Hydration heat meter for low-temperature well cementation cement slurry and measurement method

Abstract

The invention provides a hydration heat meter for low-temperature well cementation cement slurry, which comprises a freezing mechanism comprising a freezing cavity and a measuring mechanism, the at least two measuring cavities are arranged in the freezing cavity; the first reaction cup and the second reaction cup are respectively arranged in different measuring cavities; the first reaction cup is used for placing a standard sample; the second reaction cup is used for placing a contrast sample; the first galvanic couples are arranged in the measuring cavity and respectively record temperature data of the first reaction cup and the second reaction cup, and the refrigerating mechanism is used for adjusting the temperature of an annulus between the freezing cavity and the measuring cavity. According to the invention, the temperature in the freezing cavity is rapidly reduced to ensure that the temperature in the annulus can be constant, so that simulation of a real low-temperature environment is provided for well cementation cement slurry.

Description

Technical Field

[0001] The invention relates to the field of cementing equipment, in particular to a hydration heat meter for low-temperature cementing slurry and a method for measuring hydration heat release data of low-temperature cementing slurry in a waiting process. Background Art

[0002] With the development of economic activities, people's demand for oil and natural gas energy has further increased. The development of rich oil and gas resources in low-temperature areas such as deep sea and permafrost areas is imperative. In the process of oil and gas resource exploration and development in low-temperature areas, cementing operations are the key factor in ensuring the release of deepwater oil and gas resource production capacity. However, natural gas hydrate formations are often encountered during the exploration and development of oil and gas resources in low-temperature areas. The unique properties of hydrates themselves and their geological conditions have brought great challenges to cementing operations.

[0003] Hydrate is a cage-shaped compound formed by gaseous methane, ethane and propane molecules and liquid water molecules under low temperature, high pressure and suitable electrolyte conditions. It can exist stably under certain temperature and pressure, but it is easily destroyed under harsh temperature and pressure conditions, thereby decomposing into gas 160 times its own volume. The hydration reaction of cement slurry is an exothermic reaction, which is accompanied by the release of heat and the generation of new substances. Therefore, if the heat of cement hydration is too high during the cementing process, the hydrate formation will decompose due to heat, which may lead to engineering accidents such as well diameter expansion, well wall collapse, casing deformation, gas channeling, cementing quality decline, well leakage and well kick, etc., or even geological disasters such as landslides and formation slippage, causing irreparable losses.

[0004] In addition, the heat release and heat release rate of cement slurry hydration are not only important indicators of the degree and rate of cement slurry hydration, but also directly determine the evolution of cement slurry microstructure, the development of mechanical strength and the quality of cementing. It is closely related to the ambient temperature. For example, the higher the temperature, the faster the hydration reaction, the higher the hydration degree and heat release, and the higher the strength of cement paste; the lower the temperature, the slower the hydration reaction, the lower the hydration degree and heat release, and the lower the strength of cement paste. Usually, the hydration reaction of cementing cement is slow at low temperatures, and the strength is difficult to meet the requirements of cementing construction. Therefore, whether cement can quickly form strength is crucial to ensure the quality of cementing construction in low temperature environments. It can be seen that the heat release of cement hydration is an important indicator for the evaluation of low-temperature cement, and it is also a key factor in ensuring the safety and quality of cementing construction in hydrate formations.

[0005] However, most conventional cement slurry hydration calorimeters are currently designed for room temperature or high temperature conditions, which are usually 20°C to 30°C higher than the design temperature of low-temperature cement slurry, and do not have relevant refrigeration and low-temperature control functions, making it difficult to accurately test the hydration heat release performance of cement slurry below room temperature. In addition, if the cement slurry hydration calorimeter is directly placed in a low-temperature environment within its rated working environment range, it will cause problems such as frost on the instrument's circuit board, damage to the instrument, and reduced measurement accuracy, making it difficult to simulate the low-temperature cementing cement slurry waiting process under real low-temperature conditions and measure the hydration heat release data.

[0006] Therefore, it is desired in the art to provide a hydration calorimeter for low-temperature cementing slurry to solve the above technical problems. Summary of the invention

[0007] The purpose of the present invention is to propose a hydration heat meter for low-temperature cementing slurry, which can absorb the heat of the annulus between the freezing chamber and the measuring chamber by gasification of low-pressure liquid, thereby quickly reducing the temperature in the freezing chamber to ensure that the annulus can have a constant temperature, thereby providing a simulation of a real low-temperature environment for cementing slurry. In addition, a method for measuring the hydration heat of low-temperature cementing slurry is also proposed.

