RU2681790C2 - System for automatic measurement of gas content and vortex degassing of drilling fluid - Google Patents

Abstract

FIELD: measurement.SUBSTANCE: invention relates to measurement technology and can be used in the oil and gas industry in drilling rigs. For this, the system contains two similar subsystems “At the input to the well” and “At the output from the well”, which include: reversible impeller pump with electric drive, two measuring vessels under different pressures, vortex degasser, jet pump, information collection and processing unit, power unit, remote gas analyzer. In this case, the system contains a measuring module operating under pressure and connected to the lower part with the pump outlet, and the upper part through a flow meter with the inlet of the vortex degasser. Inside the measuring vessel are two pressure sensors integrated in the assembly, a temperature sensor and electrical resistivity. Atmospheric pressure measuring vessel is connected to the pump, a regulating device is located in the lower part of the vessel to limit the flow of fluid, drilling fluid is supplied to the inner pipe, and through an external pipe connected to the atmosphere, the liquid is evacuated through a jet pump, to the nozzle through a tee, pipeline and regulating device, the drilling fluid under pressure is fed from the pump outlet. Lower part of the vortex degasser is also connected to the jet pump to evacuate the degassed drilling mud, and its upper part is connected to the remote gas analyzer through the flow meter of the gas-air mixture and the vacuum pump. Measuring vessels, flow meters, electric motor and flow meters and the temperatures at the inputs of the subsystems are connected by electrical connections with the block for the collection and preliminary processing of information, which performs the functions of automatic control of the operation of the subsystem through the power unit, as well as the transfer of functions to the device for manual control and display of information on the rig.EFFECT: technical result of the invention is to improve the accuracy and reliability when measuring the density, volumetric gas content and the true density of the drilling fluid, as well as improving the efficiency of the vortex degassing of the drilling fluid due to the stabilization of thermodynamic conditions and magnetic treatment with continuous determination of the degree of degassing, that in the complex allows to increase the reliability of the automatic measurement system and bring the gas logging method to a quantitative, petrophysical reasonable level.10 cl, 1 dwg

Description

FIELD OF THE INVENTION

The invention relates to measuring equipment and can be used in the oil and gas industry at drilling rigs to determine volumetric gas saturation, true density and vortex degassing of a drilling fluid at the well entrance and exit, as a part of devices for automatic control of drilling process parameters and during geological and technological research and gas logging.

State of the art

To prevent emissions and open fountains, the hydrostatic pressure on the bottom when opening a productive formation by a well should slightly exceed the reservoir pressure. The excess hydrostatic pressure above the reservoir is determined by special regulatory documents, but should be minimal, since excessive overloading of the solution sharply reduces the penetration rate, irreversibly affects the initial filtration properties of the reservoir in the bottomhole formation zone, and provokes spontaneous hydraulic fracturing of the borehole accompanied by catastrophic departure of the solution and ejection with the transition to an open fountain. Therefore, the basis for preventing emissions and removals in the well is careful monitoring of the hydrostatic pressure of the drilling fluid column on the exposed reservoir. In drilling practice, such control is carried out by periodically measuring the density of the drilling fluid exiting the well.

However, unlike incompressible drilling fluids that do not contain a gas phase, the measurement of the density of carbonated drilling fluids does not allow determining the pressure of the drilling fluid at the bottom of the well. This is explained by the fact that the free gas contained in the drilling fluid is compressed in the well under the influence of the pressure of the liquid column and its volume concentration decreases by hundreds of times, while the density of the fluid in the well practically approaches the density of the original non-carbonated drilling fluid.

Based on this, it is necessary to determine two densities in aerated drilling mud: apparent - at the exit from the well, and true - in the wellbore. Since the apparent density does not give an idea of the pressure in the well, the hydrostatic pressure in the well should be determined by the true density.

The true density of aerated drilling fluid with sufficient accuracy for practice can be determined by the formula [Degtev NI, Zinkevich AI Control and degassing of drilling fluids. - M .: Nedra, 1978. - 152 p.]:

, (one)

where ρ _and is the true density of the drilling fluid (without gas);

ρ _g - density of aerated drilling fluid;

V _g - volumetric concentration of free gas in solution, in percent.

