CN108930534B - Correction method and device for formation temperature effect of nuclear magnetic resonance while drilling - Google Patents

Abstract

The invention provides a method and device for calibrating the influence of NMR formation temperature while drilling. The device comprises: a constant temperature and pressure box, a rock container and a drilling machine, wherein the rock container is located in the constant temperature and pressure box; the rock container A container for implanting N layers of artificial rocks made by imitating the surrounding rock of underground formations, and each layer of artificial rocks in the rock container is provided with at least one first temperature sensor; the length direction of the drill pipe of the drilling device is provided with At least one second temperature sensor. Therefore, the method and device for calibrating the influence of the NMR formation temperature while drilling provided by the present invention can measure the formation temperature in the radial direction of the rock formation.

Description

Correction method and device for formation temperature effect of nuclear magnetic resonance while drilling

technical field

The invention relates to oilfield drilling technology, in particular to a method and device for calibrating the influence of nuclear magnetic resonance formation temperature while drilling.

Background technique

In the process of oilfield exploration and development, the formation temperature plays an important role in the generation, migration and accumulation of oil and gas, and also has a non-negligible impact on the physical properties of oil, gas, water and rocks. Therefore, the study of formation temperature can solve many key problems in petroleum geological theory and oil and gas exploration and development.

In the prior art, the temperature of the underground formation is usually obtained through the well temperature logging (also known as thermal logging) curve, specifically: a logging instrument is installed on the drilling equipment. Temperature, according to the temperature measured by the logging tool, the actual temperature of the formation is obtained according to the following formula T=K(BHT-15)+15, where BHT represents the temperature measured by the logging tool, T represents the actual temperature of the formation, K is the correction coefficient, where K varies with different regions and has a close correlation with the geothermal gradient.

However, the downhole temperature measured by the logging tool through the above method is the temperature near the wellbore. However, since drilling fluid will be injected into the wellbore during the drilling process, the temperature of the drilling fluid will reduce the temperature of the formation around the wellbore, thus affecting the logging. The downhole temperature measured by the tool, in turn, leads to a decrease in the accuracy of the actual temperature obtained for the formation.

SUMMARY OF THE INVENTION

The invention provides a method and device for correcting the influence of NMR formation temperature while drilling, which is used to solve the problem that the downhole temperature measured by the logging instrument in the prior art is the temperature around the wellbore, and the formation temperature cannot be measured in the radial direction of the formation. technical issues.

A first aspect of the present invention is to provide a device for correcting the influence of NMR formation temperature while drilling, the device comprising: a constant temperature and constant pressure box, a rock container and a drilling machine, wherein the rock container is located in the constant temperature and pressure box; The rock container is a container for implanting N layers of artificial rock made by imitating the surrounding rock of the underground formation, and each layer of artificial rock in the rock container is provided with at least one first temperature sensor; the length of the drill pipe of the drilling device At least one second temperature sensor is provided in the direction.

The drill is used for drilling into the rock container from above the rock container.

The first temperature sensor is used for detecting the temperature of the artificial rock during the drilling process of the drilling machine.

The second temperature sensor is used for detecting the temperature of the wellbore drilled by the driller in the rock container during the drilling process of the driller.

Wherein, the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor are used to correct the actual temperature of the formation.

Optionally, the rock container is located in the center of the constant temperature and pressure box, and the rock container and the constant temperature and pressure box are not in contact with each other.

In a possible embodiment, the drill is used for drilling into the rock container from above the center of the rock container.

In a possible implementation manner, the constant temperature and pressure box includes a temperature compensation device, and the temperature compensation device is configured to perform temperature correction when the temperature of the constant temperature and pressure box is different from a preset temperature by a first preset value .

In a possible implementation manner, the constant temperature and pressure box includes a pressure compensation device, and the pressure compensation device is configured to perform pressure correction when the pressure of the constant temperature and pressure box is different from a preset pressure by a second preset value .

In a possible embodiment, the artificial rock of each layer has the lithologic properties of the rock of the corresponding layer of the downhole formation.

In a possible embodiment, the constant temperature and pressure box is cylindrical, and the rock container is cylindrical.

In a possible embodiment, the drill includes a drill bit and a drill pipe, wherein the drill pipe is a hollow cylindrical rod.

The cross-sectional area of the wellbore drilled by the drill bit is larger than the cross-sectional area of the drill pipe.

