unit is arranged inside the high-temperature and high-pressure reactor; the temperature measuring unit is connected to the high-temperature and high-pressure reactor; after the regulating unit collects the temperature measured by the temperature measuring unit, it controls the heating intensity of the heating unit to adjust the temperature of the high-temperature and high-pressure reactor.

In the above equipment, preferably, the tank mouth of the hydrogen sulfide tank is provided with a pressure reducing regulator.

In the above-mentioned equipment, preferably, a pressure-boosting valve is provided at the tank mouth of the hydrogen sulfide tank, and the pressure-boosting valve controls a needle valve and a one-way valve. The pressure-boosting valve is arranged at a position closer to the tank mouth of the hydrogen sulfide tank than the needle valve. More preferably, the nominal diameter of the needle valve is 5 mm. The pressure-boosting valve used in the present invention includes a needle valve capable of accurately controlling the flow rate and a one-way valve to prevent backflow. If it is detected that the system pressure drop value is greater than 0.5 MPa, the one-way valve and the needle valve are opened for pressure boosting, but the opening of the needle valve should be relatively low to ensure that the flow rate of the pressure-boosting hydrogen sulfide gas is relatively low, so as to avoid disturbance and flow shock at the outlet of the hydrogen sulfide gas in the reactor, thereby avoiding convection at the interface between crude oil and completion fluid. Therefore, the present invention preferably uses a needle valve with a nominal diameter of 5 mm.

According to a specific embodiment of the present invention, preferably, the testing equipment for the adaptability of the water-based completion fluid in hydrogen sulfide-containing crude oil also includes a carbon dioxide tank, which is connected to the pipeline connecting the hydrogen sulfide tank and the high-temperature and high-pressure reactor through a tee.

In the above device, preferably, the carbon dioxide tank and the tank port are provided with a pressure reducing regulator.

In the above device, preferably, the tank opening of the carbon dioxide tank is provided with a one-way valve, and a needle valve is provided on the pipeline connecting the three-way valve and the high-temperature and high-pressure reactor. More preferably, the nominal diameter of the needle valve is 5mm.

According to a specific embodiment of the present invention, preferably, the test equipment for the adaptability of the water-based completion fluid in hydrogen sulfide-containing crude oil further includes a hydrogen sulfide absorption device, one end of the gas discharge pipeline is connected to the high-temperature and high-pressure reactor, and the other end is connected to the hydrogen sulfide absorption device. More preferably, the hydrogen sulfide absorption device is filled with sodium hydroxide solution.

According to a specific embodiment of the present invention, preferably, the testing equipment for the adaptability of the water-based completion fluid in hydrogen sulfide-containing crude oil also includes a completion fluid storage device, one end of the completion fluid inlet pipeline is connected to the high-temperature and high-pressure reactor, and the other end is connected to the completion fluid storage device.

The present invention provides a testing method and equipment for the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil, which can simulate the interface reaction between the completion fluid and the hydrogen sulfide-containing crude oil in the formation when the completion fluid is in a well-killing state, and at the same time, the fugacity of hydrogen sulfide in the crude oil is used to express the experimental pressure. The hydrogen sulfide gas introduction method is designed, and the gravity differentiation principle is used to simulate the reaction between the completion fluid and the crude oil at the contact interface, which can more closely simulate the actual reaction state of the formation. The test result can provide a basis for whether the completion fluid can be used in a hydrogen sulfide-containing crude oil environment, thereby providing an experimental basis for the optimization of the completion fluid for high-pressure sulfur-containing oil and gas wells.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a testing device for the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil provided in Example 1.

FIG. 2 is a schematic diagram of the structure of a testing device for the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil provided in Example 2.

Description of Figure Numbers:

High temperature and high pressure reactor 1, hydrogen sulfide tank 2, completion fluid inlet pipeline 3, completion fluid storage device 4, gas discharge pipeline 5, pressure measuring device 6, hydrogen sulfide absorption device 7, heating unit 8, temperature measuring unit 9, regulating unit 10, pressure reducing regulator 11, needle valve 12, one-way valve 13, carbon dioxide tank 14, first three-way 15, second three-way 16.

