Synchronous detection device for total ions and calcium and magnesium ions in fracturing water and use method of synchronous detection device

Abstract

The invention relates to the technical field of oilfield chemical water quality detection, in particular to a synchronous detection device for total ions and calcium and magnesium ions in fracturing water and a using method thereof.The synchronous detection device comprises a sampling unit, a sample preparation unit and a detection unit, the sampling unit comprises a sampling pump, and 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, an inlet of the sampling pump is fixedly connected with a sampling pipeline, an outlet of the sampling pump is fixedly communicated with a first inlet of the buffer tank through a heating pipeline, an outlet in the bottom of the buffer tank is fixedly communicated with a reinjection pipeline, and an inlet of the precipitant storage tank is fixedly communicated with a precipitant feeding pipeline; a precipitant feeding pipeline is fixedly communicated between the precipitant storage tank and the second inlet of the buffer tank, and a precipitant metering pump is fixedly mounted on the precipitant feeding pipeline. According to the method, the performance parameters of the fracturing water can be rapidly measured on line, the construction efficiency is improved, and the method has a wide popularization prospect.

Description

Technical Field

[0001] The invention 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 method for using the device. Background Art

[0002] With the expansion of unconventional reservoir development, the demand for fracturing water has increased, resulting in a simultaneous increase in fracturing flowback fluid. At present, Xinjiang Oilfield uses salt lake water, oilfield flowback water and other sources of water as supplements. The water quality components are complex and variable, which has a great impact on the preparation and performance of fracturing fluid. Therefore, the treatment of fracturing water is particularly important for oilfields, especially in the water-scarce 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 fracturing fluid performance in oil fields mainly relies on on-site sampling and hanging experiments, which have the disadvantages of slow sampling and monitoring speed, long interval time and low work efficiency. This method cannot timely grasp the changes in water quality and fracturing fluid performance. The monovalent cations in fracturing water are mainly Na + The main high-valent cations in fracturing water are Ca 2 + Mg 2+ Mainly, and Ca 2+ and Mg 2+ The content will have a greater impact on the performance of the fracturing fluid. The content of other monovalent cations and high-valent cations in fracturing water is relatively low and does not need to be considered on site, and will not affect actual production.

[0004] Based on the above background, there is an urgent need to develop a device and method that can quickly measure the total ion concentration and calcium and magnesium ion concentration in fracturing water on site and determine the performance parameters of fracturing water to meet the needs of optimizing and dynamically adjusting the fracturing fluid preparation process. Summary of the invention

[0005] The present invention provides a synchronous detection device for total ions and calcium and magnesium ions in fracturing water and a method for using the same, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of slow speed, long cycle and low working efficiency in sampling and monitoring of fracturing water quality and calcium and magnesium ions at existing oil fields.

[0006] One of the technical solutions of the present invention is achieved through the following measures: a synchronous 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, 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 turbidity meter, 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 reinjection 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 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 turbidity meter is fixedly installed on the upper part of the buffer tank, the detection end of the turbidity meter is deep below the liquid level in the buffer tank, and an agitator is arranged in the buffer tank.

[0007] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The above-mentioned synchronous detection device for total ions and calcium and magnesium ions in fracturing water also includes a data processing unit, which includes a PLC control display. The first conductivity meter, the second conductivity meter and the turbidity meter are all electrically connected to the PLC control display.

[0008] 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 reinjection pipeline outlet 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.

[0009] The heating pipeline between the sampling pump and the first regulating valve and the reinjection pipeline between the buffer tank and the second regulating valve are both covered with a constant temperature electric heating belt.

[0010] The sampling unit, sample preparation unit, detection unit and data processing unit are all fixedly installed on a movable base.

