An oilfield water quality compatibility testing device and experimental method

Abstract

The present invention discloses an oilfield water quality compatibility testing device and an experimental method, which include a first water inlet component, a second water inlet component, a device cavity, a heating component, a nitrogen passing component, a chemical adding component, a pressure gauge, a temperature probe, a pH meter, a cylindrical filtering component, a stirring component, a filtrate sampling component, a scaling sampling component and a control component. The cylindrical filtering component is arranged inside the device cavity to divide the internal space of the device cavity into an annular space and an internal reaction space. The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space of the device cavity. Among them, the heating component is sleeved around the device cavity. The nitrogen passing component is arranged at the top of the device cavity and communicated with the annular space of the device cavity. Among them, the chemical adding component, the pressure gauge, the temperature probe and the pH meter are arranged at the top of the device cavity and connected to the internal reaction space of the device cavity. Among them, the stirring component is arranged at the central position of the internal reaction space of the device cavity.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield water quality compatibility evaluation, and particularly relates to an oilfield water quality compatibility testing device and an experimental method. Background Art

[0002] As more and more oilfields enter the middle and late stages of development, water injection development has gradually become one of the important means for oilfield stable production and increased production, and is also the main way for comprehensive utilization of produced water. The main water source is the water in the Cretaceous Luohe formation, and the Luohe formation water is rich in SO4 2- , and the produced water from the production layer is mainly the water in the Yanchang Formation of the Triassic System. This production layer water is rich in Ba 2+ , Sr 2+ . The produced water from different horizons is mixed with the injection water for reinjection, and the water quality compatibility is poor. Acid-soluble scales such as carbonate scales and acid-insoluble scales that are difficult to remove such as sulfate scales are easily formed in the wellbore, gathering and transportation system, and formation, resulting in frequent equipment maintenance and replacement, increasing the injection water pressure, reducing the recovery rate, and ultimately affecting the sustainable development of the oilfield.

[0003] At present, there is no unified standard for oilfield water quality compatibility detection. The commonly used detection methods mainly include the static method, the gravimetric method, the turbidity method, etc. These methods all have limitations, considering fewer scaling influencing factors, and have limited significance for preventing and controlling the scaling problems caused by water quality compatibility on site. The static method only considers the influence factor of temperature and cannot accurately and comprehensively reflect the water quality compatibility situation; the gravimetric method also only considers the influence factor of temperature, and it is impossible to make an accurate judgment when the scaling amount of the water quality is small; the turbidity method also only considers the influence factor of temperature, and its accuracy is greatly affected by the particle size of the scaling substances. Acid-soluble scales (carbonate scales) and acid-insoluble scales (sulfate scales) have currently become a major obstacle restricting oilfield production increase and stable production. The scaling mechanisms of acid-soluble scales (carbonate scales) and acid-insoluble scales (sulfate scales) are different, and the treatment measures are also different. Therefore, the targeted development of an oilfield water quality compatibility testing device and an experimental method has important guiding significance for the prevention and treatment of acid-soluble scales (carbonate scales) and acid-insoluble scales (sulfate scales) in oilfields.

[0004] The State Intellectual Property Office publicly disclosed an invention patent application document with the publication number of CN1062901851A and the patent name of an oilfield water injection compatibility rapid analysis device and analysis method on January 4, 2017. The solution of this patent document is to use the on-line spectrophotometry method to achieve the rapid analysis of the water sample compatibility. In principle, this solution uses the turbidity method. First, the influence of iron oxides on the results is not excluded during the measurement process; second, this solution does not consider the influence of pressure on the water sample compatibility; finally, the turbidity method test results are greatly affected by the size of the scaling particles; the present invention is different from the above patent application document.

[0005] The State Intellectual Property Office publicly disclosed an invention patent application document with the publication number CN108132178A and the patent name of an evaluation device and method for the performance of oilfield injection water on June 8, 2018. The solution in this patent document uses the gravimetric method to evaluate the performance of injection water. There are several problems in this solution that will affect the evaluation results: (1) When the amount of scaling products generated during the experiment is small, the performance of the water sample cannot be accurately evaluated; (2) The filter cup 4-3 in this solution has no taper, and the scaling products cannot be completely collected under the action of negative pressure suction; (3) This solution uses a solar heating panel 3-7 to heat the bottom of the experimental device, and uneven heating is likely to affect the evaluation results; (4) This solution does not use a material with a low surface free energy as the inner lining. During the actual experiment, the water sample is likely to adhere and scale on the surface of the device or pipeline, and complete collection cannot be achieved; (5) This solution does not mention the simulation of flow rate and cannot simulate the on-site environment; (6) This solution mainly focuses on the quantitative evaluation of the total amount of scaling products and cannot distinguish between acid-soluble scales (carbonate scales) and acid-insoluble scales (sulfate scales) commonly found in oilfields. Based on the above points, the present invention is different from the above-mentioned patent application document. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide an oilfield water quality compatibility testing device and experimental method, which overcomes the following problems in the prior art: 1: The static method only considers the influence factor of temperature and cannot accurately and comprehensively reflect the water quality compatibility situation; 2: The gravimetric method also only considers the influence factor of temperature, and accurate judgment cannot be made when the water quality scaling amount is small; 3: The turbidity method also only considers the influence factor of temperature, and its accuracy is greatly affected by the particle size of the scaling products; 4: There is no relatively comprehensive device for testing oilfield water quality compatibility in the prior art.

[0007] To solve the technical problem, the technical solution of the present invention is: an oilfield water quality compatibility testing device, including a first water inlet assembly, a second water inlet assembly, a device cavity, a heating assembly, a nitrogen inlet assembly, a chemical dosing assembly, a pressure gauge, a temperature probe, a pH meter, a cylindrical filtration assembly, a stirring assembly, a filtrate sampling assembly, a scale sampling assembly, and a control assembly. The cylindrical filtration assembly is arranged inside the device cavity, dividing the internal space of the device cavity into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtration assembly are in contact with the inner wall of the device cavity. The first water inlet assembly and the second water inlet assembly are respectively connected to the bottom of the internal reaction space of the device cavity. The heating assembly is sleeved around the device cavity. The nitrogen inlet assembly is arranged at the top of the device cavity and is communicated with the annular space of the device cavity. The chemical dosing assembly is arranged at the top of the device cavity and is connected to the internal reaction space of the device cavity. The pressure gauge, the temperature probe, and the pH meter are respectively arranged at the top of the device cavity and are connected to the internal reaction space of the device cavity. The stirring assembly is arranged at the central position of the internal reaction space of the device cavity. The filtrate sampling assembly is connected to the bottom of the annular space of the device cavity. The scale sampling assembly is connected to the bottom of the internal reaction space of the device cavity. The first water inlet assembly, the second water inlet assembly, the heating assembly, the pressure gauge, the temperature probe, the pH meter, the stirring assembly, and the scale sampling assembly are respectively electrically connected to the control assembly.

[0008] Preferably, the bottom of the device cavity is a conical structure. The upper end of the cylindrical filtration assembly is in contact with the top of the device cavity, and the lower end of the cylindrical filtration assembly is in contact with the conical structure at the bottom of the device cavity. The cylindrical filtration assembly is a cylindrical filter screen, and a plurality of through holes are provided on the cylindrical filter screen for filtering the scale products generated during the experiment, facilitating the collection of scale products. The heating assembly includes a jacket, which is arranged around the device cavity. Water or low-temperature heat-conducting oil is used for heating in the jacket with low inlet and high outlet. A liquid level gauge is also arranged on the outer side of the device cavity, which is electrically connected to the control assembly. The control assembly is a single-chip microcomputer. The inner wall of the device cavity and the surface of the cylindrical filtration assembly are both made of polytetrafluoroethylene.

[0009] Preferably, the first water inlet assembly includes a first filter element, a first injection pump, and a first injection valve. The first filter element is connected to the first injection pump through a pipeline. The first injection pump is connected to the first injection valve through a pipeline. The first injection valve is connected to the internal reaction space of the conical structure at the bottom of the device cavity through a pipeline. The second water inlet assembly includes a second filter element, a second injection pump, and a second injection valve. The second filter element is connected to the second injection pump through a pipeline. The second injection pump is connected to the second injection valve through a pipeline. The second injection valve is connected to the internal reaction space of the conical structure at the bottom of the device cavity through a pipeline. The first injection pump and the second injection pump are respectively electrically connected to the control assembly.