Detailed ways

In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

Example 1

This embodiment provides a test device for the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil, as shown in FIG1 , the device comprises: a high-temperature and high-pressure reactor 1, a hydrogen sulfide tank 2, a completion fluid inlet pipeline 3, a completion fluid storage device 4, Gas discharge pipeline 5, pressure measuring device 6, temperature control device, hydrogen sulfide absorption device 7; the temperature control device includes a heating unit 8, a temperature measuring unit 9 and a regulating unit 10;

Wherein, the hydrogen sulfide tank 2 is connected to the high-temperature and high-pressure reactor 1 through a pipeline; one end of the completion fluid inlet pipeline 3 is connected to the high-temperature and high-pressure reactor 1, and the other end is connected to the completion fluid storage device 4; one end of the gas discharge pipeline 5 is connected to the high-temperature and high-pressure reactor 1, and the other end is connected to the hydrogen sulfide absorption device 7, and the hydrogen sulfide absorption device 7 is filled with sodium hydroxide solution; the pressure measuring device 6 is arranged on the gas discharge pipeline 5 through the first three-way 15; the heating unit 8 is arranged inside the high-temperature and high-pressure reactor 1; the temperature measuring unit 9 is connected to the high-temperature and high-pressure reactor; the regulating unit 10 controls the heating intensity of the heating unit 8 after collecting the temperature measured by the temperature measuring unit 9 to adjust the temperature of the high-temperature and high-pressure reactor 1;

The tank mouth of the hydrogen sulfide tank 2 is provided with a pressure reducing regulator 11;

The tank mouth of the hydrogen sulfide tank 2 is also provided with a pressure compensation valve, which includes a needle valve 12 and a one-way valve 13; the nominal diameter of the needle valve is 5 mm.

In this embodiment, the model of the high temperature and high pressure autoclave is FCZ3-31/325C276, and the remaining devices and units are conventional devices and units in the art.

Example 2

This embodiment provides a testing device for the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil, as shown in FIG2 , the device comprises: a high-temperature and high-pressure reactor 1, a hydrogen sulfide tank 2, a carbon dioxide tank 14, a completion fluid inlet pipeline 3, a completion fluid storage device 4, a gas discharge pipeline 5, a pressure measuring device 6, a temperature control device, and a hydrogen sulfide absorption device 7; the temperature control device comprises a heating unit 8, a temperature measuring unit 9 and a regulating unit 10;

Wherein, the hydrogen sulfide tank 2 is connected to the high-temperature and high-pressure reactor 1 through a pipeline; the carbon dioxide tank 14 is connected to the pipeline connecting the hydrogen sulfide tank 2 and the high-temperature and high-pressure reactor 1 through a second tee 16; one end of the completion fluid inlet pipeline 3 is connected to the high-temperature and high-pressure reactor 1, and the other end is connected to the completion fluid storage device 4; one end of the gas discharge pipeline 5 is connected to the high-temperature and high-pressure reactor 1, and the other end is connected to the hydrogen sulfide absorption device 7, and the hydrogen sulfide absorption device 7 is filled with sodium hydroxide solution; the pressure measuring device 6 is arranged on the gas discharge pipeline 5 through a first tee 15; the heating unit 8 is arranged inside the high-temperature and high-pressure reactor 1; the temperature measuring unit 9 is connected to the high-temperature and high-pressure reactor; after the regulating unit 10 collects the temperature measured by the temperature measuring unit 9, it controls the heating intensity of the heating unit 8 to adjust the temperature of the high-temperature and high-pressure reactor 1;

The tank opening of the hydrogen sulfide tank 2 is provided with a pressure reducing regulator 11, and the tank opening of the hydrogen sulfide tank 2 is also provided with a one-way valve 13;

The tank opening of the carbon dioxide tank 14 is provided with a pressure reducing regulator 11, and the tank opening of the carbon dioxide tank 14 is also provided with a one-way valve 13;

A needle valve 12 is provided on the pipeline connecting the second three-way valve 16 and the high-temperature and high-pressure reactor 1 , and the nominal diameter of the needle valve 12 is 5 mm.

Example 3

This embodiment provides a method for testing the adaptability of a water-based completion fluid in crude oil containing hydrogen sulfide, which is performed using the testing equipment provided in Example 1. The method tests the adaptability of a CaBr ₂ /ZnCl ₂ completion fluid in crude oil containing hydrogen sulfide.

