Cable logging mechanism and method for measuring fluid flow through underground temperature

Abstract

The invention discloses a cable logging mechanism and method for measuring fluid flow through underground temperature, the mechanism comprises a temperature heating and activating device, the bottom of the temperature heating and activating device is connected with a first length adjusting device, and the bottom of the first length adjusting device is connected with a first temperature detection device; the bottom of the first temperature detection device is connected with a second length adjusting device, and the bottom of the second length adjusting device is connected with a second temperature detection device. Wherein the first temperature detection device and the second temperature detection device are respectively used for detecting the temperatures of the fluid flowing at different positions in the well so as to obtain the flow of the fluid. Through non-mechanical measurement of the cable measurement mechanism, the time difference of the excited and heated fluid passing through different sensors is measured, so that the flow velocity of the fluid is obtained. Meanwhile, the cable measuring mechanism is low in requirement for the clean environment of a shaft, wide in applicable borehole size range and short in measuring time, static measurement is adopted by an instrument, disturbance to fluid in the shaft is small, and the interpretation method is simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole fluid flow measurement, and particularly relates to a cable logging mechanism and method for measuring downhole temperature and fluid flow rate. Background Art

[0002] At present, during the exploration and development of oil and gas fields, most companies use turbine rotor flowmeters for the flow velocity test of oil and gas wellbores. For example, Schlumberger, Sondex, etc. measure the flow velocity through different turbine rotors (such as full-size rotors, in-line rotors, umbrella-type integrated flowmeters, etc.). There are also a few companies that use other methods for measurement. For example, Schlumberger uses a gas holdup meter to calculate the gas flow velocity by measuring the time difference of the gas slug passing through two gas holdup meters. OpenField uses the Doppler effect to measure the fluid flow velocity, which is still in the R & D stage and has not been commercially applied.

[0003] Downhole fluid flow velocity measurement usually uses a turbine rotor flowmeter. After real-time downhole calibration and correction and interpretation, it reflects the fluid flow velocity. Due to the mechanical structure characteristics of the turbine rotor flowmeter, it is easily affected by downhole impurities, glue, debris, etc., resulting in abnormal rotation. Moreover, it has a high requirement for the clean environment of the wellbore. The downhole turbine rotor flowmeter has a certain starting threshold for speed. When measuring statically, it cannot measure the fluid velocity of low flow rates.

[0004] At the same time, the turbine rotor flowmeter has a high requirement for the cleanliness of the wellbore. When there is a certain amount of debris or impurities in the wellbore, these impurities will have a great impact on the normal rotation of the rotor. In severe cases, the rotor will stop rotating or even be physically damaged. In addition, the turbine rotor flowmeter has a starting speed threshold. When the relative velocity of the fluid is less than the starting threshold of the rotor, the rotor will not rotate, that is, the fluid with a small flow rate cannot drive the rotor to rotate. Moreover, the linear relationship between the rotational speed of the rotor and the fluid velocity is affected by the density and viscosity of the fluid, the mechanical characteristics of the rotor (such as different sizes, different manufacturers, different specifications, different lubrication degrees), etc. Multiple measurements (generally, more than three measurements with different speeds are required for both up and down) are needed. Through multiple measurement data, real-time downhole rotor calibration is carried out. The measurement process is complex, the measurement time is long, long-term stable production downhole is required, and pulling the instrument up and down has an impact on the fluid flow velocity. The relative measurement is complex and cumbersome.

[0005] There are also other methods for measuring fluid velocity, such as the gas velocity measurement method using a holdup probe. For example, Schlumberger measures the gas velocity by setting two gas holdup probes. The positions of the two probes are fixed in the instrument, that is, the distance between the two probes is fixed. The instrument calculates the gas velocity by measuring the time difference of the gas slug passing through the two probes. Its advantages are simple interpretation and calculation methods, low hardware requirements, and intuitive and reliable results. However, this method can only measure the gas velocity and cannot evaluate the liquid phase velocity, etc. Summary of the Invention

[0006] The object of the present invention is to solve the problems in the prior art, and provides a wireline logging mechanism and method for measuring fluid flow rate with downhole temperature.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] According to the first aspect of the present invention, there is provided a wireline logging mechanism for measuring fluid flow rate with downhole temperature, including: a temperature heating and activation device, a first length adjustment device is connected to the bottom of the temperature heating and activation device, and a first temperature detection device is connected to the bottom of the first length adjustment device;

[0009] A second length adjustment device is connected to the bottom of the first temperature detection device, and a second temperature detection device is connected to the bottom of the second length adjustment device;

[0010] Wherein, the first temperature detection device and the second temperature detection device are respectively used to detect the temperature of the fluid at different positions during the flow in the well, so as to obtain the flow rate of the fluid.