[0011] The second technical solution of the present invention is achieved by the following measures: A method for using a synchronous detection device for total ions and calcium and magnesium ions in fracturing water is carried out according to the following steps: The first step is to connect the interfaces of the sampling pipeline and the reinjection pipeline to the main pipeline of the fracturing water, start the constant temperature electric heating belt, and perform constant temperature treatment on the fracturing water in the pipeline; In the second step, when the fracturing water flows through the first conductivity meter, the initial conductivity δ of the fracturing water is measured. 总 , the total ion concentration of fracturing water is calculated; The third step is to start the agitator of the buffer tank and reset the measured value of the turbidity meter to zero. Then, turn on the precipitant metering pump and inject an excess of precipitant into the buffer tank to make the Ca content in the fracturing water 2+ Mg 2+ The ions form a suspended solid to obtain a turbid liquid for fracturing water, and the turbidity value ZD of the turbid liquid for fracturing water is measured by a turbidity meter. 总 , the measured value is converted into the content of calcium and magnesium ions in the fracturing water by a data processing unit, and the precipitant is an aqueous solution of NaOH; In the fourth step, the turbid liquid for fracturing water is discharged through the reinjection pipeline, and after constant temperature treatment, the conductivity δ of the turbid liquid for fracturing water is measured. 总 ’ , Step 5: According to the turbidity value ZD 总 , conductivity of turbid liquid for fracturing water δ 总 ’ The Ca content in fracturing water was calculated by adding the amount of precipitant and 2+ and Mg 2+ Ion concentration.

[0012] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The total ion concentration in the above-mentioned fracturing water is 100 mg / L to 50,000 mg / L, and the total amount of calcium and magnesium ions is 100 mg / L to 1,500 mg / L.

[0013] The flow rate of the liquid in the sampling line and the return line is 0.1 L / min to 5 L / min.

[0014] In the first and fourth steps above, the isothermal treatment temperature is 50°C to 60°C.

[0015] In the second step above, the total ion concentration in the fracturing water is calculated according to the following formula 1: δ 总 =Kρ Formula 1 Where, ρ is the total ion concentration in fracturing water, in mg / L; δ 总 is the initial conductivity, in μs / cm; K is the conductivity coefficient.

[0016] In the fifth step above, Ca in the fracturing water 2+ and Mg 2+ The ion concentration is calculated as follows: ZD 总 =A1ρ1+A2ρ2 Formula 2 δ 总 -δ 总 ’ =K1ρ1+K2ρ2-K3ρ3 Formula 3 Where ρ1 and ρ2 are the Ca in fracturing water, 2+ and Mg 2+ Ion concentration, in mg / L; ZD 总 is the turbidity value of the turbid fluid used for fracturing, in NTU; A1 and A2 are the turbidity and Ca 2+ and Mg 2+ The constant related to the ion concentration, ρ3 is the Na added after the precipitant is added to the fracturing water in the third step. + The content of , the unit is mg / L; δ 总 ’ Indicates the conductivity of the water used for the outlet pressure, in μs / cm; K1, K2, and K3 are conductivity and Ca 2+ Mg 2+ 、Na + The relationship constant between ion concentration and

[0017] The present invention provides a device for synchronously detecting total ions and calcium and magnesium ions in fracturing water. The device can be used to quickly measure the performance parameters of fracturing water online, and the results can be displayed in real time, so as to optimize and adjust the fracturing fluid preparation process, so that the fracturing fluid meets the requirements of on-site use, provide data support for stabilizing the performance of the fracturing fluid, effectively reduce the occurrence rate of construction complexity, improve construction efficiency, provide data support for stabilizing the performance of the fracturing fluid, and have broad promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 It is a schematic diagram of the process flow of the present invention.

[0019] The codes in the accompanying drawings are: 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 turbidity meter, 8 is a sampling pipeline, 9 is a heating pipeline, 10 is a reinjection pipeline, 11 is a precipitant feed 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

[0020] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art. In the present invention, unless otherwise specified, the equipment and devices used are all known and commonly used equipment and devices in the prior art.