To restore the density of the solution, it is necessary to degass it, without resorting to its weight. However, in practice, with the slightest decrease in density due to aeration, a weighting agent is introduced into the clay mud, which almost always causes severe consequences due to a significant unreasonable increase in the pressure of the drilling fluid column on the formation.

Even if there are no outbursts and open fountains, the opening of productive formations in overweight solutions will definitely worsen the filtration properties of the reservoir due to the formation of mudding and penetration zones, reducing the production capabilities of the well, and also significantly reduce the technical and economic performance of drilling operations by reducing the speed drilling and the occurrence of various complications.

With a decrease in the density of the drilling fluid (due to the inflow of produced water, the introduction of reagents, the deposition of weighting agents or due to the appearance of free gas in the solution), it is necessary to take operational decisions on the weighting of the drilling fluid (for the first reasons) or on its degassing without weighting (when free gas appears) ) Therefore, it is necessary to quickly determine the concentration of free gas in the solution and its apparent density, after which, using the above formula (1), calculate the true density of the solution. If it meets the norm, you should degass the solution without resorting to its weight.

For the purpose of regular monitoring of the drilling fluid by the free gas content and true density, a methodology for determining the concentration of free gas in carbonated fluids by the compression method has been developed, manual and automatic devices for regular monitoring have been developed and implemented [Berezhnoy AI, Degtev NI Degassing of drilling fluids in drilling. - M .: Gostoptekhizdat, 1963. - 164 p .; Degtev N.I., Zinkevich A.I. Control and degassing of drilling fluids. - M .: Nedra, 1978. - 152 p.]. Of these sources of information are known: the plunger device VG-1 (SU147364, publ. 1962, No. 10), VG-2, the upgraded device VM-6 (hand-held devices); automatic device for continuous measurement of free gas in drilling mud, automatic AKG devices, automatic complexes AK-1 and AK-2.

The disadvantages of all known automatic devices for determining the free gas content in the drilling fluid by compression method are:

- discreteness of measurement with a cycle time of 3 minutes (20 measurements per hour);

- small volume of the measured sample (100 cubic cm);

- low measurement accuracy.

These disadvantages are not so significant in the overall control of the drilling fluid, but they do not allow the use of these devices in gas logging. For example, at a drilling speed of the reservoir layer of 60 m / h (which is typical for Western Siberia), one determination will occur in 3 m penetrations, which is unacceptable for gas logging.

A device for the continuous determination of the volumetric gas saturation of a drilling fluid by installing three high-precision pressure sensors on a detachable mouth [Lukyanov E.E., Strelchenko V.V. Geological and technological research of wells. - M .: Oil and gas, 1997. - 688 pp.], But, unfortunately, due to the low height of the detachable mouth and the small measuring base, this promising method for determining the volumetric gas saturation of the drilling fluid is far from always possible.

A device for determining the gas content of a drilling fluid according to SU 1481661, 01/12/1987, containing inductance type conductivity (resistance) sensors located in two measuring chambers under different pressures. The disadvantages of this device are the need to use a pump to supply the solution and the low accuracy of determining the gas content. These shortcomings did not allow to introduce this device into the practice of drilling operations.

A device for automatically measuring the volumetric gas content of a drilling fluid according to SU 1492239, 10/14/1987, containing a sampling and measuring chamber. When this device is in operation, sampling for analysis is carried out without using a pump to supply the solution due to the flow of drilling fluid by gravity when the receiving part is submerged under the level in the gutter. The disadvantage of this device is the low reliability when working on viscous drilling fluids. The reliable operation of the device is not conducive to the presence in it of a greater number of mechanical elements. In addition, a small sample volume and a sufficiently long cycle of its research seriously reduce its informational value.

A device SU 1046487 is known, 06/22/1982, containing a selection device, a compression chamber with pressure and level sensors located in it, according to the readings of which the volumetric gas content is determined through a computing unit. The device also works without the use of a pump, a sample of drilling fluid flows by gravity into the selection device, and then transferred to the compression chamber. The disadvantages of this device are the difficulty of its functioning at high values of the viscosity of the drilling fluid due to the small pressure drop in the trench and the low accuracy of determining the gas content both at the measurement point and in the entire flow of the drilling fluid due to the small volume of the sample and a long research cycle.