[0008] According to a first aspect of the present invention, there is provided a hydration calorimeter for low-temperature cementing slurry, comprising a freezing mechanism, which comprises a freezing chamber,

[0009] A measuring mechanism, comprising at least two measuring chambers arranged in the freezing chamber, a first reaction cup for placing a standard sample and a second reaction cup for placing a comparison sample, respectively arranged in different measuring chambers, and a plurality of first thermocouples arranged in the measuring chambers and respectively recording temperature data of the first reaction cup and the second reaction cup, and

[0010] A refrigeration mechanism is used to adjust the temperature of the annulus between the freezing chamber and the measuring chamber.

[0011] In one embodiment, the freezing chamber is configured in the form of a hollow sleeve, and the freezing mechanism further includes a kettle cover disposed above the freezing chamber, and a collector disposed below the freezing chamber and used to receive temperature data from the first thermocouple, wherein the kettle cover and the collector are both sealedly connected to the inner circumferential surface of the freezing chamber.

[0012] In one embodiment, the measuring chamber is constructed in the form of a hollow sleeve and is sealedly connected to the kettle cover and the collector respectively.

[0013] In one embodiment, the standard sample is an unhydrated cement sample, the control sample is a hydrated cement sample, and the measuring mechanism further comprises a syringe extending through the kettle cover and aligned with the first reaction cup, wherein the syringe contains slurry water for combining with the standard sample.

[0014] In one embodiment, the first thermocouple is configured in a rod-like form, and the first thermocouple is disposed longitudinally in each of the measurement cavities.

[0015] In one embodiment, the refrigeration mechanism comprises a U-shaped channel arranged outside the freezing chamber, and both ends of the U-shaped channel extend into the annulus between the freezing chamber and the measuring chamber.

[0016] In one embodiment, the refrigeration mechanism further includes a refrigeration compressor containing a gas refrigerant disposed at the inlet of the U-shaped channel, a throttle valve disposed at the outlet of the U-shaped channel, and a condenser disposed between the refrigeration compressor and the throttle valve.

[0017] The refrigeration compressor is configured to pressurize the gas refrigerant, and the pressurized gas refrigerant is converted into a low-pressure liquid through the condenser and the throttle valve and then flows to the annulus through the outlet of the U-shaped channel.

[0018] In one embodiment, the refrigeration mechanism further comprises an evaporator disposed in the annulus and configured to receive low-pressure liquid from the throttle valve, and a plurality of second thermocouples circumferentially spaced apart in the annulus and configured to record temperature data in the freezing chamber.

[0019] In one embodiment, the surfaces of the first galvanic couple, the second galvanic couple and the evaporator are coated with an epoxy resin protective layer for preventing condensation or frost.

[0020] In one embodiment, the hydration calorimeter further comprises a heat insulating layer made of foamed asbestos which is sleeved outside the freezing chamber.

[0021] In one embodiment, the hydration calorimeter further includes a controller, and the controller is respectively connected to the collector, the second thermocouple and the refrigeration compressor.

[0022] According to a second aspect of the present invention, there is provided a method for measuring the hydration heat of low-temperature cementing slurry using the hydration heat meter as described above, comprising the following steps:

[0023] S1, adding a standard sample and a comparative sample into the first reaction cup and the second reaction cup respectively;

[0024] S2, controlling the refrigeration mechanism through the controller to adjust the temperature of the annulus between the freezing chamber and the measuring chamber to the temperature required for the solidification process, and injecting slurry preparation water into the first reaction cup through the syringe;

[0025] S3. Record the temperature data of the first reaction cup and the second reaction cup respectively through the first thermocouple, and transmit the recorded temperature data to the collector.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] First, the present invention can simulate the actual low-temperature environment on site through the refrigeration mechanism.

[0028] Specifically, the first step: the gas refrigerant is pressurized by the refrigeration compressor. The second step: the pressurized gas refrigerant releases heat in the condenser to form a high-pressure liquid. The third step: the high-pressure liquid increases in volume in the throttle valve to form a low-pressure liquid. The fourth step: the low-pressure liquid absorbs heat and vaporizes in the evaporator to form a low-pressure gas.

[0029] And in the fourth step, the low-pressure liquid in the present invention is vaporized in the evaporator to form a low-pressure gas, thereby absorbing the heat in the annulus between the freezing chamber and the measuring chamber, so as to quickly reduce the temperature in the freezing chamber, thereby ensuring that the temperature in the annulus can meet the temperature requirements of the low-temperature cementing slurry during the waiting process.

