WO2015164713A1 - Procédé et système pour la détermination de la pression de début de précipitation d'asphaltènes à l'aide d'un signal dépendant de la longueur d'onde - Google Patents

Procédé et système pour la détermination de la pression de début de précipitation d'asphaltènes à l'aide d'un signal dépendant de la longueur d'onde Download PDF

Info

Publication number
WO2015164713A1
WO2015164713A1 PCT/US2015/027476 US2015027476W WO2015164713A1 WO 2015164713 A1 WO2015164713 A1 WO 2015164713A1 US 2015027476 W US2015027476 W US 2015027476W WO 2015164713 A1 WO2015164713 A1 WO 2015164713A1
Authority
WO
WIPO (PCT)
Prior art keywords
pressure
light
wavelength
transmitted light
intensity
Prior art date
Application number
PCT/US2015/027476
Other languages
English (en)
Inventor
Shunsuke FUKAGAWA
Matthew Sullivan
Elizabeth Smythe
Christopher Harrison
John Meier
Original Assignee
Schlumberger Canada Limited
Services Petroliers Schlumberger
Schlumberger Holdings Limited
Schlumberger Technology B.V.
Prad Research And Development Limited
Schlumberger Technology Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US14/262,462 external-priority patent/US20150309002A1/en
Priority claimed from US14/262,480 external-priority patent/US9568459B2/en
Application filed by Schlumberger Canada Limited, Services Petroliers Schlumberger, Schlumberger Holdings Limited, Schlumberger Technology B.V., Prad Research And Development Limited, Schlumberger Technology Corporation filed Critical Schlumberger Canada Limited
Publication of WO2015164713A1 publication Critical patent/WO2015164713A1/fr

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
    • E21B49/08—Obtaining fluid samples or testing fluids, in boreholes or wells
    • E21B49/081—Obtaining fluid samples or testing fluids, in boreholes or wells with down-hole means for trapping a fluid sample
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
    • E21B49/08—Obtaining fluid samples or testing fluids, in boreholes or wells
    • E21B49/087—Well testing, e.g. testing for reservoir productivity or formation parameters
    • E21B49/0875—Well testing, e.g. testing for reservoir productivity or formation parameters determining specific fluid parameters