The most effective drilling fluid degasser for solving problems of geological and technological research (GTI) and gas logging is the “Vortex degasser of flushing fluid” [E. Lukyanov, L.Ya. Tsygleyev, I.V. Zubchuk // Scientific and Technical Bulletin "Logger". - Tver: AIS, 2000. - Issue. 70. S. 64-79].

The disadvantages of this device are the inability to automatically determine the degree of degassing and volumetric gas content of the drilling fluid.

Known for the latest FLAIR gas logging system used in leading foreign firms [Eblard P., Bell K., Cook D. et al. The growing role of gas logging. // Oil and Gas Review, Volume 24, No. 1 (spring 2012). - S. 30-53]. The FLAIR system contains two FLEX extraction (degassing) units located on the outlet (at the entrance to the well) and reception (at the exit of the well) lines; The FLAIR analysis system compares two gas flows to adjust for recirculated gas not recovered by the mud degassing system at the exit of the well.

An additional advantage of the FLAIR system is the heating of the drilling fluid sample with FLEX devices to a constant temperature under constant pressure and volume conditions. This method provides a stable ratio of air and drilling fluid in the extraction chamber, thereby achieving high efficiency and repeatability of the process. The ability to heat the sample is especially important for deep water conditions where the return temperature of the drilling fluid can be from 10 to 15 ° C (50 to 59 ° F). At low temperatures, the internal energy of the system is insufficient for the effective release of heavy gas components from the drilling fluid. Conventional devices for isolating gas from a drilling fluid that do not heat the sample may produce inaccurate data due to the fact that more gas remains in the solution during its evolution.

Thanks to the FLEX extraction process, the FLAIR gas logging system operates under constant thermodynamic conditions, which makes it possible to calibrate the efficiency of the separation of C ₁ -C ₅ components. Heavier hydrocarbons, C ₆ -C ₈ , are more difficult to recover, but their presence can be estimated qualitatively. Calibration is combined with adjustment, which takes into account all the gas that could be sent back to the circulation system. This is achieved by installing a second FLEX device at the pump intake line, at the point of injection of the solution back into the well. Thus, the proportion of hydrocarbons pumped back into the well with the drilling fluid can be quantified. Recirculation gas correction is possible because extraction conditions are the same for both FLEX devices.

The recovered hydrocarbons are fed to a modern gas chromatograph / mass spectrometer, which is located in the room of the gas logging station, via a gas line (GVL) up to 100 m long.

The disadvantages of the FLAIR system are:

- the impossibility of determining the density of the drilling fluid at the entrance to the well, at the exit from the well and the true density of the fluid without gas;

- the impossibility of determining the degree of degassing without constant calibration of the system with a thermal vacuum degasser, which is difficult at high drilling speeds;

- the impossibility of determining the volumetric gas content of the drilling fluid regardless of its degassing (for example, by compression method).

A known system for automatically measuring the volumetric gas content and the true density of the drilling fluid (RU 2310069, 12.26.2005).

The disadvantages of this system are:

- discreteness of determination of parameters;

- lack of degassing of the drilling fluid.

Closest to the "System for the automatic measurement of volumetric gas content and vortex degassing of a drilling fluid", proposed as an invention, are the "Vortex degasser flushing fluid", the FLAIR system and devices known according to RU 2310069, 26.12.2005.

The essence and composition of the invention

The objective of the invention is to increase the accuracy and reliability when measuring the density at the inlet and outlet, gas volume, true density, temperature, conductivity and other parameters of the drilling fluid; increasing the efficiency of degassing of the drilling fluid with determining the degree of degassing; as well as improving the reliability of the system by simplifying the design, increasing the efficiency of technological decisions and automating the measurement process.

In FIG. presents a diagram of a system proposed as an invention for automatic measurement of volumetric gas content and vortex degassing of a drilling fluid, consisting of two subsystems: “At the entrance to the well” and “At the exit from the well”.

