CN104155405B - A kind of method and device measuring carbon dioxide-local water effect production precipitation capacity - Google Patents

Abstract

The invention provides a method and a device for measuring the amount of precipitation produced by the action of carbon dioxide and formation water. The method comprises: pouring formation water into a high-pressure reactor, and obtaining sample solutions at a set temperature and different pressures by adjusting the pressure; then adjusting the temperature to obtain sample solutions at a set pressure and different temperatures; titrating with hydrochloric acid solution Each time the sample solution is taken out, the ion concentration of the sample solution and the initial formation water is detected, and the ion concentration change under different temperature and pressure conditions is obtained by calculation, and then the mass of the precipitate is calculated. The present invention also provides a device that can be used in the above method. The method and device can be used to measure the amount of precipitation in each temperature and pressure change process, and establish a quantitative relationship between the influence of temperature and pressure changes on the physical properties of the reservoir.

Description

A method and device for measuring the amount of sedimentation produced by the action of carbon dioxide-formation water

technical field

The invention relates to a method and a device for measuring the amount of precipitation produced by the action of CO ₂ -formation water, and belongs to the technical field of petroleum exploitation.

Background technique

CO ₂ flooding is a very effective method to enhance oil recovery, which can not only effectively enhance oil recovery but also significantly reduce greenhouse gas emissions; during CO ₂ flooding, CO ₂ and high-salinity formation water The action will produce CaCO ₃ and other precipitation, thereby changing the reservoir physical properties (such as permeability, pore structure, etc.) and affecting the oil recovery of CO ₂ flooding. Determining the amount of precipitation caused by the interaction between CO ₂ and formation water during CO ₂ flooding is the key to research. The current _{CO 2} flooding experimental studies and numerical simulation studies seldom consider the impact of _{CO 2} and high-salinity formation water that will produce CaCO ₃ and other deposits on reservoir physical properties and recovery factors. Quantitative experimental study on the amount of sedimentation caused by the action of formation water.

_CO2 dissolves in formation water to generate carbonic acid as shown in formula (1.1):

CO ₂ +H ₂ O→H ₂ CO ₃ (1.1)

Carbonic acid is a weak acid that ionizes in two stages.

First-order ionization:

H ₂ CO ₃ →H ⁺ +HCO ₃ ^- (1.2) (the main form of carbonic acid ionization)

Secondary ionization:

HCO ₃ ^- →H ⁺ +CO ₃ ^2- (1.3) (the amount of ionization is very small, and the degree of ionization is only 10 ^-3 of the first order ionization), CO ₂ mainly exists in the form of HCO ₃ ^- and H ₂ CO ₃ in water.

When the pressure increases and the temperature decreases, the solubility of CO ₂ in water increases, CO ₂ dissolves in formation water, the reaction formula CO ₂ +H ₂ O→H ₂ CO ₃ (1.1), moves to the right, H ₂ CO ₃ Increase, so that the reaction formula H ₂ CO ₃ →H ⁺ +HCO ₃ ^- (1.2), moves to the right, H ⁺ increases, so that the reaction formula HCO ₃ ^- →H ⁺ +CO ₃ ^2- (1.3), to Move to the left to suppress the formation of CO ₃ ^2- .

Therefore, after CO ₂ is dissolved in formation water, CO ₂ mainly exists in the form of HCO ₃ ^- and H ₂ CO ₃ in the water, and forms Ca(HCO ₃ ) ₂ with Ca ²⁺ .

When the pressure decreases and the temperature increases, the solubility of CO ₂ in water decreases, and CO ₂ escapes from the water, the reaction formula CO ₂ +H ₂ O→H ₂ CO ₃ (1.1), moving to the left, H ₂ CO ₃ Decrease, so that the reaction formula H ₂ CO ₃ →H ⁺ +HCO ₃ ^- (1.2), moves to the left, H ⁺ decreases, so that the reaction formula HCO ₃ ^- →H ⁺ +CO ₃ ^2- (1.3), to Moving in the right direction, CO ₃ ^2- is generated, and CO ₃ ^2- and Ca ²⁺ in the formation generate CaCO ₃ precipitation.

The content of CaCl ₂ in CaCl ₂ type formation water is relatively high, among which Ca ²⁺ may react with CO ₃ ^2- to form insoluble matter and precipitate CaCO ₃ , which will cause formation scaling and affect the permeability of reservoir pores.