[0021] The present invention will be further described below in conjunction with embodiments: Example 1: Figure 1As shown, the synchronous 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, the detection unit includes a first conductivity meter 5, a second conductivity meter 6 and a turbidity meter 7, the sampling pump 1 inlet is fixedly connected with a sampling pipeline 8, the sampling pump 1 outlet and the first inlet of the buffer tank 2 are fixedly connected with a heating pipeline 9, and the bottom outlet of the buffer tank 2 is fixedly connected with a reinjection pipeline 10 The inlet of the precipitant storage tank 3 is fixedly connected with a precipitant feeding pipeline 11, the precipitant storage tank 3 and the second inlet of the buffer tank 2 are fixedly connected with a precipitant feeding pipeline 12, a precipitant metering pump 4 is fixedly installed on the precipitant feeding pipeline 12, a first conductivity meter 5 is fixedly installed on the heating pipeline 9, a second conductivity meter 6 is fixedly installed on the reinjection pipeline 10, a turbidity meter 7 is fixedly installed on the upper part of the buffer tank 2 (the detection end of the turbidity meter 7 is deep below the liquid level in the buffer tank 2), and an agitator 13 is arranged in the buffer tank 2.

[0022] Example 2: Figure 1 As shown, as an optimization of the above embodiment, the synchronous detection device for total ions and calcium and magnesium ions in fracturing water also includes a data processing unit, and the data processing unit includes a PLC control display 14, and the first conductivity meter 5, the second conductivity meter 6 and the turbidity meter 7 are all electrically connected to the PLC control display 14. The PLC control display 14 can be used for data collection, storage and processing.

[0023] Example 3: 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.

[0024] Example 4: Figure 1 As shown, as an optimization of the above embodiment, the heating pipeline 9 between the sampling pump 1 and the first regulating valve 15 and the reinjection pipeline 10 between the buffer tank 2 and the second regulating valve 16 are covered with a constant temperature electric heating belt. The constant temperature electric heating belt is used to perform constant temperature treatment (heating to 50°C to 60°C) on the materials in the sampling pipeline 8 and the reinjection pipeline 10 to ensure that the conductivity measurement conditions are stable and the values ​​are accurate. Similarly, in order to ensure that the temperature of the fracturing water is uniform and stable during the conductivity measurement, the first conductivity meter 5 and the second conductivity meter 6 should be installed on the side close to the first regulating valve 15 and the second regulating valve 16.

[0025] Example 5: Figure 1As shown, as an optimization of the above embodiment, the sampling unit, sample preparation unit, detection unit and data processing unit are all fixedly installed on a movable base. The synchronous detection device for total ions and calcium and magnesium ions in fracturing water adopts a movable design, which is more suitable for the dispersed characteristics of oil fields and mines.

[0026] Example 6: Figure 1 As shown, the method for using the device for synchronously detecting total ions and calcium and magnesium ions in fracturing water is carried out according to the following steps: The first step is to connect the interfaces of the sampling pipeline 8 and the reinjection pipeline 10 to the main pipeline of the fracturing water, start the constant temperature electric heating belt, and perform constant temperature treatment on the fracturing water in the pipeline; In the second step, when the fracturing water flows through the first conductivity meter 5, the initial conductivity δ of the fracturing water is measured. 总 , the total ion concentration of fracturing water is calculated; The third step is to start the agitator 13 of the buffer tank 2 and reset the measured value of the turbidity meter 7 to zero. Then, the precipitant metering pump 4 is turned on to inject an excess of precipitant into the buffer tank 2 so that the Ca in the fracturing water is 2+ Mg 2+ The ions form a suspended solid to obtain a turbid liquid for fracturing water, and the turbidity value ZD of the turbid liquid for fracturing water is measured by a turbidity meter 7. 总 , the measured value is converted into the content of calcium and magnesium ions in the fracturing water by a data processing unit, and the precipitant is an aqueous solution of NaOH; In the fourth step, the turbid liquid for fracturing water is discharged through the reinjection pipeline 10, and the conductivity δ of the turbid liquid for fracturing water is measured after constant temperature treatment. 总 ’ ; Step 5: According to the turbidity value ZD 总 , conductivity of turbid liquid for fracturing water δ 总 ’ The Ca content in fracturing water was calculated by adding the amount of precipitant and 2+ and Mg 2+ Ion concentration.