Definitions

  • This disclosure relates to fluid analysis, and more particularly to determining asphaltene onset pressure of a fluid.
  • Asphaltenes are large molecules that are dissolved within formation fluids at high pressures. As the pressure of the formation fluid is reduced, the solubility of the asphaltenes within the fluid is also reduced and the asphaltenes will begin to flocculate. The pressure at which the asphaltenes begin to flocculate is known as asphaltene onset pressure (AOP).
  • Fig. 1 shows the process of flocculation. As shown in Fig. 1, individual molecules of asphaltenes form nanoaggregates and then form clusters of nanoaggregates.
  • the asphaltene onset pressure of a formation fluid within a hydrocarbon reservoir formation is valuable information that is used for completing and producing a well.
  • the formation fluid that is extracted from the hydrocarbon reservoir is maintained above the known asphaltene onset pressure to avoid creation of asphaltene clusters within the formation.
  • a build-up of asphaltenes within the formation can curtail production of the well.
  • asphaltene onset pressure is measured in a laboratory environment by measuring light transmission through a large formation fluid sample (e.g., 10 mL -100 mL). The light transmission is measured while slowly reducing the pressure of the sample (e.g., 100 psi/hour). The sample is agitated using a mixer to maintain equilibrium within the formation fluid and to avoid asphaltene flocculation from settling within the cell. As the pressure within the formation fluid sample is decreased, at a certain pressure, the light transmission will decrease significantly. The pressure and temperature at which the light transmission will decrease significantly is the asphaltene onset pressure and the asphaltene onset temperature.
  • Fig. 2 shows how flocculation of asphaltenes reduces light transmission.
  • the pressure of the oil sample decreases and asphaltenes begin to flocculate at the asphaltene onset pressure.
  • the formation fluid sample turns opaque and reduces the transmission of light.
  • An intense light source such as a laser is used for such light transmission measurements.
  • Another laboratory technique also uses a slow depressurization technique, but identifies asphaltene flocculation using microscopic observation.
  • the light transmission technique and the microscopic observation technique are combined so that light transmission and direct observation of flocculation are performed simultaneously.
  • the bubble point pressure is the pressure at which at least a portion of a liquid changes phase to a vapor state (e.g., nucleates bubbles) at equilibrium.
  • Fig. 3 shows a formation fluid sample in a liquid state within an enclosed volume. As the size of the enclosed volume is increased, the pressure of the formation fluid sample decreases and bubbles begin to form at the bubble point pressure. This formation of bubbles will also reduce the light transmission of a formation fluid sample. The decrease in light transmission occurs because bubbles form at the bubble point and the bubbles scatter light, which reduces light transmission. Accordingly, asphaltene onset pressure can be confused with bubble point pressure because both the asphaltene onset pressure and the bubble point pressure reduce transmission of light.
  • Illustrative embodiments of the present disclosure are directed to a method for determining asphaltene onset pressure of a formation fluid.
  • the method includes positioning a wellbore tool within a wellbore and drawing a formation fluid sample into the wellbore tool.
  • the method further includes transmitting light through the formation fluid sample and detecting light that is transmitted through the sample.
  • the light is transmitted within the formation fluid along a short path length of less than 2 mm. While the light is being transmitted, the pressure of the sample is varied. Asphaltene onset pressure of the sample is determined using intensity of the transmitted light at a number of different wavelengths.
  • a wavelength dependent signal can be determined using (i) the intensity of the transmitted light at a first wavelength and (ii) the intensity of the transmitted light at a second wavelength. Creation of bubbles at the bubble point pressure will not affect this wavelength dependent signal.
  • the asphaltene onset pressure of the formation fluid sample can be determined by identifying a change in the wavelength dependent signal at a particular pressure.
  • Various embodiments of the present disclosure are also directed to a wellbore tool for determining asphaltene onset pressure of a formation fluid.
  • the tool includes a source for generating light that is transmitted along a path length through a sample of the formation fluid. The path length is less than 2 mm.
  • the tool also includes a detector system for detecting light at a plurality of wavelengths and a controller that determines the asphaltene onset pressure of the sample using intensity of the transmitted light at a number of different wavelengths.
  • Illustrative embodiments of the present disclosure are also directed to a system for analyzing a fluid sample.
  • the system includes a source for generating light that is transmitted along a path length through the fluid sample. The path length is less than 2 mm.
  • the system also includes a detector system with two or more detector modules for detecting light at a number of different wavelengths. Each detector module detects a different wavelength of the transmitted light.
  • Fig. 1 shows flocculation of asphaltenes
  • Fig. 2 shows flocculation of asphaltenes within a formation fluid sample
  • Fig. 3 shows nucleation of bubbles within a formation fluid sample
  • FIG. 4 shows a wireline logging system at a well site in accordance with one embodiment of the present disclosure
  • FIG. 5 shows a wireline tool in accordance with one embodiment of the present disclosure
  • FIG. 6 shows a system for determining asphaltene onset pressure of a fluid sample in accordance with one embodiment of the present disclosure
  • FIG. 7 shows a light detection system in accordance with one embodiment of the present disclosure
  • Fig. 8 shows a method for determining asphaltene onset pressure of a fluid sample in accordance with one embodiment of the present disclosure
  • Fig. 9A shows plots of wavelength dependent signals versus pressure for a fluid with a bubble point, but with no asphaltene onset pressure, in accordance with one embodiment of the present disclosure
  • Fig. 9B shows a plot of broadband signal versus pressure for a fluid with a bubble point, but with no asphaltene onset pressure
  • Fig. 9C shows plots of wavelength dependent signals versus pressure for a fluid with both a bubble point and an asphaltene onset pressure in accordance with one embodiment of the present disclosure
  • Fig. 9D shows a plot of broadband signal versus pressure for the fluid with both a bubble point and an asphaltene onset pressure
  • Fig. 10 shows a method for determining asphaltene onset pressure of a fluid sample in accordance with another embodiment of the present disclosure
  • Fig. 11 shows a plot of a wavelength dependent signal and pressure versus time for a crude oil sample in accordance with one embodiment of the present disclosure
  • Fig. 12 shows a plot of difference values for wavelength dependent signals versus fixed pressures for the crude oil sample in accordance with one embodiment of the present disclosure
  • Fig. 13 shows a method for detecting asphaltene onset of a formation fluid in accordance with one embodiment of the present disclosure
  • Fig. 14 shows a plot of broadband signal versus pressure for a crude oil sample with an asphaltene onset pressure in accordance with one embodiment of the present disclosure.
  • Fig. 15 shows a plot of broadband signal versus pressure for a crude oil sample without an asphaltene onset pressure in accordance with one embodiment of the present disclosure.
  • Illustrative embodiments of the disclosure are directed to a method and system for determining asphaltene onset pressure of a fluid sample, such as a formation fluid.
  • the method includes positioning a wellbore tool within a wellbore and drawing a formation fluid sample into the wellbore tool. Once within the wellbore tool, the method further includes transmitting light through the formation fluid sample and detecting light that is transmitted through the formation fluid sample. The light is transmitted within the formation fluid along a short path length of less than 2 mm. This short path length facilitates measurement of the asphaltene onset pressure. While the light is being transmitted, the pressure of the formation fluid sample is varied.
