Device for synchronous detection of total ions and calcium and magnesium ions in fracturing water and method of use thereof

Abstract

The present application relates to the technical field of oilfield chemical water quality detection, and is a device for synchronously detecting total ions and calcium and magnesium ions in fracturing water and a use method thereof. The device comprises a sampling unit, a sample preparation unit and a detection unit. The sampling unit comprises a sampling pump. The sample preparation unit comprises a buffer tank, a precipitant storage tank and a precipitant metering pump. The detection unit comprises a first conductivity meter, a second conductivity meter and a turbidimeter. The sampling pump inlet is fixedly connected with a sampling pipeline. The sampling pump outlet and the first inlet of the buffer tank are fixedly connected with a heating pipeline. The bottom outlet of the buffer tank is fixedly connected with a backfill pipeline. The precipitant storage tank inlet is fixedly connected with a precipitant feeding pipeline. The precipitant storage tank and the second inlet of the buffer tank are fixedly connected with a precipitant feeding pipeline. The precipitant feeding pipeline is fixedly installed with a precipitant metering pump. The present application can quickly and on-line measure the performance parameters of the fracturing water, improve the construction efficiency, and has a wide popularization prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield chemical water quality detection, and is a device for synchronously detecting total ions and calcium and magnesium ions in fracturing water and a use method thereof. BACKGROUND

[0002] With the expansion of the development range of unconventional reservoirs, the demand for fracturing water increases, causing the synchronous increase of fracturing flowback fluid. At present, Xinjiang Oilfield uses salt lake water, oilfield flowback water and other water from various sources as supplements, and the water quality composition is complex and changeable, which greatly affects the preparation and performance of fracturing fluid. Therefore, the treatment of fracturing water is particularly important for oilfields, especially in water-deficient areas in the west. How to reduce the consumption of water resources and reasonably treat the fracturing flowback fluid generated during oilfield development has become one of the key factors restricting oilfield development.

[0003] At present, the judgment of fracturing water quality and the performance of fracturing fluid in oilfields mainly relies on on-site sampling and hanging experiments, which has the disadvantages of slow sampling and monitoring speed, long interval time and low work efficiency. This method cannot timely master the changes of water quality and the performance of fracturing fluid. The monovalent cations in fracturing water are mainly Na + , and the high-valence cations in fracturing water are mainly Ca 2 , + , Mg 2+ , and the content of Ca 2+ and Mg 2+ has a greater impact on the performance of fracturing fluid. The content of other monovalent cations and high-valence cations in fracturing water is low, and it is unnecessary to consider them on site, which will not affect the actual production.

[0004] Based on the above background, it is urgent to develop a device and method for rapidly determining the total ion concentration and calcium and magnesium ion concentration in fracturing water on site and determining the performance parameters of fracturing water, so as to meet the needs of optimizing and dynamically adjusting the preparation process of fracturing fluid. SUMMARY

[0005] The present application provides a device for synchronously detecting total ions and calcium and magnesium ions in fracturing water and a use method thereof, which overcomes the shortcomings of the prior art and effectively solves the problems of slow sampling and monitoring speed, long cycle and low work efficiency of the existing oilfield on-site fracturing water quality and calcium and magnesium ions.

[0006] One of the technical solutions of the present application is realized by the following measures: a total ion and calcium-magnesium ion synchronous detection device for fracturing water comprises a sampling unit, a sample preparation unit and a detection unit, the sampling unit comprises a sampling pump, the sample preparation unit comprises a buffer tank, a precipitant storage tank and a precipitant metering pump, the detection unit comprises a first conductivity meter, a second conductivity meter and a turbidimeter, the sampling pump inlet is fixedly connected with a sampling pipeline, the sampling pump outlet and the first inlet of the buffer tank are fixedly communicated with a heating pipeline, the bottom outlet of the buffer tank is fixedly communicated with a reinjection pipeline, the precipitant storage tank inlet is fixedly communicated with a precipitant feeding pipeline, the precipitant storage tank and the second inlet of the buffer tank are fixedly communicated with a precipitant feeding pipeline, the precipitant metering pump is fixedly installed on the precipitant feeding pipeline, the first conductivity meter is fixedly installed on the heating pipeline, the second conductivity meter is fixedly installed on the reinjection pipeline, the turbidimeter is fixedly installed on the upper part of the buffer tank, the detection end of the turbidimeter is deep into the liquid surface below the buffer tank, and the buffer tank is provided with a stirrer.