[0027] According to the needs, the mass concentration of the precipitant that can be used is 4g / L to 10g / L.

[0028] Example 7: As an optimization of the above example, the total ion concentration in the fracturing water is 100 mg / L to 50,000 mg / L, and the total amount of calcium and magnesium ions is 100 mg / L to 1,500 mg / L.

[0029] Embodiment 8: As an optimization of the above embodiment, the flow rate of the liquid in the sampling line 8 and the return line is 0.1 L / min to 5 L / min.

[0030] Example 9: As an optimization of the above example, in the first and fourth steps, the constant temperature treatment temperature is 50°C to 60°C.

[0031] Example 10: As an optimization of the above example, in the second step, the total ion concentration in the fracturing water is calculated according to the following formula 1: δ 总 =Kρ Formula 1 Where, ρ is the total ion concentration in fracturing water, in mg / L; δ 总 is the initial conductivity, in μs / cm; K is the conductivity coefficient. The K value can be determined by the relationship between the total ion concentration of fracturing water and the conductivity.

[0032] Example 11: As an optimization of the above example, in the fifth step, Ca in the fracturing water 2+ and Mg 2+ The ion concentration is calculated as follows: ZD 总 =A1ρ1+A2ρ2 Formula 2 δ 总 -δ 总 ’ =K1ρ1+K2ρ2-K3ρ3 Formula 3 Where ρ1 and ρ2 are the Ca in fracturing water, 2+ and Mg 2+ Ion concentration, in mg / L; ZD 总 is the turbidity value of the turbid fluid used for fracturing, in NTU; A1 and A2 are the turbidity and Ca 2+ and Mg 2+ The constant related to the ion concentration, ρ3 is the Na added after the precipitant is added to the fracturing water in the third step. + The content of , the unit is mg / L; δ 总 ’ It indicates the conductivity of the water used for the outlet pressure, in μs / cm. K1, K2, and K3 are the conductivity and Ca 2+ Mg 2+ 、Na + The relationship constant between ion concentration and A1. A2 can be represented by Ca 2+ and Mg 2+ The turbidity values ​​of the ion series standard solutions and the turbidity values ​​of the turbid solutions obtained after adding the precipitant are fitted. K1, K2, and K3 can be obtained by respectively obtaining the known concentrations of Ca 2+ Mg 2+ 、Na + The relationship between the solution and the measured conductivity is determined.

[0033] The device for synchronously detecting total ions and calcium and magnesium ions in fracturing water of the present invention realizes online real-time monitoring of the total ion concentration and calcium and magnesium ion concentration in fracturing water, and the monitoring data is fed back to the fracturing fluid preparation system online in real time, so as to optimize and adjust the fracturing fluid preparation process in a targeted manner.

[0034] In summary, the device for synchronous detection of total ions and calcium and magnesium ions in fracturing water of the present invention is flexible and lightweight, simple, fast and efficient to operate, can effectively improve construction efficiency, and reduce on-site manual labor intensity. The use of the present invention in the process of fracturing water treatment can timely obtain fracturing water performance parameters, can effectively reduce the incidence of complex on-site construction, and improve construction efficiency; it is convenient to optimize and adjust the fracturing fluid preparation process.

[0035] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A synchronous detection device for total ions and calcium and magnesium ions in fracturing water, characterized in that It includes a sampling unit, a sample preparation unit and a detection unit. The sampling unit includes a sampling pump. 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 turbidity meter. The sampling pump inlet is fixedly connected with a sampling pipeline. A heating pipeline is fixedly connected between the sampling pump outlet and the first inlet of the buffer tank. A re-injection pipeline is fixedly connected to the bottom outlet of the buffer tank. A precipitant storage tank inlet is fixedly connected with a precipitant feeding pipeline. A precipitant storage tank and the second inlet of the buffer tank are fixedly connected with a precipitant feeding pipeline. A 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 re-injection pipeline. A turbidity meter is fixedly installed on the upper part of the buffer tank. An agitator is arranged in the buffer tank.