During CO ₂ injection and formation displacement, CO ₂ reacts with water to form H ₂ CO ₃ , and the solution is acidic. Under acidic conditions, CO ₂ mainly exists in the form of HCO ₃ ^- and H ₂ CO ₃ in water, while HCO ₃ ^- Ca(HCO ₃ ) ₂ and Mg(HCO ₃ ) ₂ formed by combining with Ca ²⁺ and Mg ²⁺ are soluble in water, so CaCO ₃ and MgCO ₃ scale will not be formed to block reservoir pores.

When the partial pressure of CO ₂ in the solution decreases, the reaction proceeds to the left, and the slow rate of pressure drop decomposes the Ca(HCO ₃ ) ₂ in the solution to form CaCO ₃ scale.

There is also a testing method in the prior art, which is to use a scanning electron microscope to observe the appearance of rock slices, put formation water and rock slices in a high-pressure reactor, close the reactor, and then inject CO ₂ . Keep the temperature and pressure for 24 hours, then take out the rock slices, and then observe the rock slices with a scanning electron microscope, and compare the changes in the appearance of the rock slices before and after the reaction to judge whether precipitation has occurred. This method can only qualitatively observe whether precipitation has occurred, but cannot obtain the exact value of the precipitation amount. In addition, this method can only observe the sedimentation of rock slices when the pressure is reduced to atmospheric pressure, but cannot observe the sedimentation when the pressure is lowered to higher than one atmospheric pressure (such as 5 MPa).

There is also a test method in the prior art, which is to put formation water and rock slices in the autoclave, then inject CO ₂ , keep it at the set temperature and pressure for 24 hours, stir the solution, then take out 10mL, use Filter the solution with filter paper, dry the filter paper, measure the weight of the filter paper with the precipitate, and subtract the mass of the original filter paper to obtain the mass of the precipitate. This method can only measure the amount of sediment when the pressure is lowered to atmospheric pressure, but cannot measure the amount of sediment when the pressure drops higher than one atmospheric pressure (such as 5MPa).

Contents of the invention

In order to solve the above-mentioned technical problems, the object of the present invention is to provide a method for measuring the amount of precipitation produced by the action of CO ₂ -formation water, by which the amount of precipitation under different temperature and pressure conditions can be easily tested.

The purpose of the present invention is also to provide a device for measuring the amount of precipitation produced by CO ₂ -formation water action which can be used in the above method.

In order to achieve the above object, the present invention at first provides a method for measuring CO ₂ -action of formation water to produce precipitation, which comprises the following steps:

Pour formation water into the high-pressure reactor, close the high-pressure reactor, raise the temperature to the set temperature, and inject a sufficient amount of _CO2 according to the solubility of _CO2 at the set temperature and the first predetermined boost pressure value , to increase the pressure to the first predetermined boost pressure value, keep it for more than 24 hours, and take out an appropriate amount of solution in the middle of the autoclave;

Then raise the pressure to the second predetermined boost pressure value, and keep it for more than 24 hours, and then take out an appropriate amount of solution from the middle of the autoclave;

The pressure is raised to each predetermined boost pressure value in turn, and the operations of keeping it for more than 24 hours and taking out an appropriate amount of solution in the middle of the autoclave are carried out respectively;

Then step down to each predetermined step-down pressure value and carry out the operations of keeping for more than 24 hours and taking out an appropriate amount of solution in the middle of the autoclave;

Afterwards, pour formation water into the autoclave, close the autoclave, inject a sufficient amount of _CO2 according to the solubility of _CO2 at the set pressure and the first predetermined heating temperature, and raise the pressure to the set temperature. pressure, and raise the temperature of the autoclave to the first predetermined temperature rise temperature value, keep it for more than 24h, and take out an appropriate amount of solution in the middle of the autoclave;

Then raise the temperature to the second predetermined heating temperature value, and keep it for more than 24 hours, and then take out an appropriate amount of solution from the middle part of the autoclave;

Sequentially raise the temperature to each predetermined heating temperature value, respectively carry out the operations of keeping for more than 24 hours and taking out an appropriate amount of solution in the middle of the autoclave;

Then lower the temperature to each predetermined cooling temperature value in turn and carry out the operations of keeping for more than 24 hours and taking out an appropriate amount of solution in the middle of the autoclave;

Titrate the sample solution taken out each time with hydrochloric acid solution, and then use an ion chromatograph to detect the ion concentration of the sample solution taken out each time and the initial formation water, and use the ion concentration of the initial formation water to subtract the ion concentration of the liquid taken out each time to obtain different The ion concentration change under temperature and pressure conditions, and then calculate the mass of the precipitate according to the molecular weight of the precipitate.