[0030] Secondly, since the low-pressure liquid in the annulus between the freezing chamber and the measuring chamber achieves the refrigeration effect by absorbing heat and gasifying, the electronic components and joints in the freezing chamber are very likely to corrode and frost in a low-temperature environment. Therefore, the present invention improves the corrosion resistance and frost resistance of the electronic components in the hydration calorimeter for low-temperature cementing cement slurry by coating the surfaces of the first galvanic couple, the second galvanic couple and the evaporator with an epoxy resin protective layer for preventing condensation or frost, thereby improving the service life of the hydration calorimeter for low-temperature cementing cement slurry and ensuring that the electronic components can always have accurate testing accuracy.

[0031] Third, since the refrigeration system of the present invention is cyclic, it can ensure that the annulus between the freezing chamber and the measuring chamber has a constant temperature, and further provide a good and stable simulation environment for the standard sample (unhydrated cement sample) to improve the accuracy of the temperature data recorded by the first thermocouple. Specifically, in the fourth step of the refrigeration process, the low-pressure gas formed by the vaporization of the low-pressure liquid can enter the refrigeration compressor again, and the refrigeration process of the first step, the second step, the third step and the fourth step can be performed cyclically, thereby ensuring that the annulus has a constant temperature.

[0032] In addition, since the freezing chamber, kettle cover and collector are constructed into a closed structure, it is ensured that the gas refrigerant is not lost during the refrigeration process, so as to improve the circulation capacity of the refrigerant in the refrigeration mechanism, thereby improving the energy saving and flexibility of the hydration calorimeter used for low-temperature cementing slurry.

[0033] Fourthly, the present invention can accurately record the real-time temperature change data in the freezing chamber by circumferentially setting a plurality of second thermocouples in the annulus between the freezing chamber and the measuring chamber, and can also control the refrigeration mechanism by the controller to achieve precise regulation of the temperature in the freezing chamber. Thus, the temperature in the annulus can always be kept constant, thereby providing a good and stable simulation environment for the standard sample (unhydrated cement sample) to improve the accuracy of the temperature data recorded by the first thermocouple.

[0034] Fifth, the present invention can accurately record the hydration heat release performance (heat release and heat release rate) and temperature data of cement slurry at low temperature through the first galvanic couple. Specifically, each measuring cavity corresponds to only one first galvanic couple. Therefore, the temperature data of the first reaction cup and the second reaction cup can be accurately recorded at the same time through multiple first galvanic couples, thereby improving the accuracy of the experimental data.

[0035] In addition, since the two ends of the measuring cavity are sealedly connected to the kettle cover and the collector respectively, the measuring cavity can have good sealing under the joint action of the kettle cover and the collector, thereby effectively eliminating the influence of the outside world on the experimental environment and improving the accuracy of the experimental data.

[0036] In addition, since the first galvanic couples are longitudinally arranged in each measuring cavity, the temperature data in the measuring cavity can be comprehensively measured. In this way, the first galvanic couple and the reaction cup (the first reaction cup and the second reaction cup) can have a larger contact area, thereby ensuring that the first galvanic couple can accurately record the temperature change data of the reaction cup, so as to improve the ability of the present invention to obtain the heat energy and temperature change data released by the cementing cement slurry during the hydration process and the accuracy of the obtained data, thereby realizing the test of the low-temperature hydration thermal performance of the cementing cement slurry under room temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present invention will be described in detail below in conjunction with the accompanying drawings, in which:

[0038] Figure 1 The structure of the hydration calorimeter for low-temperature cement slurry according to the present invention is schematically shown.

[0039] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0040] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0041] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0042] In the present invention, unless otherwise clearly stipulated and limited, terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements.

[0043] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] The present invention will be further described below in conjunction with the accompanying drawings.

[0045] Figure 1 The structure of a hydration calorimeter 100 for low-temperature cement slurry according to the present invention is schematically shown.

[0046] like Figure 1 As shown, according to the first aspect of the present invention, a hydration calorimeter 100 for low-temperature cementing slurry is provided, which includes a freezing mechanism. Preferably, the freezing mechanism includes a freezing chamber 11, a kettle cover 12 and a collector 13.

[0047] In one embodiment, the freezing chamber 11 is configured as a hollow sleeve-shaped cavity, so as to accommodate the measuring chamber 21 (described below). The kettle cover 12 is disposed above the freezing chamber 11 and can partially form a sealed connection with the inner peripheral surface of the freezing chamber 11. The collector 13 is disposed below the freezing chamber 11 and can partially form a sealed connection with the inner peripheral surface of the freezing chamber 11.

