A drilling fluid resistivity meter

Abstract

The application discloses a kind of drilling fluid resistivity measuring instrument, including test host, resistance cell and temperature sensor, temperature sensor is inserted in resistance cell;Test host is provided with control circuit and control panel, control panel is connected with control circuit, control circuit includes power module, sine wave generator, range automatic selection module, effective value acquisition module, main control module and temperature acquisition module, temperature conversion unit is provided in main control module, and main control module is connected with control panel;The first electrode end of resistance cell is grounded, and the second electrode end of resistance cell is connected with effective value acquisition module, and the second electrode end of resistance cell is connected with range automatic selection module.The drilling fluid resistivity measuring instrument with the above structure is used for the rapid and reliable detection of the resistivity of small sample drilling fluid, convenient to use, can display the conductivity of drilling fluid under current ambient temperature, and can also display the resistivity under conversion temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resistivity detection, in particular to a drilling fluid resistivity measuring instrument. BACKGROUND

[0002] Resistivity is a physical quantity used to represent the electrical resistance characteristics of a substance, mainly representing the resistance to electric current. The smaller the resistivity, the better the electrical conductivity. The size of the resistivity is not only related to the type of the substance, but also the temperature, which is an important factor affecting the resistivity. Resistivity can also be used to calculate electrical conductivity, thermal conductivity, and power factor of thermoelectric materials.

[0003] Drilling fluid resistivity is an important parameter in drilling. When drilling through oil, gas, and water layers, the value will change. During drilling, the drilling fluid is continuously circulating. When the formation pressure is greater than the drilling fluid column pressure, the fluid in the formation enters the drilling fluid and returns to the wellhead with the drilling fluid. Therefore, the collection of data has a strong time factor. If the time is missed, the collected data may be incomplete or not collected at all. The mud tank used in the past has a large volume, which is not convenient to use on site, affecting the accuracy of the measurement results. Therefore, it is urgent to develop a drilling fluid resistivity measuring instrument for convenient field operation. SUMMARY

[0004] The purpose of the present application is to provide a drilling fluid resistivity measuring instrument that can quickly and reliably detect the resistivity of drilling fluid with small samples, is convenient to use, and can display the electrical conductivity of the drilling fluid at the current ambient temperature and the resistivity at the converted temperature.

[0005] To achieve the above purpose, the present application provides a drilling fluid resistivity measuring instrument, which comprises a test host, a resistance cell and a temperature sensor, the temperature sensor is inserted into the resistance cell;

[0006] The test host is provided with a control circuit and a control panel, the control panel is connected with the control circuit, the control circuit comprises a power module, a sine wave generator, an automatic range selection module, an effective value acquisition module, a main control module and a temperature acquisition module, the temperature acquisition module is connected with the temperature sensor, the temperature acquisition module, the sine wave generator and the effective value acquisition module are connected with the main control module, the sine wave generator is connected with the automatic range selection module, the automatic range selection module is connected with the effective value acquisition module, the main control module is provided with a temperature conversion unit, and the main control module is connected with the control panel;

[0007] The first electrode end of the resistance cell is grounded, the second electrode end of the resistance cell is connected with the effective value acquisition module, and the second electrode end of the resistance cell is connected with the automatic range selection module.

[0008] Preferably, the resistance cell comprises a transparent resin cavity, a suction head and a rubber suction capsule, the suction head and the rubber suction capsule are arranged at two ends of the transparent resin cavity respectively, and the transparent resin cavity is provided with a first electrode and a second electrode at two ends respectively.

[0009] Preferably, the transparent resin cavity is provided with a jack in the middle, and the temperature sensor is inserted into the jack.

[0010] Preferably, the control panel is provided with a display screen, an operation lamp, an electrode seat and operation keys, the operation keys comprise a page turning key, a shift / save key, a power-on / backlight key and a test key, the electrode seat is provided with an electrode male port, and female ports of the first electrode and the second electrode are connected with the electrode male port.