In the above method, the predetermined boosting pressure value and the predetermined depressurizing pressure value in the boosting process and the depressurizing process can be selected according to needs, and can be in the form of an arithmetic sequence, for example, the boosting process is controlled as 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, the step-down process control is 20MPa, 15MPa, 10MPa, 5MPa, 0.1MPa, etc. At the same time, the relevant set temperature can also be selected according to needs. In the process of boosting and depressurizing, after each boosting or depressurizing, the operation of keeping for more than 24 hours and taking out an appropriate amount of solution (which can meet the detection of the ion chromatograph) in the middle of the reactor is carried out to obtain the corresponding sample solution. Preferably, the volume of the solution taken out in the middle of the reactor is 10 mL.

In the above method, the predetermined heating temperature value and the predetermined cooling temperature value in the heating process and cooling process can be selected according to the needs, and can be in the form of an arithmetic sequence, for example, the heating process is controlled as 20°C, 30°C, 40°C 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, the cooling process control is 90°C, 80°C, 70°C, 60°C, 50°C, 40°C, 30°C, 20°C, etc. At the same time, the relevant set pressure can also be selected according to the needs. During the heating and cooling process, after each heating or cooling, the operation of keeping for more than 24 hours and taking out an appropriate amount of solution (which can meet the detection of the ion chromatograph) in the middle of the reactor is carried out to obtain the corresponding sample solution.

In the above method, preferably, a step of establishing a relationship curve among the set temperature, pressure and sediment quality is also included.

In the above method, preferably, the ion concentration of the sample solution taken out each time and the initial formation water is mainly Ca ²⁺ concentration detected by an ion chromatograph.

In the above method, the formation water added in the autoclave can meet the needs of the test, and a certain space is left for injecting _CO2 . Preferably, the addition of the formation water is 200mL to the volume of the autoclave 2/3 of. The volume of the above-mentioned autoclave can be greater than 500mL, and the volume range is preferably 500-2000mL.

According to a specific embodiment of the present invention, preferably, the above-mentioned method may include the following specific steps:

Pour formation water into the autoclave, close the autoclave, raise the temperature to the set temperature, pour formation water into the autoclave according to _CO2 , close the autoclave, and raise the temperature to the set temperature Set the temperature, according to the solubility of CO ₂ at the set temperature and 5MPa, inject a sufficient amount of CO ₂ to raise the pressure to 5MPa, keep it for 24h, and take out 10mL of the solution in the middle of the autoclave;

Then raise the pressure to 10MPa and keep it for 24h, then take out 10mL solution from the middle of the autoclave;

Increase the pressure to 15MPa, 20MPa, and 25MPa in turn, and perform the operations of maintaining for 24 hours and taking out 10mL of the solution in the middle of the autoclave;

Then reduce the pressure to 20MPa, 15MPa, 10MPa, 5MPa, 0.1MPa in turn, and carry out the operation of keeping for 24h and taking out 10mL of the solution in the middle of the autoclave;

Afterwards, pour formation water into the autoclave, close the autoclave, raise the pressure to the set pressure, and inject a sufficient amount of _CO2 according to the solubility of _CO2 at the set pressure at 20°C to make the pressure Raise to 20°C, keep for 24h, take out 10mL solution in the middle of the autoclave;

Then raise the pressure to 30°C and keep it for 24h, then take out 10mL of the solution from the middle of the autoclave;

Increase the pressure to 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, and 100°C in sequence, and perform the operations of keeping for 24 hours and taking out 10mL of the solution in the middle of the autoclave;

Then reduce the pressure to 90°C, 80°C, 70°C, 60°C, 50°C, 40°C, 30°C, and 20°C in sequence, and keep for 24 hours and take out 10mL of the solution from the middle of the autoclave;

Titrate the sample solution taken out each time with hydrochloric acid solution, and then use an ion chromatograph to detect the ion concentration of the sample solution taken out each time and the initial formation water, and use the ion concentration of the initial formation water to subtract the ion concentration of the liquid taken out each time to obtain different Changes in ion concentration under temperature and pressure conditions, and then calculate the mass of the precipitate according to the molecular weight of the precipitate;

Establish a relationship curve between the set temperature, pressure and the quality of the sediment.