[0048] Preferably, the freezing chamber 11, the kettle cover 12 and the collector 13 are constructed into a closed structure, so as to ensure that the temperature in the freezing chamber 11 can always be maintained within a constant range, so as to achieve the purpose of simulating the waiting process of cementing slurry under low temperature conditions, thereby significantly improving the accuracy of the experimental data. The content is introduced below.

[0049] In a preferred embodiment, the kettle cover 12 is made of a heat-insulating material, so as to effectively isolate the interference of external heat sources and provide a good simulation environment for the cementing slurry.

[0050] In a specific embodiment, the applicable temperature of the cementing slurry (waiting for setting process) is in the range of -8°C to 4°C. It should be noted that the low temperature environment described in the present invention is the above temperature range.

[0051] According to the present invention, the hydration calorimeter 100 for low temperature cementing slurry further comprises a measuring mechanism. Figure 1 As shown, the measuring mechanism includes a measuring chamber 21 , a first reaction cup 201 and a second reaction cup 202 .

[0052] In one embodiment, at least two measuring chambers 21 are provided, and both are installed in the freezing chamber 11. Preferably, the measuring chamber 21 is constructed in the form of a hollow sleeve, and the top end of the measuring chamber 21 is sealedly connected to the kettle cover 12, and the bottom end of the measuring chamber 21 is sealedly connected to the collector 13. As a result, the measuring chamber 21 can have good sealing after being combined with the kettle cover 12 and the collector 13, thereby effectively preventing the influence of the outside world on the experimental environment, so as to improve the accuracy of the experimental data.

[0053] In one embodiment, the first reaction cup 201 and the second reaction cup 202 have the same structure and are placed in different measuring chambers 21 . In other words, each measuring chamber 21 corresponds to only one reaction cup (the first reaction cup 201 or the second reaction cup 202 ).

[0054] Preferably, a standard sample is placed in the first reaction cup 201, and the standard sample is an unhydrated cement sample (cementing slurry). The cement sample needs to be combined with an appropriate amount of mixing water (described below) to promote the cementing slurry to hydrate and release heat. At that time, the first galvanic couple 22 (described below) can be used to comprehensively record the heat energy released and the temperature change data during the hydration of the cementing slurry.

[0055] Preferably, a comparison sample is placed in the second reaction cup 202, which is a cement sample (cementing slurry) that has been completely hydrated. The cement sample serves as a control group for the cement sample in the first reaction cup 201 to facilitate the subsequent recording and analysis of the heat energy released and the temperature change data during the hydration of the cementing slurry.

[0056] In one embodiment, Figure 1 As shown, the measuring mechanism further includes a first thermocouple 22. A plurality of first thermocouples 22 are provided, and are respectively located in different measuring chambers 21. In other words, each measuring chamber 21 corresponds to only one first thermocouple 22. Thus, the temperature data of the first reaction cup 201 and the second reaction cup 202 can be accurately recorded simultaneously through a plurality of first thermocouples 22, thereby improving the accuracy of the experimental data.

[0057] In a specific embodiment, the first thermocouples 22 are connected to the collector 13, so that the recorded temperature data about the first reaction cup 201 and the second reaction cup 202 can be transmitted in real time, so that accurate and timely data can be obtained.

[0058] In a preferred embodiment, the first galvanic couple 22 is configured in a rod-like form, and the first galvanic couple 22 is longitudinally arranged in each measuring cavity 21, so that the temperature in the measuring cavity 21 can be fully measured. In this way, the first galvanic couple 22 and the reaction cup (the first reaction cup 201 or the second reaction cup 202) can have a larger contact area, thereby ensuring that the first galvanic couple 22 can accurately record the temperature change of the reaction cup (the first reaction cup 201 or the second reaction cup 202), so as to improve the ability of the present invention to obtain the heat energy and temperature change data released by the low-temperature cementing slurry during the hydration process and the accuracy of the obtained data, thereby realizing the test of the hydration thermal performance of the low-temperature cementing slurry under room temperature.

[0059] In one embodiment, Figure 1 As shown, the measuring mechanism further includes a syringe 23. The syringe 23 is configured to extend through the kettle cover 12, and the outlet of the syringe 23 is aligned with the first reaction cup 201, so that the slurry preparation water in the syringe 23 can be accurately injected into the first reaction cup 201. Preferably, the syringe 23 contains slurry preparation water for combining with the standard sample (unhydrated cement sample).

[0060] It is easy to understand that when the freezing chamber 11 meets the temperature required for the cementing cement slurry waiting process under the action of the refrigeration mechanism (introduced below), the slurry preparation water can be injected into the first reaction cup 201 through the syringe 23, so that the standard sample in the first reaction cup 201 can be smoothly combined with the slurry preparation water to perform hydration and heat release.

