Fluid component real-time measurement system based on formation tester

Abstract

The fluid component real-time measurement system comprises a sensor cylinder and a circuit cylinder which are installed in the formation tester, and a bottom liquid inlet and an upper liquid outlet of the sensor cylinder are communicated with a fluid channel lower portion and a fluid channel upper portion of a fluid channel of the formation tester respectively; a fluid measuring channel is arranged in the sensor cylinder, and a plurality of sensors are mounted in the fluid measuring channel; a measuring system circuit is arranged in the circuit cylinder; excitation lines and signal transmission lines of the plurality of sensors are packaged through a sealing technology, then led out to the circuit cylinder and connected with the measuring system circuit. Power supply and signal transmission of the measuring system circuit are connected with a circuit of the formation tester through the sealing technology. Therefore, real-time, rapid and accurate measurement of formation fluid components is realized.

Description

Technical Field

[0001] The present application relates to the field of formation testing, and in particular to a real-time measurement system for fluid components based on a formation tester. Background Art

[0002] In the field of formation testing, fluid component measurement is an important means of evaluating the potential of oil and gas reservoirs. Traditional formation testing technology obtains measurement results by sampling and analyzing on the ground. This method has the following limitations: 1. It cannot achieve real-time monitoring; 2. It cannot determine whether the fluid comes from the formation during the sampling process.

[0003] It is more meaningful in practice to be able to measure the fluid components in the sampling channel in real time, give parameters such as water content or oil content and gas content, and monitor the changes of the fluid in the sampling channel in real time to ensure that the sample taken is closer to the fluid in the formation. Therefore, a new type of formation tester measuring nipple is urgently needed, which can integrate multiple sensors to achieve fast and accurate measurement of parameters such as water content or oil content of fluid components. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the purpose of the present application is to propose a real-time fluid component measurement system based on a formation tester to achieve real-time, rapid and accurate measurement of formation fluid components.

[0006] To achieve the above-mentioned purpose, the embodiment of the present application proposes a real-time measurement system of fluid components based on a formation tester, comprising a sensor tube and a circuit tube installed in the formation tester, wherein the bottom liquid inlet and the upper liquid outlet of the sensor tube are respectively connected to the lower part and the upper part of the fluid channel of the formation tester;

[0007] A fluid measurement channel is provided in the sensor tube, and a plurality of sensors are installed in the fluid measurement channel; a measurement system circuit is provided in the circuit tube; the excitation lines and signal transmission lines of the plurality of sensors are packaged through a sealing process and then led out to the circuit tube and connected to the measurement system circuit; the power supply and signal transmission of the measurement system circuit are connected to the circuit of the formation tester through a sealing process.

[0008] In some implementations, the plurality of sensors includes a conductivity sensor, a conductivity probe, and a fiber optic probe.

[0009] In some implementations, the fluid component real-time measurement system further includes a data processing device, wherein the data processing device is used to:

[0010] According to the output signals of the conductivity probe, the optical fiber probe and the conductivity sensor, the fluid type of the current fluid is determined, wherein the fluid type includes gas-water two-phase flow, oil-water two-phase flow and oil-gas-water three-phase flow;

[0011] Based on the interpretation rules corresponding to the fluid type of the current fluid, obtain relevant relationship diagrams and / or formulas; wherein, the interpretation rules for gas-water two-phase flow include a relationship diagram of the relationship curve between the output signal of the optical fiber probe and the gas volume, the interpretation rules for oil-water two-phase flow include a linear relationship formula between the water content index and the proportion water content, and the interpretation rules for oil-gas-water three-phase flow include a relationship diagram of the relationship curve between the water content index and the proportion water content under different gas volumes;

[0012] According to the experimental calibration chart and / or formula, one or more of the water content, oil content and gas content of the current fluid are obtained.

[0013] In some implementations, the data processing device is used to:

[0014] determining whether the current fluid is a slug flow according to the output signal of the conductivity probe;

[0015] When the current fluid is a slug flow and the output signal of the conductivity probe is at a low level, it is determined that the current fluid is a pure water phase;

[0016] When the current fluid is a slug flow and the output signal of the conductivity probe is not at a low level, judging whether the slug flow is a gas slug or an oil slug according to the output signal of the optical fiber probe, and calculating the volume of the single-phase flow of the slug flow according to the duration and flow channel area of ​​the output signal of the optical fiber probe;

[0017] In the case that the current fluid is not a slug flow, it is determined whether the fluid contains gas based on the output signal of the optical fiber probe; if the fluid does not contain gas, the water content is obtained by interpolating the relationship diagram between the proportion water content and the water content index in the interpretation procedure of the oil-water two-phase flow in combination with the output signal of the conductivity sensor; if the fluid contains gas, the gas content is obtained by interpolating the relationship diagram between the output signal of the optical fiber probe and the gas volume in the interpretation procedure of the gas-water two-phase flow, and then the water content is obtained by interpolating the relationship diagram between the water content index and the proportion water content under different gas volumes in the interpretation procedure of the oil-gas-water three-phase flow.