[0007] The following is a further optimization or / and improvement of one of the above-mentioned technical solutions of the present application:

[0008] The total ion and calcium-magnesium ion synchronous detection device for fracturing water further comprises a data processing unit, and the data processing unit comprises a PLC control display, and the first conductivity meter, the second conductivity meter and the turbidimeter are electrically connected with the PLC control display.

[0009] A first adjusting valve is fixedly installed on the heating pipeline between the first conductivity meter and the buffer tank, a second adjusting valve is fixedly installed between the reinjection pipeline outlet and the second conductivity meter, and a third adjusting valve is fixedly installed on the precipitant feeding pipeline between the precipitant metering pump and the buffer tank.

[0010] Constant temperature electric heating tapes are wrapped outside the heating pipeline between the sampling pump and the first adjusting valve and the reinjection pipeline between the buffer tank and the second adjusting valve.

[0011] The sampling unit, the sample preparation unit, the detection unit and the data processing unit are all fixedly installed on a movable base.

[0012] The second technical solution of the present application is realized by the following measures: a use method of a total ion and calcium-magnesium ion synchronous detection device for fracturing water, which is performed according to the following steps:

[0013] In the first step, the interfaces of the sampling pipeline and the reinjection pipeline are connected with the main pipeline of the fracturing water, and the constant temperature electric heating tapes are started to perform constant temperature treatment on the fracturing water in the pipeline;

[0014] In the second step, when the fracturing water flows through the first conductivity meter, the initial conductivity δ 总 of the fracturing water is measured, and the total ion concentration of the fracturing water is calculated;

[0015] Third step, start the buffer tank agitator, and the turbidimeter measurement value at this time is zero, then open the precipitant metering pump, to the buffer tank injection of excess precipitant, so that the fracturing water in Ca 2+ , Mg 2+ ion to form a suspension of fracturing water turbidity liquid, using turbidity meter to measure the turbidity of fracturing water turbidity liquid ZD 总 , the measured value is converted by the data processing unit to obtain the content of calcium and magnesium ions in the fracturing water, the precipitant is NaOH aqueous solution;

[0016] Fourth step, fracturing water turbidity liquid through the injection pipeline discharge, constant temperature treatment using the conductivity of fracturing water turbidity liquid δ 总 ’ ,

[0017] Fifth step, according to the turbidity value ZD 总 , the conductivity of fracturing water turbidity liquid δ 总 ’ and the amount of precipitant to calculate the concentration of Ca 2+ and Mg 2+ ion in the fracturing water.

[0018] The following is one of the above technical solutions of the invention is further optimized or / and improvement:

[0019] The total ion concentration in the above fracturing water is 100mg / L to 50000mg / L, and the total amount of calcium and magnesium ions is 100mg / L to 1500mg / L.

[0020] The flow rate of the liquid in the above sampling pipeline and reflux pipeline is 0.1L / min to 5L / min.

[0021] In the above first step and fourth step, the constant temperature treatment temperature is 50℃ to 60℃.

[0022] In the above second step, the total ion concentration in the fracturing water is calculated according to the following formula 1:

[0023] δ 总 =Kρ formula 1

[0024] In the formula, ρ is the total ion concentration in the fracturing water, unit mg / L; δ 总 is the initial conductivity, unit μs / cm; K is the conductivity coefficient.