  • a wavelength dependent signal can be determined using (i) the intensity of the transmitted light at a first wavelength and (ii) the intensity of the transmitted light at a second wavelength. Creation of bubbles at the bubble point pressure will not affect this wavelength dependent signal.
  • the asphaltene onset pressure of the fluid sample can be determined by identifying a change in the wavelength dependent signal at a particular pressure. Details of various embodiments are discussed below.
  • Fig. 4 shows one example of a wireline logging system 400 at a well site.
  • the wireline logging system 400 can be used to implement measurements of asphaltene onset pressure, as described herein.
  • a wireline tool 402 is lowered into a wellbore 404 that traverses a formation 406 using a cable 408 and a winch 410.
  • the wireline tool 402 is lowered down into the wellbore 404 and makes a number of measurements of the adjacent formation 406 at a plurality of sampling locations along the wellbore 404.
  • the data from these measurements is communicated through the cable 408 to surface equipment 412, which may include a computer system for storing and processing the data obtained by the wireline tool 402.
  • the surface equipment 412 includes a truck that supports the wireline tool 402. In another embodiment, however, the surface equipment may be located within a cabin on an off-shore platform.
  • Fig. 5 shows a more detailed view of the wireline tool 402.
  • the wireline tool includes 402 a selectively extendable fluid admitting assembly (e.g., probe) 502.
  • This assembly 502 extends into the formation 406 and withdraws formation fluid from the formation 406 (e.g., samples the formation) and into the wireline tool 402.
  • the formation fluid flows through the assembly 502 and into a flow line 504 within a housing 506 of the tool 402.
  • a pump (not shown) can be used to withdraw the formation fluid from the formation 406 and pass the fluid through the flow line 504.
  • the wireline tool 402 may also include a selectively extendable anchoring member 508 that is arranged to press the probe 502 assembly against the formation 406.
  • the wireline tool 402 also includes a fluid analyzer module 510 for analyzing at least a portion of the fluid in the flow line 504.
  • the fluid analyzer module 510 includes a system for determining asphaltene onset pressure of a fluid sample.
  • Fig. 6 shows a more detailed view of a system 600 for determining asphaltene onset pressure of a fluid sample.
  • the system 600 includes a housing 602 that defines a detection chamber 604 for at least partially containing the fluid sample.
  • the housing 602 is formed from a metal material, such as steel or aluminum.
  • the detection chamber 604 is a channel that receives a fluid sample that is extracted from the flow line 504 of the wireline tool 402.
  • the channel may be a micro fluidic channel that has a smallest diameter of less than 1 mm.
  • the system 600 also includes a light source 606 for generating light that passes through the fluid sample and a light detector system 608 for detecting transmitted light.
  • the light can be of a variety of different wavelengths and can include visible light, ultraviolet light, and/or infrared light (e.g., near infrared light or mid-infrared light).
  • the light source 606 is a tungsten halogen lamp that generates light and provides the light to a first optical fiber 612.
  • a first ball lens 614 serves as both a window preventing outflow of the fluid sample and a lens that collimates the light from the optical fiber 612 into the detection chamber 604.
  • the system 600 also includes a second ball lens 616 that serves as both a window preventing outflow and a lens that focuses the light signal from the detection chamber onto a second optical fiber 618.
  • the second optical fiber 618 provides the transmitted light to the light detector system 608 (e.g., that includes one or more photodiodes).
  • the light detector system 608 translates the transmitted light into a transmitted light signal that is representative of the intensity of the transmitted light.
  • Fig. 7 shows a light detector system 700 in accordance with one embodiment of the present disclosure.
  • a light source 606 generates light that passes through a first ball lens 614 and into a fluid sample.
  • a second ball lens 616 focuses the light signal from the detection chamber 604 onto a second optical fiber 618.
  • a splitter 702 splits light from the second optical fiber 618 and passes the light to a set of optical fibers 704.
  • the set of optical fibers 704 provide the light from the splitter 702 to a number of detector modules.
  • the light detector system 700 includes four wavelength-specific detector modules 702, 704, 706, and 708 for detecting light at a number of different specific wavelengths (e.g., the wavelength-specific detector modules are set to four specific spectroscopic channels).
  • the light detector system 700 also includes a broadband detector module 710 that detects intensity of light over a wide range of wavelengths and is used to determine whether a phase change has occurred within the fluid sample (e.g., asphaltene onset or bubble point).
  • the wavelength- specific detector modules 702, 704, 706, and 708 include optical filters 712 that transmit a specific wavelength of light while filtering out other wavelengths, such as interference filters.
  • Each detector module includes a detector 716 for detecting light that is transmitted through the filters 712 (e.g., a photodiode). In the case of the broadband detector module 710, a filter is not used.
  • Each detector module also includes a set of optics 714 for directing light from the set of optical fibers 704 through the filters 712 and onto the detectors 716.
  • the detector system uses two detector modules (e.g., one module is set to 1070 nm and the other module is set to 1600 nm). Furthermore, for certain applications, the detector system uses a single detector module (e.g., a single broadband module).
  • the light from the source 606 is transmitted within the fluid sample along a short path length 625.
  • the path length is a distance within a detection chamber between optical elements, such as ball lenses or windows.
  • the path length is represented by reference symbol d and is the distance between ball lenses 614 and 616.
  • this path length is a short path length of less than 2 mm. In other embodiments, the path length is less than 1 mm. This short path length facilitates measurement of the asphaltene onset pressure.
  • Longer path lengths within formation fluids produce greater scattering and absorption of light. This is particularly true for asphaltenes which produce clusters and sediments that scatter light.
  • the inventors took an approach that is contrary to what they understood to be conventional wisdom. They shortened the path length to less than 2 mm.
  • the short path length produces a reliable light signal, while permitting use of a more energy efficient light source, in contrast to the intense light source used in laboratory techniques.
  • the more energy efficient light source is particularly beneficial for wellbore applications, which have low power constraints and high temperature operating conditions.
  • Those in the art recognize significant disincentives associated with using short path lengths within flow lines that contain formation fluids. Use of short path lengths risks clogging the flow line, particularly when asphaltenes flocculate within the flow line. Nevertheless, the inventors recognized that this is not a significant risk because repressurization of the formation fluid can be used to re-dissolve flocculated asphaltenes and then flush away the formation fluid, even in such small flow lines.
  • the system 600 also includes a pressure unit 626 for changing the pressure within the fluid sample and a pressure sensor 628 that monitors the pressure of the fluid sample.
  • the pressure unit 626 is not drawn to scale in Fig. 6.
  • the pressure unit 626 is a piston that is in communication with the detection chamber 604 and that expands the volume of the fluid sample to decrease the pressure of the sample within the detection chamber.
  • a pressure sensor 628 is used to monitor the actual pressure within the fluid sample.
  • the pressure sensor 628 can be a strain gauge or a resonating pressure gauge.
  • the system 600 may include valves 622 and 624 that remain closed when the pressure unit 626 is varying the pressure of the fluid sample.
  • the valves are needle valves that use a metal seal to isolate the sample.