[0018] In some implementations, the fluid component real-time measurement system also includes an experimental device, which obtains interpretation procedures corresponding to different fluid types and relationship diagrams and / or formulas involved in the interpretation procedures by implementing the implementation process of gas-water two-phase flow, the implementation process of oil-water two-phase flow, and the implementation process of oil-gas-water three-phase flow; the experimental device includes an experimental wellbore, an oil pump, a water pump, an air pump, an oil tank, a water tank, and a liquid receiving container; the experimental wellbore includes a liquid inlet at the bottom of the wellbore and a liquid outlet at the top of the wellbore, and the liquid inlet of the oil pump is connected to the liquid outlet of the wellbore. The oil tank is connected, and the liquid outlet of the oil pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline with a valve; the liquid inlet of the water pump is connected to the water tank, and the liquid outlet of the water pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline with a valve; the air pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline, and the liquid outlet at the top of the wellbore is connected to the liquid receiving container; the sensor tube is installed in the experimental wellbore, and the bottom liquid inlet and the upper liquid outlet of the sensor tube are respectively connected to the bottom liquid inlet and the top liquid outlet of the wellbore.

[0019] In some implementations, the measurement system circuit includes a connected single-chip microcomputer and a sensor interface circuit, and the sensor interface circuit includes a conductivity sensor interface circuit, a conductivity probe interface circuit, and a fiber optic probe interface circuit;

[0020] The conductivity sensor interface circuit includes a first positive and negative pulse synthesis module, a voltage-controlled constant current source module and an amplification module. The waveform generator inside the single-chip microcomputer is connected to the excitation end of the conductivity sensor through the first positive and negative pulse synthesis module and the voltage-controlled constant current source module in sequence; the measurement end of the conductivity sensor is connected to the average value detection module inside the single-chip microcomputer through the amplification module.

[0021] The conductivity probe interface circuit includes a second positive and negative pulse synthesis module and a driving circuit module. The waveform generator inside the single-chip microcomputer is connected to the conductivity probe through the second positive and negative pulse synthesis module and the driving circuit module in sequence. The conductivity probe is also connected to the average value detection and comparison module inside the single-chip microcomputer.

[0022] The fiber optic probe interface circuit comprises a fiber optic probe interface, and the fiber optic probe is connected to the analog-to-digital acquisition channel of the single-chip microcomputer via the fiber optic probe interface.

[0023] In some implementations, the measurement system circuit also includes a temperature compensation module inside the microcontroller, which measures the real-time temperature through a temperature sensor inside the microcontroller, and performs temperature compensation on the sensor signals of the multiple sensors according to the changing rules of the sensor signals at different temperatures.

[0024] In some implementations, the measurement system circuit also includes a power management module, which is used to measure the overall power supply of the measurement system circuit, including a +12V voltage used by the measurement system circuit, a +5V voltage used by the optical fiber probe, and a -5V voltage required for the operation of other chips in the measurement system circuit except the single-chip microcomputer.

[0025] In some implementations, the bottom liquid inlet and the upper liquid outlet of the sensor tube are sealedly connected to the lower portion and the upper portion of the fluid channel of the formation tester, respectively.

[0026] In some implementations, the sensor tube and the circuit tube are installed on a short section that matches the lower end of the short section where the sampling cavity of the formation tester is located.

[0027] The real-time fluid component measurement system based on the formation tester provided in the present application realizes real-time, rapid and accurate measurement of the formation fluid components through a sensor tube arranged in the sampling chamber of the formation tester and multiple sensors arranged therein, a circuit tube and a measurement system circuit therein.

[0028] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0030] Figure 1 A structural schematic diagram of a real-time measurement system for fluid components based on a formation tester provided in an embodiment of the present application;

[0031] Figure 2 A circuit diagram of a measurement system circuit provided in an embodiment of the present application.

[0032] Figure 3 A schematic diagram of an experimental device provided in an embodiment of the present application.

[0033] Figure 4 A graph showing the relationship between the output signal and gas volume of a fiber optic probe provided in an embodiment of the present application.

[0034] Figure 5 A relationship diagram between the water content ratio and the water content index in an oil-water two-phase mixture provided in an embodiment of the present application.

[0035] Figure 6 A relationship diagram between the moisture index of a conductivity sensor and the proportional moisture content under different gas volumes provided in an embodiment of the present application.