The method comprises the following steps:

(1) The basic properties and main ion content of the completion fluid to be tested (i.e., CaBr ₂ /ZnCl ₂ completion fluid) were tested at 24°C, -28°C, and 100°C, respectively. The basic properties include density, turbidity, pH value, viscosity, and crystallization temperature. The density tester (model SY-1/3), pH tester (model STARTER 300), turbidity tester (model 1900C), and other equipment and instruments used are all conventional in the art. The results are shown in Tables 1 to 4.

Table 1 Basic performance test results of CaBr ₂ /ZnCl ₂ completion fluid at different temperatures

Initial screening:

(a)-1 Pump 1000 mL of crude oil into a high temperature and high pressure reactor, and then introduce hydrogen sulfide gas into the high temperature and high pressure reactor for 2 hours until the crude oil is saturated with hydrogen sulfide;

(a)-2 Use activated carbon to deoxygenate the completion fluid to be tested, and then pass 1000 mL of the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(a)-3 heating the high temperature and high pressure reactor to a set temperature of 100°C, adjusting its pressure to normal pressure as the set pressure, and then keeping it stable; measuring the temperature of the high temperature and high pressure reactor every 3 days, and if the temperature is different from the set temperature, adjusting the temperature of the high temperature and high pressure reactor to make it the same as the set temperature; wherein the temperature of the high temperature and high pressure reactor is adjusted by the intensity of heating;

(a)-4 After reaching the set reaction time, stop heating and cool the high temperature and high pressure reactor to room temperature. out the fluid therein; wherein the set reaction times are 1 day, 3 days, 7 days, 15 days, and 30 days respectively;

(a)-5 At 1 day, 3 days, 7 days, 15 days and 30 days, the basic properties and main ion content of the completion fluid after the reaction were tested at room temperature and pressure, respectively. The basic properties test of the completion fluid after the reaction at least includes density test and pH value test. The results are shown in Tables 3 and 4;

(a)-6 Preliminary judgment on whether the completion fluid is suitable for crude oil containing hydrogen sulfide: From the data in Tables 3 and 4, it can be seen that the pH value of the completion fluid to be tested is less than 2, the density change of the completion fluid before and after the reaction is less than 0.2SG, the amount of precipitation of the completion fluid after the reaction after passing through a 400-mesh filter is more than 100g/1000mL, there is obvious precipitation, and the results of repeated experiments are consistent (i.e., the experimental results of 1 day, 3 days, 7 days, 15 days, and 30 days are consistent), and the change of the zinc ion content of the completion fluid before and after the reaction is more than 0.05kg/L in some repeated experiments. Therefore, it is preliminarily judged that the completion fluid is not suitable for crude oil containing hydrogen sulfide;

However, the completion fluid is still subjected to the following steps (2) to (8) to ultimately determine whether the completion fluid is suitable for crude oil containing hydrogen sulfide;

(2) Calculate the fugacity of hydrogen sulfide according to the following formula (1), and use the calculated fugacity of hydrogen sulfide as the set pressure of the experiment.

In formula (1), is the fugacity of hydrogen sulfide, in MPa; is the partial pressure of hydrogen sulfide, in MPa; is the fugacity coefficient;

The partial pressure of hydrogen sulfide is the partial pressure of hydrogen sulfide in the hydrogen sulfide-containing crude oil. The specific calculation method is conventional in the art. Generally speaking, it is obtained by multiplying the total system pressure (that is, the formation pressure of the hydrogen sulfide-containing crude oil) by the molar fraction of hydrogen sulfide in the gas phase. The fugacity coefficient According to the calculation formula for the fugacity coefficient of the components in the mixture obtained by combining the SRK equation with the one-parameter van der Waals mixing rule disclosed on pages 6 to 8 in "Improvement of the SRK equation and its application in phase equilibrium calculation" (Luo Mingjian, master's degree thesis of Tianjin University, December 2005), that is, formula (2-34), the fugacity of hydrogen sulfide is calculated to be 5.8 MPa;

(3) 1000 mL of crude oil was pumped into a high temperature and high pressure reactor, and then hydrogen sulfide gas was introduced into the high temperature and high pressure reactor for 2 hours until the crude oil was saturated with hydrogen sulfide;