The subsystem "At the entrance to the well" analyzes the solution taken from the pipe 1 connecting the tank 2 to the mud pump (not shown in the diagram); contains a receiving filter with a mesh 3, a receiving pipe 4 with a ball valve 5, mounted in a pipe 1 through a manhole cover 6, in which a temperature sensor and a flow indicator 7 are mounted. The upper part of the receiving pipe 4 passes through a heater 8 and is connected to the pump inlet 9, driven by a frequency-controlled explosion-proof electric motor 10. The output of the pump 9 through a tee 11 is connected to a measuring vessel 12, in which pressure, temperature and conductivity sensors are integrated in the assembly 13. A part of the solution flow through the pipe water 15, 16 through the flow meter 17 is supplied to the vortex degasser 18 through the swirl 19. A tube 20 is introduced into the middle part of the vortex degasser 18, through the flow meter 21 and the hydrophobic filter 22 connected with the atmosphere. A hydrophobic filter 23 is placed in the upper part of the vortex degasser 18, through which the gas-air mixture (HW) released from the drilling fluid through the pipe 24, through the dehumidifier 25 and the dhw meter 26 is supplied to the inlet of the vacuum pump 27, from which

the excess pressure is forced through the sensor system of the remote gas analyzer 28. Part of the DHW flow, bypassing the sensors, can be fed through the nozzle 29 via a gas line to the GTI station for additional analysis on a chromatograph or mass spectrometer.

The portable gas analyzer 28 provides with a time constant of 15-25 s information on the content in the hot water supply: oxygen (0-21% by volume), carbon dioxide (0-10% by volume), hydrogen (0-5% by volume), methane (0-100 % vol.), C _{2 + higher.} (0-20% by volume), hydrogen sulfide (0-100 ppm) and humidity (0-98% relative).

The drilling fluid is evacuated from the vortex degasser using a jet pump 34, into which a nozzle 35 is introduced, into which a portion of the drilling fluid enters through a pipe 36 from the tee 11. The amount of the fluid supplied to the jet pump is controlled by the device 30. Through the other control device 30, a portion of the drilling fluid fed to the measuring device 31, which determines the properties of the drilling fluid at atmospheric pressure using an assembly of sensors 32, screwed through a sealing device 33. Evacuation of the drill the solution from the measuring device 31 at atmospheric pressure is carried out by a jet pump 34 due to the nozzle 35 connected by a pipe 36 through the regulating device 30 through a tee 11 to the pump 9. The atmospheric pressure in the measuring vessel 31 is maintained due to the connection with the atmosphere of the upper part of the measuring device, free from drilling fluid through nozzle 37 .

A drilling fluid that has passed a cycle of measuring properties in devices 12 and 31 and is degassed is discharged by a jet pump 34 into a container 2 . The heater 8 and the explosion-proof electric motor 10 are supplied from the power unit 38 , coupled to the information collection and pre-processing unit 39 , the outputs of which are transmitted via communication lines to the station for geological and technological research (GTI), and also transmitted to the manual control and information display device drilling 40 .

In order to isolate dissolved gas from the drilling fluid at the inlet of the measuring vessel 12, part of the drilling fluid supplied for degassing is magnetically processed using a device 41 , powered by a power unit 38 through the information collection and preprocessing unit 39 .

Information from the temperature and flow sensor 7 , the sensor assembly in the meter to the degasser (pressure, temperature, conductivity) 13 , the liquid flow rate 17 , the air flow rate 21 , the air-gas mixture flow rate 26 , the external gas analyzer 28 , the sensor assembly in the meter at atmospheric pressure (pressure, temperature, conductivity) 32 is collected in the unit for collecting and preprocessing information 39 (communication lines not shown).

The subsystem "At the exit from the well" is a complete analogy of the subsystem "At the entrance to the well" except that pipe 1 here, the pipe going to the vibrating screen unit, the temperature sensor and flow indicator 7 characterize the total flow exiting the well to the vibrating screen; capacity 2 - capacity under vibrating screens, where the solution is discharged after determining the properties (parameters) of the solution and degassing.

The information collected and processed in blocks 39 of both subsystems is transmitted via communication lines to the GTI station (not shown) and to devices for manual control and display of information on the drill 40 in the form of a driller’s panel, supervisor’s monitor, bourmaster’s monitor, solution specialist’s monitor, and via satellite to the upper level of drilling management. As a feedback to the block 39 , control signals are received from the CSTI, in particular, a signal about the operation of the mud pumps.

Brief Description of the Drawing

In FIG. presents a diagram of a system proposed as an invention for automatic measurement of volumetric gas content and vortex degassing of a drilling fluid, consisting of two subsystems: “At the entrance to the well” and “At the exit from the well”.