[0036] Figure 7 A flowchart of a method for interpreting sensor data provided in an embodiment of the present application.

[0037] In the figure:

[0038] 1- measurement system circuit, 2- upper part of fluid channel, 3- optical fiber probe, 4- conductivity probe, 5- conductivity sensor, 6- lower part of fluid channel, 7- shell of formation tester, 8- experimental wellbore, 9- organic glass tube, 10- sensor tube, 11- liquid inlet at the bottom of wellbore, 12- liquid outlet at the top of wellbore, 13- pump liquid end, 14- data receiving end. DETAILED DESCRIPTION

[0039] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0040] The following describes a real-time fluid component measurement system based on a formation tester according to an embodiment of the present application with reference to the accompanying drawings.

[0041] Figure 1 This is a schematic diagram of the structure of a real-time measurement system for fluid components based on a formation tester provided in an embodiment of the present application. Figure 1 As shown, the real-time measurement system of fluid components based on the formation tester may include: a sensor tube and a circuit tube installed in the formation tester, wherein the bottom liquid inlet and the upper liquid outlet of the sensor tube are respectively connected to the fluid channel lower part 6 and the fluid channel upper part 2 of the fluid channel of the formation tester;

[0042] A fluid measurement channel is provided in the sensor tube, and a plurality of sensors are installed in the fluid measurement channel; a measurement system circuit 1 is provided in the circuit tube; the excitation lines and signal transmission lines of the plurality of sensors are packaged through a sealing process and then led out to the circuit tube and connected to the measurement system circuit 1; the power supply and signal transmission of the measurement system circuit 1 are connected to the circuit of the formation tester through a sealing process.

[0043] like Figure 1 As shown, a sensor tube and a circuit tube are installed side by side in the shell 7 of the formation tester.

[0044] Thus, the fluid sample to be measured is collected through the fluid measurement channel of the sensor tube, and the fluid sample is provided for the subsequent multiple sensors. The multiple sensors and measurement system circuits in the fluid measurement channel of the sensor tube realize real-time, rapid and accurate measurement of the formation fluid components.

[0045] In some embodiments, the sensor tube and the circuit tube are installed on a short section that matches the lower end of the short section where the sampling cavity of the formation tester is located.

[0046] In some embodiments, the multiple sensors include a conductivity sensor 5, a conductivity probe 4 and an optical fiber probe 3, wherein the conductivity sensor 5 is used to measure the water content of the fluid sample, the conductivity probe 4 is used to detect oil bubbles in the fluid sample, and the optical fiber probe 3 is used to measure the gas content in the fluid sample.

[0047] Specifically, the conductivity sensor 5 is installed in the sampling channel 2 to measure the water content of the fluid sample; the conductivity sensor 5 can measure the water content of the fluid in real time, provide continuous and stable measurement data, and has advantages in measuring the average water content of a section of fluid. The conductivity probe 4 is installed in the sampling channel 2 to detect oil bubbles in the fluid sample, and has a sensitive instantaneous response to the oil bubbles, especially in the case of oil bubble agglomeration and intermittent oil discharge, with high measurement accuracy. It is specially designed for oil bubble detection, has a fast response characteristic, and can accurately identify oil bubble agglomeration and intermittent oil discharge. The optical fiber probe 3 is installed in the sampling channel 2 to measure the gas content in the fluid sample and to correct the measurement results of other sensors; the optical fiber probe 3 is sensitive to gas response and can measure the gas output or gas holdup rate, and is used to calibrate the conductivity sensor 5 and the conductivity probe 4 to give the water content and oil content.

[0048] In some implementations, the multiple sensors are installed sequentially along the axial direction of the fluid measuring channel by fasteners, that is, the conductivity sensor 5, the conductivity probe 4 and the optical fiber probe 3 are installed sequentially in the fluid measuring channel along the axial direction of the fluid measuring channel by fasteners to achieve structural reliability.

[0049] This embodiment adopts a modular design concept to ensure the installation accuracy of each sensor and meet the sealing requirements under high temperature and high pressure environments.

[0050] In some implementations, the bottom liquid inlet and the upper liquid outlet of the sensor tube are sealed and connected to the lower part and the upper part of the fluid channel of the formation tester, respectively. That is, the structural interface design of the sensor tube should fully consider the tight connection with the sampling channel of the formation tester, and ensure the sealing of the connection with the sampling channel to prevent the fluid from leaking from the sampling channel to the outside of the channel.