(4) deoxygenating the completion fluid to be tested using activated carbon, and then introducing 1000 mL of the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(5) heating the high-temperature and high-pressure reactor to a set temperature of 100° C., and adjusting its pressure to the set pressure obtained in step (2), i.e., 5.8 MPa, and then keeping it stable; measuring the temperature and pressure of the high-temperature and high-pressure reactor every 3 days, and if the temperature and/or pressure are different from the set temperature and/or set pressure, adjusting the temperature and/or pressure of the high-temperature and high-pressure reactor to make them the same as the set temperature and set pressure;

The temperature of the high-temperature and high-pressure reactor is adjusted by the intensity of heating, and the pressure of the high-temperature and high-pressure reactor is adjusted by introducing hydrogen sulfide gas. When the measured pressure of the high-temperature and high-pressure reactor is lower than the set pressure by more than 0.5 MPa, hydrogen sulfide gas is introduced into the high-temperature and high-pressure reactor to supplement the pressure to the set pressure. When the pressure is adjusted, the flow rate of the hydrogen sulfide gas is less than 10 mm/min, and the flow rate is 200 mL/min.

(6) After the set reaction time is reached, the pressure is released, the heating is stopped, the high temperature and high pressure reactor is cooled to room temperature, and the fluid therein is discharged; wherein the set reaction time is 7 days;

(7) Testing the basic properties and main ion content of the completion fluid after the reaction at normal temperature and pressure, wherein the basic properties testing of the completion fluid after the reaction at least includes density testing and pH value testing, and the results are shown in Table 2, Table 3 and Table 4;

Table 2 Test results of basic properties and main ion content of completion fluid before and after reaction at normal temperature and pressure

Table 3 Test results of basic properties of CaBr ₂ /ZnCl ₂ completion fluid before and after reaction at normal temperature and pressure

Table 4 Detection results of main ion content of CaBr ₂ /ZnCl ₂ completion fluid before and after reaction at normal temperature and pressure

(8) The results are as follows: the pH value of the completion fluid to be tested is less than 2, and the density change of the completion fluid before and after the reaction is less than 0.2SG. However, the amount of precipitation of the completion fluid after the reaction after passing through a 400-mesh filter is more than 100 g/1000 mL, and there is obvious precipitation. Therefore, the completion fluid is not suitable for crude oil containing hydrogen sulfide.

Claims

A method for testing the adaptability of a water-based completion fluid in crude oil containing hydrogen sulfide comprises the following steps:

(1) testing the completion fluid to be tested, wherein the testing at least includes testing the basic properties of the completion fluid to be tested, and the basic properties testing of the completion fluid to be tested at least includes density testing;

(2) pumping crude oil into a high-temperature and high-pressure reactor, and then introducing hydrogen sulfide gas into the high-temperature and high-pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide;

(3) deoxygenating the completion fluid to be tested, and then introducing the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(4) heating the high-temperature and high-pressure reactor to a set temperature, adjusting its pressure to a set pressure, wherein the set pressure is the fugacity of hydrogen sulfide, and then keeping it stable; measuring the temperature and pressure of the high-temperature and high-pressure reactor at regular intervals, and if the temperature and/or pressure are different from the set temperature and/or set pressure, adjusting the temperature and/or pressure of the high-temperature and high-pressure reactor to make them the same as the set temperature and set pressure;

(5) After the set reaction time is reached, the pressure is released, the heating is stopped, the high temperature and high pressure reactor is cooled to room temperature, and the fluid therein is discharged;

(6) testing the completion fluid after the reaction, wherein the testing at least includes testing the basic properties of the completion fluid after the reaction, and the basic properties of the completion fluid after the reaction at least includes density testing;

(7) Based at least on the test result of the completion fluid to be tested obtained in step (1) and the test result of the completion fluid after reaction obtained in step (6), determine whether the completion fluid is suitable for use in crude oil containing hydrogen sulfide.
The method for testing the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1, wherein the testing method further comprises a preliminary screening after step (1), wherein the preliminary screening comprises:

(a)-1 Pump crude oil into a high temperature and high pressure reactor, and then introduce hydrogen sulfide gas into the high temperature and high pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide;

(a)-2 Deoxygenate the completion fluid to be tested, and then introduce the deoxygenated completion fluid to be tested into a high-temperature and high-pressure reactor;