[0010] Preferably, the nitrogen supply assembly includes a nitrogen pipeline and a nitrogen valve, wherein one end of the nitrogen pipeline is connected to a gas source, wherein the other end of the nitrogen pipeline passes from the top of the device cavity into the bottom of the annular space, and a nitrogen valve is arranged between the nitrogen pipeline and the gas source.

[0011] Preferably, the dosing assembly comprises a dosing hopper and a dosing valve, wherein the lower end of the dosing hopper is connected to the dosing valve and is arranged at the top of the inner reaction space of the device cavity.

[0012] Preferably, the stirring assembly includes a transmission assembly and a paddle stirrer, wherein the surface of the paddle stirrer is made of polytetrafluoroethylene, wherein the transmission assembly is arranged at the top center position of the device cavity, and the lower end of the transmission assembly is connected to the paddle stirrer, wherein the paddle stirrer is arranged in the inner reaction space of the device cavity, and wherein the transmission assembly is electrically connected to the control assembly.

[0013] Preferably, the filtrate sampling assembly includes a first filtrate sampling valve, an outlet filter element, a second filtrate sampling valve and a third filtrate sampling valve, wherein one end of the first filtrate sampling valve is connected to the bottom of the annular space of the cavity of the pipeline connecting device, and the other end of the first filtrate sampling valve is connected to the outlet filter element, the second filtrate sampling valve and the third filtrate sampling valve in sequence through a pipeline.

[0014] Preferably, the scale sampling assembly includes a first scale sampling valve, a level meter, a hopper and a second scale sampling valve, wherein one end of the first scale sampling valve is connected to the bottom of the reaction space in the cavity of the device through a pipeline, wherein the other end of the first scale sampling valve is connected to the hopper through a pipeline, the level meter is arranged on the hopper, wherein the level meter is electrically connected to the control assembly, and wherein the second scale sampling valve is connected to the bottom of the hopper through a pipeline.

[0015] Preferably, an experimental method of the oilfield water compatibility testing device as described in any one of the above items comprises the following steps:

[0016] Step 1) Analyze and detect the characteristic cations of the water samples respectively, where the cation concentration of water sample 1 is recorded as C 水样1 , the cation concentration of water sample 2 is recorded as C 水样2 ;

[0017] Step 2) Use the nitrogen gas supply component to replace the gas inside the device cavity, use the first water inlet component and the second water inlet component to pump in the set volume of water sample 1 and water sample 2 respectively, turn on the heating component, raise the temperature to the test temperature, turn on the stirring component to keep the flow rate consistent with the on-site flow rate, increase the pressure to the test pressure through the nitrogen gas supply component, react at a constant temperature, and then pressurize the filtrate through the filtrate sampling component to detect the characteristic cation content, and the cation concentration is recorded as C 总 ;

[0018] Step 3) The acid-soluble scale generated during the acid dissolution test of the dosing component can be quantitatively distinguished from the acid-insoluble scale; the filtrate is taken through the filtrate sampling component under pressure to detect the characteristic cation content, and the cation concentration is recorded as C 酸 , the total amount of acid insoluble scale is calculated by the cation content before and after scaling; when the amount of scaling products is large, the scaling products are sampled through the scaling sampling component for component analysis;

[0019] Step 4) After calculating the amount of acid-soluble scale and acid-insoluble scale respectively, the total amount of water scaling can be calculated, thus achieving qualitative and quantitative test and analysis of the compatibility of oilfield water quality.

[0020] Preferably, the acid-soluble scale in step 3) is carbonate scale, wherein carbonate scale includes calcium carbonate scale, barium carbonate scale and strontium carbonate scale, and the acid-insoluble scale is sulfate scale, wherein sulfate scale includes calcium sulfate scale, barium sulfate scale and strontium sulfate scale, and the calculation formula of the carbonate scale is:

[0021] m 碳酸盐 =m 碳酸钙+ m 碳酸钡+ m 碳酸锶 =

[0022]

[0023] Where:

[0024] m 碳酸盐 is the mass of carbonate scale, mg;

[0025] m 碳酸钙 is the mass of calcium carbonate scale, mg;

[0026] m 碳酸钡 is the mass of barium carbonate scale, mg;

[0027] m 碳酸锶 is the mass of strontium carbonate scale, mg;

[0028] V1 is the volume of water sample 1, ml;

[0029] V2 is the volume of water sample 2, ml;

[0030] C 加酸钙 is the calcium ion concentration after acid addition, mg / L;

[0031] C 未加酸钙 is the calcium ion concentration without acid addition, mg / L;

[0032] C 加酸钡 is the barium ion concentration after acid addition, mg / L;

[0033] C 未加酸钡 is the barium ion concentration without acid addition, mg / L;

[0034] C 加酸锶 is the strontium ion concentration after adding acid, mg / L;

[0035] C 未加酸锶 is the strontium ion concentration without adding acid, mg / L;

[0036] M 碳酸钙 is the relative molecular mass of calcium carbonate; M 碳酸钡 is the relative molecular mass of barium carbonate; M 碳酸锶 is the relative molecular mass of strontium carbonate; M 钙 is the relative atomic mass of calcium; M 钡 is the relative atomic mass of barium; M 锶 is the relative atomic mass of strontium;

[0037] The calculation formula for the sulfate scale is as follows:

[0038] m 硫酸盐 =m 硫酸钙+ m 硫酸钡+ m 硫酸锶 =

[0039]

[0040] In the formula:

[0041] m 硫酸盐 is the mass of the sulfate scale, mg;

[0042] m 硫酸钙 is the mass of the calcium sulfate scale, mg;

[0043] m 硫酸钡 is the mass of the barium sulfate scale, mg;

[0044] m 硫酸锶 is the mass of the strontium sulfate scale, mg;

[0045] V1 is the volume of water sample 1, ml;

[0046] V2 is the volume of water sample 2, ml;

[0047] C 1钙 is the calcium ion concentration of water sample 1, mg / L;

[0048] C 2钙 is the calcium ion concentration of water sample 2, mg / L;

[0049] C 1钡 is the barium ion concentration of water sample 1, mg / L;

[0050] C 2钡 is the barium ion concentration of water sample 2, mg / L;

[0051] C 1锶is the strontium ion concentration of water sample 1, mg / L;

[0052] C 2锶 is the strontium ion concentration of water sample 2, mg / L;

[0053] C 加酸钙 is the calcium ion concentration of the water sample after adding acid, mg / L;

[0054] C 加酸钡 is the barium ion concentration of the water sample after adding acid, mg / L;

[0055] C 加酸锶 is the strontium ion concentration of the water sample after adding acid, mg / L;

[0056] M 硫酸钙 is the relative molecular mass of calcium sulfate; M barium sulfate is the relative molecular mass of barium sulfate; M strontium sulfate is the relative molecular mass of strontium sulfate; M calcium is the relative atomic mass of calcium; M barium is the relative atomic mass of barium; M strontium is the relative atomic mass of strontium.

[0057] Compared with the prior art, the advantages of the present invention are as follows:

[0058] (1) The oilfield water quality compatibility test device of the present invention includes a first water inlet component, a second water inlet component, a device cavity, a heating component, a nitrogen gas passing component, a chemical adding component, a pressure gauge, a temperature probe, a pH meter, a cylindrical filtering component, a stirring component, a filtrate sampling component, a scale sampling component and a control component. The water samples are added to the device cavity by the first water inlet component and the second water inlet component, the device cavity is heated by the heating component, nitrogen gas is passed into the device cavity by the nitrogen gas passing component for gas replacement, acid or scale inhibitor is added by the chemical adding component, the pressure, temperature and pH are respectively detected by the pressure gauge, the temperature probe and the pH meter, the scale is filtered by the cylindrical filtering component, the stirring component is used for stirring to keep the flow rate consistent with the on-site flow rate, the filtrate is sampled by the filtrate sampling component, the scale is sampled by the scale sampling component, and the comprehensive control is carried out by the control component; the oilfield water quality compatibility test device of the present invention is used for the oilfield water quality compatibility test, has the adjustment functions of different parameters such as pressure, temperature, flow rate, dissolved oxygen, etc., comprehensively considers various factors for the water quality dynamic compatibility experiment, can more realistically simulate the on-site environment, and realizes the qualitative and quantitative test analysis of the oilfield water quality compatibility;