During the drilling process of the drill, drilling fluid is injected from the hollow cylindrical rod of the drill pipe, and passes through the gap between the wall of the wellbore drilled by the drill bit and the drill pipe backflow.

In a possible implementation manner, at least one first temperature sensor is provided in the radial direction of each layer of artificial rock of the rock container.

A second aspect of the present invention is to provide a method for calibrating the influence of NMR while drilling formation temperature, which is applied to the apparatus for calibrating the influence of NMR while drilling formation temperature according to the first aspect of the present invention.

The method includes:

for acquiring the first temperature detected by the first temperature sensor and the second temperature detected by the second temperature sensor during the drilling process of the drilling machine;

The first temperature is used as the simulated detection temperature of the formation, and the second temperature is used as the simulated detection temperature of the drilled wellbore. The corresponding relationship between the simulated detection temperature of and the simulated detection temperature of the borehole.

In a possible implementation manner, when actually drilling the formation, the actual temperature of the formation is determined according to the corresponding relationship and the actual detected temperature of the drilled wellbore.

In the method and device for calibrating the influence of NMR formation temperature while drilling provided by the present invention, by setting temperature sensors at different radial depths of the artificial rock layer, in the process of simulating drilling, not only can the simulated detection temperature of the wellbore be obtained, but also The simulated detection temperature of the stratum at different radial depths of the rock layer at the corresponding wellbore depth position, so that the corresponding relationship between the simulated detection temperature of the wellbore and the simulated detection temperature of the formation can be obtained. Since the temperature inside the rock layer is less affected by the temperature of the drilling fluid, in actual logging, according to the depth and temperature information of the wellbore obtained during actual logging, the temperature of the wellbore and the different diameters of the rock layer at the corresponding wellbore depth position To a certain extent, the temperature information of the formation can fully represent the real temperature information of the formation, and can be used to calculate the relevant formation parameters, which can improve the logging calculation to a certain extent. Accuracy of formation parameters.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of a complete simulated drilling device according to an embodiment of the present invention;

2 is a schematic cross-sectional view of the distribution of first temperature sensors in an artificial rock formation according to an embodiment of the present invention;

3 is a schematic structural diagram of a constant temperature and pressure box according to an embodiment of the present invention;

4 is a schematic diagram of a rock container according to an embodiment of the present invention;

5 is a cross-sectional view of a drill pipe and a wellbore according to an embodiment of the present invention;

FIG. 6 is a schematic flowchart of a method for correcting the influence of formation temperature by NMR while drilling provided by the present invention.

Symbol Description:

1: constant temperature and pressure box;

2: rock container;

3: Driller;

4: the first temperature sensor;

5: Drill pipe;

6: The gap between the drill pipe and the wall of the wellbore;

7: Wellbore.

Detailed ways

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. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Concepts used in this application and their explanations:

The simulated detection temperature of the formation: the temperature on the artificial rock layer measured by the device in the present application during simulated drilling.

Simulated detection temperature of the wellbore: the temperature in the wellbore measured by the device in the present application when drilling is simulated.

The actual detection temperature of the wellbore: In actual logging, the temperature in the wellbore measured by the temperature sensor on the logging tool.

Actual temperature of the formation: In actual logging, the temperature of the formation that cannot be measured by the temperature sensor on the logging tool.

In the prior art, the temperature of the underground formation is usually obtained through the well temperature logging (also known as thermal logging) curve. Specifically, a logging instrument is installed on the drilling equipment. When the drilling equipment is drilled into the formation, the logging instrument will measure the downhole Temperature, according to the temperature measured by the logging tool, the actual temperature of the formation is obtained according to the following formula T=K(BHT-15)+15, where BHT represents the temperature measured by the logging tool, T represents the actual temperature of the formation, K is the correction coefficient, where K varies with different regions and has a close correlation with the geothermal gradient.

However, the downhole temperature measured by the logging instrument through the above method is the temperature near the wellbore. However, during the drilling process, drilling fluid will be injected into the wellbore, and the temperature of the drilling fluid will reduce the temperature around the wellbore, thus affecting the logging instrument. The measured downhole temperature, in turn, leads to a decrease in the accuracy of the actual temperature obtained for the formation.