  • other valves can be used, such as valves that use rubber seals.
  • the valves 622 and 624 can couple the detection chamber 604 to (i) a sample bottle within the wellbore tool, (ii) a flow line within the wellbore tool, (iii) a waste disposal system within the wellbore tool, or (iv) any combination of such elements.
  • the valves 622 and 624 are opened to introduce a new fluid sample into the detection chamber 604 from a flow line and an old sample is flushed out into a waste disposal system.
  • the volume of the detection chamber 604 (between the valves 622 and 624) is less than 1 mL.
  • This small volume size provides for use of small sample volumes, which, in turn, permits measurements on a number of different sample volumes without significantly depleting available fluid. Small sample volumes are particularly beneficial in wellbore applications where the volume of formation fluid drawn into the wellbore tool is limited.
  • the system 600 may also include a temperature detector 629, such as a resistive temperature detector (RTD), that is in thermal communication with the fluid sample and measures the temperature of the fluid sample.
  • a temperature detector 629 such as a resistive temperature detector (RTD)
  • RTD resistive temperature detector
  • the temperature detector 629 is in thermal contact with the housing 602 and can measure the temperature of the fluid sample within the detection chamber 604.
  • the system 600 also includes a controller 630 for controlling the system 600 and processing signals that are received from various components within the system.
  • the controller 630 receives one or more transmitted light signals that are representative of the intensity of the transmitted light from the light detector system 608 and one or more detector modules.
  • the controller 630 may use the transmitted light signal from two or more wavelength-specific detector modules to determine a wavelength dependent signal. A process for determining a wavelength dependent signal is further described below.
  • the controller 630 can also be in electronic communication with the pressure unit 626 and the pressure sensor 628.
  • the controller 630 modifies the pressure within the detection chamber 604 by controlling the pressure unit 626 and also monitors the actual pressure within the sample by interpreting an output pressure signal from the pressure sensor 628.
  • the controller samples the output pressure signal at a sampling rate of between 10 Hz and 60 Hz.
  • the controller 630 may also maintain timing (e.g., synchronization) between the transmitted light signal from the light detector 608 and the output pressure signal within the sample so that corresponding portions between the transmitted light signal and the output pressure signal can be identified.
  • the controller 630 may sample the transmitted light signal at a high sampling rate, such as 100 Hz.
  • the controller 630 samples the transmitted light signal at a frequency of at least 25 Hz.
  • Illustrative embodiments of the system 600 are not limited to the embodiments shown in Figs. 6 and 7.
  • a flat planar window can serve to prevent outflow of the fluid and a ball lens can be positioned behind the planar window.
  • a light emitting diode LED is used in place of the tungsten halogen lamp.
  • Fig. 8 shows a method 800 for determining asphaltene onset pressure of a formation fluid.
  • the method can be implemented by the systems described above (e.g., system 600 and light detection system 700).
  • a wellbore tool is positioned within a wellbore that traverses a formation.
  • the wellbore tool may be a wireline tool, such as the one shown in Fig. 5, or some other tool, such as a logging-while-drilling (LWD) tool.
  • LWD logging-while-drilling
  • the formation fluid is drawn into the wellbore tool.
  • the formation fluid can be drawn into the wellbore tool using a probe that extends into the formation and withdraws the formation fluid from the formation.
  • the formation fluid within the wellbore may enter the wellbore tool through a port within the housing of the tool.
  • process 806 light is transmitted through a sample of the formation fluid and, at process 808, the transmitted light is detected.
  • These processes can be implemented using the system described in Fig. 6.
  • the light is transmitted through the sample along a path length that is less than 2 mm.
  • the short path length produces a reliable light signal.
  • the light is detected by a detector system that can detect intensity of light at a number of different wavelengths.
  • the pressure of the formation fluid sample is varied. For example, in one embodiment, the pressure of the formation fluid sample is decreased from 5000 psi to 2500 psi. In illustrative embodiments, the pressure is lowered at a rate between 1 to 200 psi per second. This decrease in pressure may be performed incrementally, in steps, and/or continuously. The decrease in pressure also occurs while the system is transmitting and detecting light.
  • Process 810 can be performed by the pressure unit and monitored by the pressure sensor, as described above.
  • the pressure unit decreases the pressure within the fluid sample, the fluid sample will eventually reach the asphaltene onset pressure.
  • the intensity of the transmitted light will decrease due to scattering and absorption caused by the flocculated asphaltenes.
  • the amount of scattering and absorption caused by the flocculated asphaltenes will depend on the wavelength of the light.
  • bubble point pressure and below the bubble point pressure
  • the method can determine the asphaltene onset pressure of the fluid sample, while distinguishing the asphaltene onset pressure from phase transitions, such as bubble point.
  • the asphaltene onset pressure can be determined by (i) comparing an intensity of transmitted light at a first wavelength (e.g., 1070 nm) to an intensity of transmitted light at a second wavelength (e.g., 1600 nm) and identifying a relative change between the two intensities in proportion to baseline intensity for each wavelength.
  • the intensity of the transmitted light at the first wavelength and the intensity of the transmitted light at the second wavelength can be compared by, for example, subtracting one from the other and/or dividing one from the other (e.g., a ratio).
  • the baseline intensity for each wavelength can be determined at any point before the asphaltene onset pressure is reached (e.g., before the pressure variation in process 810 is initiated).
  • the wavelengths should be selected so that the relative change can be reliably identified. Generally, a large difference in the wavelengths produces a large relative change.
  • the difference between the first wavelength and the second wavelength is at least 100 nm. In another embodiment, the difference between the first wavelength and the second wavelength is at least 1000 nm.
  • Wavelength dependent signal (t) [I( lt t)— ⁇ ( ⁇ 2 , t)]— [I(X lt t 0 )— ⁇ ( ⁇ 2 , t 0 )]
  • Equation 1 the intensity of the transmitted light can be represented as an optical density, which can be determined according to the following relationship:
  • Optical Density — log 10 — Eq. 2 where I[ n corresponds to the intensity provided by the light source and 7 0Ut corresponds to the light detected at the detector (e.g., after a portion of the light is absorbed by the sample).
  • Equation 1 is one example of a relationship that can be used to determine a wavelength dependent signal.
  • Other relationships can also be used to determine the wave length dependent signal.
  • wavelength dependent signal is determined by subtracting a baseline ratio for the two intensities at different wavelengths from a ratio for the two intensities at time (t), as shown in the following relationship:
  • the asphaltene onset pressure of the fluid sample can be determined using the wavelength dependent signal. As explained above, at the asphaltene onset pressure, asphaltenes will flocculate and this behavior will result in a change within the wavelength dependent signal.
  • the asphaltene onset pressure of the fluid sample is determined by identifying a change within the wavelength dependent signal as the pressure of the fluid sample is decreased. In a particular embodiment, the asphaltene onset pressure of the fluid sample is determined by identifying an increase within the wavelength dependent signal as the pressure of the fluid sample is decreased.
  • Fig. 9A shows plots of wavelength dependent signals versus pressure for a fluid with a bubble point, but with no asphaltene onset pressure.
  • the wavelength dependent signal was determined according to Equation 1 using wavelengths of 1070 nm and 1600 nm (plot 902) and wavelengths of 1445 nm and 1600 nm (plot 904).