[0059] (2) The heating method of the heating device of the present invention is surface heating, which avoids the influence of local overheating on the compatibility test results; by adjusting the pH value of the water sample to dissolve the acid-soluble scale (carbonate scale), and detecting the characteristic cations of the filtrate, the main scale types of the acid-soluble scale (carbonate scale) and acid-insoluble scale (sulfate scale) in the oil field can be qualitatively and quantitatively determined; the lining material of the device cavity is polytetrafluoroethylene material, which has low surface free energy, is not easy to scale, and is easy to collect and sample the scale. When the amount of scale is large, the water quality compatibility can be determined by analyzing the composition of the scale. The scale inhibition rate of the scale inhibitor can be evaluated by means of ion detection, morphology analysis, etc., and the chelation, dispersion, and deformity properties of the scale inhibitor can be determined to determine the scale inhibition mechanism of the scale inhibitor; inert gas replacement deoxygenation is used during the experiment to eliminate the influence of oxygen and iron oxides on the experimental results; the system is kept at a slightly positive pressure by the nitrogen system, and sampling is convenient and quick;

[0060] (3) The present invention proposes a device and experimental method for testing the compatibility of oilfield water quality. The device and experimental method start from the main factors of scaling, simulate the compatibility experiment of water quality after mixing on site, determine the compatibility of water quality by analyzing the characteristic scaling cations of the filtrate, and combine pH value adjustment, ion detection, scaling component analysis and other means to achieve quantitative and qualitative analysis of acid-soluble scale (carbonate scale) and acid-insoluble scale (sulfate scale) common in oilfields, providing guidance for scaling prevention and control in oilfields;

[0061] (4) The oilfield water compatibility testing device of the present invention has a simple structure, is practical and convenient, and has strong practicability, and can be widely used in water quality compatibility testing experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 , a schematic structural diagram of an oilfield water compatibility testing device according to the present invention;

[0063] Figure 2 , scale sample component analysis diagram of Example 9 of the present invention.

[0064] Description of reference numerals:

[0065] 1-first filter element, 2-second filter element, 3-first sampling pump, 4-second sampling pump, 5-first sampling valve, 6-second sampling valve, 7-device cavity, 8-heating component, 9-nitrogen pipeline, 10-nitrogen valve, 11-dosing component, 12-pressure gauge, 13-temperature probe, 14-pH meter, 15-cylindrical filtering device, 16-liquid level meter, 17-stirring component, 18-first filtrate sampling valve, 19-outlet filter element, 20-second filtrate sampling valve, 21-third filtrate sampling valve, 22-first scale sample sampling valve, 23-level meter, 24-hopper, 25-second scale sample sampling valve. DETAILED DESCRIPTION

[0066] The specific implementation manners of the present invention will be described below in conjunction with embodiments:

[0067] It should be noted that the structures, ratios, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0068] At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration, and are not used to limit the scope in which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope in which the present invention can be implemented.

[0069] Embodiment 1

[0070] As Figure 1 shown, the present invention discloses an oilfield water quality compatibility testing device, including a first water inlet assembly, a second water inlet assembly, a device cavity 7, a heating assembly 8, a nitrogen passing assembly, a chemical adding assembly 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering assembly 15, a stirring assembly 17, a filtrate sampling assembly, a scaling sampling assembly and a control assembly. The cylindrical filtering assembly 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper end and the lower end of the cylindrical filtering assembly 15 are in contact with the inner wall of the device cavity 7. The first water inlet assembly and the second water inlet assembly are respectively connected to the bottom of the internal reaction space of the device cavity 7. The heating assembly 8 is sleeved outside the device cavity 7. The nitrogen passing assembly is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical adding assembly 11 is arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13 and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring assembly 17 is arranged at the central position of the internal reaction space of the device cavity 7. The filtrate sampling assembly is connected to the bottom of the annular space of the device cavity 7. The scaling sampling assembly is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet assembly, the second water inlet assembly, the heating assembly 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring assembly 17 and the scaling sampling assembly are respectively electrically connected to the control assembly.

[0071] Embodiment 2

[0072] As Figure 1As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, which includes a first water inlet component, a second water inlet component, a device cavity 7, a heating component 8, a nitrogen gas passing component, a chemical dosing component 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering component 15, a stirring component 17, a filtrate sampling component, a scale sampling component and a control component. The cylindrical filtering component 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtering component 15 are in contact with the inner wall of the device cavity 7. The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space in the device cavity 7. The heating component 8 is sleeved around the device cavity 7. The nitrogen gas passing component is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical dosing component 11 is arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13 and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring component 17 is arranged at the central position of the internal reaction space in the device cavity 7. The filtrate sampling component is connected to the bottom of the annular space of the device cavity 7. The scale sampling component is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet component, the second water inlet component, the heating component 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring component 17 and the scale sampling component are respectively electrically connected to the control component.

[0073] Preferably, as Figure 1 shown in the figure, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filtering component 15 is in contact with the top of the device cavity 7. The lower end of the cylindrical filtering component 15 is in contact with the conical structure at the bottom of the device cavity 7. The cylindrical filtering component 15 is a cylindrical filter screen, and a plurality of through holes are provided on the cylindrical filter screen for filtering the scale products generated during the experiment, which is convenient for collecting the scale products. The heating component 8 includes a jacket, which is arranged around the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket in a low-in and high-out manner. A liquid level gauge 16 is also arranged on the outer side of the device cavity 7. The liquid level gauge 16 is electrically connected to the control component. The control component is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filtering component 15 are both made of polytetrafluoroethylene.

[0074] Example 3

[0075] As Figure 1As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, which includes a first water inlet component, a second water inlet component, a device cavity 7, a heating component 8, a nitrogen passing component, a chemical dosing component 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering component 15, a stirring component 17, a filtrate sampling component, a scale sampling component and a control component. The cylindrical filtering component 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtering component 15 are in contact with the inner wall of the device cavity 7. The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space of the device cavity 7. The heating component 8 is sleeved around the device cavity 7. The nitrogen passing component is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical dosing component 11 is arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13 and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring component 17 is arranged at the central position of the internal reaction space of the device cavity 7. The filtrate sampling component is connected to the bottom of the annular space of the device cavity 7. The scale sampling component is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet component, the second water inlet component, the heating component 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring component 17 and the scale sampling component are respectively electrically connected to the control component.

[0076] Preferably, as Figure 1 shown in the figure, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filtering component 15 is in contact with the top of the device cavity 7. The lower end of the cylindrical filtering component 15 is in contact with the conical structure at the bottom of the device cavity 7. The cylindrical filtering component 15 is a cylindrical filter screen, and a plurality of through holes are provided on the cylindrical filter screen for filtering the scale products generated during the experiment, which is convenient for collecting the scale products. The heating component 8 includes a jacket, which is arranged around the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket with low-in and high-out. A liquid level gauge 16 is also arranged on the outer side of the device cavity 7. The liquid level gauge 16 is electrically connected to the control component. The control component is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filtering component 15 are both made of polytetrafluoroethylene.

[0077] Preferably, as Figure 1As shown in the figure, the first water inlet assembly includes a first filter element 1, a first sampling pump 3, and a first sampling valve 5. The first filter element 1 is connected to the first sampling pump 3 through a pipeline. The first sampling pump 3 is connected to the first sampling valve 5 through a pipeline. The first sampling valve 5 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The second water inlet assembly includes a second filter element 2, a second sampling pump 4, and a second sampling valve 6. The second filter element 2 is connected to the second sampling pump 4 through a pipeline. The second sampling pump 4 is connected to the second sampling valve 6 through a pipeline. The second sampling valve 6 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The first sampling pump 3 and the second sampling pump 4 are respectively electrically connected to the control assembly.

[0078] Example 4

[0079] As Figure 1 As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, including a first water inlet assembly, a second water inlet assembly, a device cavity 7, a heating assembly 8, a nitrogen gas passing assembly, a chemical adding assembly 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering assembly 15, a stirring assembly 17, a filtrate sampling assembly, a scale sampling assembly, and a control assembly. The cylindrical filtering assembly 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an inner reaction space. The upper and lower ends of the cylindrical filtering assembly 15 are attached to the inner wall of the device cavity 7. The first water inlet assembly and the second water inlet assembly are respectively connected to the bottom of the inner reaction space in the device cavity 7. The heating assembly 8 is sleeved around the device cavity 7. The nitrogen gas passing assembly is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical adding assembly 11 is arranged at the top of the device cavity 7 and connected to the inner reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13, and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the inner reaction space of the device cavity 7. The stirring assembly 17 is arranged at the central position of the inner reaction space of the device cavity 7. The filtrate sampling assembly is connected to the bottom of the annular space of the device cavity 7. The scale sampling assembly is connected to the bottom of the inner reaction space of the device cavity 7. The first water inlet assembly, the second water inlet assembly, the heating assembly 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring assembly 17, and the scale sampling assembly are respectively electrically connected to the control assembly.