(a)-3 Heat the high-temperature and high-pressure reactor to a set temperature, adjust its pressure to normal pressure as the set pressure, and then keep it stable; measure the temperature of the high-temperature and high-pressure reactor at regular intervals, and if the temperature is different from the set temperature, adjust the temperature of the high-temperature and high-pressure reactor to make it the same as the set temperature;

(a)-4 After reaching the set reaction time, stop heating, cool the high temperature and high pressure reactor to room temperature, and discharge the fluid therein;

(a)-5 testing the completion fluid after the reaction, wherein the testing at least includes testing the basic properties of the completion fluid after the reaction, and the basic properties of the completion fluid after the reaction at least includes density testing;

(a)-6 Based at least on the test results of the completion fluid to be tested and the test results of the completion fluid after reaction, a preliminary judgment is made. Whether the completion fluid is suitable for crude oil containing hydrogen sulfide is determined by performing steps (2) to (7) on the completion fluid that is initially determined to be suitable for crude oil containing hydrogen sulfide, so as to finally determine whether the completion fluid is suitable for crude oil containing hydrogen sulfide.
According to the method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil as described in claim 2, step (a)-6 also includes: for the completion fluid that is initially judged to be unsuitable for hydrogen sulfide-containing crude oil, steps (2) to (7) are also performed to finally judge whether the completion fluid is suitable for hydrogen sulfide-containing crude oil.
According to the test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1, wherein, in step (1), the basic performance test of the completion fluid to be tested also includes one or a combination of pH value detection, viscosity detection, crystallization temperature detection and turbidity detection.
According to the method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil as claimed in claim 1, wherein in step (1), the testing of the completion fluid to be tested also includes testing the ion content of the completion fluid to be tested.
The method for testing the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein in step (2) and step (a)-1, the amount of crude oil pumped into the high-temperature and high-pressure reactor is 1000 to 3000 mL;

In step (2) and step (a)-1, the time for introducing hydrogen sulfide gas is 1.5 to 2.5 hours.
The method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein step (2) and step (a)-1 further comprise: introducing carbon dioxide gas into the high-temperature and high-pressure reactor for a period of time until the crude oil is saturated with hydrogen sulfide and carbon dioxide.
The method for testing the adaptability of a water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein in step (3) and step (a)-2, the amount of the deoxygenated completion fluid to be tested introduced into the high-temperature and high-pressure reactor is 1000 to 3000 mL.
The method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein in step (4) and step (a)-3, the set temperature is the crude oil temperature of the working formation of the completion fluid to be tested.
The method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1, wherein, in step (4), the temperature and pressure of the high-temperature and high-pressure reactor are measured every 60 to 80 hours.
The method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 2, wherein in step (a)-3, the temperature of the high-temperature and high-pressure reactor is measured once every 24 to 80 hours.
According to claim 1, the test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil, wherein, in step (4), the temperature of the high-temperature and high-pressure reactor is adjusted by the intensity of heating, and the pressure of the high-temperature and high-pressure reactor is adjusted by introducing hydrogen sulfide gas; when the measured pressure of the high-temperature and high-pressure reactor is lower than the set pressure by more than 0.5 MPa, hydrogen sulfide gas is introduced into the high-temperature and high-pressure reactor to supplement the pressure to the set pressure; when the pressure is adjusted, the flow rate of the hydrogen sulfide gas is less than 10 mm/min, and the flow rate is 150 to 250 mL/min.
The method for testing the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein in step (5), the set reaction time is 6-8 days;

In step (a)-4, the set reaction time is 1 day to 2 months.
According to the test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein, in step (6) and step (a)-5, the basic performance test of the completion fluid after the reaction also includes one or a combination of pH value detection, viscosity detection, crystallization temperature detection and turbidity detection.
According to the test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1 or 2, wherein, in step (6) and step (a)-5, the detection of the completion fluid after the reaction also includes detecting the ion content of the completion fluid after the reaction.
According to the test method for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 1, wherein, in step (7), judging whether the completion fluid is suitable for hydrogen sulfide-containing crude oil includes the following manner: if the density change of the completion fluid before and after the reaction is greater than 0.2SG or there is obvious precipitation in the completion fluid after the reaction, then the completion fluid is not suitable for hydrogen sulfide-containing crude oil; the obvious precipitation is that the amount of precipitation after passing through a 300-400 mesh filter is 100g/1000mL or more;