[0025] In the above fifth step, the concentration of Ca 2+ and Mg 2+ ion in the fracturing water is calculated according to the following formula:

[0026] ZD 总A1p1+A2p2 Equation 2

[0027] delta 总 -delta 总 ’ =K1p1+K2p2-K3p3 Equation 3

[0028] In the formula, p1 and p2 are respectively Ca 2+ and Mg 2+ ion concentrations in fracturing water, in mg / L; ZD 总 is the turbidity value of the fracturing water turbid liquid, in NTU; A1 and A2 are respectively the relationship constants of turbidity and Ca 2+ and Mg 2+ ion concentrations; p3 is the content of Na + increased in the fracturing water after adding a precipitant in the third step, in mg / L; delta 总 ’ represents the conductivity of the outlet pressure water, in mu s / cm; K1, K2 and K3 are respectively the relationship constants of conductivity and Ca 2+ , Mg 2+ and Na + ion concentrations.

[0029] The application provides a synchronous detection device for total ions and Ca and Mg ions in fracturing water, which can quickly and on-line determine performance parameters of the fracturing water, and display the results in real time, so that the fracturing liquid preparation process is optimized and adjusted, the fracturing liquid meets the requirements of field use, the performance of the fracturing liquid is supported by data, the incidence of complex construction is effectively reduced, the construction efficiency is improved, the performance of the fracturing liquid is supported by data, and the device has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are schematic diagrams of the process flow of the application. Figure 1 The accompanying drawings are schematic diagrams of the process flow of the application.

[0031] In the drawings, 1 is a sampling pump, 2 is a buffer tank, 3 is a precipitant storage tank, 4 is a precipitant metering pump, 5 is a first conductivity meter, 6 is a second conductivity meter, 7 is a turbidimeter, 8 is a sampling pipeline, 9 is a heating pipeline, 10 is a backfilling pipeline, 11 is a precipitant feeding pipeline, 12 is a precipitant feeding pipeline, 13 is a stirrer, 14 is a PLC control display, 15 is a first regulating valve, 16 is a second regulating valve, and 17 is a third regulating valve. DETAILED DESCRIPTION

[0032] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art. Unless otherwise specified, the equipment and apparatus used in this invention are all well-known and commonly used equipment and apparatus in the art.

[0033] The present invention will be further described below with reference to embodiments:

[0034] Example 1: As Figure 1 As shown, the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water includes a sampling unit, a sample preparation unit, and a detection unit. The sampling unit includes a sampling pump 1, the sample preparation unit includes a buffer tank 2, a precipitant storage tank 3, and a precipitant metering pump 4, and the detection unit includes a first conductivity meter 5, a second conductivity meter 6, and a turbidimeter 7. A sampling pipeline 8 is fixedly connected to the inlet of the sampling pump 1, a heating pipeline 9 is fixedly connected between the outlet of the sampling pump 1 and the first inlet of the buffer tank 2, and a reinjection pipeline 10 is fixedly connected to the bottom outlet of the buffer tank 2. The inlet of the precipitant storage tank 3 is fixedly connected to the precipitant feed pipeline 11. The precipitant storage tank 3 and the second inlet of the buffer tank 2 are fixedly connected to the precipitant feeding pipeline 12. The precipitant metering pump 4 is fixedly installed on the precipitant feeding pipeline 12. The first conductivity meter 5 is fixedly installed on the heating pipeline 9. The second conductivity meter 6 is fixedly installed on the reinjection pipeline 10. The turbidity meter 7 is fixedly installed on the upper part of the buffer tank 2 (the probe of the turbidity meter 7 extends below the liquid surface inside the buffer tank 2). The agitator 13 is installed inside the buffer tank 2.

[0035] Example 2: As Figure 1 As shown, as an optimization of the above embodiment, the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water further includes a data processing unit. The data processing unit includes a PLC control display 14, and the first conductivity meter 5, the second conductivity meter 6, and the turbidimeter 7 are all electrically connected to the PLC control display 14. The PLC control display 14 can be used for data acquisition, storage, and processing.