[0080] Preferably, as Figure 1As shown, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filter assembly 15 is in contact with the top of the device cavity 7, and the lower end of the cylindrical filter assembly 15 is in contact with the conical structure at the bottom of the device cavity 7. The cylindrical filter assembly 15 is a cylindrical filter net, and there are multiple through holes on the cylindrical filter net for filtering the scaling products generated during the experiment, facilitating the collection of scaling products. The heating assembly 8 includes a jacket, which is arranged outside the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket with a low-in and high-out flow pattern. A liquid level gauge 16 is also provided outside the device cavity 7, and the liquid level gauge 16 is electrically connected to the control assembly, which is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filter assembly 15 are both made of polytetrafluoroethylene material.

[0081] Preferably, as Figure 1 shown, the first water inlet assembly includes a first filter element 1, a first sampling pump 3, and a first sampling valve 5. The first filter element 1 is connected to the first sampling pump 3 through a pipeline, the first sampling pump 3 is connected to the first sampling valve 5 through a pipeline, and the first sampling valve 5 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The second water inlet assembly includes a second filter element 2, a second sampling pump 4, and a second sampling valve 6. The second filter element 2 is connected to the second sampling pump 4 through a pipeline, the second sampling pump 4 is connected to the second sampling valve 6 through a pipeline, and the second sampling valve 6 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The first sampling pump 3 and the second sampling pump 4 are respectively electrically connected to the control assembly.

[0082] Preferably, as Figure 1 shown, the nitrogen gas passing assembly includes a nitrogen gas pipeline 9 and a nitrogen gas valve 10. One end of the nitrogen gas pipeline 9 is connected to a gas source, and the other end of the nitrogen gas pipeline 9 passes through the top of the device cavity 7 and enters the bottom of the annular space. A nitrogen gas valve 10 is provided between the nitrogen gas pipeline 9 and the gas source.

[0083] Preferably, as Figure 1 shown, the chemical dosing assembly 11 includes a chemical dosing hopper and a chemical dosing valve. The lower end of the chemical dosing hopper is connected to the chemical dosing valve and is arranged at the top of the inner reaction space of the device cavity 7.

[0084] Example 5

[0085] As Figure 1As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, which includes a first water inlet component, a second water inlet component, a device cavity 7, a heating component 8, a nitrogen purging component, a chemical dosing component 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering component 15, a stirring component 17, a filtrate sampling component, a scale sampling component and a control component. The cylindrical filtering component 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtering component 15 are in contact with the inner wall of the device cavity 7. The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space of the device cavity 7. The heating component 8 is sleeved around the device cavity 7. The nitrogen purging component is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical dosing component 11 is arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13 and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring component 17 is arranged at the central position of the internal reaction space of the device cavity 7. The filtrate sampling component is connected to the bottom of the annular space of the device cavity 7. The scale sampling component is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet component, the second water inlet component, the heating component 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring component 17 and the scale sampling component are respectively electrically connected to the control component.

[0086] Preferably, as Figure 1 shown in the figure, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filtering component 15 is in contact with the top of the device cavity 7. The lower end of the cylindrical filtering component 15 is in contact with the conical structure at the bottom of the device cavity 7. The cylindrical filtering component 15 is a cylindrical filter net, and a plurality of through holes are provided on the cylindrical filter net for filtering the scale products generated during the experiment, which is convenient for collecting the scale products. The heating component 8 includes a jacket, which is arranged around the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket in a low-in and high-out manner. A liquid level gauge 16 is also arranged on the outer side of the device cavity 7, and the liquid level gauge 16 is electrically connected to the control component. The control component is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filtering component 15 are both made of polytetrafluoroethylene.

[0087] Preferably, as Figure 1As shown, the first water inlet assembly includes a first filter element 1, a first sampling pump 3, and a first sampling valve 5. The first filter element 1 is connected to the first sampling pump 3 through a pipeline. The first sampling pump 3 is connected to the first sampling valve 5 through a pipeline. The first sampling valve 5 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The second water inlet assembly includes a second filter element 2, a second sampling pump 4, and a second sampling valve 6. The second filter element 2 is connected to the second sampling pump 4 through a pipeline. The second sampling pump 4 is connected to the second sampling valve 6 through a pipeline. The second sampling valve 6 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The first sampling pump 3 and the second sampling pump 4 are respectively electrically connected to the control assembly.

[0088] Preferably, as Figure 1 shown, the nitrogen gas passing assembly includes a nitrogen gas pipeline 9 and a nitrogen gas valve 10. One end of the nitrogen gas pipeline 9 is connected to a gas source. The other end of the nitrogen gas pipeline 9 passes through the top of the device cavity 7 and enters the bottom of the annular space. A nitrogen gas valve 10 is provided between the nitrogen gas pipeline 9 and the gas source.

[0089] Preferably, as Figure 1 shown, the chemical addition assembly 11 includes a chemical addition hopper and a chemical addition valve. The lower end of the chemical addition hopper is connected to the chemical addition valve and is arranged at the top of the inner reaction space of the device cavity 7.

[0090] Preferably, as Figure 1 shown, the stirring assembly 17 includes a transmission assembly and a paddle-shaped stirrer. The surface of the paddle-shaped stirrer is made of polytetrafluoroethylene. The transmission assembly is arranged at the center position of the top of the device cavity 7. The lower end of the transmission assembly is connected to the paddle-shaped stirrer. The paddle-shaped stirrer is arranged in the inner reaction space of the device cavity 7. The transmission assembly is electrically connected to the control assembly.

[0091] Preferably, as Figure 1 shown, the filtrate sampling assembly includes a first filtrate sampling valve 18, an outlet filter element 19, a second filtrate sampling valve 20, and a third filtrate sampling valve 21. One end of the first filtrate sampling valve 18 is connected to the bottom of the annular space of the device cavity 7 through a pipeline. The other end of the first filtrate sampling valve 18 is connected to the outlet filter element 19, the second filtrate sampling valve 20, and the third filtrate sampling valve 21 in sequence through a pipeline.

[0092] Example 6

[0093] As Figure 1As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, which includes a first water inlet component, a second water inlet component, a device cavity 7, a heating component 8, a nitrogen passing component, a chemical dosing component 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering component 15, a stirring component 17, a filtrate sampling component, a scaling sampling component and a control component. The cylindrical filtering component 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtering component 15 are attached to the inner wall of the device cavity 7. The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space in the device cavity 7. The heating component 8 is sleeved around the device cavity 7. The nitrogen passing component is arranged at the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The chemical dosing component 11 is arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13 and the pH meter 14 are respectively arranged at the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring component 17 is arranged at the central position of the internal reaction space in the device cavity 7. The filtrate sampling component is connected to the bottom of the annular space of the device cavity 7. The scaling sampling component is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet component, the second water inlet component, the heating component 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring component 17 and the scaling sampling component are respectively electrically connected to the control component.

[0094] Preferably, as Figure 1 shown, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filtering component 15 is attached to the top of the device cavity 7. The lower end of the cylindrical filtering component 15 is attached to the conical structure at the bottom of the device cavity 7. The cylindrical filtering component 15 is a cylindrical filter screen, and a plurality of through holes are provided on the cylindrical filter screen for filtering the scaling products generated during the experiment, which is convenient for collecting the scaling products. The heating component 8 includes a jacket, which is arranged around the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket with low-in and high-out. A liquid level gauge 16 is also arranged outside the device cavity 7, and the liquid level gauge 16 is electrically connected to the control component. The control component is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filtering component 15 are both made of polytetrafluoroethylene.

[0095] Preferably, as Figure 1As shown, the first water inlet assembly includes a first filter element 1, a first sampling pump 3, and a first sampling valve 5. The first filter element 1 is connected to the first sampling pump 3 through a pipeline. The first sampling pump 3 is connected to the first sampling valve 5 through a pipeline. The first sampling valve 5 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The second water inlet assembly includes a second filter element 2, a second sampling pump 4, and a second sampling valve 6. The second filter element 2 is connected to the second sampling pump 4 through a pipeline. The second sampling pump 4 is connected to the second sampling valve 6 through a pipeline. The second sampling valve 6 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The first sampling pump 3 and the second sampling pump 4 are respectively electrically connected to the control assembly.