[0011] Furthermore, the temperature heating and activation device, the first length adjustment device, the first temperature detection device, the second length adjustment device and the second temperature detection device are all connected by quick connectors in sequence.

[0012] Furthermore, the temperature heating and activation device is a temperature heating and activation module.

[0013] Furthermore, the first length adjustment device is a first instrument extension rod.

[0014] Furthermore, the first temperature detection device is a first temperature sensor.

[0015] Furthermore, the second length adjustment device is a second instrument extension rod.

[0016] Furthermore, the second temperature detection device is a second temperature sensor.

[0017] Furthermore, the distance between the first temperature sensor and the temperature heating and activation module is 3m, and the distance between the second temperature sensor and the first temperature sensor is 1m.

[0018] According to a second aspect of the present invention, there is provided a method for measuring the flow rate of a fluid by downhole temperature measurement, which is carried out by using the cable logging mechanism described above, and includes:

[0019] Assemble the instrument;

[0020] Determine the working mode of the assembled instrument according to the measurement target;

[0021] Set the measurement period according to the working mode.

[0022] Further, the assembly of the instrument specifically includes: connecting and fixing the temperature heating and activation module, the first instrument extension rod, the first temperature sensor, the second instrument extension rod, and the second temperature sensor in sequence through quick connectors.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] By non-mechanical measurement of the cable measurement mechanism, the time difference of the activated and heated fluid passing through different sensors is measured, so as to obtain the flow rate of the fluid. At the same time, the cable measurement mechanism has low requirements for the wellbore cleaning environment, a wide applicable wellbore size range, short measurement time, the instrument adopts static measurement, has little disturbance to the fluid in the wellbore, and the interpretation method is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 Schematic assembly diagram of the cable logging mechanism for downhole temperature measurement of fluid flow rate provided by the present invention;

[0027] Figure 2 Schematic operation diagram of the cable logging mechanism for downhole temperature measurement of fluid flow rate provided by the present invention;

[0028] Figure 3 Schematic layout diagram of the perforation horizons of the method for downhole temperature measurement of fluid flow rate provided by the present invention;

[0029] Figure 4 Schematic flow diagram of the method for downhole temperature measurement of fluid flow rate provided by the present invention;

[0030] Wherein: 1. Temperature heating and activation module; 2. First instrument extension rod; 3. First temperature sensor; 4. Second instrument extension rod; 5. Second temperature sensor; 6. Telemetry gamma module; 7. Production well casing; 8. Completion string; 9. First perforation interval; 10. Second perforation interval; 11. Third perforation interval. Specific implementation manners

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. Components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

[0032] Therefore, the detailed description of the embodiments of the present invention provided in the drawings below is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] It should be noted that like reference numerals and letters denote like items in the following figures. Therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

[0034] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship when the product of the invention is normally placed. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, terms such as "first" and "second" are only used for distinguishing descriptions and cannot be construed as indicating or implying relative importance.

[0035] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0036] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly specified and limited, if the terms "set", "installed", "connected", "connected" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0037] The following further describes the present invention in detail with reference to the drawings:

[0038] The present invention provides a cable logging mechanism and method for measuring the flow rate of fluid by downhole temperature.

[0039] According to the first aspect of the embodiments of the present invention, a cable logging mechanism for measuring the flow rate of fluid by downhole temperature is provided, including a temperature heating and activation device. The bottom of the temperature heating and activation device is connected with a first length adjustment device, and the bottom of the first length adjustment device is connected with a first temperature detection device; the bottom of the first temperature detection device is connected with a second length adjustment device, and the bottom of the second length adjustment device is connected with a second temperature detection device; wherein, the first temperature detection device and the second temperature detection device are respectively used to detect the temperature of the fluid at different positions during the flow in the well, so as to obtain the flow rate of the fluid. Further, as Figure 1 shown, the temperature heating and activation device, the first length adjustment device, the first temperature detection device, the second length adjustment device and the second temperature detection device are all connected by quick connectors in sequence, and the quick connectors adopt the logging standard connectors produced by the Logging Company of PetroChina; in this embodiment, the temperature heating and activation device is the temperature heating and activation module 1, the first length adjustment device is the first instrument extension rod 2, the first temperature detection device is the first temperature sensor 3, the second length adjustment device is the second instrument extension rod 4, and the second temperature detection device is the second temperature sensor 5; wherein, the first instrument extension rod 2 and the first temperature sensor 3 are assembled into the first thermometer, the second instrument extension rod 4 and the second temperature sensor 5 form the second thermometer, and the distance between the first temperature sensor 3 and the temperature heating and activation module 1 is 3m, and the distance between the second temperature sensor 5 and the first temperature sensor 3 is 1m. Before measuring the fluid in the well, as Figure 2As shown in the figure, a telemetry gamma module 6, model Elog-05, is fixedly installed at the bottom of the second temperature sensor 5. After assembling all components on the ground, they are connected to the cable through a cable quick connector. On the one hand, the cable can be used for carrying, and on the other hand, it is connected to the surface acquisition system (IWAS multi-functional modular and complete redundant architecture design, including a programmable general power module, an integrated high-end acquisition and data recording processor for operating downhole instruments) and surface power supply (Elog-06) through the cable for power supply and data transmission. Specifically, the cable is an enhanced seven-core cable.