Considering the above problems, the present invention provides a correction device for the influence of NMR formation temperature while drilling. By setting a temperature sensor on the radial depth of each layer of artificial rock, the radial depth of the artificial rock in the simulated drilling process can be obtained. temperature information.

The technical solutions of the present invention will be described in detail below through specific embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

FIG. 1 is a schematic structural diagram of a complete simulated drilling device according to an embodiment of the present invention. As shown in FIG. 1 , the device for correcting the influence of NMR formation temperature while drilling provided by the present invention includes: a constant temperature and pressure chamber 1 , a rock container 2 and a drill 3 . The rock container 2 is located in the constant temperature and pressure box 1 .

During the simulated drilling process, it is necessary to ensure that the environment where the rock container 2 is located is consistent with the actual formation environment, so as to ensure the accuracy of the obtained temperature data. Therefore, the temperature and pressure set in the constant temperature and pressure box 1 are the location where the surrounding rock of the underground formation is located. Actual temperature and pressure in real formations.

In order to ensure that the temperature data obtained by the simulation device can more accurately reflect the real situation, the physical properties of a large number of rocks collected from the formation during actual drilling and well logging work can be studied, and artificially produced artificially similar to the surrounding rock of the underground formation. N-layer artificial rock with consistent rock properties, and the N-layer artificial rock is implanted in the rock container 2 . Meanwhile, each layer of artificial rock is provided with at least one first temperature sensor 4 (not shown in FIG. 1 ).

The drill 3 includes two parts, a drill bit and a drill pipe. The drill 3 is used to drill from above the rock container 2 toward the rock container 2 , and the drill bit on the drill 3 can be rotated at will, thereby changing the drilling direction of the drill 3 . Wherein, when making artificial rock, it is necessary to reserve a drilling path that the drilling machine 3 may pass through for the drilling machine 3, and the artificial core does not place the first temperature sensor 4 on the drilling path that the drilling machine 3 may pass through. At the same time, at least one second temperature sensor is provided along the length direction of the drill pipe of the drilling machine 3, and a pressure measuring instrument corresponding to each second temperature sensor is provided. Since different formation depths in the artificial rock correspond to different formation pressures, the pressure can be used to represent the formation depth, so that the depth information of the artificial rock where the temperature is measured by the second temperature sensor is obtained by using the pressure measuring instrument.

The first temperature sensor 4 is used to detect the temperature information of the artificial rock during the drilling process of the driller 3; the second temperature sensor is used to detect that the driller 3 is in the rock container during the drilling process of the driller 3 The temperature of the drilled wellbore.

The temperature detected by the first temperature sensor 4 and the temperature detected by the second temperature sensor are used to correct the actual temperature of the formation.

Optionally, in the device for correcting the influence of NMR formation temperature while drilling provided by the present invention, in order to ensure the stability of the temperature and pressure of the artificial rock in the rock container 2, when the rock container 2 is fixed inside the constant temperature and pressure box 1, The constant temperature and pressure box 1 and the rock container 2 are not in contact with each other.

In some embodiments of the present invention, a drilling rig is used to drill into the rock container 2 starting from above the center of the rock container 2 .

In some embodiments of the present invention, in order to ensure that the whole drilling process of the drilling device 3 can more accurately simulate the real drilling process, it is necessary to keep the temperature in the constant temperature and pressure box 1 and the real underground formation surrounding rock corresponding to the artificial rock. The temperature (ie, the preset temperature) is the same, so a temperature compensation device is provided in the constant temperature and pressure box 1 . The temperature compensation device is used to perform temperature correction when the temperature of the constant temperature and pressure box 1 differs from the preset temperature by a first preset value, that is, when the temperature in the constant temperature and pressure box 1 is higher or lower than the preset temperature, the first preset value When the temperature is equal to the value, the temperature compensation device adjusts the temperature in the constant temperature and pressure box 1 so that the difference between the adjusted temperature in the constant temperature and pressure box 1 and the preset temperature is within the first preset value. The application does not limit the size of the first preset value, for example, the first preset value may be 0.1 degrees Celsius, 0.2 degrees Celsius, and the specific size can be selected according to actual needs.