[0011] Preferably, the range automatic selection module comprises a first operational amplifier circuit, a voltage follower circuit and a range automatic selection circuit connected in sequence, the range automatic selection circuit is provided with 16 measurement resistance channels, when the absolute value of the difference between the voltage value of the current measurement resistance channel and the voltage value of the resistance cell is greater than 10% of the current measurement resistance channel, the first measurement resistance channel is entered, and then the next measurement resistance channel is entered until the absolute value of the difference between the voltage value of the current measurement resistance channel and the voltage value of the resistance cell is less than or equal to 10% of the current measurement resistance channel, and the measurement resistance channel is selected, the sinusoidal wave generator is connected with the first operational amplifier circuit, and the range automatic selection circuit is connected with the second electrode end of the resistance cell.

[0012] Preferably, the effective value acquisition module comprises a second operational amplifier circuit and an effective value acquisition circuit connected in sequence, the second operational amplifier circuit is connected with the second electrode end of the resistance cell, and the effective value acquisition circuit is connected with the main control module.

[0013] Preferably, the temperature acquisition module comprises a data acquisition circuit and a third operational amplifier circuit connected in sequence, the third operational amplifier circuit is connected with the main control module, and the data acquisition circuit is connected with the temperature sensor.

[0014] Preferably, the temperature conversion unit is used for calculating the resistivity at the conversion temperature, and the calculation formula is as follows:

[0015]

[0016] Wherein, R2 is the resistivity at the conversion temperature, R1 is the resistivity at the actual temperature, T1 is the conversion temperature, and T2 is the actual temperature.

[0017] Therefore, the drilling fluid resistivity measuring instrument with the above structure has the following beneficial effects:

[0018] (1) The sampling detection of the drilling fluid is carried out by using the resistance cell, and the drilling fluid resistivity can be quickly and reliably detected for small samples.

[0019] (2) The temperature conversion unit is arranged, and the drilling fluid conductivity at the current ambient temperature and the resistivity at the converted temperature can be displayed.

[0020] The technical solutions of the present application will be further described in detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a circuit principle block diagram of the drilling fluid resistivity measuring instrument of the present application;

[0022] Figure 2 It is a control panel structure schematic diagram of the present application;

[0023] Figure 3 It is a resistance cell structure schematic diagram of the present application;

[0024] Figure 4 It is a structure schematic diagram of the resistance cell during installation.

[0025] REFERENCE NUMERALS

[0026] 1, control panel; 11, display screen; 12, running light; 13, electrode seat; 14, page key; 15, shift / save key; 16, test key; 17, power-on / backlight key; 2, transparent resin cavity; 3, rubber suction sac; 4, suction head; 5, temperature sensor. DETAILED DESCRIPTION

[0027] EXAMPLE

[0028] Figure 1 It is a circuit principle block diagram of the drilling fluid resistivity measuring instrument of the present application, Figure 2 It is a control panel structure schematic diagram of the present application, Figure 3 It is a resistance cell structure schematic diagram of the present application, Figure 4 It is a structure schematic diagram of the resistance cell during installation, as shown in the figure, a drilling fluid resistivity measuring instrument, comprising a test host, a resistance cell and a temperature sensor 5.

[0029] The test host is internally provided with a control circuit and a control panel 1, and the control circuit comprises a power module, a sine wave generator, an automatic range selection module, an effective value acquisition module, a main control module and a temperature acquisition module. The power module provides the temperature power supply for the whole. The main control module is connected with the sine wave generator, the first electrode end of the resistance cell is grounded, the second electrode end of the resistance cell is connected with the effective value acquisition module, and the second electrode end of the resistance cell is connected with the automatic range selection module. The automatic range selection module comprises a first operational amplifier circuit, a voltage follower circuit and an automatic range selection circuit connected in sequence, the automatic range selection circuit is provided with 16 measuring resistance channels, enters the first measuring resistance channel first, and when the absolute value of the difference between the voltage value of the resistance cell and the voltage value of the current measuring resistance channel is greater than 10% of the current measuring resistance channel, enters the next measuring resistance channel, until the absolute value of the difference between the voltage value of the current measuring resistance channel and the voltage value of the current measuring resistance channel is less than or equal to 10% of the current measuring resistance channel, selects the measuring resistance channel, the sine wave generator is connected with the first operational amplifier circuit, and the automatic range selection circuit is connected with the second electrode end of the resistance cell. The effective value acquisition module is used for acquiring the effective voltage and comprises a second operational amplifier circuit and an effective value acquisition circuit connected in sequence, the second operational amplifier circuit is connected with the second electrode end of the resistance cell, the effective value acquisition circuit is connected with the main control module, and the effective voltage is input to the main control module for resistance rate calculation. The main control module is internally provided with a temperature conversion unit, and the temperature conversion unit is used for calculating the resistance rate at the conversion temperature, and the calculation formula is as follows:

[0030]

[0031] Wherein, R2 is the resistance rate at the conversion temperature, R1 is the resistance rate at the actual temperature, T1 is the conversion temperature (the control panel is set), and T2 is the actual temperature (acquired by the temperature sensor).

[0032] The temperature collection module comprises a data collection circuit and a third operational amplifier circuit connected in sequence, the third operational amplifier circuit is connected with the main control module, the data collection circuit is connected with the temperature sensor 5, and the temperature sensor 5 is inserted into the resistance cell. The resistance cell comprises a transparent resin cavity 2, a suction head 4 and a rubber suction capsule 3, the suction head 4 and the rubber suction capsule 3 are arranged at two ends of the transparent resin cavity 2 respectively, the transparent resin cavity 2 is transparent and easy to observe and clean, the rubber suction capsule 3 is used to suck the sample liquid into the transparent resin cavity 2, the rubber suction capsule 3 is repeatedly pressed to empty and suck the sample liquid in the transparent resin cavity 2 for multiple times, so that the inner wall is completely wetted and free of bubbles, and the liquid in the transparent resin cavity 2 is ensured to fill the two ends of the resistance cell. The first electrode and the second electrode are arranged at the two ends of the transparent resin cavity 2 respectively. The electrode seat 13 is provided with an electrode male port, and the female ports of the first electrode and the second electrode are connected with the electrode male port. The first electrode and the second electrode of the transparent resin cavity 2 are connected to the electrode seat 13 of the test host, and good contact is maintained, and the sample liquid is waited to reach room temperature. The control panel 1 is connected with the main control module, the control panel 1 is provided with a display screen 11, a running lamp 12, an electrode seat 13 and operation keys, the operation keys comprise a page turning key 14, a shift / save key 15, a power-on / backlight key 17 and a test key 16, and the operation keys have the following functions: the power-on / backlight key is used for powering on the system, turning on or off the backlight during the running process, and powering off the system after long pressing for 3 seconds; the page turning key is used for cyclically entering different function menu areas by pressing the key; the shift / save key is used for selecting a key (short pressing) or a save key (long pressing) to move a cursor and modify and save data; and the test key is used for starting or stopping the test in the normal running test, and the key is used for modifying parameters in the parameter setting process.

[0033] The specific operation steps are as follows:

[0034] Step S1: the power-on / backlight key is pressed, the system is powered on and initialized, and the display screen displays the battery capacity and fault codes.

[0035] Step S2: the page turning key is pressed, the corresponding function menu is cyclically entered, the conversion temperature value is modified, the shift key cursor is moved, the test key cursor bit number is increased by 1, the page turning key enters the self-check page and automatically saves the set conversion temperature value.

[0036] Step S3: after entering the page, self-checking is performed, if the self-checking result is not considered, the page turning key is directly pressed to return to the initial page. If the self-checking is performed, the system displays the actual test and theoretical test results, if the results are quite different, automatic calibration is performed through long pressing of the save key, and then automatic self-checking is performed again to verify the calibration result.

[0037] Step S4: flush the resistance cell with the liquid to be measured several times, empty the gas in the resistance cell, inject the sample liquid to be measured into the resistance cell using a rubber suction sac 3, require that the liquid in the resistance cell is free of bubbles, and wipe the surface of the resistance cell and the liquid in the electrode hole.