Designations:

1 - pipe; 2 - capacity; 3 - receiving filter with mesh; 4 - a reception pipe; 5 - ball valve; 6 - manhole cover; 7 - temperature sensor and flow indicator; 8 - heater; 9 - pump inlet; 10 - electric motor; 11 - tee; 12, 31 - measuring vessel; 13, 32 - assembly of sensors; 14, 33 - nodes of sealing and fastening; 15, 16, 24, 36 - pipeline; 17, 21 - flow meter; 18 - vortex degasser; 19 - swirl; 20 - tube; 22, 23 - hydrophobic filter; 25 - water separator; 26 - dhw meter; 27 - input of the vacuum pump; 28 - remote gas analyzer; 29, 37 - fitting; 30 - regulatory device; 30 - regulatory device; 34 - jet pump; 35 - nozzle; 38 - power unit; 39 - block collection and preliminary processing of information; 40 - a device for manual control and display of information on the rig; 41 is a magnetic processing device.

Information on the rig:

- driller board;

- supervisor monitor;

- Burmaster monitor;

- monitor specialist solutions;

- to the top level of management.

The implementation of the invention

The operation of the claimed system is as follows.

When there are flows at the entrance to the well and at the exit from it and a signal on the flow indicators 7, the system switches from standby to working mode. When this voltage is applied to the magnetic processing device 41, the heater 8 and the electric motor 10. The drilling fluid through open ball valves 5 enters the pump 9. At the output of the pump 9, the drilling fluid under excess pressure enters the measuring vessels 12 and vortex degassers 18 and in parallel through pipelines 36 through control devices 30 it enters the measuring vessels 31 and nozzles 35 of the jet pumps 34, evacuating the degassed drilling fluid from the bottom of the vortex degassers 18 and measuring vessels 31 with the discharge of drilling fluid that has passed the cycle of measurement and degassing, in the appropriate tank 2.

Flow control is carried out by control devices 30 so that the time constant of the subsystems (the time of complete updating of the drilling fluid in the measuring vessels) is equal to ~ 5 ÷ 10 s. Thus, when the volume of the measuring vessels 12, 31 is, for example, 1500 ÷ 2500 cm ³ , the flow rate through the measuring vessels 12 should be close to 250 cm ³ / s, which is measured by flow meters 17. The solution after degassing from the bottom of the degassers 18 and the measuring vessels 31 are evacuated mainly due to the gravitational effect with the addition of the ejecting effect of the jet pumps 34, therefore, the flow rate through line 36 to two branches will be approximately 300 cm ³ / s. At the same time, the operating pressures P ₁ in the measuring vessels 12 and P ₂ in the measuring vessels 31 are set in the subsystems, which is recorded by the sensors in assemblies 13, 32 (pressure, temperature, electrical resistivity).

If the pressure in the measuring vessels 31 is set close to atmospheric due to the connection with the atmosphere through the fitting 37, then

measuring vessels 12 due to the preloaded streams by devices 30 and 19, an increased pressure with respect to atmospheric pressure (for example, 50 kPa excess) is established. The initial adjustment of the flow rate of the pump 9 is made by changing the frequency of the voltage supplied to the electric motor 10 through the power unit 38.

The heating intensity of the drilling fluid supplied to the subsystem is implemented by the power unit 38 from the data collection and pre-processing unit 39 at the given solution temperature, the measurement range of which is set within + 30 ° С ÷ + 80 ° С. Auto-adjustment of temperature is performed according to the readings of temperature sensors in assemblies 13.32.

The assemblies 13, 32, screwed into the measuring vessels 12, 31 through the sealing and fastening units 14, 33, contain: two pressure sensors per 100 kPa redundant, spaced 400–500 mm apart from the measuring base, a temperature sensor in the range 0–100 ° C s resolution ± 0.1 ° C, four-electrode resistivity resistivity (MES) of the drilling fluid with a measurement range of 0.01 ÷ 20 Ohm⋅m. The electrodes of the resistivity sensor are ring-shaped, which provides volumetric coverage of the measuring volume, and temperature compensation is provided by the temperature sensor.

The working pressures in the measuring vessels 12, 31 are determined by the readings of the lower pressure sensors in the assemblies 13, 32 (P _a and P _d ), and

the density of the drilling fluid in the measuring vessels 12 , 31 at operating pressures are determined by the pressure difference between the lower and upper sensors, divided by the value of the measuring base Δ h .