[0096] Preferably, as Figure 1 shown, the nitrogen gas passing assembly includes a nitrogen gas pipeline 9 and a nitrogen gas valve 10. One end of the nitrogen gas pipeline 9 is connected to a gas source. The other end of the nitrogen gas pipeline 9 passes through the top of the device cavity 7 and enters the bottom of the annular space. A nitrogen gas valve 10 is provided between the nitrogen gas pipeline 9 and the gas source.

[0097] Preferably, as Figure 1 shown, the chemical addition assembly 11 includes a chemical addition hopper and a chemical addition valve. The lower end of the chemical addition hopper is connected to the chemical addition valve and is arranged at the top of the inner reaction space of the device cavity 7.

[0098] Preferably, as Figure 1 shown, the stirring assembly 17 includes a transmission assembly and a paddle-shaped stirrer. The surface of the paddle-shaped stirrer is made of polytetrafluoroethylene. The transmission assembly is arranged at the center position at the top of the device cavity 7. The lower end of the transmission assembly is connected to the paddle-shaped stirrer. The paddle-shaped stirrer is arranged in the inner reaction space of the device cavity 7. The transmission assembly is electrically connected to the control assembly.

[0099] Preferably, as Figure 1 shown, the filtrate sampling assembly includes a first filtrate sampling valve 18, an outlet filter element 19, a second filtrate sampling valve 20, and a third filtrate sampling valve 21. One end of the first filtrate sampling valve 18 is connected to the bottom of the annular space of the device cavity 7 through a pipeline. The other end of the first filtrate sampling valve 18 is connected to the outlet filter element 19, the second filtrate sampling valve 20, and the third filtrate sampling valve 21 in sequence through a pipeline.

[0100] Preferably, as Figure 1As shown in the figure, the scale sampling assembly includes a first scale sample sampling valve 22, a level gauge 23, a hopper 24, and a second scale sample sampling valve 25. One end of the first scale sample sampling valve 22 is connected to the bottom of the reaction space in the device cavity 7 through a pipeline, and the other end of the first scale sample sampling valve 22 is connected to the hopper 24 through a pipeline. The level gauge 23 is arranged on the hopper 24, and the level gauge 23 is electrically connected to the control assembly. The second scale sample sampling valve 25 is connected to the bottom of the hopper 24 through a pipeline.

[0101] Example 7

[0102] As Figure 1 As shown in the figure, the present invention discloses an oilfield water quality compatibility testing device, which includes a first water inlet assembly, a second water inlet assembly, a device cavity 7, a heating assembly 8, a nitrogen passing assembly, a medicine adding assembly 11, a pressure gauge 12, a temperature probe 13, a pH meter 14, a cylindrical filtering assembly 15, a stirring assembly 17, a filtrate sampling assembly, a scale sampling assembly, and a control assembly. The cylindrical filtering assembly 15 is arranged inside the device cavity 7 to divide the internal space of the device cavity 7 into an annular space and an internal reaction space. The upper end and the lower end of the cylindrical filtering assembly 15 are attached to the inner wall of the device cavity 7. The first water inlet assembly and the second water inlet assembly are respectively connected to the bottom of the reaction space in the device cavity 7. The heating assembly 8 is sleeved around the device cavity 7. The nitrogen passing assembly is arranged on the top of the device cavity 7 and communicated with the annular space of the device cavity 7. The medicine adding assembly 11 is arranged on the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The pressure gauge 12, the temperature probe 13, and the pH meter 14 are respectively arranged on the top of the device cavity 7 and connected to the internal reaction space of the device cavity 7. The stirring assembly 17 is arranged at the central position of the internal reaction space of the device cavity 7. The filtrate sampling assembly is connected to the bottom of the annular space of the device cavity 7. The scale sampling assembly is connected to the bottom of the internal reaction space of the device cavity 7. The first water inlet assembly, the second water inlet assembly, the heating assembly 8, the pressure gauge 12, the temperature probe 13, the pH meter 14, the stirring assembly 17, and the scale sampling assembly are respectively electrically connected to the control assembly.

[0103] Preferably, as Figure 1As shown, the bottom of the device cavity 7 is a conical structure. The upper end of the cylindrical filter assembly 15 fits against the top of the device cavity 7, and the lower end of the cylindrical filter assembly 15 fits against the conical structure at the bottom of the device cavity 7. The cylindrical filter assembly 15 is a cylindrical filter screen, and multiple through-holes are provided on the cylindrical filter screen for filtering the scaling products generated during the experiment, facilitating the collection of the scaling products. The heating assembly 8 includes a jacket, which is arranged on the periphery of the device cavity 7. Water or low-temperature heat-conducting oil is used for heating in the jacket with a low-in and high-out flow pattern. A liquid level gauge 16 is also provided on the outer side of the device cavity 7, and the liquid level gauge 16 is electrically connected to the control assembly, which is a single-chip microcomputer. The inner wall of the device cavity 7 and the surface of the cylindrical filter assembly 15 are both made of polytetrafluoroethylene material.

[0104] Preferably, as Figure 1 shown, the first water inlet assembly includes a first filter element 1, a first sampling pump 3, and a first sampling valve 5. The first filter element 1 is connected to the first sampling pump 3 through a pipeline, the first sampling pump 3 is connected to the first sampling valve 5 through a pipeline, and the first sampling valve 5 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The second water inlet assembly includes a second filter element 2, a second sampling pump 4, and a second sampling valve 6. The second filter element 2 is connected to the second sampling pump 4 through a pipeline, the second sampling pump 4 is connected to the second sampling valve 6 through a pipeline, and the second sampling valve 6 is connected to the inner reaction space of the conical structure at the bottom of the device cavity 7 through a pipeline. The first sampling pump 3 and the second sampling pump 4 are respectively electrically connected to the control assembly.

[0105] Preferably, as Figure 1 shown, the nitrogen gas passing assembly includes a nitrogen gas pipeline 9 and a nitrogen gas valve 10. One end of the nitrogen gas pipeline 9 is connected to a gas source, and the other end of the nitrogen gas pipeline 9 passes through the top of the device cavity 7 and enters the bottom of the annular space. A nitrogen gas valve 10 is provided between the nitrogen gas pipeline 9 and the gas source.

[0106] Preferably, as Figure 1 shown, the chemical addition assembly 11 includes a chemical addition hopper and a chemical addition valve. The lower end of the chemical addition hopper is connected to the chemical addition valve and is arranged at the top of the inner reaction space of the device cavity 7.

[0107] Preferably, as Figure 1 shown, the stirring assembly 17 includes a transmission assembly and a paddle-shaped stirrer. The surface of the paddle-shaped stirrer is made of polytetrafluoroethylene material. The transmission assembly is arranged at the center position of the top of the device cavity 7. The lower end of the transmission assembly is connected to the paddle-shaped stirrer. The paddle-shaped stirrer is arranged in the inner reaction space of the device cavity 7, and the transmission assembly is electrically connected to the control assembly.

[0108] Preferably, as Figure 1As shown, the filtrate sampling assembly includes a first filtrate sampling valve 18, an outlet filter element 19, a second filtrate sampling valve 20 and a third filtrate sampling valve 21, wherein one end of the first filtrate sampling valve 18 is connected to the bottom of the annular space of the device cavity 7 through a pipeline, and the other end of the first filtrate sampling valve 18 is connected to the outlet filter element 19, the second filtrate sampling valve 20 and the third filtrate sampling valve 21 in sequence through a pipeline.

[0109] Preferably, Figure 1 As shown, the scaling sampling assembly includes a first scaling sampling valve 22, a level meter 23, a hopper 24 and a second scaling sampling valve 25, wherein one end of the first scaling sampling valve 22 is connected to the bottom of the reaction space in the device cavity 7 through a pipeline, wherein the other end of the first scaling sampling valve 22 is connected to the hopper 24 through a pipeline, wherein the level meter 23 is arranged on the hopper 24, wherein the level meter 23 is electrically connected to the control assembly, wherein the second scaling sampling valve 25 is connected to the bottom of the hopper 24 through a pipeline.