[0061] In one embodiment, Figure 1As shown, the measuring mechanism also includes a rotating screw 24 disposed above the kettle cover 12 and connected to the syringe 23. It is easy to understand that the syringe 23 can be pushed to inject the slurry preparation water into the first reaction cup 201 by simply turning the rotating screw 24 downward. In this way, the problem of affecting the injection of slurry preparation water due to accidental touching of the syringe 23 during the simulation process can be effectively prevented, so that the waiting process of cementing cement slurry can be truly simulated.

[0062] According to the present invention, the hydration calorimeter 100 for low-temperature cementing slurry further comprises a refrigeration mechanism. Preferably, the refrigeration mechanism can adjust the temperature of the annulus 101 between the freezing chamber 11 and the measuring chamber 21. Specifically, on the one hand, the refrigeration mechanism can adjust the temperature in the annulus 101 to meet the temperature required by the low-temperature cementing slurry during the waiting process; on the other hand, the refrigeration mechanism can ensure that the annulus 101 has a constant temperature through low-pressure liquid gasification, thereby providing a good and stable simulation environment for the standard sample (unhydrated cement sample), further improving the accuracy of the temperature data recorded by the first thermocouple 22.

[0063] In one embodiment, Figure 1 As shown, the refrigeration mechanism includes a U-shaped channel 31 , a refrigeration compressor 32 , a throttle valve 33 and a condenser pipe 34 .

[0064] In a preferred embodiment, the U-shaped channel 31 is partially disposed outside the freezing chamber 11. Both ends of the U-shaped channel 31 extend into the freezing chamber 11, respectively, thereby facilitating the transport of the refrigerant (low-pressure liquid) to the evaporator 35 (described below) to achieve the purpose of rapidly adjusting the temperature in the freezing chamber 11.

[0065] In a preferred embodiment, the refrigeration compressor 32 is disposed at the inlet 301 of the U-shaped channel 31, and a certain amount of gas refrigerant is contained in the refrigeration compressor 32. Specifically, the refrigeration compressor 32 is configured to pressurize the gas refrigerant, and the pressurized gas refrigerant flows to the condenser 34.

[0066] In a preferred embodiment, the condenser 34 is disposed between the refrigeration compressor 32 and the throttle valve 33, and the condenser 34 is configured to receive the pressurized gas refrigerant from the refrigeration compressor 32. Specifically, the pressurized gas refrigerant can release heat in the condenser 34 to form a high-pressure liquid, and further flow toward the throttle valve 33.

[0067] In a preferred embodiment, the throttle valve 33 is disposed at the outlet 302 of the U-shaped channel 31, and the throttle valve 33 is configured to receive high-pressure liquid from the condenser 34. Specifically, the high-pressure liquid can increase in volume in the throttle valve 33 to form low-pressure liquid, and further flow to the evaporator 35.

[0068] According to a specific embodiment of the present invention, the refrigeration compressor 32 is configured to pressurize the gas refrigerant, and the pressurized gas refrigerant forms a high-pressure liquid in the condenser 34, and the high-pressure liquid forms a low-pressure liquid through the throttle valve 33. Finally, the low-pressure liquid flows through the outlet 302 of the U-shaped channel 31 to the evaporator 35 in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, and is vaporized in the evaporator 35 to achieve the purpose of lowering the temperature in the annulus 101.

[0069] In one embodiment, Figure 1 As shown, the refrigeration mechanism further includes an evaporator 35. The evaporator 35 is disposed in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, and is capable of receiving low-pressure liquid from the throttle valve 33. Specifically, the low-pressure liquid absorbs heat and vaporizes in the evaporator 35 to form a low-pressure gas, thereby being able to quickly reduce the temperature in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, so as to ensure that the temperature in the annulus 101 can meet the temperature required for the cementing slurry waiting process.

[0070] In one embodiment, the evaporator 35 is configured in a spiral shape to be sleeved in the annulus 101 between the freezing chamber 11 and the measuring chamber 21 .

[0071] In a preferred embodiment, the refrigeration system formed by the refrigeration mechanism is a cyclic process.

[0072] The first step: the gas refrigerant is pressurized by the refrigeration compressor 32 .

[0073] Step 2: The pressurized gas refrigerant releases heat in the condenser tube 34 to form a high-pressure liquid.

[0074] Step 3: The high-pressure liquid increases in volume in the throttle valve 33 to form a low-pressure liquid.