[0040] Lower the assembled cable logging mechanism into the target interval. After the cable logging mechanism reaches the downhole measurement position, the instrument is left stationary. Then, set the measurement mode in the surface acquisition system, and the logging data is transmitted to the surface acquisition system through the cable. During the measurement, a production profile test is carried out in a vertical oil-producing well. The purpose of the test is to measure the oil production profile and determine the oil production of each producing layer under a production regime, such as Figure 3 As shown in the figure, below the completion string 8 in the production well casing 7, from top to bottom are the first perforation interval 9, the second perforation interval 10, and the third perforation interval 11. The inner diameter of the downhole casing is 101 mm. The distance between the first perforation interval 9 and the second perforation interval 10 is 52 m, and the distance between the second perforation interval 10 and the third perforation interval 11 is 113 m.

[0041] In this embodiment, the specific measurement principle downhole is as follows: Start the high-power temperature heating and excitation module 1 through the cable, and intermittently heat the downhole flowing fluid in a wide-frequency long-pulse manner; when the excited and heated fluid passes through the first thermometer, the first thermometer can detect the pulse signal of the fluid temperature, for example, the fluctuation signal of the high-temperature or relatively low-temperature fluid temperature changing with time. Record the time of the high-temperature peak signal detected by the first thermometer as t1; when the excited and heated fluid passes through the second thermometer, the second thermometer can also detect the pulse signal of the well fluid temperature, such as the fluctuation signal of the high-temperature or relatively low-temperature fluid temperature changing with time. For example, a certain high-temperature peak signal detected by the first thermometer is detected by the second thermometer, and its time is recorded as t2. The flow velocity calculation formula of the downhole fluid is v = L2 / (t2 - t1). During the detection process, the signal-to-noise ratio of the acquired data can be optimized by optimizing the temperature excitation pulse time.

[0042] In a possible embodiment, as Figure 2 and Figure 3 shown, taking the downhole fluid target being oil as an example, in Figure 2In it, the flow direction of the oil fluid is: flowing from the temperature heating and intensifying module 1 to the telemetry gamma module 6; first, optimize the working mode of the temperature heating and intensifying module 1, set the operation mode of the temperature heating and intensifying module 1 to have a heating cycle of 10 seconds, a 10-second waiting intermittent pulse, and after cycling three periods, wait for 30 seconds. The acquisition software on the ground acquisition system records the heating pulse current in the time domain and the temperature readings of the first thermometer and the second thermometer in the time domain; finally, record each heating pulse and the readings of the two thermometers in the time domain, select the data with good signal-to-noise ratio, record the time t1 when the temperature on the first thermometer starts to rise and fluctuate, and then record the time t2 when the second thermometer records the same temperature rise and fluctuation. The measurement time of the third perforation layer 11 is t2 - t1 = 41.21 seconds, and then calculate the oil fluid velocity v = 1 / (t2 - t1) = 0.02427, with the unit m / s. The fluid flow rate is Q = πD2*v / 4 = 16.797m 3 / d; finally, repeat the operation mode of the three operation cycles and the measurement time of the third perforation layer 11, and calculate the total fluid flow rates of the first perforation layer 9 and the second perforation layer 10 to be 35.869m 3 / d and 24.172m 3 / d respectively. By calculating the production at the downhole temperature and pressure corresponding to each perforation layer: for the first perforation layer 9, it is 35.869 - 24.172 = 11.70m 3 / d, for the second perforation layer 10, it is 24.172 - 16.797 = 7.375m 3 / d, and for the third perforation layer 11, it is 16.797m 3 / d. The production of these three perforation layers is the production under the downhole temperature and pressure conditions; at the same time, this cable logging mechanism can also be applied in injection wells, and only need to reverse the temperature heating and intensifying module with the first thermometer and the second thermometer, and the measurement principle is the same as the principle of measuring oil fluid in this embodiment.