[0051] In some embodiments, the measurement system circuit 1 is used to provide excitation signals for multiple sensors and process sensor signals, such as Figure 3 As shown, the measurement system circuit 1 includes a connected single chip microcomputer and a sensor interface circuit, and the sensor interface circuit includes a conductivity sensor interface circuit, a conductivity probe interface circuit and an optical fiber probe interface circuit;

[0052] The conductivity sensor interface circuit includes a first positive and negative pulse synthesis module, a voltage-controlled constant current source module and an amplification module. The waveform generator inside the single-chip microcomputer is connected to the excitation end of the conductivity sensor 5 through the first positive and negative pulse synthesis module and the voltage-controlled constant current source module in sequence; the measurement end of the conductivity sensor 5 is connected to the average value detection module inside the single-chip microcomputer through the amplification module.

[0053] The conductivity probe interface circuit includes a second positive and negative pulse synthesis module and a driving circuit module. The waveform generator inside the single-chip microcomputer is connected to the conductivity probe 4 through the second positive and negative pulse synthesis module and the driving circuit module in sequence. The conductivity probe 4 is also connected to the average value detection and comparison module inside the single-chip microcomputer.

[0054] The fiber optic probe interface circuit includes a fiber optic probe interface, and the fiber optic probe 3 is connected to the analog-to-digital acquisition channel of the single-chip microcomputer via the fiber optic probe interface.

[0055] In some embodiments, the measurement system circuit 1 also includes a temperature compensation module inside the single-chip microcomputer. The temperature compensation module measures the real-time temperature through the temperature sensor inside the single-chip microcomputer, and performs temperature compensation on the sensor signals of the multiple sensors according to the changing rules of the sensor signals at different temperatures to improve the measurement accuracy.

[0056] In some embodiments, the measurement system circuit 1 also includes a power management module, which is used to measure the overall power supply of the measurement system circuit 1, including the +12V voltage used by the measurement system circuit 1, the +5V voltage used by the optical fiber probe 3, and the -5V voltage required for the operation of other chips in the measurement system circuit 1 except the single-chip microcomputer.

[0057] The measurement system circuit of this embodiment adopts a miniaturized, low-power design, integrates signal processing and data transmission functions, and is compatible with the circuit system of the existing formation tester. The communication between the measurement system circuit and the formation tester adopts a coding method, and the signal processing is mainly completed by the combination of a single-chip microcomputer and peripheral devices. The single-chip microcomputer processes the signals generated by the conductivity sensor, the conductivity probe and the optical fiber probe into three voltage signals, which are encoded and transmitted by the CNN controller inside the single-chip microcomputer to the CNN transceiver of the formation tester circuit, that is, finally uploaded to the formation tester master control system. That is, the water content, oil content and gas content of the fluid sample are calculated by the single-chip microcomputer according to the output signals of the conductivity sensor, the conductivity probe and the optical fiber probe, and then these three sets of data are uploaded to the formation tester circuit.

[0058] The real-time measurement system of fluid components based on a formation tester in the embodiment of the present application realizes synchronous real-time, rapid and accurate measurement of parameters such as water content, oil content and gas content of the formation fluid through a sensor tube arranged in the sampling chamber of the formation tester and multiple sensors arranged therein, a circuit tube and a measurement system circuit therein. The measurement has high accuracy and strong stability, thereby being able to provide more comprehensive measurement results of formation fluid components and expand the measurement range, which will contribute to the accuracy of oil and gas reservoir development and evaluation and provide more reliable technical support for the development of oil and gas fields.

[0059] In some embodiments, the fluid component real-time measurement system further comprises a data processing device, wherein the data processing device is used to:

[0060] According to the output signals of the conductivity probe, the optical fiber probe and the conductivity sensor, the fluid type of the current fluid is determined, wherein the fluid type includes gas-water two-phase flow, oil-water two-phase flow, oil-gas-water three-phase flow and slug flow;

[0061] Based on the interpretation rules corresponding to the fluid type of the current fluid, obtain relevant relationship diagrams and / or formulas; wherein, the interpretation rules for gas-water two-phase flow include a relationship diagram of the relationship curve between the output signal of the optical fiber probe and the gas volume, the interpretation rules for oil-water two-phase flow include a linear relationship formula between the water content index and the proportion water content, and the interpretation rules for oil-gas-water three-phase flow include a relationship diagram of the relationship curve between the water content index and the proportion water content under different gas volumes;

[0062] According to the experimental calibration chart and / or formula, one or more of the water content, oil content and gas content of the current fluid are obtained.

[0063] The data processing device may be a data processing unit of a formation tester or an independent data processing unit, such as a host computer on the ground.