[0036] Example 3: As Figure 1 As shown, as an optimization of the above embodiment, a first regulating valve 15 is fixedly installed on the heating pipeline 9 between the first conductivity meter 5 and the buffer tank 2, a second regulating valve 16 is fixedly installed between the outlet of the reinjection pipeline 10 and the second conductivity meter 6, and a third regulating valve 17 is fixedly installed on the precipitant feeding pipeline 12 between the precipitant metering pump 4 and the buffer tank 2.

[0037] Example 4: Figure 1As shown in the above embodiment, as an optimization of the above embodiment, the heating line 9 between the sampling pump 1 and the first regulating valve 15 and the back injection line 10 between the buffer tank 2 and the second regulating valve 16 are both wrapped with a thermostat electric heating belt. The thermostat electric heating belt is used for constant temperature treatment (heating to 50-60℃) of the materials in the sampling line 8 and the back injection line 10, so as to ensure stable measurement conditions and accurate values of the electric conductivity. Similarly, in order to ensure uniform and stable temperature of the fracturing water during the electric conductivity measurement, the installation positions of the first electric conductivity meter 5 and the second electric conductivity meter 6 should be located on the side close to the first regulating valve 15 and the second regulating valve 16.

[0038] Embodiment 5: as shown in the above embodiment, Figure 1 As an optimization of the above embodiment, the sampling unit, the sample preparation unit, the detection unit and the data processing unit are all fixedly installed on the movable base. The movable design of the total ion and calcium-magnesium ion synchronous detection device for fracturing water is more suitable for the dispersed characteristics of oilfield mines.

[0039] Embodiment 6: as shown in the above embodiment, Figure 1 The use method of the total ion and calcium-magnesium ion synchronous detection device for fracturing water is as follows:

[0040] Firstly, the interfaces of the sampling line 8 and the back injection line 10 are connected with the main pipeline of the fracturing water, and the thermostat electric heating belt is started to perform constant temperature treatment on the fracturing water in the pipeline;

[0041] Secondly, when the fracturing water flows through the first electric conductivity meter 5, the initial electric conductivity δ 总 of the fracturing water is measured, and the total ion concentration of the fracturing water is calculated;

[0042] Thirdly, the agitator 13 of the buffer tank 2 is started, and the measurement value of the turbidimeter 7 is cleared, and then the precipitant metering pump 4 is opened to inject excess precipitant into the buffer tank 2, so that the Ca 2+ , Mg 2+ ions in the fracturing water form a suspension to obtain a fracturing water turbid liquid, and the turbidity value ZD 总 of the fracturing water turbid liquid is measured by the turbidimeter 7, and the content of calcium-magnesium ions in the fracturing water is calculated by the data processing unit, and the precipitant is an aqueous solution of NaOH;

[0043] Fourthly, the fracturing water turbid liquid is discharged through the back injection line 10, and the electric conductivity δ 总 ’ of the fracturing water turbid liquid after constant temperature treatment is measured;

[0044] Fifthly, according to the turbidity value ZD 总 , the electric conductivity δ 总 ’and the amount of the precipitant added is calculated to obtain Ca 2+ and Mg 2+ ion concentrations in the fracturing water.

[0045] The mass concentration of the precipitant used can be 4 g / L to 10 g / L as needed.

[0046] Example 7: As an optimization of the above examples, the total ion concentration in the fracturing water is 100 mg / L to 50,000 mg / L, and the total amount of Ca

[0047] Example 8: As an optimization of the above examples, the flow rate of the liquid in the sampling line 8 and the return line is 0.1 L / min to 5 L / min.

[0048] Example 9: As an optimization of the above examples, the constant temperature treatment temperature in the first step and the fourth step is 50°C to 60°C.

[0049] Example 10: As an optimization of the above examples, in the second step, the total ion concentration in the fracturing water is calculated according to the following Formula 1:

[0050] δ 总 = Kp Formula 1

[0051] In the formula, p is the total ion concentration in the fracturing water, in mg / L; δ 总 is the initial conductivity, in μs / cm; and K is the conductivity coefficient. The value of K can be determined from the relationship between the fracturing water with known total ion concentration and the conductivity.