In the above method, the concentration of the hydrochloric acid solution used has no special influence, and the total amount is sufficient. Preferably, the concentration of the hydrochloric acid solution is about 10 wt%.

During the _CO2 displacement process, _CO2 dissolves in formation water with high salinity, and when conditions such as temperature and pressure change, precipitation such as CaCO3 occurs, which affects the physical properties _of the reservoir and the recovery factor. Using the present invention The method provided above can easily measure the amount of precipitation under different temperature and pressure conditions, and provide help for quantitative research on the influence of temperature and pressure changes on the amount of precipitation.

The present invention also provides a device for measuring the amount of sedimentation produced by the action of _CO2 -formation water, which includes a back pressure buffer, a pressure gauge, a back pressure valve, a test tube, a high-pressure reaction kettle, and a back pressure pump, wherein:

The back pressure buffer is connected to the back pressure valve, and a pressure gauge is provided on the connecting pipeline between the two;

The back pressure valve is also connected with the top inlet of the test tube and the autoclave respectively;

The top of the high-pressure reactor is provided with an emptying port, and the outlet at the bottom of the high-pressure reactor communicates with the back pressure pump.

In the above-mentioned devices, the high-pressure reactor is used to provide a high-temperature and high-pressure reaction space, which can be heated and pressurized to maintain a certain temperature and pressure, and is the main place for the reaction. The temperature range of the high-pressure reactor can be from room temperature to 180°C, and the pressure range can be 0-70MPa.

The back pressure valve, back pressure buffer, back pressure pump and pressure gauge form a back pressure control system, so that the pressure in the reactor is not lower than the set pressure when the liquid is taken. When the pressure in the reactor is lower than the set pressure, the liquid will be automatically stopped, and the liquid will only be discharged when the pressure in the reactor is higher than the set pressure. The back pressure valve is a control switch component. Back pressure snubbers are used to keep the pressure constant. The back pressure pump is used to provide pressure, and the pressure gauge is used to observe the pressure. The test tube is used to withdraw the solution from the middle of the autoclave and measure the amount of liquid withdrawn.

The above-mentioned method and device provided by the present invention can measure the amount of precipitation in each temperature and pressure change process, establish the quantitative relationship of the impact of temperature and pressure changes on the physical properties of the reservoir, thereby adding temperature and pressure in the _CO2 flooding process The quantitative impact of changes on reservoir physical properties makes the parameter optimization research in the _CO2 flooding process more accurate.

Description of drawings

Fig. 1 is a schematic structural diagram of the device for measuring the amount of precipitation produced by the action of CO ₂ -formation water in Example 1.

Fig. 2 is a diagram showing the variation of CaCO ₃ precipitation with the increase and decrease of pressure.

Fig. 3 is a graph showing the variation of CaCO ₃ precipitation with increasing and decreasing temperature.

Explanation of main figures and symbols:

Back pressure buffer 1 Pressure gauge 2 Back pressure valve 3 Test tube 4 High pressure reactor 5 Back pressure pump 6

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 described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

Example 1

This embodiment provides a device for measuring the amount of sedimentation produced by the action of CO ₂ -formation water. Its structure is shown in Figure 1. The device includes a back pressure buffer 1, a pressure gauge 2, a back pressure valve 3, and a test tube 4 , high pressure reactor 5, back pressure pump 6, wherein:

The back pressure buffer 1 is connected to the back pressure valve 3, and a pressure gauge 2 is provided on the connecting pipeline between the two;

Back pressure valve 3 is also connected with the top inlet of test tube 4 and autoclave 5 respectively;

The top of the autoclave 5 is provided with an empty port, and the outlet at the bottom of the autoclave 5 communicates with the back pressure pump 6;

Moreover, corresponding valves are respectively provided at appropriate positions of the device.