[0064] In some embodiments, the data processing device is specifically configured to:

[0065] determining whether the current fluid is a slug flow according to the output signal of the conductivity probe;

[0066] When the current fluid is a slug flow and the output signal of the conductivity probe is at a low level, it is determined that the current fluid is a pure water phase;

[0067] When the current fluid is a slug flow and the output signal of the conductivity probe is not at a low level, judging whether the slug flow is a gas slug or an oil slug according to the output signal of the optical fiber probe, and calculating the volume of the single-phase flow of the slug flow according to the duration and flow channel area of ​​the output signal of the optical fiber probe;

[0068] In the case that the current fluid is not a slug flow, it is determined whether the fluid contains gas based on the output signal of the optical fiber probe; if the fluid does not contain gas, the water content is obtained by interpolating the relationship diagram between the proportion water content and the water content index in the interpretation procedure of the oil-water two-phase flow in combination with the output signal of the conductivity sensor; if the fluid contains gas, the gas content is obtained by interpolating the relationship diagram between the output signal of the optical fiber probe and the gas volume in the interpretation procedure of the gas-water two-phase flow, and then the water content is obtained by interpolating the relationship diagram between the water content index and the proportion water content under different gas volumes in the interpretation procedure of the oil-gas-water three-phase flow.

[0069] In some embodiments, the fluid component real-time measurement system further comprises an experimental device, wherein the experimental device obtains interpretation procedures corresponding to different fluid types and relationship diagrams and / or formulas involved in the interpretation procedures by implementing the gas-water two-phase flow implementation process, the oil-water two-phase flow implementation process, and the oil-gas-water three-phase flow implementation process; Figure 3 As shown, the experimental device includes an experimental wellbore 8, a pump liquid end 13, a data receiving end 14 and a liquid receiving container, the experimental wellbore 8 includes a liquid inlet 11 at the bottom of the wellbore and a liquid outlet 12 at the top of the wellbore, and the middle part of the experimental wellbore 8 is a plexiglass tube 9; the pump liquid end 13 includes an oil pump, a water pump, an air pump, an oil tank and a water tank, the liquid inlet of the oil pump is connected to the oil tank, and the liquid outlet of the oil pump is connected to the liquid inlet 11 at the bottom of the wellbore through a pipeline with a valve; the liquid inlet of the water pump is connected to the water tank, and the liquid outlet of the water pump is connected to the liquid inlet 11 at the bottom of the wellbore through a pipeline with a valve; the air pump is connected to the liquid inlet 11 at the bottom of the wellbore through a pipeline, and the liquid outlet 12 at the top of the wellbore is connected to the liquid receiving container; the sensor tube 10 is installed in the experimental wellbore 8, and the bottom liquid inlet and the upper liquid outlet of the sensor tube 10 are respectively connected to the liquid inlet 11 at the bottom of the wellbore and the liquid outlet 12 at the top of the wellbore. The oil pump, water pump and air pump can pump the required oil, water and gas into the fluid channel of the sensor tube 10 through the liquid inlet at the bottom of the wellbore in a fixed proportion, ensuring that multiple sensors can perform real-time measurement of the fluid flowing over their surface; the wiring of multiple sensors passes through the upper end of the experimental wellbore and is connected to the circuit board, on which the measurement system circuit is set.

[0070] The fiber optic probe is sensitive to gas response and basically does not change in water and oil. The fiber optic probe is used to measure the gas output or gas holdup rate. Through the output signal of the fiber optic probe, a relationship chart between the gas volume and the fiber optic probe response is established to achieve an accurate interpretation of the gas-water two-phase flow.

[0071] The conductivity sensor has an advantage in measuring the average value of the water content of a section of fluid. Through the output signal of the conductivity sensor, a relationship chart between the water content index and the proportion water content in the oil-water two-phase is established.

[0072] The conductivity probe has a sensitive instantaneous response to oil bubbles, especially when oil bubbles are clustered and oil is discharged intermittently. The duration and volume of each segment plug are calculated through the output signal of the conductivity probe.

[0073] The implementation process of gas-water two-phase flow, the implementation process of oil-water two-phase flow, and the implementation process of oil-gas-water three-phase flow are explained below through specific examples.

[0074] 1. Implementation process of gas-water two-phase flow.

[0075] For example, different gas volumes are pumped into a test wellbore filled with water, such as 70ml / min, 150ml / min, 200ml / min, 250ml / min, and 300ml / min of gas; the different gas volumes can be distinguished by the response of the fiber optic probe, and the curves under each gas volume are averaged to obtain the relationship curve between the gas volume and the response of the fiber optic probe. The experimental results show that the response of the fiber optic probe increases with the increase of gas volume, and the Pearson correlation coefficient is as high as 0.958.

[0076] Interpretation procedures for gas-water two-phase flow: The relationship between the output signal of the fiber optic probe and the gas volume, such as Figure 4 shown.