[0075] Step 4: The low-pressure liquid absorbs heat and vaporizes in the evaporator 35 to form a low-pressure gas.

[0076] Thereafter, the low-pressure gas can enter the refrigeration compressor 32 again for pressurization, thereby performing the first, second, third and fourth steps of the cycle again to ensure that the annulus 101 between the freezing chamber 11 and the measuring chamber 21 can have a constant temperature, and further provide a good and stable low-temperature simulation environment for the standard sample (unhydrated cement sample) to improve the accuracy of the temperature data recorded by the first thermocouple 22.

[0077] In one embodiment, Figure 1As shown, the refrigeration mechanism also includes a second galvanic couple 36. Preferably, a plurality of second galvanic couples 36 are arranged at intervals along the circumference of the annulus 101 between the freezing chamber 11 and the measuring chamber 21. In this way, the temperature data in the annulus 101 can be accurately recorded by the second galvanic couple 36, and when the temperature fluctuates, the refrigeration mechanism can be adaptively adjusted to ensure that the annulus 101 has a constant temperature, further providing a good and stable simulation environment for the standard sample (unhydrated cement sample).

[0078] In a preferred embodiment, the surfaces of the first galvanic couple 22, the second galvanic couple 36 and the evaporator 35 are coated with an epoxy resin protective layer for preventing condensation or frost. Since the low-pressure liquid is cooled by absorbing heat and gasifying in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, the joints in the freezing chamber 11 are very prone to corrosion and frost. In this way, the corrosion resistance and frost resistance of the components in the hydration calorimeter 100 for low-temperature cementing slurry can be effectively improved, thereby increasing the service life of the hydration calorimeter for low-temperature cementing slurry and ensuring that the electronic components can always have accurate testing accuracy.

[0079] According to the present invention, Figure 1 As shown, the hydration calorimeter 100 for low-temperature cementing slurry further includes a controller 4. Preferably, the controller 4 is connected to the collector 13, the second thermocouple 36 and the refrigeration compressor 32 respectively.

[0080] In this way, on the one hand, the controller 4 can obtain the temperature data in the reaction cups (the first reaction cup 201 and the second reaction cup 202) in real time through the collector 13 and can obtain the temperature data in the annulus 101 between the freezing chamber 11 and the measuring chamber 21 through the second thermocouple 36, which is helpful for subsequent data analysis. On the other hand, the controller 4 can adjust the temperature of the annulus 101 in real time through the refrigeration mechanism, thereby ensuring that the annulus 101 can have a constant temperature, and further provide a good and stable simulation environment for the standard sample (unhydrated cement sample).

[0081] In one embodiment, the hydration calorimeter 100 for low-temperature cementing slurry further comprises a heat insulation layer sleeved outside the freezing chamber 11. Preferably, the heat insulation layer is made of foamed asbestos, so as to isolate the interference of external heat sources and ensure that the annulus 101 can have a constant temperature under the action of the refrigeration mechanism.

[0082] According to a second aspect of the present invention, a method for measuring the hydration heat of low-temperature cementing slurry using the hydration heat meter 100 as described above is provided, comprising the following steps:

[0083] First, a standard sample and a comparative sample are added into the first reaction cup 201 and the second reaction cup 202 respectively.

[0084] Preferably, the standard sample is an unhydrated cement sample; and the comparative sample is a fully hydrated cement sample.

[0085] Then, the controller 4 controls the refrigeration mechanism to adjust the temperature of the annulus 101 between the freezing chamber 11 and the measuring chamber 21 to a low temperature environment (the temperature required for the condensation process).

[0086] During this stage, the controller 4 monitors the temperature in the annulus 101 in real time through the second thermocouple 36, and adjusts the temperature in the annulus 101 in real time through the refrigeration mechanism to ensure that the annulus 101 can have a constant temperature, further providing a good and stable simulation environment for the standard sample (unhydrated cement sample).

[0087] Afterwards, the preparation water is injected into the first reaction cup 201 through the syringe 23, so that the standard sample in the first reaction cup 201 is combined with the preparation water and starts to release heat, thereby realizing the test of the low-temperature hydration thermal performance of the cementing slurry at room temperature.

[0088] Finally, the temperature data of the first reaction cup 201 and the second reaction cup 202 are recorded respectively by the first thermocouple 22, and the recorded temperature data are transmitted to the collector 13, so as to be converted into a cement hydration heat and heat release rate change curve, thereby simulating the cement hydration process in a low-temperature field environment to the greatest extent.

[0089] Compared with the prior art, the present invention has the following advantages.

[0090] First, the present invention can simulate the actual low-temperature environment on site through the refrigeration mechanism.