[0110] Preferably, an experimental method of the oilfield water compatibility testing device as described in any one of the above items comprises the following steps:

[0111] Step 1) Analyze and detect the characteristic cations of the water samples respectively, where the cation concentration of water sample 1 is recorded as C 水样1 , the cation concentration of water sample 2 is recorded as C 水样2 ;

[0112] Step 2) Use the nitrogen gas supply assembly to replace the gas inside the device cavity 7, use the first water inlet assembly and the second water inlet assembly to pump in the set volume of water sample 1 and water sample 2 respectively, turn on the heating assembly 8, raise the temperature to the test temperature, turn on the stirring assembly 17 to keep the flow rate consistent with the on-site flow rate, increase the pressure to the test pressure through the nitrogen gas supply assembly, react at a constant temperature, and then pressurize the filtrate through the filtrate sampling assembly to detect the characteristic cation content, and the cation concentration is recorded as C 总 ;

[0113] Step 3) The acid-soluble scale generated during the test can be quantitatively distinguished by adding acid to the dosing component 11 to dissolve the acid-soluble scale and the acid-insoluble scale; the filtrate is pressurized through the filtrate sampling component to detect the characteristic cation content, and the cation concentration is recorded as C 酸 , the total amount of acid insoluble scale is calculated by the cation content before and after scaling; when the amount of scaling products is large, the scaling products are sampled through the scaling sampling component for component analysis;

[0114] After calculating the amount of acid-soluble scale and acid-insoluble scale respectively in step 4, the total amount of water scaling can be calculated, thereby achieving qualitative and quantitative test and analysis of the compatibility of oilfield water quality.

[0115] Preferably, in step 3), the acid-soluble scale is carbonate scale, where the carbonate scale includes calcium carbonate scale, barium carbonate scale and strontium carbonate scale, and the acid-insoluble scale is sulfate scale, where the sulfate scale includes calcium sulfate scale, barium sulfate scale and strontium sulfate scale. The calculation formula for the carbonate scale is:

[0116] m 碳酸盐 =m 碳酸钙+ m 碳酸钡+ m 碳酸锶 =

[0117]

[0118] In the formula:

[0119] m 碳酸盐 is the mass of carbonate scale, mg;

[0120] m 碳酸钙 is the mass of calcium carbonate scale, mg;

[0121] m 碳酸钡 is the mass of barium carbonate scale, mg;

[0122] m 碳酸锶 is the mass of strontium carbonate scale, mg;

[0123] V1 is the volume of water sample 1, ml;

[0124] V2 is the volume of water sample 2, ml;

[0125] C 加酸钙 is the calcium ion concentration after adding acid, mg / L;

[0126] C 未加酸钙 is the calcium ion concentration without adding acid, mg / L;

[0127] C 加酸钡 is the barium ion concentration after adding acid, mg / L;

[0128] C 未加酸钡 is the barium ion concentration without adding acid, mg / L;

[0129] C 加酸锶 is the strontium ion concentration after adding acid, mg / L;

[0130] C 未加酸锶 is the strontium ion concentration without adding acid, mg / L;

[0131] M 碳酸钙 is the relative molecular mass of calcium carbonate; M 碳酸钡 is the relative molecular mass of barium carbonate; M 碳酸锶 is the relative molecular mass of strontium carbonate; M 钙 is the relative atomic mass of calcium; M 钡 is the relative atomic mass of barium; M锶 is the relative atomic mass of strontium;

[0132] The calculation formula for the sulfate scale is:

[0133] m 硫酸盐 = m 硫酸钙+ m 硫酸钡+ m 硫酸锶 =

[0134]

[0135] In the formula:

[0136] m 硫酸盐 is the mass of the sulfate scale, mg;

[0137] m 硫酸钙 is the mass of the calcium sulfate scale, mg;

[0138] m 硫酸钡 is the mass of the barium sulfate scale, mg;

[0139] m 硫酸锶 is the mass of the strontium sulfate scale, mg;

[0140] V1 is the volume of water sample 1, ml;

[0141] V2 is the volume of water sample 2, ml;

[0142] C 1钙 is the calcium ion concentration of water sample 1, mg / L;

[0143] C 2钙 is the calcium ion concentration of water sample 2, mg / L;

[0144] C 1钡 is the barium ion concentration of water sample 1, mg / L;

[0145] C 2钡 is the barium ion concentration of water sample 2, mg / L;

[0146] C 1锶 is the strontium ion concentration of water sample 1, mg / L;

[0147] C 2锶 is the strontium ion concentration of water sample 2, mg / L;

[0148] C 加酸钙 is the calcium ion concentration after adding acid to the water sample, mg / L;

[0149] C 加酸钡 is the barium ion concentration after adding acid to the water sample, mg / L;

[0150] C 加酸锶 is the strontium ion concentration after adding acid to the water sample, mg / L;

[0151] M 硫酸钙 is the relative molecular mass of calcium sulfate; M 硫酸钡 is the relative molecular mass of barium sulfate; M 硫酸锶 is the relative molecular mass of strontium sulfate; M 钙 is the relative atomic mass of calcium; M 钡 is the relative atomic mass of barium; M 锶 is the relative atomic mass of strontium.

[0152] The first filter element 1 and the second filter element 2 are filtering devices, which are installed on the sampling pipeline before the sampling pump. Their function is to filter solid suspended matters and iron oxides in the water sample to ensure the water quality is clean and the subsequent experiments can proceed smoothly.

[0153] The device cavity 7 is a compatibility experiment site, and its inner lining is made of low surface energy material, such as polytetrafluoroethylene material, to reduce the adhesion of scaling products on the cavity surface. The bottom end of the device cavity is a conical structure, which is convenient for the collection and capture of scaling products under the stirring action.

[0154] The heating component 8 is a circulating heating device, which is located outside the device cavity. The reaction vessel is designed with a jacket, with low inlet and high outlet. Water or low-temperature heat transfer oil is used for heating in the jacket, and the temperature is controlled by the temperature probe 13; during the heating process, the entire cavity surface is heated, and the heating is more uniform, and the compatibility experiment process will not be affected by excessive local heat.

[0155] The nitrogen pipeline 9 and the nitrogen valve 10 are used for nitrogen transportation, connecting the gas source and the device cavity, and the pressure is controlled by the pressure gauge 12; nitrogen is an inert gas, which can replace the air in the device cavity 7 before the experiment to reduce the oxygen content and avoid the influence of iron oxides on the experimental results during the experiment; during the experiment, it is used as a pressure source and a replacement gas source to simulate the on-site pressure environment and eliminate the influence of other dissolved gases on the experiment. During the sampling process, nitrogen pressurization is convenient for sampling.

[0156] The dosing component 11 is located at the upper end of the device cavity 7 and is used for adding chemicals such as acids and scale inhibitors. Adding acid dissolves the acid-soluble scale generated during the experiment, and the pH value is controlled by the pH meter 14, which can distinguish and detect acid-soluble scale carbonate scale and acid-insoluble scale sulfate scale; combined with ion detection, morphology analysis and other means, the scale inhibition rate of the scale inhibitor can be evaluated, and the chelation, dispersion, deformation and other properties of the scale inhibitor can be determined to determine the scale inhibition mechanism of the scale inhibitor.

[0157] The cylindrical filter component 15 is located inside the device cavity 7, has a certain annulus with the inner wall of the device cavity 7, and is tightly fitted with the device cavity 7 at the upper and lower ends, playing a sealing role. Its function is to filter the scaling products generated during the experiment, facilitate the collection of scaling products; ensure the cleanliness of the filtrate and ensure the accurate detection of the filtrate cations in the future.

[0158] The stirring assembly 17 includes a transmission component and a paddle-shaped stirrer. The transmission component is located at the top of the device cavity 7 and functions to stir the water sample, adjust the stirring speed to simulate the on-site flow rate, and achieve multi-parameter adjustment of the compatibility experiment.

[0159] The outlet filter element 19 is a filtering device located behind the first filtrate sampling valve 18 and functions to filter the scaling products in the filtrate to ensure the accuracy of the detection results.

[0160] The pipeline, the inner wall of the device, the stirrer, etc. are all lined or wrapped with a low surface free energy material such as polytetrafluoroethylene.

[0161] Example 8

[0162] Analysis of the component and total amount of scaling in a single water sample

[0163] Analyze and detect the characteristic cations of the water quality; use nitrogen to displace the gas in the device cavity; pump a certain volume of water sample into the device with an injection pump; turn on the heating assembly, raise the temperature to the test temperature, turn on the stirring assembly (the flow rate refers to the on-site flow rate, measured by the linear velocity), add acid to adjust the pH value, increase the pressure to the test pressure, and conduct a constant-temperature reaction to dissolve the acid-soluble scale carbonate scale; take the filtrate under pressure to detect the content of characteristic cations; determine the content of acid-soluble scale carbonate scale and acid-insoluble scale sulfate scale through the cation content before and after scaling, and combine the component of the scale to determine the total amount of water quality scaling.

[0164] Example 9

[0165] Compatibility test and experimental analysis of two different water samples

[0166] Take water sample 1 from a water source well in a certain oilfield and produced water sample 2 for a compatibility test, and detect the initial scaling characteristic cation concentration of the two water samples. The results are shown in Table 1.