[0077] Therefore, the gas content of the current fluid can be obtained through the relationship curve between the output signal of the optical fiber probe and the gas volume and the collected output signal of the optical fiber probe.

[0078] 2. Implementation process of oil-water two-phase flow.

[0079] For example, first, turn on the water pump, the water flow rate is 180ml / min, and measure the output frequency of the conductivity sensor in the full water state, that is, the full water value; then turn on the oil pump, the oil flow rates are 3ml / min, 4.5ml / min, 7.5ml / min, 11ml / min, and 16ml / min, respectively, and the proportion water content range is 91.8%-98.3%. Take the average of the response curves of the conductivity sensor under each oil volume, and the ratio of the full water value to the average value to obtain the water content index, and finally obtain the relationship between the water content index and the proportion water content under oil and water two phases, as shown in Figure 5 The experimental results show that the moisture index increases with the increase of the mix moisture content and has good resolution.

[0080] Interpretation procedure for oil-water two-phase flow: Based on the linear relationship between the response of the conductivity sensor (water content index) and the proportion of water content:

[0081] Yw=1.4769Kw+0.4893 (1)

[0082] Among them, Yw is the moisture index and Kw is the mix moisture content.

[0083] That is to say, the fiber optic probe determines that the current fluid is oil-water two-phase. Figure 5 A linear relationship equation between the moisture index and the proportion moisture content is established, that is, a linear equation of one variable Yw = 1.4769Kw + 0.4893. Substituting the mean value of the moisture index output curve of the conductivity sensor into the linear relationship equation, the moisture content can be obtained. Then the oil content is calculated based on the moisture content.

[0084] 3. Implementation process of oil, gas and water three-phase flow.

[0085] Based on the two-phase flow experiment, gas is introduced into the sensor tube, the gas volume is changed, and the relationship between the moisture index and the proportion moisture content under different gas volumes is verified. The following are the specific experimental steps.

[0086] This experiment was divided into four groups:

[0087] Group 1: gas volume 70ml / min, water flow rate is about 180ml / min, and oil flow rate is adjusted according to 3ml / min, 4.5ml / min, 7.5ml / min, 11ml / min, and 16ml / min;

[0088] The second group: gas volume is 125ml / min, water flow is about 176ml / min, and oil flow is adjusted according to 3ml / min, 4.5ml / min, 7.5ml / min, 11ml / min, and 16ml / min;

[0089] The third group: the gas volume is 180ml / min, the water flow rate is about 184ml / min, and the oil flow rate is adjusted according to 3ml / min, 4.5ml / min, 7.5ml / min, 11ml / min, and 16ml / min;

[0090] Group 4: gas volume 235ml / min, water flow rate is about 180ml / min, and oil flow rate is adjusted according to 3ml / min, 4.5ml / min, 7.5ml / min, 11ml / min, and 16ml / min.

[0091] For each set of experimental data, a relationship curve between the moisture index and the proportion moisture content is drawn, and a relationship diagram between the moisture index and the proportion moisture content under different gas volumes can be obtained, such as Figure 6 shown.

[0092] Figure 6The applicable scope is when the gas volume is greater than 70ml / min. When the gas volume is known, the water content of the ratio is deduced according to the water content index under the corresponding gas volume. When the gas content is less than 70ml / min, the water content index is obtained according to the bottom value of the three-phase flow output signal, and then Figure 5 The two-phase flow diagram shown is used to obtain the proportional moisture content.

[0093] Interpretation procedure for three-phase flow: Combine the relationship between gas volume and water content index and proportion water content to obtain the water content of the fluid.

[0094] Interpretation procedure for gas volume less than 70 ml / min: When the oil, gas and water three-phase gas volume is relatively small, the bottom boundary of the miscibility value output curve of the conductivity sensor is close to the output value of the oil and water two-phase, so the water index can be calculated by the bottom boundary of the miscibility value, and then the water content can be calculated by equation (1).

[0095] Interpretation procedure for gas volume greater than 70ml / min: Measure the output signal of the fiber optic probe, take the average of the stable section, and obtain the gas volume through the relationship between the output signal of the fiber optic probe and the gas volume. Combined with the water content index measured by the conductivity sensor, the water content in the oil-water two-phase can be obtained through the relationship diagram between the water content index of the conductivity sensor and the water content in the oil-water two-phase under different gas volumes.

[0096] Therefore, the embodiment of the present application can determine whether the current fluid is two-phase flow, three-phase flow or slug flow through the output signals of the conductivity probe, optical fiber probe and conductivity sensor; call the corresponding interpretation procedure, and calculate the water content, oil content and gas content in real time in combination with the experimental calibration chart.