[0091] Specifically, the first step: the gas refrigerant is pressurized by the refrigeration compressor 32. The second step: the pressurized gas refrigerant releases heat in the condenser 34 to form a high-pressure liquid. The third step: the high-pressure liquid increases in volume in the throttle valve 33 to form a low-pressure liquid. The fourth step: the low-pressure liquid absorbs heat and vaporizes in the evaporator 35 to form a low-pressure gas.

[0092] And in the fourth step, the low-pressure liquid in the present invention is vaporized in the evaporator 35 to form a low-pressure gas, thereby absorbing the heat in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, so as to quickly reduce the temperature in the freezing chamber 11, thereby ensuring that the temperature in the annulus 101 can meet the temperature requirements of the cement slurry waiting process.

[0093] Secondly, since the low-pressure liquid in the annulus 101 between the freezing chamber 11 and the measuring chamber 21 achieves the cooling effect by absorbing heat and gasifying, the joints in the freezing chamber 11 are very prone to corrosion and frost. Therefore, the present invention coats the surfaces of the first galvanic couple 22, the second galvanic couple 36 and the evaporator 35 with an epoxy resin protective layer for preventing condensation or frost, so as to improve the corrosion resistance and frost resistance of the components in the hydration calorimeter 100 for low-temperature cementing slurry, thereby improving the service life of the hydration calorimeter for low-temperature cementing slurry and ensuring that the electronic components can always have accurate testing accuracy.

[0094] Third, since the refrigeration system of the present invention is cyclic, it can ensure that the annulus 101 between the freezing chamber 11 and the measuring chamber 21 can have a constant temperature, and further provide a good and stable simulation environment for the standard sample (unhydrated cement sample) to improve the accuracy of the temperature data recorded by the first thermocouple 22. Specifically, in the fourth step of the refrigeration process, the low-pressure gas formed by the gasification of the low-pressure liquid can enter the refrigeration compressor 32 again, and the refrigeration process of the first step, the second step, the third step and the fourth step can be performed cyclically, thereby ensuring that the annulus 101 can have a constant temperature.

[0095] In addition, since the freezing chamber 11, the kettle cover 12 and the collector 13 are constructed into a closed structure, it is ensured that the gas refrigerant is not lost during the refrigeration process, thereby improving the circulation capacity of the refrigerant in the refrigeration mechanism, thereby improving the energy saving and flexibility of the hydration calorimeter 100 for low-temperature cementing cement slurry.

[0096] Fourthly, the present invention can accurately record the real-time temperature change data in the freezing chamber 11 by circumferentially arranging a plurality of second galvanic couples 36 in the annulus 101 between the freezing chamber 11 and the measuring chamber 21, and can also control the refrigeration mechanism through the controller 4 to achieve precise control of the temperature in the freezing chamber 11. Thus, the temperature in the annulus 101 can always be kept constant, thereby providing a good and stable simulation environment for the standard sample (unhydrated cement sample) to improve the accuracy of the temperature data recorded by the first galvanic couple 22.

[0097] Fifth, the present invention can accurately record the hydration heat release performance (heat release and heat release rate) and temperature data of cement slurry at low temperature through the first galvanic couple 22. Specifically, each measuring cavity 21 corresponds to only one first galvanic couple 22. Therefore, the temperature data of the first reaction cup 201 and the second reaction cup 202 can be accurately recorded at the same time through multiple first galvanic couples 22, thereby improving the accuracy of the experimental data.

[0098] In addition, since the two ends of the measuring chamber 21 are sealedly connected to the kettle cover 12 and the collector 13, the measuring chamber 21 can have good sealing performance under the joint action of the kettle cover 12 and the collector 13, thereby effectively preventing the influence of the outside world on the experimental environment, so as to improve the accuracy of the experimental data.

[0099] In addition, since the first galvanic couple 22 is longitudinally arranged in each measuring cavity 21, the temperature in the measuring cavity 21 can be comprehensively measured. In this way, the first galvanic couple 22 and the reaction cup (the first reaction cup 201 and the second reaction cup 202) can have a larger contact area, thereby ensuring that the first galvanic couple 22 can accurately record the temperature change of the reaction cup, so as to improve the ability of the present invention to obtain the heat energy and temperature change data released by the low-temperature cementing slurry during the hydration process and the accuracy of the obtained data, thereby realizing the test of the low-temperature hydration thermal performance of the cementing slurry under room temperature.