At the same time, the pressure in the constant temperature and pressure box 1 meets the same requirements as the pressure (ie preset pressure) of the real underground formation surrounding rock corresponding to the artificial rock, so the constant temperature and pressure box 1 is provided with a pressure compensation device. The pressure compensation device is used to perform temperature correction when the pressure of the constant temperature and pressure tank 1 is different from the preset pressure by the first preset value, that is, when the pressure in the constant temperature and pressure tank 1 is higher or lower than the preset pressure, the second preset value When the value is equal to or higher, the pressure compensation device adjusts the pressure in the constant temperature and pressure tank 1 so that the difference between the adjusted pressure in the constant temperature and pressure tank 1 and the preset pressure is within the second preset value. Wherein, the present application does not limit the size of the second preset value, for example, the second preset value may be 10pa, 15pa, and the specific size can be selected according to actual needs.

In some embodiments of the present invention, the artificial rock of each layer has the lithologic properties of the rock of the corresponding layer of the downhole formation. Since the artificial rock is artificially simulated according to the physical properties of the real stratum, the physical properties of the stratum rocks at different depths in the real stratum are different, so the artificial rock of each layer is made according to the rock physical properties of the corresponding layer of rock, which can make the artificial rock closer to reality. The petrophysical properties of the corresponding layer of rock in the formation can make the data obtained in the final simulated drilling more accurate. For example, in the direction from top to bottom of the real stratum, the order is rock layer a, rock layer b, rock layer c, rock layer d, etc., then in the direction from top to bottom, the rock container 2 is sequentially arranged with rocks with rock layer a The artificial rock with the characteristics of the rock layer b, the artificial rock with the rock characteristics of the rock layer c, the artificial rock with the rock characteristics of the rock layer d, and the like.

FIG. 2 is a schematic cross-sectional view of the distribution of first temperature sensors in the artificial rock formation according to an embodiment of the present invention. In an embodiment of the device for correcting the influence of NMR formation temperature while drilling provided by the present invention, as shown in FIG. 2 , at least one first temperature sensor 4 is provided in the radial direction of each layer of artificial rock in the rock container. Preferably, during the drilling process of the driller, due to the inflow of drilling fluid, for the same layer of artificial rock, the temperature change of the area on the artificial rock close to the wellbore will be more obvious than that of other areas, so in the same layer When installing the first temperature sensor 4 on the radial depth of the artificial rock, following the principle of taking the wellbore as the origin and extending radially upward, the installation density of the first temperature sensor 4 is gradually sparse in the radial depth of each layer of artificial rock.

FIG. 3 is a schematic structural diagram of a constant temperature and constant pressure box according to an embodiment of the present invention. As shown in FIG. 3 , in the device for correcting the influence of formation temperature by NMR while drilling, the shape of the constant temperature and constant pressure box 1 and 1 is a cylinder, for example, a rectangular parallelepiped or a cylinder.

FIG. 4 is a schematic diagram of a rock container according to an embodiment of the present invention. In the device for correcting the influence of formation temperature by nuclear magnetic resonance while drilling, the shape of the rock container 2 is a cylinder, for example, a rectangular parallelepiped or a cylinder. As shown in FIG. 4 , for the rock container 2, in order to ensure that the temperature difference measured by at least one first temperature sensor at the same radial depth from the center of the artificial rock on each layer of the artificial rock in the rock container 2 is Within the allowable error range, the rock container 2 is preferably cylindrical.

The drilling device 3 is made by reducing and processing according to the actual drilling equipment, and the drilling device 3 includes a drill bit and a drill pipe. Among them, the drill bit of the drilling device 3 is used to break up the rock in the formation and form a wellbore. The drill rod of the drilling device 3 is a hollow cylindrical rod, which is used to inject drilling fluid into the wellbore during the drilling process.

5 is a cross-sectional view of a drill pipe and a wellbore according to an embodiment of the present invention. As shown in FIG. 5 , the cross-sectional area of the drill pipe is smaller than the cross-sectional area of the wellbore 7 drilled by the drill bit of the drill 3. Therefore, between the drill pipe of the drill 3 and the well wall of the wellbore 7 drilled by the drill 3 There is a void 6. During the drilling process of the drilling device 3, the drilling fluid is injected from the hollow cylindrical rod 5 of the drill pipe, and flows back through the gap 6 between the well wall of the wellbore 7 and the drill pipe.