[0052] Example 11: As an optimization of the above examples, in the fifth step, the Ca 2+ and Mg 2+ ion concentrations in the fracturing water are calculated according to the following formula:

[0053] ZD 总 = A1p1 + A2p2 Formula 2

[0054] δ 总 - δ 总 ’ = K1p1 + K2p2 - K3p3 Formula 3

[0055] In the formula, p1 and p2 are the Ca 2+ and Mg 2+ ion concentrations in the fracturing water, in mg / L; ZD 总 is the turbidity value of the fracturing water turbid liquid, in NTU; A1 and A2 are the turbidity and Ca 2+ and Mg 2+K1, K2, K3 are the relationship constants of ion concentration, and p3 is the content of Na + increased in the fracturing water after adding the precipitant in the third step, in mg / L 总 ’ represents the conductivity of the outlet pressure water, in μs / cm, and K1, K2, K3 are the relationship constants of ion concentration. 2+ 2+ + A1, A2 can be fitted by the turbidity values of the turbid liquid obtained after adding the precipitant to the Ca 2+ and Mg 2+ ion series standard solution.K1, K2, K3 can be determined by the relationship between the known concentration of Ca 2+ , Mg 2+ , Na + solution and the measured conductivity.

[0056] The total ion and calcium-magnesium ion synchronous detection device for fracturing water realizes online real-time monitoring of the total ion concentration and the calcium-magnesium ion concentration in the fracturing water, and the monitoring data is fed back to the fracturing fluid preparation system in real time, so that the fracturing fluid preparation process can be optimized and adjusted.

[0057] In summary, the total ion and calcium-magnesium ion synchronous detection device for fracturing water is flexible, portable, simple and fast to operate, and efficient, which can effectively improve the construction efficiency and reduce the labor intensity of the site, and the performance parameters of the fracturing water can be obtained in time in the fracturing water treatment process, which can effectively reduce the incidence of complex site construction and improve the construction efficiency; the fracturing fluid preparation process can be optimized and adjusted conveniently.

[0058] The above technical features constitute the embodiments of the present application, which have strong adaptability and implementation effect, and unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.​