Example 2

This embodiment provides a method for measuring the amount of precipitation produced by the action of CO ₂ -formation water, which can be carried out using the device provided in Embodiment 1. The method includes the following steps:

Pour 1 L of CaCl ₂ type formation water (please refer to Table 1 for specific parameters) into the high-pressure reactor, close the reactor, raise the temperature to 30°C, and inject 500 mL of CO ₂ with a pressure of 5 MPa to make the pressure reach 5MPa, keep for 24h, take out 10mL solution in the middle of the reactor;

Then raise the pressure to 10MPa, and maintain the pressure for 24h, then take out 10mL of the solution from the middle of the reactor; increase the pressure to 15MPa, 20MPa in turn, repeat the maintenance for 24h and take out 10mL of the solution from the middle of the reactor operation;

Then step down to 15MPa, 10MPa, 5MPa, 0.1MPa and take samples;

Afterwards, pour 1L of CaCl ₂ formation water into the autoclave, close the autoclave, inject CO ₂ to raise the pressure to 10MPa, and at the same time, raise the temperature to 20°C and keep it for 24 hours. Take out 10mL solution;

Then raise the temperature to 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C in sequence, repeat the operation of holding for 24 hours and taking out 10mL of the solution from the middle of the reactor;

Then cool down to 90°C, 80°C, 70°C, 60°C, 50°C, 40°C, 30°C, 20°C in turn and take samples;

Titrate each sample solution with hydrochloric acid solution, and then use an ion chromatograph to measure the Ca ²⁺ concentration of the liquid taken out each time and the initial formation water, and subtract the Ca ²⁺ concentration of the liquid taken out each time from the Ca ²⁺ concentration of the initial formation water , to obtain the variation of Ca ²⁺ concentration under different temperature and pressure conditions (the Ca ²⁺ concentration and CaCO ₃ precipitation in formation water under different pressures are shown in Table 2, and the Ca ²⁺ concentration and CaCO ₃ precipitation in formation water during the heating process As shown in Table ₃ , formation water Ca2 ⁺ concentration and CaCO3 precipitation are shown in Table 4) during the cooling process), and then calculate the CaCO3 quality according to the molecular weight of the precipitate _;

Set up temperature, pressure and CaCO ₃ Precipitation amount (quality) relational curve, wherein, CaCO ₃ Precipitation amount increases with pressure and decreases change graph as shown in Figure 2, CaCO ₃ Precipitation amount increases with temperature and decreases change graph as shown in Fig. 3.

Table 1 Related parameters of formation water

Table 2 Ca ²⁺ concentration and CaCO ₃ precipitation in formation water under different pressures

Pressure (MPa) 5 10 15 20 15 10 5 0.1 Ca ²⁺ concentration (mg/L) 19880 19880 19880 19880 19878 19877 19869 19817 CaCO ₃ precipitation amount (mg/L) 0 0 0 0 3.7 7.4 25.0 157.1

Table 3 Ca ²⁺ concentration and CaCO ₃ precipitation in formation water during heating process

temperature(℃) 20 30 40 50 60 70 80 90 100 Ca ²⁺ concentration (mg/L) 19880 19877 19874 19871 19869 19866 19863 19861 19860 CaCO ₃ precipitation amount (mg/L) 0.00 8.02 15.79 22.53 27.93 34.64 42.71 48.42 50.00

Table 4 Ca ²⁺ concentration and CaCO ₃ precipitation in formation water during the cooling process

temperature(℃) 100 90 80 70 60 50 40 30 20 Ca ²⁺ concentration (mg/L) 19880 19880 19880 19880 19880 19880 19880 19880 19880 CaCO ₃ precipitation amount (mg/L) 0 0 0 0 0 0 0 0 0

According to the curves given in Figure 2 and Figure 3, the quantitative influence of different temperature and pressure changes on the physical properties of the reservoir can be determined during the CO ₂ flooding process, thereby helping to determine various parameters in the CO ₂ flooding process.

Claims (9)

1. measure a method for carbon dioxide-local water effect production precipitation capacity, it comprises the following steps:

In autoclave, pour local water into, close good autoclave, temperature is elevated to design temperature, according to CO ₂solubleness under design temperature, the first predetermined boost pressure value, injects enough CO ₂, make pressure be increased to the first predetermined boost pressure value, keep more than 24h, take out appropriate solution at the middle part of autoclave;

Again pressure is elevated to the second predetermined boost pressure value, and keeps more than 24h, and then take out appropriate solution from the middle part of autoclave;

Successively pressure is elevated to each predetermined boost pressure value, carries out the operation keeping more than 24h and take out appropriate solution at the middle part of autoclave respectively;

And then be depressured to each predetermined step-down force value successively and carry out respectively keeping more than 24h and taking out the operation of appropriate solution at the middle part of autoclave;