2. The synchronous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 1, characterized in that It also includes a data processing unit, which includes a PLC control display. The first conductivity meter, the second conductivity meter and the turbidity meter are all electrically connected to the PLC control display.

3. The synchronous 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 reinjection pipeline outlet 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 synchronous 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 and the reinjection pipeline between the buffer tank and the second regulating valve are both covered with a constant temperature electric heating belt.

5. The synchronous detection device for total ions and calcium and magnesium ions in fracturing water according to claim 2, 3 or 4, characterized in that The sampling unit, the sample preparation unit, the detection unit and the data processing unit are all fixedly installed on the movable base.

6. A method for using the device for synchronously detecting total ions and calcium and magnesium ions in fracturing water according to any one of claims 1 to 5, characterized in that Follow these steps: The first step is to connect the interfaces of the sampling pipeline and the reinjection pipeline to the main pipeline of the fracturing water, start the constant temperature electric heating belt, and perform constant temperature treatment on the fracturing water in the pipeline; In the second step, when the fracturing water flows through the first conductivity meter, the initial conductivity δ of the fracturing water is measured. 总 , the total ion concentration of fracturing water is calculated; The third step is to start the agitator of the buffer tank and reset the measured value of the turbidity meter to zero. Then, turn on the precipitant metering pump and inject an excess of precipitant into the buffer tank to make the Ca content in the fracturing water 2+ Mg 2+ The ions form a suspended solid to obtain a turbid liquid for fracturing water, and the turbidity value ZD of the turbid liquid for fracturing water is measured by a turbidity meter. 总 , the measured value is converted into the content of calcium and magnesium ions in the fracturing water by a data processing unit, and the precipitant is an aqueous solution of NaOH; In the fourth step, the turbid liquid for fracturing water is discharged through the reinjection pipeline, and after constant temperature treatment, the conductivity δ of the turbid liquid for fracturing water is measured. 总 ’ , Step 5: According to the turbidity value ZD 总 , conductivity of turbid liquid for fracturing water δ 总 ’ The Ca content in fracturing water was calculated by adding the amount of precipitant and 2+ and Mg 2+ Ion concentration.

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

8. The method for using the device for synchronously detecting total ions and calcium and magnesium ions in fracturing water according to claim 6 or 7, characterized in that The flow rate of the liquid in the sampling line and the reflux line is 0.1 L / min to 5 L / min; or / and, in the first step and the fourth step, the constant temperature treatment temperature is 50° C. to 60° C.

9. The method for using the device for synchronously detecting total ions and calcium and magnesium ions in fracturing water according to any one of claims 6 to 8, characterized in that In the second step, the total ion concentration in the fracturing water is calculated according to Formula 1: d 总 =Kρ formula1 Where, ρ is the total ion concentration in fracturing water, in mg / L; δ 总 is the initial conductivity, in μs / cm; K is the conductivity coefficient.

10. The method for using the device for synchronously detecting total ions and calcium and magnesium ions in fracturing water according to any one of claims 6 to 7, characterized in that In the fifth step, Ca in the fracturing water 2+ and Mg 2+ The ion concentration is calculated as follows: ZD 总 = A1ρ1 + A2ρ2 Equation 2 d 总 -d 总 ’ =K1ρ1+K2ρ2-K3ρ3 Equation 3 Where ρ1 and ρ2 are the Ca in fracturing water, 2+ and Mg 2+ Ion concentration, in mg / L; ZD 总 is the turbidity value of the turbid fluid used for fracturing, in NTU; A1 and A2 are the turbidity and Ca 2+ and Mg 2+ The constant related to the ion concentration, ρ3 is the Na added after the precipitant is added to the fracturing water in the third step. + The content of , the unit is mg / L; δ 总 ’ Indicates the conductivity of the water used for the outlet pressure, in μs / cm; K1, K2, and K3 are conductivity and Ca 2+ Mg 2+ 、Na + The relationship constant between ion concentration and

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