  • Fig. 9B shows a plot of a broadband signal (plot 906) versus pressure for the fluid with a bubble point, but with no asphaltene onset pressure.
  • the broadband signal was generated by a broadband detector module, as described above in Fig. 7.
  • Fig. 9C shows plots of wavelength dependent signals versus pressure for a fluid with both a bubble point and an asphaltene onset pressure.
  • Fig. 9D shows a plot of a broadband signal (plot 906) versus pressure for the fluid with both a bubble point and an asphaltene onset pressure.
  • the wavelength dependent signal remains constant while the pressure within the sample is decreased.
  • both wavelength dependent signals 902 and 904 suddenly increase below 4000 psi.
  • the sudden increase is greater in plot 902 because of the large difference in wavelengths used to generate the signal.
  • This sudden increase indicates that the asphaltenes have started flocculating and the pressure at which this increase happens is the asphaltene onset pressure.
  • the asphaltene onset pressure is approximately 4000 psi. Since there is no asphaltene onset pressure in Fig. 9A, both wavelength dependent signals 902 and 904 remain unchanged as the pressure is reduced in that figure (903).
  • the asphaltene onset pressure can be confirmed by identifying a change within the broadband signal that corresponds in pressure to the change in the wavelength dependent signal.
  • Fig. 9D shows a corresponding decrease in the broadband signal at 4000 psi.
  • the wavelength dependent signal remains unaffected by formation of bubbles within the fluid sample.
  • Fig. 9B shows a decrease in broadband signal at approximately 2070 psi and Fig. 9D shows a decrease in broadband signal at approximately 2650 psi. These decreases are associated with bubble points.
  • both wavelength dependent signals 902 and 904 remain unchanged during the bubble point (903).
  • Fig. 9C the wavelength dependent signals 902 and 904 have some noise below the bubble point, but both signals stop increasing once bubbles appear (905). In this manner, the bubble point and asphaltene onset pressure can be identified and distinguished.
  • Fig. 10 shows another method 1000 for determining asphaltene onset pressure of a formation fluid.
  • the method can be implemented by the systems described above (e.g., system 600).
  • a sample of formation fluid Prior to the first process 1002, a sample of formation fluid enters the detection chamber of the system.
  • the formation fluid sample is extracted from a flow line of a wellbore tool (e.g., a wireline or logging-while-drilling (LWD) tool), which, in turn, was extracted from a location-of-interest within the formation.
  • a wellbore tool e.g., a wireline or logging-while-drilling (LWD) tool
  • the method thus begins at process 1002, which transmits light through the formation fluid sample using a light source.
  • the light is transmitted through the sample along a path length that is less than 2 mm.
  • the short path length produces a reliable light signal.
  • the pressure of the formation fluid sample is varied. For example, in one embodiment, the pressure of the formation fluid sample is decreased until asphaltene flocculation occurs. In one example, the pressure is decreased from an initial pressure of 10,000 psi to a pressure of 6,000 psi. This decrease in pressure may be performed incrementally, in steps, and/or continuously. The behavior of asphaltene flocculation depends on the rate of depressurization.
  • Rapid depressurization may overshoot the actual asphaltene onset pressure. Accordingly, in various embodiments, the pressure is decreased so that a more accurate measure of asphaltene onset pressure is determined. In illustrative embodiments, the rate of depressurization is between 10 to 100 psi/second.
  • process 1006 intensity of the transmitted light during depressurization is detected.
  • this process is performed using a broadband detection module and a broadband signal, as described above.
  • this process is performed using the detection system described in Fig. 7, which detects the intensity of light at a number of different wavelengths and outputs a wavelength dependent signal.
  • a change in intensity of the transmitted light during depressurization is identified.
  • This change represents asphaltene flocculation.
  • the intensity of the transmitted light signal will increase.
  • a reversal of this trend may indicate asphaltene flocculation.
  • Any one of the broadband signal, the wavelength dependent signal, or both can be used to identify the asphaltene flocculation.
  • the wavelength dependent signal beneficially identifies asphaltene flocculation, while distinguishing asphaltene flocculation, from phase changes, such as bubble point.
  • the pressure of the formation fluid sample is increased to a fixed pressure. Although the depressurization rate is slow, once asphaltene flocculation is observed, the pressure of the formation fluid sample is rapidly increased to reduce time at lower pressures (e.g., 100 psi per second). This rapid increase in pressure increases the reversibility of the flocculation process. Also, at the lower pressures, the sample may produce undesirable sedimentation. Sedimentation is the settling of flocculated asphaltenes within the formation fluid sample. Thus, in various embodiments, the rapid increase in pressure helps prevent clogging in system that use short light path lengths.
  • the transmitted light signal will slowly increase and then suddenly start to decrease. The sudden decrease indicates sedimentation within the fluid. If sedimentation is detected in this manner, then the equilibrated signal should be extrapolated from recorded signal that occurs before the sedimentation.
  • Fig. 11 shows a plot of a wavelength dependent signal (1101) and pressure (1103) versus time for a crude oil sample with an asphaltene onset pressure. Processes 1002 to 1012 were applied to the sample. The pressure of the oil sample was slowly reduced from 10,000 psi. At 6,000 psi, a change in the wavelength dependent signal is identified. The oil sample is then pressurized to a fixed pressure of 7,750 psi. The sample is maintained at this pressure for over 200 seconds so that the wavelength dependent signal can move towards a steady state. An exponential fit 1100 is applied to the signal data to extrapolate an equilibrated signal. At about 450 seconds, the wavelength dependent signal decreases. This decrease may indicate sedimentation. Accordingly, the portion of the wavelength dependent signal after 450 seconds is not used to determine the equilibrated signal.
  • processes 1002 to 1012 are repeated a number of times for different fixed pressures (e.g., 2, 3, 5, 10, or 20).
  • a lowest desirable fixed pressure can be used initially and the fixed pressure of each subsequent repetition is incrementally increased by a pressure value (e.g., 100 psi, 250 psi, 500 psi, or 1000 psi).
  • the number of fixed pressures and size of each increment will depend on available time and desired accuracy.
  • the repetitions are performed until full recovery of the transmitted light signal is obtained.
  • the number of repetitions may depend on the outcome of process 1016 below. For example, the processes are repeated until an accurate asphaltene onset pressure for the fluid sample is determined in process 1016 below.
  • processes 1002 to 1012 are repeated for different formation fluid samples. After process 1012, the formation fluid sample is flushed from the detection chamber and a new formation fluid sample enters the detection chamber. Processes 1002 to 1012 are performed on the new formation fluid sample. Using a new formation fluid sample for each repetition is beneficial because the depressurization process 1004 may produce irreversible sedimentation and decrease the amount of signal recovery observable during each repetition. As explained above, in illustrative embodiments, the volume of the detection chamber is small (e.g., less than 1 mL) and this small volume provides for many repetitions using different samples without significantly depleting available fluid.
  • processes 1010 to 1012 are repeated for the same formation fluid sample.
  • the fixed pressure is incrementally increased from a lowest desirable pressure and the intensity of transmitted light is recorded at each fixed pressure (e.g., extrapolated).
  • the asphaltene onset pressure of the fluid sample is determined using (i) the intensity of the transmitted light during each depressurization (e.g., intensity of wavelength dependent signal in process 1006) and (ii) the intensity of transmitted light at each of the different fixed pressures (e.g., intensity of equilibrated wavelength dependent signal in process 1012).