[0043] According to the second aspect of the embodiment of the present invention, a method for measuring the fluid flow rate at downhole temperature is provided. The method is carried out by using the cable logging mechanism as described above, as Figure 4 shown, including:

[0044] S101. Assemble the instrument; specifically, connect and fix the temperature heating and activation module 1, the first instrument extension rod 2, the first temperature sensor 3, the second instrument extension rod 4, and the second temperature sensor 5 in sequence using well logging quick connectors. Then, install the EILog-05 telemetry module at the bottom of the second temperature sensor 5, and optimize the lengths of the first instrument extension rod 2 and the second instrument extension rod 4 according to the heat conduction properties of the fluid to be measured in the wellbore. It should be noted that the first instrument extension rod 2 and the first temperature sensor 3 are assembled into the first thermometer, and the second instrument extension rod 4 and the second temperature sensor 5 form the second thermometer. Moreover, the distance between the first temperature sensor 3 and the temperature heating and activation module 1 is 3 m, and the distance between the second temperature sensor 5 and the first temperature sensor 3 is 1 m. Finally, the measurement method is designed as point measurement, and the point measurement position is 3 m above the perforation interval. A total of three point measurement positions are designed, namely the first perforation interval 9, the second perforation interval 10, and the third perforation interval 11. The inner diameter of the downhole casing is 101 mm, the distance between the first perforation interval 9 and the second perforation interval 10 is 52 m, and the distance between the second perforation interval 10 and the third perforation interval 11 is 113 m.

[0045] S102. Determine the working mode of the assembled instrument according to the measurement target; since the measurement target is oil fluid, the operation mode of the temperature heating and activation module 1 is set as one cycle every 10 seconds, with a 10-second waiting intermittent pulse mode.

[0046] S103. Set the measurement period according to the working mode; specifically, according to the set one cycle every 10 seconds with a 10-second waiting intermittent pulse mode, the measurement period is specifically set to three. After cycling three periods, wait for 30 seconds. The acquisition software on the ground acquisition system records the heating pulse current in the time domain and the temperature readings of the first thermometer and the second thermometer in the time domain. Finally, record the heating pulses and the readings of the two thermometers in the time domain, select the data with good signal-to-noise ratio, record the time t1 when the temperature on the first thermometer starts to rise and fluctuate, and the subsequent time t2 when the second thermometer records the same temperature rise and fluctuation. Calculate the production of the three perforation intervals based on the three measurement periods and the two times t1 and t2.

[0047] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cable logging mechanism for measuring fluid flow by downhole temperature, characterized in that, it includes: A temperature heating and activation device, the bottom of the temperature heating and activation device is connected with a first length adjustment device, and the bottom of the first length adjustment device is connected with a first temperature detection device; The bottom of the first temperature detection device is connected with a second length adjustment device, and the bottom of the second length adjustment device is connected with a second temperature detection device; Wherein, the first temperature detection device and the second temperature detection device are respectively used to detect the temperature of the fluid at different positions during the flow in the well, so as to obtain the flow rate of the fluid.

2. The cable logging mechanism according to claim 1, characterized in that, The temperature heating and activation device, the first length adjustment device, the first temperature detection device, the second length adjustment device and the second temperature detection device are all connected by quick connectors in sequence.

3. The cable logging mechanism according to claim 2, characterized in that, The temperature heating and activation device is a temperature heating and activation module (1).

4. The cable logging mechanism according to claim 2, characterized in that, The first length adjustment device is a first instrument extension rod (2).

5. The cable logging mechanism according to claim 2, characterized in that, The first temperature detection device is a first temperature sensor (3).

6. The cable logging mechanism according to claim 2, characterized in that, The second length adjustment device is a second instrument extension rod (4).

7. The cable logging mechanism according to claim 2, characterized in that, The second temperature detection device is a second temperature sensor (5).

8. The cable logging mechanism according to claim 2, characterized in that, The distance between the first temperature sensor (3) and the temperature heating and activation module (1) is 3m, and the distance between the second temperature sensor (5) and the first temperature sensor (3) is 1m.

9. A method for measuring fluid flow by downhole temperature, characterized in that, The method is carried out by using the cable logging mechanism according to any one of claims 1-8, and includes: Assembling the instrument; Determining the working mode of the assembled instrument according to the measurement target; Setting the measurement period according to the working mode.

10. The method according to claim 9, characterized in that, The assembling of the instrument specifically includes: connecting and fixing the temperature heating and activation module, the first instrument extension rod, the first temperature sensor, the second instrument extension rod and the second temperature sensor in sequence through quick connectors.

Images