Specifically, during the drilling process of the driller 3, the drill bit of the driller 3 needs to break the rocks in the formation, so rock debris will be generated, and these rock debris will hinder the drill bit of the driller 3 from continuing to drill, so During the drilling process of the driller 3, drilling fluid needs to be injected to take out the rock debris. The drilling fluid is injected from the hollow cylindrical rod 5 of the drill pipe of the drilling device 3 to the drill bit of the drilling device 3, thereby entering the wellbore 7, and the drilling fluid will contain a large amount of rock debris. Since the pressure deeper in the formation is greater than the formation pressure above it, the drilling fluid in the wellbore 7 moves along the drill pipe of the driller 3 and the wellbore 7 drilled by the driller 3 under the action of the pressure difference. The space 6 between the walls flows out of the wellbore, and the rock debris also flows out with the drilling fluid to achieve the purpose of cleaning the wellbore. Among them, the drilling fluid can be clear water, drilling fluid, clay-free flushing fluid, emulsion, etc., which can be selected according to actual needs.

After the drilling fluid enters the wellbore 7, since the temperature of the drilling fluid is lower than the temperature of the artificial rock, the temperature of the drilling fluid will reduce the temperature of the formation around the wellbore 7, so the temperature measured by the second temperature sensor cannot truly reflect formation temperature. At the same time, although the drilling fluid will gradually intrude into the artificial rock along the radial direction, it will affect the radial temperature of the artificial rock. However, the drilling fluid does not invade into the artificial rock in large quantities, so the temperature inside the artificial rock is less affected by the temperature of the drilling fluid, so the temperature measured by the first temperature sensor placed radially on the artificial rock is closer to the actual formation temperature.

By using the correction device for the influence of the NMR formation temperature while drilling in the present invention, not only the temperature information on the radial depth of the artificial rock can be obtained, but also the dynamic temperature information on the radial depth of the artificial rock can be obtained, so as to provide information for the exploration and exploitation of the oil field. provide more accurate information.

Based on the above-mentioned correction device for the influence of NMR while drilling formation temperature, the method for calibrating the influence of formation temperature of NMR while drilling provided by the present invention will be described below.

FIG. 6 is a schematic flowchart of a method for correcting the influence of formation temperature by NMR while drilling provided by the present invention. As shown in Figure 6, the method includes:

S101. During the drilling process of the drilling machine, acquire a first temperature detected by the first temperature sensor and a second temperature detected by the second temperature sensor.

Specifically, when the driller 3 starts to work, the first temperature sensor 4 in each layer of the artificial rock in the rock container 2 and the second temperature sensor located on the drill pipe of the driller 3 are turned on. At the same time, the first temperature sensor 4 starts to measure the temperature information at different radial depths of the artificial rock, and transmits the temperature information to the computer; the second temperature sensor starts to measure the temperature information in the wellbore and transmits the temperature information to the computer.

During the drilling process of the driller 3, the first temperature sensors arranged on each layer of the artificial rock transmit the temperatures at different radial depths of the layer to the calculator in real time. Each second temperature sensor provided on the driller 3 transmits the temperature of the wellbore where it is located to the calculator. At the same time, the pressure measuring instrument detects the pressure at the position of the second temperature sensor in the wellbore and transmits it to the computer. The computer records the time the drill 3 reaches each layer of artificial rock.

For example, when the drill 3 reaches the artificial rock depth h ₀ , the computer records the time when the drill 3 reaches h ₀ , and the pressure measuring device on the drill 3 at h ₀ transmits the pressure information to the computer. The second temperature sensor of the driller 3 at h ₀ measures the temperature in the borehole at this time and transmits the temperature to the computer. At the same time, the first temperature sensor on the artificial rock layer corresponding to the depth h ₀ on the artificial rock measures the temperature at different radial depths of the layer, and transmits the temperature information to the computer.

When the drill 3 continues to drill downward, the second temperature sensor located in the length direction of the drill pipe of the drill 3 will reach h ₀ in sequence. When one of the second temperature sensors reaches h ₀ , the pressure side measuring instrument corresponding to the second temperature sensor will detect that the second temperature sensor reaches h ₀ , and the second temperature sensor measures h ₀ in the wellbore at this time. temperature and transfer it to the computer. In addition, due to the radial invasion of the artificial rock by the drilling fluid, the temperature at the radial depth of the artificial rock will also change. According to the degree of drilling fluid invasion, the temperature changes are also different. A temperature sensor 4 measures the temperature of the artificial rock at different radial depths in real time, and transmits it to the computer. At the same time, the time of drilling fluid intrusion on this layer of artificial rock is recorded in the computer.