[0097] In the case of slug flow, the output signal of the optical fiber probe is combined with the output signal of the conductivity probe to determine whether it is a gas slug or an oil slug. If the output signal of the optical fiber probe is stable around its peak value, it is determined to be a gas slug. If the output signal of the optical fiber probe is stable at 2100 and the output signal of the conductivity probe is stable around its peak value, it is determined to be an oil slug. The volume per unit time of various slugs can be calculated based on the cross-sectional area of ​​the sensor according to the duration of the sensor's output signal.

[0098] Interpretation procedures for slug flow: By analyzing the output signals of the fiber optic probe and the conductivity probe, determine whether there is a gas slug or an oil slug, and calculate the duration and volume of each slug.

[0099] After obtaining the corresponding interpretation procedures and related relationship diagrams and / or formulas for different fluid types through experiments, the flow chart of the method for interpreting sensor data is as follows: Figure 7As shown, the measurement data of the conductivity probe, fiber optic probe and conductivity sensor are obtained. Then, the conductivity probe data is used to determine whether it is a slug flow. If it is a slug flow and the conductivity probe data is at a low level, it is determined to be a pure water phase; otherwise, the fiber optic probe data needs to be integrated to further determine whether the slug is a pure gas phase or a pure oil phase. By determining the duration and the flow channel area, the volume of the slug single-phase flow can be calculated. If it is not a slug flow, it is necessary to determine whether it contains gas based on the fiber optic probe data to determine whether the fluid type is a two-phase flow or a three-phase flow. If it does not contain gas, combined with the conductivity sensor data, use Figure 5 After interpolating the relationship between the water content and water content index of the oil-water two-phase ratio shown in the figure, the water content is calculated, and then the oil content is obtained based on the sum of the water content and the oil content being 1, so as to interpret the oil-water two-phase flow. Figure 4 The relationship between the optical fiber output signal and the gas volume is shown in the figure. The gas content is obtained by interpolation. Figure 6 The relationship between the water content index and the proportion water content under different gas volumes shown in the figure is interpolated to obtain the water content, and then the oil content is calculated based on the water content.

[0100] Therefore, the embodiment of the present application can accurately measure fluid components at low flow rates through a combination of multiple sensors, and convert sensor data into specific fluid component information, such as water content, oil content and gas content, through a specific interpretation model, thereby providing a more accurate and reliable fluid component interpretation method for the field of formation testing.

[0101] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0102] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0103] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A real-time measurement system for fluid components based on a formation tester, characterized in that: It comprises a sensor tube and a circuit tube installed in a formation tester, wherein a bottom liquid inlet and an upper liquid outlet of the sensor tube are respectively connected with a lower part of a fluid channel and an upper part of a fluid channel of the formation tester; A fluid measurement channel is provided in the sensor tube, and a plurality of sensors are installed in the fluid measurement channel; a measurement system circuit is provided in the circuit tube; the excitation lines and signal transmission lines of the plurality of sensors are packaged through a sealing process and then led out to the circuit tube and connected to the measurement system circuit; the power supply and signal transmission of the measurement system circuit are connected to the circuit of the formation tester through a sealing process.

2. The real-time fluid component measurement system based on the formation tester according to claim 1, characterized in that: The plurality of sensors include conductivity sensors, conductivity probes, and fiber optic probes.

3. The real-time measurement system for fluid components based on a formation tester according to claim 2, characterized in that: The fluid component real-time measurement system further comprises a data processing device, wherein the data processing device is used for: According to the output signals of the conductivity probe, the optical fiber probe and the conductivity sensor, the fluid type of the current fluid is determined, wherein the fluid type includes gas-water two-phase flow, oil-water two-phase flow and oil-gas-water three-phase flow; Based on the interpretation rules corresponding to the fluid type of the current fluid, obtain relevant relationship diagrams and / or formulas; wherein, the interpretation rules for gas-water two-phase flow include a relationship diagram of the relationship curve between the output signal of the optical fiber probe and the gas volume, the interpretation rules for oil-water two-phase flow include a linear relationship formula between the water content index and the proportion water content, and the interpretation rules for oil-gas-water three-phase flow include a relationship diagram of the relationship curve between the water content index and the proportion water content under different gas volumes; According to the experimental calibration chart and / or formula, one or more of the water content, oil content and gas content of the current fluid are obtained.