Claims

1. A method for using a device for simultaneous detection of total ions and calcium and magnesium ions in fracturing water, characterized in that... The simultaneous detection device for total ions and calcium and magnesium ions in fracturing water includes a sampling unit, a sample preparation unit, and a detection unit. The sampling unit includes a sampling pump, and the sample preparation unit includes a buffer tank, a precipitant storage tank, and a precipitant metering pump. The detection unit includes a first conductivity meter, a second conductivity meter, and a turbidimeter. A sampling pipeline is fixedly connected to the inlet of the sampling pump. A heating pipeline is fixedly connected between the outlet of the sampling pump and the first inlet of the buffer tank. A reinjection pipeline is fixedly connected to the bottom outlet of the buffer tank. A precipitant feed pipeline is fixedly connected to the inlet of the precipitant storage tank. A precipitant feeding pipeline is fixedly connected between the precipitant storage tank and the second inlet of the buffer tank. A precipitant metering pump is fixedly installed on the precipitant feeding pipeline. A first conductivity meter is fixedly installed on the heating pipeline. A second conductivity meter is fixedly installed on the reinjection pipeline. A turbidimeter is fixedly installed on the upper part of the buffer tank. A stirrer is installed inside the buffer tank. The method of use Includes the following steps: The first step is to connect the interfaces of the sampling pipeline and the reinjection pipeline to the main fracturing water pipeline, and start the constant temperature electric heating belt to keep the fracturing water in the pipeline at a constant temperature. The second step involves measuring the initial conductivity δ of the fracturing water as it flows through the first conductivity meter. 总 The total ion concentration in the fracturing water was calculated. The third step is to start the agitator in the buffer tank and zero the turbidity meter reading. Then, turn on the precipitant metering pump to inject excess precipitant into the buffer tank, allowing the Ca in the fracturing water to rise. 2+ Mg 2+ Ions form a suspension, resulting in a turbid fracturing water solution. The turbidity value (ZD) of the turbid fracturing water solution is measured using a turbidimeter. 总 The measured values ​​are converted by the data processing unit to obtain the content of calcium and magnesium ions in the fracturing water, and the precipitant is an aqueous solution of NaOH; The fourth step involves draining the fracturing water turbidity through the reinjection pipeline, and after isothermal treatment, measuring the conductivity δ of the fracturing water turbidity at this point. 总 ’ , Fifth step, based on the turbidity value ZD 总 The conductivity δ of fracturing water turbidity 总 ’ The amount of Ca in the fracturing water was calculated based on the amount of precipitant added. 2+ and Mg 2+ Ion concentration; In the second step, the total ion concentration in the fracturing water is calculated using the following formula: d 总 =Kρ formula 1 In the formula, ρ is the total ion concentration in the fracturing water, in mg / L; δ 总 The initial conductivity is given in μs / cm; K is the conductivity coefficient, the value of which is determined by the relationship between the total ion concentration of fracturing water and its conductivity. In the fifth step, Ca in the fracturing water 2+ and Mg 2+ The ion concentration is calculated using the following formula: ZD 总 = A1ρ1 + A2ρ2 Equation 2 d 总 -d 总 ’ =K1ρ1+K2ρ2-K3ρ3 Equation 3 In the formula, ρ1 and ρ2 are the Ca in the fracturing water, respectively. 2+ and Mg 2+ Ion concentration, in mg / L; ZD 总 The values ​​for turbidity in fracturing water turbidity are shown in NTU; A1 and A2 are the turbidity and Ca2+ values, respectively. 2+ and Mg 2+ The relationship constants between ion concentrations, A1 and A2, are derived from Ca 2+ and Mg 2 + The turbidity values ​​of the ion series standard solutions and the resulting turbid liquid after adding the precipitant were obtained by fitting the turbidity values; ρ3 represents the increase in Na+ after adding the precipitant to the fracturing water in the third step. + The content is expressed in mg / L; δ 总 ’ The conductivity of the outlet pressure water is expressed in μs / cm; K1, K2, and K3 are the conductivity and Ca, respectively. 2+ Mg 2+ Na + The relationship constants K1, K2, and K3 for ion concentrations are derived from known concentrations of Ca. 2+ Mg 2+ Na + The relationship between the solution and the measured conductivity was determined.

2. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 1, characterized in that... The simultaneous detection device for total ions and calcium and magnesium ions in fracturing water also includes a data processing unit, which includes a PLC-controlled display. The first conductivity meter, the second conductivity meter, and the turbidimeter are all electrically connected to the PLC-controlled display.

3. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 1 or 2, characterized in that... A first regulating valve is fixedly installed on the heating pipeline between the first conductivity meter and the buffer tank; a second regulating valve is fixedly installed between the outlet of the reinjection pipeline and the second conductivity meter; and a third regulating valve is fixedly installed on the precipitant feeding pipeline between the precipitant metering pump and the buffer tank.

4. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 3, characterized in that... The heating pipeline between the sampling pump and the first regulating valve, the buffer tank, and the reinjection pipeline between the second regulating valve are all covered with constant temperature electric heating belts.

5. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 2, characterized in that... The sampling unit, sample preparation unit, detection unit, and data processing unit are all fixedly installed on a movable base.

6. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 1, characterized in that... The total ion concentration in fracturing water is 100 mg / L to 50,000 mg / L, and the total calcium and magnesium ion concentration is 100 mg / L to 1,500 mg / L.

7. The method of using the simultaneous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 1 or 6, characterized in that... The flow rate of the liquid in the sampling line and the return line is 0.1 L / min to 5 L / min; or / and, in the first and fourth steps, the isothermal treatment temperature is 50°C to 60°C.

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