(2) (3)

,

,

,

- показания нижних и верхних датчиков давлений при атмосферном (Р _а) и повышенном (Р _д) давлениях в измерительных сосудах 12, 31 соответственно.Where

,

,

,

- readings of the lower and upper pressure sensors at atmospheric ( P _a ) and high ( P _d ) pressures in the measuring vessels 12 , 31, respectively.

The range of measurement of the density of the drilling fluid from 800 to 2500 kg / m ³ .

The values of ρ _a and ρ _d at R _a and R _d , as well as the volumetric gas content of G _about , are determined with a frequency of at least 10 times per second.

The volumetric gas content of G _about is determined by the expression

(4)

(four)

for example , if

P _a = 105 kPa (absolute);

P _d = 155 kPa;

ρ _d = 1150 kg / m ³ ;

ρ _a = 1127 kg / m ³ ,

then

а

but

The true density of the drilling fluid (density without gas) is determined by the expression (1)

where ρ _g is the density of the carbonated solution at values of G _about .

for example , for ρ_g = 1150 kg / m³ andG _about = 5.947%

The error in determining G _about by equation (4) with Δ h = 400-500 mm is more than ± 0.2%. More roughly, with an error of the order of ± 1.0%, the volumetric gas content is determined by equation (5) by resistivity in vessels 12 , 31 :

(5)

(5)

where R _a is the value of electrical resistivity (resistivity) in the measuring vessels 31 (at atmospheric pressure P _a ), Ohm ∙ m;

R _d - resistivity value in measuring vessels 12 (at elevated pressures P _d ), Ohm )m.

for example atR _but = 2,325 Ohm ∙ m (at 104 kPa abs.) AndR _d = 2.285 Ohm⋅m (at 155 kPa abs.)

Since the temperature in the measuring vessels 12 and 31 is the same, when using relations, the introduction of a temperature correction in the values of R (resistivity) is not required.

The system operates all the time while the circulation of the drilling fluid. In order to prevent clogging of the filter mesh 3 with slurry, electric motors 10 are reversed every minute for a time of ~ 1 s to create a reverse pressure pulse and clean the filter mesh. This function is programmed in advance through blocks 39 and 38. When the circulation ceases, the signal is received from the flow sensors 7, the motors 10 are reversed for a period of ~ 15 s to clean the subsystem of the drilling fluid. After that, the system goes into standby mode with the power units turned off.

During the functioning of the proposed system for automatic measurement of gas volume and vortex degassing of a drilling fluid, in addition to solving the main problem, other parameters are also determined, in particular, the degassing coefficient, which is determined automatically in continuous mode by simple calculations.

The gas content in the drilling fluid (in cm ³ / s

(6)

(6)

where Q _W - the flow rate of the drilling fluid supplied to the degasser (sensor 17 in Fig. 1), cm ³ / s;

G _about - volumetric gas content of the drilling fluid, determined by the expression (4),%.

The amount of gas entering the degasser from the drilling fluid

(7)

(7)

where Q _dhw is the flow rate of the gas-air mixture from the degasser (sensor 26 in Fig.), cm ³ / s.

Degassing coefficient

(8)

(8)

for example :

G _about = 9.5%;

Q _in = 30 cm ³ / s;

Q _dhw = 3000 cm ³ / min = 50 cm ³ / s;

Q _w = 250 cm ³ / s.

Then

As a result of using the system for automatic measurement of volumetric gas content and vortex degassing of a drilling fluid proposed as an invention, it is possible to obtain the following parameters in real time that have independent significance (see table).

Table

No. p / p Parameter Name At the entrance At the exit one Mud temperature before heating + + 2 Volumetric gas content of the solution + + 3 Mud density + + four True solution density + + 5 Conductivity (resistivity) of the solution + + 6 Mud degassing with determination of degassing coefficient
Analysis of the evolved air-gas mixture with the determination of :
1. oxygen (O ₂ );
2. carbon dioxide (CO ₂ );
3. hydrogen (H ₂ );
4. hydrogen sulfide (H ₂ S)
5. methane (CH ₄ );
6. heavy hydrocarbons (C ₂₊ )
Transfer of hot water for analysis on a chromatograph / mass spectrometer +
+
+
+
+
+
+
+ +
+
+
+
+
+
+
+

The presence of these essential features of the device proposed as an invention, allows to achieve the task.