Before step S101 , the method further includes: firstly, fixing the rock container 2 containing the artificial rock in the constant temperature and pressure box 1 with the set temperature and pressure, and then closing the constant temperature and pressure box 1 . The rock container 2 is placed in the constant temperature and pressure box 1 for a period of time, so that the internal and external temperature and pressure of the artificial rock are consistent, that is, consistent with the real formation temperature and pressure. Then, a small hole is opened on the constant temperature and constant pressure box 1 for the drilling device 3 to enter.

S102. The first temperature is used as the simulated detection temperature of the formation, and the second temperature is used as the simulated detection temperature of the wellbore. Correspondence between the simulated detection temperature and the simulated detection temperature of the wellbore.

Specifically, first, the first temperature on each layer of the artificial rock corresponding to different radial depths measured by the first temperature sensor collected by the computer, and the second temperature corresponding to different depths in the wellbore measured by the second temperature sensor are artificially processed. Filter, that is, delete the temperature data of the first temperature and the second temperature that have no value to the result. For example, the second temperature measured by the second temperature sensor that does not enter the wellbore when the driller 3 just starts drilling, when the temperature of the drilling fluid no longer affects the temperature of the wellbore and the first temperature measured after the artificial rock layer is radially raised in the greenhouse A temperature and a second temperature, etc.

Then, various data obtained by the computer are sorted, and the second temperature and the first temperature are sorted and classified according to the depth of the wellbore and the radial depth of the artificial rock layer corresponding to the depth of the wellbore.

Finally, under the condition of the same wellbore depth and the same radial depth on the artificial rock layer corresponding to the wellbore depth, a temperature correction chart is established according to the data obtained by the computer, wherein the temperature correction chart is a three-dimensional Cartesian coordinate system. Among them, the X-axis is the simulated detection temperature of the wellbore, that is, the second temperature. The Y-axis is the simulated detection temperature of the formation, that is, the first temperature, wherein, when there are at least two first temperature sensors at the same radial depth on each layer of artificial rock, the first temperature is all the first temperatures at the radial depth. The average value of the temperature measured by a temperature sensor. The Z axis represents time. When the drill 3 reaches a certain depth of artificial rock, the drilling fluid will affect the temperature in the wellbore at this depth, and as time changes, the drilling fluid will affect the temperature in the wellbore at this depth. The effect of temperature decreases gradually, that is, the X-axis and Z-axis represent the simulated detection temperature of the wellbore as a function of time. At the same time, the drilling fluid will invade along the radial direction on each layer of artificial rock, so the temperature of the drilling fluid will also affect the temperature at the radial depth of the artificial rock layer, and the degree of drilling fluid intrusion in the radial direction is different, which affects the The degree of change varies. At the same time, with the change of time, the influence of drilling fluid on the temperature at different radial depths gradually decreases, that is, the Y-axis and Z-axis represent the curves of the simulated detection temperature of the formation as a function of time. In this way, a temperature correction chart corresponding to the correspondence between the simulated detection temperature of the formation and the simulated detection temperature of the wellbore at any depth of the wellbore and the radial depth is obtained. At the same time, the relationship between the simulated detection temperature and time of the wellbore at any wellbore depth and the relationship between the simulated detection temperature and time of the formation at different radial depths can also be obtained through the temperature correction chart.

The method of this embodiment further includes: when actually drilling the formation, determining the actual temperature of the formation according to the corresponding relationship and the actual detected temperature of the wellbore. During actual drilling, the temperature measuring instrument cannot measure the temperature in the radial direction of the formation, and can only obtain the actual detection temperature of the wellbore. In addition, since the temperature of the wellbore is affected by the temperature of the drilling fluid, the actual detection temperature of the wellbore obtained is quite different from the actual temperature of the formation, so the actual detection temperature of the wellbore cannot be used to represent the actual temperature of the formation.

Therefore, during actual drilling, the actual detection temperature of the wellbore can be obtained, which corresponds to the simulated detection temperature of the wellbore on the temperature correction chart. Therefore, when the wellbore depth is determined, according to the actual detection temperature of the wellbore, the simulated detection temperature of the only formation corresponding to different radial depths can be obtained on the temperature correction chart. Since the temperature of the drilling fluid has little effect on the temperature in the radial direction of the formation, the simulated detection temperature of the formation obtained on the temperature correction chart can completely represent the actual temperature of the formation to a certain extent. At the same time, on the temperature correction chart, you can also see the time-varying law of the actual detection temperature of the wellbore, as well as the time-varying law of the actual temperature of the formation at different radial depths.