[0167] Table 1 Initial characteristic scaling cation concentration of water samples

[0168] Name <![CDATA[Ca 2+ , mg / L]]> <![CDATA[Ba 2+ , mg / L]]> <![CDATA[Sr 2+ , mg / L]]> Water sample 1 376.8 0.0 0.0 Water sample 2 3465.6 980.3 499.5

[0169] Use nitrogen to displace the gas in the device cavity; use an injection pump to pump 500 ml of each water sample volume at a ratio of 1:1; turn on the heating assembly, raise the temperature to the on-site temperature of 50 °C, turn on the stirring assembly to reach a linear velocity of 0.3 m / s, increase the pressure to the test pressure of 0.05 Mpa, and conduct a constant-temperature reaction for 8 h; take the filtrate to detect the characteristic cation concentration, and the results are shown in Table 2; add acid until the pH is less than 1, continuously stir for 1 h, take the filtrate to detect the characteristic cation concentration, and the results are shown in Table 2.

[0170] Table 2 Characteristic scaling cation concentration of the filtrate before and after adding acid

[0171] Name <![CDATA[Ca 2+ , mg / L]]> <![CDATA[Ba 2+ , mg / L]]> <![CDATA[Sr 2+ , mg / L]]> Without adding acid 1875.5 35.7 28.5 Adding acid 1901.1 38.8 33.2

[0172] The acid-insoluble scale can be calculated according to the above formula: m 酸不溶垢硫酸盐 = 1289.31 mg

[0173] The acid-soluble scale can be calculated according to the above formula: m 酸溶垢碳酸盐 = 76.30 mg

[0174] The total mass of water quality scaling = m 酸溶垢碳酸盐 + m 酸不溶垢硫酸盐 = 76.30 + 1289.31 = 1365.61 mg = 1.3656 g

[0175] Samples of the scale generated during the water quality compatibility experiment were taken through the scale sample valve, dried and kept at a constant temperature at 105 °C, weighed, and the mass of the scale sample was 1.2867 g, which was close to the calculated data. The scale sample was subjected to component analysis, and the analysis results are shown in Figure 2 , Figure 2 The component analysis results of the scale sample showed that more than 95% of the components of the scale sample were barium strontium sulfate, which was consistent with the calculated data, indicating that when the scaling amount was large, the component analysis method could accurately qualitatively analyze the scaling products formed in the water quality compatibility experiment.

[0176] The main performance evaluation of the scale inhibitor in Example 10 is based on barium sulfate

[0177] Configure samples according to the requirements of the standard Q / SY126-2014 "Technical Specification for Corrosion Inhibitors and Scale Inhibitors for Oilfield Water Treatment", analyze and detect the iconic cations in the water quality; use nitrogen to replace the gas in the device cavity; pump a certain volume of water samples into the device in proportion by an injection pump; add the scale inhibitor as required; turn on the heating component and the stirring component, heat up to the test temperature, and react at a constant temperature; pressurize to take the filtrate and detect the content of the iconic cations; calculate the scale inhibition rate of the scale inhibitor through the cation content before and after scaling; take samples of the scaling products for microscopic morphology analysis to determine the chelating, dispersing, and deforming properties of the scale inhibitor, and determine the scale inhibition mechanism of the scale inhibitor.

[0178] The working principle of the present invention is as follows:

[0179] As Figure 1As shown, the oilfield water compatibility testing device of the present invention comprises a first water inlet component, a second water inlet component, a device cavity, a heating component, a nitrogen gas passing component, a dosing component, a pressure gauge, a temperature probe, a pH meter, a cylindrical filter component, a stirring component, a filtrate sampling component, a scaling sampling component and a control component. The first water inlet component and the second water inlet component are used to add a water sample to the device cavity, the heating component is used to heat the device cavity, the nitrogen gas passing component is used to pass nitrogen into the device cavity for gas replacement, the dosing component is used to add acid or scale inhibitor, and the pressure gauge, the temperature probe and the pH meter are used to detect the pressure respectively. Pressure, temperature and pH, use a cylindrical filter component to filter scale, use a stirring component to stir to keep the flow rate consistent with the on-site flow rate, use a filtrate sampling component to sample filtrate, use a scaling sampling component to sample scaling, and use a control component to perform comprehensive control; the oilfield water quality compatibility testing device of the present invention is used for oilfield water quality compatibility testing, has the adjustment function of different parameters such as pressure, temperature, flow rate, dissolved oxygen, etc., comprehensively considers various factors to perform water quality dynamic compatibility experiments, can more realistically simulate the on-site environment, and realize qualitative and quantitative test and analysis of oilfield water quality compatibility.

[0180] The heating method of the heating device of the present invention is surface heating, so as to avoid the influence of local overheating on the compatibility test results; by adjusting the pH value of the water sample to dissolve the acid-soluble scale (carbonate scale), and detecting the characteristic cations of the filtrate, the main scale types of the acid-soluble scale (carbonate scale) and the acid-insoluble scale (sulfate scale) of the oil field can be qualitatively and quantitatively determined; the lining material of the device cavity is polytetrafluoroethylene material, which has low surface free energy, is not easy to scale, and is easy to collect and sample the scales. When the scale amount is large, the water quality compatibility can be determined by analyzing the composition of the scales; the scale inhibition rate of the scale inhibitor can be evaluated by means of ion detection, morphology analysis, etc., and the chelation, dispersion, deformity and other properties of the scale inhibitor can be determined, and the scale inhibition mechanism of the scale inhibitor can be determined; inert gas replacement deoxygenation is adopted in the experimental process to eliminate the influence of oxygen and iron oxides on the experimental results; the system is kept at a slightly positive pressure by a nitrogen system, and sampling is convenient and fast.

[0181] The invention proposes a device and an experimental method for testing the compatibility of oilfield water quality. The device and the experimental method start from the main factors of scaling, simulate the compatibility experiment of water quality after mixing on site, determine the water quality compatibility by analyzing the characteristic scaling cations of the filtrate, and realize quantitative and qualitative analysis of acid-soluble scale (carbonate scale) and acid-insoluble scale (sulfate scale), which are common scales in oilfields, by combining means such as pH value adjustment, ion detection and scaling component analysis, so as to provide guidance for scaling prevention and control in oilfields.

[0182] The oilfield water compatibility testing device of the present invention has simple structure, is practical and convenient, has strong practicability, and can be widely used in water quality compatibility testing experiments.

[0183] The above has described the preferred embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

[0184] Many other changes and modifications can be made without departing from the concept and scope of the present invention. It should be understood that the present invention is not limited to specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. An oilfield water quality compatibility testing device, characterized in that: It includes a first water inlet component, a second water inlet component, a device cavity (7), a heating component (8), a nitrogen gas passing component, a chemical dosing component (11), a pressure gauge (12), a temperature probe (13), a pH meter (14), a cylindrical filtering component (15), a stirring component (17), a filtrate sampling component, a scaling sampling component and a control component. The cylindrical filtering component (15) is arranged inside the device cavity (7) to divide the internal space of the device cavity (7) into an annular space and an internal reaction space. The upper and lower ends of the cylindrical filtering component (15) are in contact with the inner wall of the device cavity (7). The first water inlet component and the second water inlet component are respectively connected to the bottom of the internal reaction space of the device cavity (7). The heating component (8) is sleeved around the device cavity (7). The nitrogen gas passing component is arranged at the top of the device cavity (7) and communicated with the annular space of the device cavity (7). The chemical dosing component (11) is arranged at the top of the device cavity (7) and connected to the internal reaction space of the device cavity (7). The pressure gauge (12), the temperature probe (13) and the pH meter (14) are respectively arranged at the top of the device cavity (7) and connected to the internal reaction space of the device cavity (7). The stirring component (17) is arranged at the central position of the internal reaction space of the device cavity (7). The filtrate sampling component is connected to the bottom of the annular space of the device cavity (7). The scaling sampling component is connected to the bottom of the internal reaction space of the device cavity (7). The first water inlet component, the second water inlet component, the heating component (8), the pressure gauge (12), the temperature probe (13), the pH meter (14), the stirring component (17), the scaling sampling component are respectively electrically connected to the control component; The chemical dosing component (11) includes a chemical dosing hopper and a chemical dosing valve. The lower end of the chemical dosing hopper is connected to the chemical dosing valve and is arranged at the top of the internal reaction space of the device cavity (7); The stirring component (17) includes a transmission component and a paddle-shaped stirrer. The transmission component is arranged at the central position of the top of the device cavity (7). The lower end of the transmission component is connected to the paddle-shaped stirrer. The paddle-shaped stirrer is arranged in the internal reaction space of the device cavity (7).