[0100] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the disclosure scope of the present invention, and such changes or modifications should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A hydration calorimeter for low-temperature cementing slurry, comprising: A freezing mechanism comprising a freezing chamber (11), A measuring mechanism, comprising at least two measuring chambers (21) arranged in the freezing chamber (11), a first reaction cup (201) for placing a standard sample and a second reaction cup (202) for placing a comparison sample, respectively arranged in different measuring chambers (21), and a plurality of first thermocouples (22) arranged in the measuring chamber (21) and respectively recording the temperature data of the first reaction cup (201) and the second reaction cup (202); and A refrigeration mechanism for adjusting the temperature of an annulus (101) between the freezing chamber (11) and the measuring chamber (21).

2. The hydration calorimeter for low-temperature cementing slurry according to claim 1, characterized in that: The freezing chamber (11) is constructed in the form of a hollow sleeve, and the freezing mechanism further comprises a kettle cover (12) arranged above the freezing chamber (11), and a collector (13) arranged below the freezing chamber (11) and used to receive temperature data from the first thermocouple (22), wherein the kettle cover (12) and the collector (13) are both sealedly connected to the inner circumferential surface of the freezing chamber (11).

3. The hydration calorimeter for low-temperature cementing slurry according to claim 2, characterized in that: The measuring chamber (21) is constructed in the form of a hollow sleeve and is sealedly connected to the kettle cover (12) and the collector (13) respectively.

4. The hydration calorimeter for low-temperature cementing slurry according to claim 3, characterized in that: The standard sample is an unhydrated cement sample, and the comparison sample is a hydrated cement sample. The measuring mechanism also includes a syringe (23) extending through the kettle cover (12) and aligned with the first reaction cup (201), and the syringe (23) contains slurry water for combining with the standard sample.

5. The hydration calorimeter for low-temperature cementing slurry according to claim 4, characterized in that: The first thermocouple (22) is configured in a rod-like form and is disposed longitudinally in each of the measuring cavities (21).

6. The hydration calorimeter for low-temperature cementing slurry according to claim 5, characterized in that: The refrigeration mechanism comprises a U-shaped channel (31) arranged outside the freezing chamber (11), and both ends of the U-shaped channel (31) extend into an annulus (101) between the freezing chamber (11) and the measuring chamber (21).

7. The hydration calorimeter for low-temperature cementing slurry according to claim 6, characterized in that: The refrigeration mechanism further comprises a refrigeration compressor (32) containing a gaseous refrigerant and arranged at an inlet (301) of the U-shaped channel (31), a throttle valve (33) arranged at an outlet (302) of the U-shaped channel (31), and a condenser pipe (34) arranged between the refrigeration compressor (32) and the throttle valve (33). The refrigeration compressor (32) is configured to pressurize the gas refrigerant, and the pressurized gas refrigerant forms a low-pressure liquid through the condenser (34) and the throttle valve (33) and then flows to the annulus (101) through the outlet (302) of the U-shaped channel (31).

8. The hydration calorimeter for low-temperature cementing slurry according to claim 7, characterized in that: The refrigeration mechanism also includes an evaporator (35) arranged in the annulus (101) and used to receive low-pressure liquid from the throttle valve (33), and a plurality of second thermocouples (36) arranged in the annulus (101) along a circumferential interval and used to record temperature data in the freezing chamber (11).

9. The hydration calorimeter for low-temperature cementing slurry according to claim 8, characterized in that: The surfaces of the first galvanic couple (22), the second galvanic couple (36) and the evaporator (35) are coated with an epoxy resin protective layer for preventing condensation or frost.

10. The hydration calorimeter for low-temperature cementing slurry according to any one of claims 1 to 9, characterized in that: The hydration calorimeter also includes a heat insulation layer made of foam asbestos and sleeved outside the freezing chamber (11).

11. The hydration calorimeter for low-temperature cementing slurry according to claim 9, characterized in that: The hydration calorimeter further comprises a controller (4), and the controller (4) is respectively connected to the collector (13), the second thermocouple (36) and the refrigeration compressor (32).

12. A method for measuring the hydration heat of low-temperature cementing slurry using a hydration heat meter according to any one of claims 1 to 11, comprising the following steps: S1, adding a standard sample and a comparative sample into the first reaction cup (201) and the second reaction cup (202) respectively; S2, controlling the refrigeration mechanism through the controller (4) to adjust the temperature of the annulus (101) between the freezing chamber (11) and the measuring chamber (21) to a low temperature environment, and injecting slurry preparation water into the first reaction cup (201) through the syringe (23); S3. Record the temperature data of the first reaction cup (201) and the second reaction cup (202) respectively through the first thermocouple (22), and transmit the recorded temperature data to the collector (13).

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