  • the asphaltene onset pressure is determined by subtracting (i) the equilibrated intensity of the transmitted light at each fixed pressure (during each process 1012) from (ii) the intensity of the transmitted light during depressurization corresponding to each fixed pressure (during each respective process 1006) to determine difference values at each of the different fixed pressures. For example, in Fig.
  • the difference value is 0.025 for a fixed pressure of 7,750 psi.
  • the difference value is determined by subtracting an extrapolated intensity of 0.412 at the fixed pressure (1102) from an intensity of 0.437 (1104), which is the intensity of the wavelength dependent signal at 7,750 psi during the depressurization process 1006.
  • Dashed line 1106 shows how the intensity of the transmitted light during depressurization (that corresponds to the fixed pressure) is determined.
  • the asphaltene onset pressure can be determined by identifying a difference value that is (i) a value of zero, (ii) a steady state value, or (iii) both.
  • the fixed pressure that corresponds to the identified difference value is the asphaltene onset pressure.
  • a difference value of zero will be representative of the asphaltene onset pressure.
  • a difference value that corresponds to a first steady state value (with increasing pressure) will be representative of the asphaltene onset pressure.
  • Fig. 12 shows a plot of difference values for wavelength dependent signals versus fixed pressures for the crude oil sample.
  • Processes 1002 to 1014 were applied to the sample.
  • Processes 1002 to 1012 were initially applied for a fixed pressure of 6,500 psi.
  • Processes 1002 to 1012 were repeated 8 times and the fixed pressures were incremented by 250 psi.
  • Point 1202 corresponds to the difference value determined from Fig. 11.
  • the plot reaches a steady state value at point 1204, which corresponds to a fixed pressure of 8,000.
  • the asphaltene onset pressure of the crude oil sample is 8,000 psi. This value compares well with an asphaltene onset pressure of 8,030 psi, which was determined using a time intensive laboratory technique.
  • the method 1300 can be performed by the detection system 600 shown in Fig. 6, but can also be implemented by other systems.
  • the method begins at process 1302, where light is transmitted through a sample of formation fluid using a light source.
  • the intensity of the transmitted light is detected while the pressure of the formation fluid sample is decreased to a predetermined pressure.
  • the depressurization begins at an initial pressure that corresponds to formation or wellbore pressure. The pressure is then decreased to a lower pressure value.
  • the lower pressure value can be selected by identifying a decrease within the intensity of the transmitted light as the pressure of the sample is decreased.
  • the lower pressure value can be a predetermined pressure value that is selected so that the value is greater than the bubble point pressure of the formation fluid sample. Lowering the pressure below the bubble point pressure will cause bubbles to nucleate and their presence will complicate identification of the asphaltene onset pressure.
  • the bubble point pressure can be determined or estimated from other known methods, such as the method described in U.S. Patent Application Serial No. 13/800,896, filed on March 13, 2013, which is hereby incorporated by reference in its entirety.
  • the intensity of the transmitted light is decreased while increasing pressure of the formation fluid sample.
  • the pressurization process begins at the lower pressure value and in some embodiments, continues to the initial pressure.
  • the intensity of the light signal is recorded during the depressurization process 1304 and the pressurization process 1306. These processes can be performed using a broadband signal or a wavelength dependent signal, as described above.
  • the behavior of asphaltene flocculation depends on a rate of depressurization.
  • the dissolution of asphaltenes will also depend on a rate of pressurization.
  • the depressurization process 1304 and the pressurization process 1306 are performed slowly so that a more accurate measure of asphaltene onset pressure is determined.
  • the rate of depressurization and pressurization is less than 100 psi/second (e.g., less than 50 psi, 20 psi, or 10 psi).
  • Hysteresis may also be caused by bubbles produced when the bubble point is reached.
  • the bubble point is excluded from affecting the measurement (i) by selecting the lower pressure value to be above the bubble point pressure or (ii) by distinguishing between hysteresis produced by asphaltenes and bubbles.
  • Hysteresis caused by asphaltenes shows a much slower recovery than hysteresis caused by bubbles.
  • the method 1300 can be used to determine upper and lower bounds for the asphaltene onset pressure.
  • the lower pressure value can be used as the lower bound for the asphaltene onset pressure.
  • An upper bound can be determined by identifying a pressure at which the intensity of transmitted light during the depressurization process 1302 and the intensity of transmitted light during the pressurization process 1304 intersect (e.g., the lowest pressure where the intensity values are equal).
  • Fig. 14 shows a plot of broadband signal versus pressure for a crude oil sample with an asphaltene onset pressure. Processes 1302 to 1318 were applied to the sample. The pressure of the oil sample was slowly reduced from 10,000 psi to 4,000 psi.
  • the plot shows that asphaltene flocculation occurred within the oil sample because a large difference in transmitted light intensity between depressurization and pressurization in present within the plot.
  • the plot forms a loop 1402, which shows hysteresis and is an indicator that asphaltene flocculation occurred.
  • the plot can be used to determine the upper and lower bounds for the asphaltene onset pressure.
  • the lower bound of the asphaltene onset pressure corresponds to 4,400 psi, where the intensity of the transmitted light decreases during the depressurization process 1404.
  • the upper bound of the asphaltene onset pressure corresponds to 9,000 psi, where the intensity of transmitted light during the depressurization process and the intensity of transmitted light during the pressurization process intersect 1406.
  • Fig. 15 shows a plot of broadband signal versus pressure for a crude oil sample without an asphaltene onset pressure. Processes 1302 to 1318 were applied to the sample. The pressure of the oil sample was slowly reduced from 14,000 psi to 4,000 psi. Then, the pressure of the oil sample was increased from 4,000 psi to 14,000 psi. The plot shows that the asphaltene flocculation did not occur because the transmitted light during the depressurization process corresponds to transmitted light during the pressurization process. Hysteresis does not appear in the plot. In both Fig. 14 and 15, pressure was not dropped below the bubble point pressure of the samples.
  • the asphaltene onset pressure is determined for a particular temperature.
  • the asphaltene onset pressure is a function of both the pressure of the fluid sample and the temperature of the fluid sample.
  • the temperature at which the asphaltene onset pressure occurs can be measured by a temperature detector, such as the temperature detector 629 shown in Fig. 6.
  • the controller is located within the wellbore tool along with the system for determining asphaltene onset pressure.
  • processes (i)-(x) can be performed within the wellbore tool.
  • the controller is located at the surface as part of the surface equipment (e.g., the truck 412 in Fig. 4) and some or all of processes (i)-(x) are performed at the surface by the surface equipment.
  • a first controller is included within the borehole tool and a second controller is located at the surface as part of the surface equipment.
  • the processes (i)- (x) can be split between the two controllers.
  • some of processes (i)-(x) are performed at a location that is remote from the well site, such as an office building or a laboratory.
  • the computer system may further include a memory such as a semiconductor memory device (e.g., a RAM, ROM, PROM, EEPROM, or Flash-Programmable RAM), a magnetic memory device (e.g., a diskette or fixed disk), an optical memory device (e.g., a CD-ROM), a PC card (e.g., PCMCIA card), or other memory device.
  • a semiconductor memory device e.g., a RAM, ROM, PROM, EEPROM, or Flash-Programmable RAM
  • a magnetic memory device e.g., a diskette or fixed disk