4. The real-time fluid component measurement system based on the formation tester according to claim 3 is characterized in that: The data processing device is used for: determining whether the current fluid is a slug flow according to the output signal of the conductivity probe; When the current fluid is a slug flow and the output signal of the conductivity probe is at a low level, it is determined that the current fluid is a pure water phase; When the current fluid is a slug flow and the output signal of the conductivity probe is not at a low level, judging whether the slug flow is a gas slug or an oil slug according to the output signal of the optical fiber probe, and calculating the volume of the single-phase flow of the slug flow according to the duration and flow channel area of ​​the output signal of the optical fiber probe; In the case that the current fluid is not a slug flow, judging whether the fluid contains gas according to the output signal of the optical fiber probe; If the fluid does not contain gas, the output signal of the conductivity sensor is combined with the relationship diagram between the proportion water content and the water content index in the interpretation procedure of the oil-water two-phase flow to obtain the water content after interpolation; If it contains gas, the gas content is obtained by interpolating the relationship diagram between the output signal of the optical fiber probe and the gas volume in the interpretation procedure of gas-water two-phase flow, and then the water content is obtained by interpolating the relationship diagram between the water content index and the proportional water content under different gas volumes in the interpretation procedure of oil-gas-water three-phase flow.

5. The real-time fluid component measurement system based on formation tester according to claim 3, characterized in that: The real-time measurement system for fluid components also includes an experimental device, which obtains the interpretation procedures corresponding to different fluid types and the relationship diagrams and / or formulas involved in the interpretation procedures by implementing the implementation process of gas-water two-phase flow, the implementation process of oil-water two-phase flow and the implementation process of oil-gas-water three-phase flow; the experimental device includes an experimental wellbore, an oil pump, a water pump, an air pump, an oil tank, a water tank and a liquid receiving container, the experimental wellbore includes a liquid inlet at the bottom of the wellbore and a liquid outlet at the top of the wellbore, the liquid inlet of the oil pump is connected to the oil tank, and the liquid outlet of the oil pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline with a valve; the liquid inlet of the water pump is connected to the water tank, and the liquid outlet of the water pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline with a valve; the air pump is connected to the liquid inlet at the bottom of the wellbore through a pipeline, and the liquid outlet at the top of the wellbore is connected to the liquid receiving container; the sensor tube is installed in the experimental wellbore, and the bottom liquid inlet and the upper liquid outlet of the sensor tube are respectively connected to the liquid inlet at the bottom of the wellbore and the liquid outlet at the top of the wellbore.

6. The real-time fluid component measurement system based on the formation tester according to claim 2, characterized in that: The measurement system circuit includes a connected single chip microcomputer and a sensor interface circuit, and the sensor interface circuit includes a conductivity sensor interface circuit, a conductivity probe interface circuit and an optical fiber probe interface circuit; The conductivity sensor interface circuit includes a first positive and negative pulse synthesis module, a voltage-controlled constant current source module and an amplification module. The waveform generator inside the single-chip microcomputer is connected to the excitation end of the conductivity sensor through the first positive and negative pulse synthesis module and the voltage-controlled constant current source module in sequence; the measurement end of the conductivity sensor is connected to the average value detection module inside the single-chip microcomputer through the amplification module. The conductivity probe interface circuit includes a second positive and negative pulse synthesis module and a driving circuit module. The waveform generator inside the single-chip microcomputer is connected to the conductivity probe through the second positive and negative pulse synthesis module and the driving circuit module in sequence. The conductivity probe is also connected to the average value detection and comparison module inside the single-chip microcomputer. The fiber optic probe interface circuit comprises a fiber optic probe interface, and the fiber optic probe is connected to the analog-to-digital acquisition channel of the single-chip microcomputer via the fiber optic probe interface.

7. The real-time measurement system for fluid components based on a formation tester according to claim 5, characterized in that: The measurement system circuit also includes a temperature compensation module inside the single-chip microcomputer. The temperature compensation module measures the real-time temperature through the temperature sensor inside the single-chip microcomputer, and performs temperature compensation on the sensor signals of the multiple sensors according to the variation rules of the sensor signals at different temperatures.

8. The real-time fluid component measurement system based on a formation tester according to claim 5, characterized in that: The measurement system circuit also includes a power management module, which is used to measure the overall power supply of the measurement system circuit, including the +12V voltage used by the measurement system circuit, the +5V voltage used by the optical fiber probe, and the -5V voltage required for the operation of other chips in the measurement system circuit except the single-chip microcomputer.

9. The real-time fluid component measurement system based on a formation tester according to claim 1, characterized in that: The bottom liquid inlet and the upper liquid outlet of the sensor tube are respectively sealed and connected to the lower part and the upper part of the fluid channel of the formation tester.

10. The real-time fluid component measurement system based on a formation tester according to claim 1, characterized in that: The sensor tube and the circuit tube are installed on a short section matched with the lower end of the short section where the sampling cavity of the formation tester is located.

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