The proposed system differs from the closest devices subjected to comparison by a number of features, in particular:

- an integrated approach to solving the problem, allowing to transfer the status of gas logging from a qualitative method to a quantitative, petrophysically sound method;

- the continuity of information both on gas volumetric content and on degassing of the drilling fluid, which significantly increases the resolution of the gas logging method;

- a significant increase in the reliability of the system due to a number of claimed features that are absent in the prototypes.

Claims (10)

1. A system for automatically measuring the volumetric gas content and vortex degassing of a drilling fluid, containing two similar subsystems: “At the entrance to the well” and “At the exit from the well”, which include: a reversible pump with electric drive, two measuring vessels under different pressures, a vortex degasser, jet pump, information collection and processing unit, power unit, remote gas analyzer, characterized in that the measuring module operating under overpressure is connected to the pump outlet via a tee bottom and and upper part of the fluid flow through the meter is connected to the inlet of the vortex degasser; inside the measuring vessel there are two pressure sensors combined in the assembly, a temperature sensor and electrical resistivity; a measuring vessel operating under atmospheric pressure is connected to the pump through a tee and pipe, a regulating device is located in the lower part of the vessel to limit the flow of fluid, drilling fluid is supplied to the inner pipe, and the fluid is evacuated through an external pipe connected to the atmosphere through the jet pump , into the nozzle of which, through a tee, pipeline and control device, the drilling fluid under pressure is supplied from the pump outlet; the lower part of the vortex degasser is also connected to the jet pump to evacuate the degassed drilling fluid, and its upper part is connected to a remote gas analyzer through a gas-air mixture flow meter and a vacuum pump; measuring vessels, flow meters, an electric motor, and flow and temperature meters at the inputs of the subsystems are electrically connected to a data collection and preprocessing unit that performs the functions of automatically controlling the operation of the subsystem through the power unit, as well as transferring some of the functions to the manual control device and displaying information on the rig. 2. The system according to p. 1, characterized in that the selected devices located in the receiving and supply pipes are mounted on the covers of the respective hatches, on which the flow indicators and flow temperature meters are located; the upper part of the receiving pipe is connected to ball shut-off valves, and in the pipe section before entering the pump there is a heating device with the necessary range of heating intensity of the incoming drilling fluid. 3. The system according to claim 1, characterized in that the drilling fluid density meter in the measuring vessels is made on two pressure sensors for a range of 100 kPa overpressure spaced on a measuring base Δh≥400 mm. 4. The system according to claim 1, characterized in that the resistivity meter in the measuring vessels is made in the form of a four-electrode system, the electrodes of which are circular, which provides volumetric coverage of the measuring volume, and temperature compensation is provided by temperature sensors located there. 5. The system according to claim 1, characterized in that the explosion-proof frequency-controlled electric motor is programmed to generate a 1-minute reverse pulse of pressure for 1 second to clean the filter mesh and to backwash for 10 seconds when the circulation stops. 6. The system according to claim 1, characterized in that the heating of the selected drilling fluid by the heating device through the power unit is programmed by the information collection and pre-processing unit and maintained through the temperature sensors in the measuring vessels in the range of 35 ÷ 80 ° C as specified. 7. The system according to p. 1, characterized in that the start-up and shutdown of the system is carried out through the flow indicators in the selection points with the appearance or absence of signals from the indicators. 8. The system according to claim 1, characterized in that a tube is introduced into the middle part of the vortex degasser for supplying air to the vortex degasser through a hydrophobic filter and an air flow meter, which ensures the maintenance of atmospheric pressure in the vortex degasser and determination of the volume of the gas-air mixture (DHW), released in the vortex degasser. 9. The system according to claim 1, characterized in that the calculation of the volumetric gas content of the drilling fluid is made through the ratio of the density of the drilling fluid in the measuring vessels and the ratio of the working pressures in these vessels. 10. The system according to claim 1, characterized in that the duplicate calculation of the volumetric gas content of the drilling fluid is made through the ratio of the electrical resistivity of the fluid in the measuring vessels and the ratio of the working pressures in these vessels.

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