  • an optical memory device e.g., a CD-ROM
  • PC card e.g., PCMCIA card
  • the computer instructions may be distributed in any form as a removable storage medium with accompanying printed or electronic documentation (e.g., shrink wrapped software), preloaded with a computer system (e.g., on system ROM or fixed disk), or distributed from a server or electronic bulletin board over a communication system (e.g., the Internet or World Wide Web).
  • a removable storage medium with accompanying printed or electronic documentation (e.g., shrink wrapped software), preloaded with a computer system (e.g., on system ROM or fixed disk), or distributed from a server or electronic bulletin board over a communication system (e.g., the Internet or World Wide Web).
  • a communication system e.g., the Internet or World Wide Web
  • the controller may include discrete electronic components coupled to a printed circuit board, integrated circuitry (e.g., Application Specific Integrated Circuits (ASIC)), and/or programmable logic devices (e.g., a Field Programmable Gate Arrays (FPGA)). Any of the methods and processes described above can be implemented using such logic devices.
  • ASIC Application Specific Integrated Circuits
  • FPGA Field Programmable Gate Arrays
  • Illustrative embodiments of the present disclosure are not limited to wireline logging operations, such as the ones shown in Fig. 1 and 2.
  • the embodiments described herein can also be used with any suitable means of conveyance, such coiled tubing or drill pipe.
  • various embodiments of the present disclosure may also be applied in logging-while-drilling (LWD) operations, sampling-while-drilling operations, measuring- while-drilling operations, production logging operations, or any other operation where sampling of formation fluid is performed.
  • LWD logging-while-drilling
  • the methods and systems described herein are not limited to analyzing a set of particular fluids.
  • Various embodiments of methods and systems described herein can be used to analyze hydrocarbons (e.g., dark oils, heavy oils, volatile oils, and black oils).
  • the present disclosure introduces a method for determining asphaltene onset pressure of a formation fluid, the method comprising: (a) transmitting light through a sample of the formation fluid; (b) decreasing pressure of the formation fluid sample; (c) detecting intensity of the transmitted light during depressurization; (d) identifying a change in intensity of the transmitted light during depressurization representative of asphaltene flocculation; (e) increasing pressure of the formation fluid sample to a fixed pressure; (f) detecting intensity of the transmitted light at the fixed pressure; (g) repeating processes (a) to (f) for a plurality of different fixed pressures; and (h) determining the asphaltene onset pressure of the fluid sample using (i) the intensity of the transmitted light from each process (c) and (ii) the intensity of the transmitted light from each process (f).
  • the formation fluid sample may comprises a volume equal to or less than 1 mL.
  • Determining the asphaltene onset pressure of the fluid sample may comprise subtracting (i) the intensity of the transmitted light for process (f) at each different fixed pressure from (ii) the intensity of the transmitted light corresponding to the fixed pressure for each process (c) to determine difference values for each different fixed pressure.
  • the asphaltene onset pressure may be determined by identifying a difference value representing at least one of (i) a value of zero and (ii) a steady state value.
  • the asphaltene onset pressure may be determined by identifying a fixed pressure corresponding to the identified difference value.
  • the method for determining asphaltene onset pressure may comprise determining the intensity of the transmitted light at the fixed pressure by (i) allowing the intensity of the transmitted light to equilibrate at the fixed pressure and (ii) identifying the equilibrated intensity.
  • the method for determining asphaltene onset pressure may comprise determining the intensity of the transmitted light at the fixed pressure by extrapolating an equilibrated intensity of the transmitted light at the fixed pressure.
  • extrapolating the equilibrated intensity of the transmitted light may comprise applying an exponential fit to the intensity of the transmitted light at the fixed pressure.
  • the transmitted light may travel along a path length through the fluid sample that is less than 2 mm.
  • processes (c) and (f) may comprise detecting intensity of transmitted light at a first wavelength and a second wavelength.
  • Such method may comprise determining a wavelength dependent signal using (i) the intensity of the transmitted light at a first wavelength and (ii) the intensity of the transmitted light at a second wavelength.
  • Such method process (h) may comprise determining the asphaltene onset pressure of the formation fluid using (i) the wavelength dependent signal during each process (c) and (ii) the wavelength dependent signal during each process (f).
  • the present disclosure also introduces a system for determining asphaltene onset pressure of a formation fluid, the system comprising: a source for generating light that is transmitted through a sample of the formation fluid; a detector for detecting light transmitted through the formation fluid sample; a pressure control unit configured to vary pressure of the formation fluid sample; and a controller configured to determine the asphaltene onset pressure of the formation fluid using (i) intensity of the transmitted light detected during each depressurization of the formation fluid sample and (ii) intensity of the transmitted light at a plurality of fixed pressures.
  • the transmitted light may travel along a path length through the fluid sample that is less than 2 mm.
  • the system may be incorporated into a wellbore tool.
  • the wellbore tool may comprise: a probe for withdrawing the formation fluid sample from a formation and into the wellbore tool.
  • the system for determining asphaltene onset pressure may comprise a detection chamber for at least partially containing the fluid sample, wherein the detection chamber has a volume equal to or less than 1 mL.
  • the present disclosure also introduces a method for determining asphaltene onset pressure of a formation fluid, the method comprising: (a) transmitting light through a sample of the formation fluid; (b) decreasing pressure of the formation fluid sample; (c) detecting intensity of the transmitted light during depressurization; (d) identifying a change in intensity of the transmitted light during depressurization; (e) increasing pressure of the formation fluid sample to a fixed pressure; (f) detecting intensity of the transmitted light at the fixed pressure; (g) repeating processes (e) to (f) for a plurality of different fixed pressures; and (h) determining the asphaltene onset pressure of the fluid sample using (i) the intensity of the transmitted light during depressurization and (ii) the intensity of the transmitted light at each of the different fixed pressures.
  • the method for determining asphaltene onset pressure may comprise positioning a wellbore tool within a wellbore; drawing the formation fluid into the wellbore tool; and performing processes (a) to (g) within the wellbore tool.
  • processes (e) to (f) may be repeated for the same formation fluid sample.
  • the present disclosure also introduces a method for detecting asphaltene onset of a formation fluid, the method comprising: (a) transmitting light through a sample of the formation fluid; (b) detecting intensity of the transmitted light while decreasing pressure of the formation fluid sample; (c) detecting intensity of the transmitted light while increasing pressure of the formation fluid sample; and (d) detecting asphaltene onset within the sample by identifying a difference in intensity between transmitted light during process (b) and transmitted light during process (c).
  • an upper bound for asphaltene onset pressure may be determined by identifying a pressure at which the intensity of transmitted light during process (b) and the intensity of transmitted light during process (c) intersect.
  • the method for determining asphaltene onset pressure may comprise positioning a wellbore tool within a wellbore; drawing the formation fluid into the wellbore tool; and performing processes (a) to (c) within the wellbore tool.
  • various embodiments of the present disclosure are not limited to oil and gas field applications.
  • the methods and systems described herein can also be applied to, for example, petrochemical refining and chemical manufacturing.