According to the actual measured temperature of the wellbore, the simulated detection temperature of the formation, which is very close to the actual temperature of the formation, can be obtained through the temperature correction chart. Using the detection temperature of the formation to calculate parameters such as formation porosity can improve the accuracy of the parameters. At the same time, the measuring instruments used during drilling are adjusted according to the detection temperature of the formation to improve the logging accuracy. According to the time-varying laws of the simulated detection temperature of the wellbore and the simulated detection temperature of the formation displayed on the temperature correction chart, more accurate logging information can be obtained, such as the relative permeability of oil and water, the fluid properties in the rock, etc. Provide more accurate information for oilfield survey and development.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. scope.

Claims (11)

1. A correction device for nuclear magnetic resonance while drilling formation temperature influence is characterized by comprising: the device comprises a constant temperature and constant pressure box, a rock container and a drilling rig, wherein the rock container is positioned in the constant temperature and constant pressure box; the rock container is a container implanted with N layers of artificial rocks manufactured by imitating surrounding rocks of underground strata, and each layer of artificial rocks of the rock container is internally provided with at least one first temperature sensor; at least one second temperature sensor is arranged in the length direction of a drill rod of the drilling rig; the temperature and the pressure set in the constant temperature and constant pressure box are the actual temperature and the actual pressure in the real stratum where the underground stratum surrounding rock is located;

The drill rig is used for drilling from above the rock container to the rock container;

The first temperature sensor is used for detecting the temperature of the artificial rock during the drilling process of the drilling machine;

The second temperature sensor is used for detecting the temperature of a borehole drilled by the drilling machine in the rock container during the drilling process of the drilling machine;

Wherein the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor are used to correct the actual temperature of the formation.

2. The apparatus of claim 1, wherein the rock container is located at the very center of the oven, and the rock container and the oven are not in contact with each other.

3. The apparatus of claim 1 or 2, wherein the drill is adapted to drill into the rock container from just above the centre of the rock container.

4. The device according to claim 1 or 2, wherein the constant temperature and pressure tank comprises a temperature compensation device for performing temperature correction when the temperature of the constant temperature and pressure tank differs from a preset temperature by a first preset value.

5. The device according to claim 1 or 2, wherein the constant temperature and pressure tank comprises a pressure compensation device for performing pressure correction when the pressure of the constant temperature and pressure tank is different from a preset pressure by a second preset value.

6. An apparatus according to claim 1 or 2, wherein the artificial rock of each layer has petrophysical properties of the rock of the corresponding layer of the downhole formation.

7. The apparatus of claim 1 or 2, wherein the thermostatted constant pressure tank is cylindrical and the rock container is cylindrical.

8. The apparatus of claim 1 or 2, wherein the drill comprises a drill bit, wherein the drill bit is a hollow cylindrical rod;

The cross-sectional area of the borehole drilled by the drill bit is larger than that of the drill rod;

During drilling of the drill string, drilling fluid is injected from within the hollow cylindrical shaft of the drill string and returns through a space between a wall of a borehole drilled by the drill bit and the drill string.

9. An apparatus according to claim 1 or 2, characterized in that at least one first temperature sensor is arranged in the radial direction of each layer of artificial rock of the rock container.

10. A method for correcting the influence of the temperature of a nuclear magnetic resonance formation while drilling, which is applied to the device for correcting the influence of the temperature of the nuclear magnetic resonance formation while drilling according to any one of claims 1 to 9;

The method comprises the following steps:

The temperature sensor is used for acquiring a first temperature detected by the first temperature sensor and a second temperature detected by the second temperature sensor during the drilling process of the drilling machine;

And determining the corresponding relation between the simulated detection temperature of the stratum and the simulated detection temperature of the borehole when the drilling rig drills into the stratum according to the first temperature and the second temperature.

11. The method of claim 10, further comprising:

And when the stratum is actually drilled, determining the actual temperature of the stratum according to the corresponding relation and the actual detection temperature of the drilled well hole.

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