[0038] Step S5: connect the resistance cell to the electrode seat 13 of the test host, ensure that the liquid in the resistance cell fills both ends of the resistance cell, maintain good contact, and then wait for the sample liquid to be measured to reach room temperature.

[0039] Step S6: press the test key to test, and automatically switch the measurement and range according to the actual situation. The process data will change constantly, and the resistivity at the current temperature and the resistivity at the conversion temperature are obtained.

[0040] Therefore, the drilling fluid resistivity measuring instrument with the above structure can quickly and reliably detect the resistivity of the drilling fluid for small samples, is convenient to use, can display the conductivity of the drilling fluid at the current ambient temperature, and can also display the resistivity at the conversion temperature.

[0041] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A drilling fluid resistivity meter, characterized by: The test host, the resistance pool and the temperature sensor are included, and the temperature sensor is inserted into the resistance pool; The control circuit and the control panel are arranged in the test host, the control panel is connected with the control circuit, the control circuit includes the power module, the sine wave generator, the range automatic selection module, the effective value acquisition module, the main control module and the temperature acquisition module, the temperature acquisition module is connected with the temperature sensor, the temperature acquisition module, the sine wave generator and the effective value acquisition module are connected with the main control module, the sine wave generator is connected with the range automatic selection module, the range automatic selection module includes the first operational amplifier circuit, the voltage follower circuit and the range automatic selection circuit which are connected in sequence, the range automatic selection circuit is provided with 16 measuring resistance channels, the first measuring resistance channel is entered first, if the absolute value of the difference between the voltage value of the resistance pool and the current measuring resistance channel is greater than 10% of the current measuring resistance channel, the next measuring resistance channel is entered, until the absolute value of the difference between the voltage value of the current measuring resistance channel is less than or equal to 10% of the current measuring resistance channel, the measuring resistance channel is selected, the sine wave generator is connected with the first operational amplifier circuit, and the range automatic selection circuit is connected with the second electrode end of the resistance pool; the range automatic selection module is connected with the effective value acquisition module, the effective value acquisition module includes the second operational amplifier circuit and the effective value acquisition circuit which are connected in sequence, the second operational amplifier circuit is connected with the second electrode end of the resistance pool, and the effective value acquisition circuit is connected with the main control module; the temperature conversion unit is arranged in the main control module, the temperature conversion unit is used for calculating the resistivity at the conversion temperature, and the main control module is connected with the control panel; The first electrode end of the resistance pool is grounded, the second electrode end of the resistance pool is connected with the effective value acquisition module, and the second electrode end of the resistance pool is connected with the range automatic selection module; the resistance pool includes a transparent resin cavity, a suction head and a rubber suction capsule, the suction head and the rubber suction capsule are arranged at two ends of the transparent resin cavity respectively, and the first electrode and the second electrode are arranged at two ends of the transparent resin cavity respectively.

2. The drilling fluid resistivity meter of claim 1, wherein: A jack is arranged in the middle of the transparent resin cavity, and the temperature sensor is inserted into the jack.

3. A drilling fluid resistivity measuring instrument according to claim 2, characterised in that: A display screen, a running lamp, an electrode seat and operation keys are arranged on the control panel, the operation keys include a page turning key, a shift / saving key, a power-on / backlight key and a test key, the electrode seat is provided with an electrode male port, and female ports of the first electrode and the second electrode are connected with the electrode male port.

4. A drilling fluid resistivity measuring instrument according to claim 3, characterised in that: The temperature acquisition module includes a data acquisition circuit and a third operational amplifier circuit which are connected in sequence, the third operational amplifier circuit is connected with the main control module, and the data acquisition circuit is connected with the temperature sensor.

5. A drilling fluid resistivity measuring instrument according to claim 4, characterised in that: The temperature conversion unit is used for calculating the resistivity at the conversion temperature, and the calculation formula is as follows: ， wherein, is the resistivity at the conversion temperature, is the resistivity at the actual temperature, is the conversion temperature, is the actual temperature.

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