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

La présente invention concerne des procédés et des systèmes pour la détermination de la pression de début de précipitation d'asphaltènes d'un fluide de formation. Le procédé comprend le positionnement d'un outil de puits de forage à l'intérieur d'un puits de forage et l'opération consistant à amener un échantillon de fluide de formation dans l'outil de puits de forage. Le procédé comprend en outre la transmission de lumière à travers l'échantillon et la détection de lumière qui est transmise à travers l'échantillon. La lumière est transmise au sein de l'échantillon sur une courte longueur de trajet inférieure à 2 mm. Tandis que la lumière est transmise, la pression de l'échantillon est amenée à varier. Un signal dépendant de la longueur d'onde est déterminé à l'aide de (i) l'intensité de la lumière transmise à une première longueur d'onde et (ii) l'intensité de la lumière transmise à une seconde longueur d'onde. La pression de début de précipitation d'asphaltènes de l'échantillon est déterminée par identification d'un changement dans le signal dépendant de la longueur d'onde à une pression particulière.
PCT/US2015/027476 2014-04-25 2015-04-24 Procédé et système pour la détermination de la pression de début de précipitation d'asphaltènes à l'aide d'un signal dépendant de la longueur d'onde WO2015164713A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US14/262,480 2014-04-25
US14/262,462 US20150309002A1 (en) 2014-04-25 2014-04-25 Method and system for determining asphaltene onset pressure using a wavelength dependent signal
US14/262,462 2014-04-25
US14/262,480 US9568459B2 (en) 2014-04-25 2014-04-25 Method and system for determining asphaltene onset pressure using a using depressurization and pressurization

Publications (1)

Publication Number Publication Date
WO2015164713A1 true WO2015164713A1 (fr) 2015-10-29

Family

ID=54333248

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2015/027476 WO2015164713A1 (fr) 2014-04-25 2015-04-24 Procédé et système pour la détermination de la pression de début de précipitation d'asphaltènes à l'aide d'un signal dépendant de la longueur d'onde

Country Status (1)

Country Link
WO (1) WO2015164713A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020322A1 (fr) * 1999-09-14 2001-03-22 Schlumberger Limited Procede et dispositif de determination de la pression de depart d'une precipitation d'asphaltene
US20020139929A1 (en) * 2001-01-29 2002-10-03 Mullins Oliver C. Methods and apparatus for determining precipitation onset pressure of asphaltenes
JP2007502432A (ja) * 2003-05-06 2007-02-08 ベイカー ヒューズ インコーポレイテッド 炭化水素試料の分析用の波長可変ダイオードレーザ分光計を用いる方法及び装置
US20100263442A1 (en) * 2009-04-17 2010-10-21 Kai Hsu Methods and apparatus for analyzing a downhole fluid
EP2315000A2 (fr) * 2009-10-20 2011-04-27 Schlumberger Technology B.V. Procédés et appareil permettant de déterminer les pressions à changement de phase

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001020322A1 (fr) * 1999-09-14 2001-03-22 Schlumberger Limited Procede et dispositif de determination de la pression de depart d'une precipitation d'asphaltene
US20020139929A1 (en) * 2001-01-29 2002-10-03 Mullins Oliver C. Methods and apparatus for determining precipitation onset pressure of asphaltenes
JP2007502432A (ja) * 2003-05-06 2007-02-08 ベイカー ヒューズ インコーポレイテッド 炭化水素試料の分析用の波長可変ダイオードレーザ分光計を用いる方法及び装置
US20100263442A1 (en) * 2009-04-17 2010-10-21 Kai Hsu Methods and apparatus for analyzing a downhole fluid
EP2315000A2 (fr) * 2009-10-20 2011-04-27 Schlumberger Technology B.V. Procédés et appareil permettant de déterminer les pressions à changement de phase

Similar Documents

Publication Publication Date Title
US8528396B2 (en) Phase separation detection in downhole fluid sampling
US6388251B1 (en) Optical probe for analysis of formation fluids
US7937223B2 (en) Downhole fluid analysis
US7705982B2 (en) Methods and apparatus for analyzing fluid properties of emulsions using fluorescence spectroscopy
US7826050B2 (en) System and method for dual path length optical analysis of fluids downhole
US11946370B2 (en) Method and system for determining asphaltene onset pressure
US20140110105A1 (en) Systems and Methods of Monitoring a Multiphase Fluid
US20140268156A1 (en) Method and system for determining bubble point pressure
NO20141097L (no) Forfinelse av signal ved optisk fluid-analyse
GB2462906A (en) Analyzing a downhole fluid by decreasing the density of a fluid sample
NO325811B1 (no) Fremgangsmate og anordning for a pavise duggutfelling i nedihulls formasjonsfluidprove
US9689858B2 (en) Method and apparatus for measuring asphaltene onset conditions and yields of crude oils
CN101984344A (zh) 地层岩性实时在线识别装置及其识别方法
US20150354345A1 (en) Methods and Systems for Analyzing Flow
US9568459B2 (en) Method and system for determining asphaltene onset pressure using a using depressurization and pressurization
US20150309002A1 (en) Method and system for determining asphaltene onset pressure using a wavelength dependent signal
WO2001020322A1 (fr) Procede et dispositif de determination de la pression de depart d'une precipitation d'asphaltene
US20220074303A1 (en) Determining reservoir fluid properties from downhole fluid analysis data using machine learning
RU2373523C2 (ru) Способ (варианты) и устройство для анализа свойств флюида эмульсий с использованием флуоресцентной спектроскопии
US20230313680A1 (en) Determination of downhole formation fluid contamination and certain component concentrations
GB2391939A (en) Method of analysing a formation fluid from a formation surrounding a wellbore having a borehole fluid
EP1604187B1 (fr) Procede et dispositif pour l'evaluation quantitative de methane en trou de forage, par spectroscopie dans l'infrarouge proche
WO2015164713A1 (fr) Procédé et système pour la détermination de la pression de début de précipitation d'asphaltènes à l'aide d'un signal dépendant de la longueur d'onde
US8717549B2 (en) Methods and apparatus to detect contaminants on a fluid sensor
WO2016072976A1 (fr) Détection de phase gazeuse de constituants d'un échantillon de fluide de fond de trou

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15782703

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15782703

Country of ref document: EP

Kind code of ref document: A1