Preferably, in step (7), judging whether the completion fluid is suitable for crude oil containing hydrogen sulfide further comprises the following manner: if the pH value of the completion fluid to be tested is greater than 2, or if the viscosity of the completion fluid before and after the reaction changes by more than 10 mPa.s, or if the crystallization temperature of the completion fluid before and after the reaction changes by more than 5°C, or if the turbidity of the completion fluid before and after the reaction changes by more than 10 NTU, then the completion fluid is not suitable for crude oil containing hydrogen sulfide;

Preferably, in step (7), judging whether the completion fluid is suitable for crude oil containing hydrogen sulfide further comprises the following method: if the change in the main ion content of the completion fluid before and after the reaction is greater than 0.05 kg/L, the completion fluid is not suitable for crude oil containing hydrogen sulfide.
The test method for the adaptability of a water-based completion fluid in a crude oil containing hydrogen sulfide according to claim 2, wherein in step (a)-6, the preliminary judgment of whether the completion fluid is suitable for the crude oil containing hydrogen sulfide includes the following manners: if the density change of the completion fluid before and after the reaction is greater than 0.2SG or there is obvious precipitation in the completion fluid after the reaction, the completion fluid is not suitable for the crude oil containing hydrogen sulfide; if the density change of the completion fluid before and after the reaction is less than 0.2SG and there is no obvious precipitation in the completion fluid after the reaction, it is preliminarily judged that the completion fluid is suitable for the crude oil containing hydrogen sulfide; the obvious precipitation is the amount of precipitation after passing through a 300-400 mesh filter screen of more than 100g/1000mL;

Preferably, in step (a)-6, the preliminary determination of whether the completion fluid is suitable for crude oil containing hydrogen sulfide further comprises the following manner: if the pH value of the completion fluid to be tested is greater than 2, or if the viscosity of the completion fluid before and after the reaction changes by more than 10 mPa.s, or if the crystallization temperature of the completion fluid before and after the reaction changes by more than 5°C, or if the turbidity of the completion fluid before and after the reaction changes by more than 10, then the completion fluid is not suitable for crude oil containing hydrogen sulfide;

Preferably, in step (a)-6, it is preliminarily determined whether the completion fluid is suitable for further use in crude oil containing hydrogen sulfide. The method includes the following: if the change in the main ion content of the completion fluid before and after the reaction is greater than 0.05 kg/L, the completion fluid is not suitable for crude oil containing hydrogen sulfide.
A testing device for the adaptability of a water-based completion fluid in a hydrogen sulfide-containing crude oil, the device being used to implement the testing method for the adaptability of a water-based completion fluid in a hydrogen sulfide-containing crude oil as described in any one of claims 1 to 17, the device comprising at least: a high-temperature and high-pressure reactor, a hydrogen sulfide tank, a completion fluid inlet pipeline, a gas outlet pipeline, a pressure measuring device, and a temperature control device; the temperature control device comprising a heating unit, a temperature measuring unit, and a regulating unit;

Wherein, the hydrogen sulfide tank is connected to the high-temperature and high-pressure reactor through a pipeline; the completion fluid inlet pipeline is connected to the high-temperature and high-pressure reactor; the gas exhaust pipeline is connected to the high-temperature and high-pressure reactor; the pressure measuring device is arranged on the gas exhaust pipeline through a tee; the heating unit is arranged inside the high-temperature and high-pressure reactor; the temperature measuring unit is connected to the high-temperature and high-pressure reactor; after the regulating unit collects the temperature measured by the temperature measuring unit, it controls the heating intensity of the heating unit to adjust the temperature of the high-temperature and high-pressure reactor.
The testing equipment for the adaptability of water-based completion fluid in crude oil containing hydrogen sulfide according to claim 18, wherein the tank mouth of the hydrogen sulfide tank is provided with a pressure reducing regulator;

The tank mouth of the hydrogen sulfide tank is provided with a pressure-compensating valve, and the pressure-compensating valve controls a needle valve and a one-way valve.
The testing equipment for the adaptability of water-based completion fluid in hydrogen sulfide-containing crude oil according to claim 18, wherein the testing equipment also includes a carbon dioxide tank, and the carbon dioxide tank is connected to the pipeline connecting the hydrogen sulfide tank and the high-temperature and high-pressure reactor through a tee.