2. The oilfield water quality compatibility testing device according to claim 1, wherein: The bottom of the device cavity (7) is a conical structure. The upper end of the cylindrical filtering component (15) is in contact with the top of the device cavity (7). The lower end of the cylindrical filtering component (15) is in contact with the conical structure at the bottom of the device cavity (7). The cylindrical filtering component (15) is a cylindrical filter screen. There are multiple through holes on the cylindrical filter screen for filtering the scaling products generated during the experiment to facilitate the collection of scaling products. The heating component (8) includes a jacket. The jacket is arranged around the device cavity (7). Water or low-temperature heat-conducting oil is used for heating in the jacket in a low-in and high-out manner. A liquid level gauge (16) is also arranged on the outer side of the device cavity (7). The liquid level gauge (16) is electrically connected to the control component. The control component is a single-chip microcomputer. The inner wall of the device cavity (7) and the surface of the cylindrical filtering component (15) are both made of polytetrafluoroethylene material.

3. The oilfield water quality compatibility testing device according to claim 2, wherein: The first water inlet assembly includes a first filter element (1), a first sample injection pump (3) and a first sample injection valve (5). The first filter element (1) is connected to the first sample injection pump (3) through a pipeline. The first sample injection pump (3) is connected to the first sample injection valve (5) through a pipeline. The first sample injection valve (5) is connected to the inner reaction space of the conical structure at the bottom of the device cavity (7) through a pipeline. The second water inlet assembly includes a second filter element (2), a second sample injection pump (4) and a second sample injection valve (6). The second filter element (2) is connected to the second sample injection pump (4) through a pipeline. The second sample injection pump (4) is connected to the second sample injection valve (6) through a pipeline. The second sample injection valve (6) is connected to the inner reaction space of the conical structure at the bottom of the device cavity (7) through a pipeline. The first sample injection pump (3) and the second sample injection pump (4) are respectively electrically connected to the control assembly.

4. The oilfield water quality compatibility testing device according to claim 1, characterized in that: The nitrogen gas passing assembly includes a nitrogen gas pipeline (9) and a nitrogen gas valve (10). One end of the nitrogen gas pipeline (9) is connected to a gas source. The other end of the nitrogen gas pipeline (9) passes through the top of the device cavity (7) and enters the bottom of the annular space. A nitrogen gas valve (10) is arranged between the nitrogen gas pipeline (9) and the gas source.

5. The oilfield water quality compatibility testing device according to claim 1, characterized in that: The surface of the paddle-shaped stirrer is made of polytetrafluoroethylene.

6. The oilfield water quality compatibility testing device according to claim 1, wherein: The transmission assembly is electrically connected to the control assembly.

7. The oilfield water quality compatibility testing device according to claim 1, characterized in that: The filtrate sampling assembly includes a first filtrate sampling valve (18), an outlet filter element (19), a second filtrate sampling valve (20) and a third filtrate sampling valve (21). One end of the first filtrate sampling valve (18) is connected to the bottom of the annular space of the device cavity (7) through a pipeline. The other end of the first filtrate sampling valve (18) is connected to the outlet filter element (19), the second filtrate sampling valve (20) and the third filtrate sampling valve (21) in sequence through a pipeline.

8. An oilfield water quality compatibility testing device according to claim 1, characterized in that: The scale sampling assembly includes a first scale sample sampling valve (22), a level gauge (23), a hopper (24) and a second scale sample sampling valve (25). One end of the first scale sample sampling valve (22) is connected to the bottom of the inner reaction space of the device cavity (7) through a pipeline. The other end of the first scale sample sampling valve (22) is connected to the hopper (24) through a pipeline. The level gauge (23) is arranged on the hopper (24). The level gauge (23) is electrically connected to the control assembly. The second scale sample sampling valve (25) is connected to the bottom of the hopper (24) through a pipeline.

9. An experimental method for an oilfield water quality compatibility testing device as described in any one of claims 1 - 8, characterized in that, Including the following steps: Step 1) Analyze and detect the characteristic cations of the water samples respectively, where the cation concentration of water sample 1 is recorded as C 水样1 , the cation concentration of water sample 2 is recorded as C 水样2 ; Step 2) Use the nitrogen purging component to conduct gas replacement inside the device cavity (7). Pump in a set volume of water sample 1 and water sample 2 using the first water inlet component and the second water inlet component respectively. Turn on the heating component (8) and raise the temperature to the test temperature. Turn on the stirring component (17) to make the flow rate consistent with the on-site flow rate. Boost the pressure to the test pressure through the nitrogen purging component, and carry out a constant-temperature reaction. Then, take the filtrate through the filtrate sampling component under pressure to detect the content of the marker cation, and record the cation concentration as C 总 ; Step 3) The acid-soluble scale generated during the test is dissolved by adding acid through the dosing component (11), and the acid-soluble scale and the acid-insoluble scale can be quantitatively distinguished; the filtrate is taken by the filtrate sampling component under pressure to detect the characteristic cation content, and the cation concentration is recorded as C 酸 , the total amount of acid insoluble scale is calculated by the cation content before and after scaling; when the amount of scaling products is large, the scaling products are sampled through the scaling sampling component for component analysis; In step 4), after calculating the amounts of acid-soluble scale and acid-insoluble scale respectively, the total water quality scaling amount can be calculated to realize the qualitative and quantitative test analysis of the compatibility of oilfield water quality.

10. The experimental method of an oilfield water quality compatibility testing device according to claim 9, characterized in that: In step 3), the acid-soluble scale is carbonate scale, and the carbonate scale includes calcium carbonate scale, barium carbonate scale and strontium carbonate scale. The acid-insoluble scale is sulfate scale, and the sulfate scale includes calcium sulfate scale, barium sulfate scale and strontium sulfate scale. The calculation formula for the carbonate scale is: In the formula: m 碳酸盐 is the mass of carbonate scale, mg; m 碳酸钙 is the mass of calcium carbonate scale, mg; m 碳酸钡 is the mass of barium carbonate scale, mg; m 碳酸锶 is the mass of strontium carbonate scale, mg; V1 is the volume of water sample 1, ml; V2 is the volume of water sample 2, ml; C 加酸钙 is the calcium ion concentration after adding acid, mg / L; C 未加酸钙 Calcium ion concentration without adding acid, mg / L; C 加酸钡 is the barium ion concentration after adding acid, mg / L; C 未加酸钡 is the barium ion concentration without adding acid, mg / L; C 加酸锶 is the strontium ion concentration after adding acid, mg / L; C 未加酸锶 is the strontium ion concentration without adding acid, mg / L; M 碳酸钙 is the relative molecular mass of calcium carbonate; M 碳酸钡 is the relative molecular mass of barium carbonate; M 碳酸锶 is the relative molecular mass of strontium carbonate; M 钙 is the relative atomic mass of calcium; M 钡 is the relative atomic mass of barium; M 锶 is the relative atomic mass of strontium; The calculation formula for the sulfate scale is as follows: In the formula: m 硫酸盐 is the mass of sulfate scale, mg; m 硫酸钙 is the mass of calcium sulfate scale, mg; m 硫酸钡 is the mass of barium sulfate scale, mg; m 硫酸锶 is the mass of strontium sulfate scale, mg; V1 is the volume of water sample 1, ml; V2 is the volume of water sample 2, ml; C 1钙 Calcium ion concentration of water sample 1, mg / L; C 2钙 is the calcium ion concentration of water sample 2, mg / L; C 1钡 is the barium ion concentration of water sample 1, mg / L; C 2钡 is the barium ion concentration of water sample 2, mg / L; C 1锶 is the strontium ion concentration of water sample 1, mg / L; C 2锶 Strontium ion concentration of water sample 2, mg / L; C 加酸钙 Calcium ion concentration after adding acid to the water sample, mg / L; C 加酸钡 is the barium ion concentration after adding acid to the water sample, mg / L; C 加酸锶 Strontium ion concentration after adding acid to the water sample, mg / L; M 硫酸钙 is the relative molecular mass of calcium sulfate; M 硫酸钡 is the relative molecular mass of barium sulfate; M 硫酸锶 is the relative molecular mass of strontium sulfate; M 钙 is the relative atomic mass of calcium; M 钡 is the relative atomic mass of barium; M 锶 is the relative atomic mass of strontium.

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