Afterwards, in autoclave, pour local water into, close good autoclave, according to CO ₂solubleness under set pressure, the first predetermined warming temperature value, injects enough CO ₂, pressure is elevated to set pressure, and the temperature of autoclave is increased to the first predetermined warming temperature value, keep more than 24h, take out appropriate solution at the middle part of autoclave;

Again temperature is elevated to the second predetermined warming temperature value, and keeps more than 24h, and then take out appropriate solution from the middle part of autoclave;

Successively temperature is elevated to each predetermined warming temperature value, carries out the operation keeping more than 24h and take out appropriate solution at the middle part of autoclave respectively;

And then cool to each predetermined cooling temperature value successively and the operation carried out maintenance more than 24h respectively and take out appropriate solution at the middle part of autoclave;

With the sample solution that hydrochloric acid solution titration is taken out at every turn, then ion chromatograph is utilized to detect each sample solution of taking-up and the ion concentration of initial local water, the ion concentration of initial local water is utilized to deduct each ion concentration of taking out liquid, obtain the ion concentration variable quantity under different temperatures, pressure condition, then calculate sedimentary quality according to sedimentary Molecular weights.

2. method according to claim 1, wherein, the method is further comprising the steps of:

Set up the relation curve between design temperature, pressure, sedimentary quality.

3. method according to claim 1, wherein, the ion concentration utilizing ion chromatograph to detect sample solution and the initial local water at every turn taken out is Ca ²⁺concentration.

4. method according to claim 1, wherein, the addition of described local water is that 200mL is to 2/3 of described autoclave volume.

5. method according to claim 4, wherein, the volume of described autoclave is 500-2000mL.

6. method according to claim 1, wherein, the volume of the solution taken out at the middle part of autoclave is 10mL.

7. method according to claim 1, wherein, the method comprises the following steps:

In autoclave, pour local water into, close good autoclave, temperature is elevated to design temperature, according to CO ₂solubleness under design temperature, 5MPa, injects enough CO ₂, make pressure be increased to 5MPa, keep 24h, take out 10mL solution at the middle part of autoclave;

Again pressure is elevated to 10MPa, and keeps 24h, then take out 10mL solution from the middle part of autoclave;

Successively pressure is elevated to 15MPa, 20MPa, 25MPa, carries out the operation keeping 24h and take out 10mL solution at the middle part of autoclave respectively;

And then be depressured to 20MPa, 15MPa, 10MPa, 5MPa, 0.1MPa successively and carry out respectively keeping 24h and the operation at the middle part of autoclave taking-up 10mL solution;

Afterwards, in autoclave, pour local water into, close good autoclave, pressure is elevated to set pressure, according to CO ₂in set pressure, solubleness at 20 DEG C, inject enough CO ₂, elevate the temperature to 20 DEG C, keep 24h, take out 10mL solution at the middle part of autoclave;

Again temperature is elevated to 30 DEG C, and keeps 24h, then take out 10mL solution from the middle part of autoclave;

Successively temperature is elevated to 40 DEG C, 50 DEG C, 60 DEG C, 70 DEG C, 80 DEG C, 90 DEG C, 100 DEG C, carries out the operation keeping 24h and take out 10mL solution at the middle part of autoclave respectively;

And then cool to 90 DEG C, 80 DEG C, 70 DEG C, 60 DEG C, 50 DEG C, 40 DEG C, 30 DEG C, 20 DEG C successively and carry out respectively keeping 24h and the operation at the middle part of autoclave taking-up 10mL solution;

With the sample solution that hydrochloric acid solution titration is taken out at every turn, then ion chromatograph is utilized to detect each sample solution of taking-up and the ion concentration of initial local water, the ion concentration of initial local water is utilized to deduct each ion concentration of taking out liquid, obtain the ion concentration variable quantity under different temperatures, pressure condition, then calculate sedimentary quality according to sedimentary Molecular weights;

Set up the relation curve between design temperature, pressure, sedimentary quality.

8. the method according to claim 1 or 7, wherein, the concentration of described hydrochloric acid solution is 10wt%.

9. measure a device for carbon dioxide-local water effect production precipitation capacity for the method described in any one of claim 1-8, it comprises back pressure impact damper, tensimeter, check valve, test tube, autoclave, backpressure pump, wherein:

Described back pressure impact damper is connected with described check valve, and the connecting line of the two is provided with tensimeter;

Described check valve is also connected with the top entry of described test tube and autoclave respectively;

The top of described autoclave is provided with an evacuation port, and the outlet at bottom of described autoclave is communicated with described backpressure pump.