Underground temperature and pressure gradient testing method

Abstract

The invention discloses a temperature and pressure gradient testing method, which comprises the following steps of: putting a testing device into a single-well shaft at a constant speed, pulling back the testing device when the testing device reaches a bottommost testing point, and ensuring that the testing device does not stop in the whole process, thereby solving the problem that the traditional steel wire pressure test needs to stop, and then obtaining testing data on the testing device. The testing device descends at a constant speed, so that the well depth data are easy to calculate, then a temperature and pressure data table is compiled according to the testing data and the well depth data, finally the temperature gradient and the pressure gradient are calculated according to the temperature and pressure data table, the whole process is simple and convenient, the testing time is shortened, and the testing efficiency is improved. And the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil well testing, and in particular to a method for testing downhole temperature and pressure gradient. Background Art

[0002] The recording of downhole temperature and pressure gradient data of oil and gas wells is generally obtained by wireline well testing. By inserting a high-precision thermometer and pressure gauge, the temperature and pressure values ​​in the wellbore at rest or in a flowing state can be accurately obtained. By establishing a relationship between the obtained temperature and pressure values ​​and the vertical depth, the temperature and pressure gradient can be obtained. The geothermal gradient can be used to study the characteristics of geological structures, and it also plays an important role in studying the formation and distribution of minerals. The pressure gradient reflects the degree of change in the vertical pressure of the formation. The value of the pressure gradient of the unused reservoir is mainly affected by the density of the formation liquid. The applied pressure gradient can be used to determine the oil (gas) water interface. The pressure gradient of the used reservoir can be used for the state of the fluid in the wellbore, the determination of the oil (gas) water interface, pressure conversion, etc., so it is particularly important to record accurate temperature and pressure data.

[0003] However, the commonly used test method at present requires staying at the designed depth of the oil and gas wellbore for 5 minutes or even longer to obtain temperature and pressure data during the wireline pressure test. This greatly increases the test time and restricts the efficiency of the temperature and pressure gradient test. Summary of the invention

[0004] The purpose of the present invention is to provide a downhole temperature and pressure gradient testing method to overcome the problem that in the prior art wireline pressure testing, it is necessary to stay at the designed depth of the oil or gas wellbore for 5 minutes or even longer to obtain temperature and pressure data, which greatly increases the testing time and restricts the efficiency of the temperature and pressure gradient test.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A downhole temperature and pressure gradient testing method, comprising:

[0007] The test device is placed into the wellbore of a single well at a uniform speed;

[0008] After the test device reaches the bottom test point, pull back the test device;

[0009] Obtain test data on the test device, and obtain the well depth data corresponding to each time point in combination with the lowering time;

[0010] Prepare temperature and pressure data tables based on test data and well depth data;

[0011] Calculate the temperature gradient and pressure gradient based on the temperature and pressure data table.

[0012] Preferably, the testing device comprises an electronic thermometer and a data storage device.

[0013] Preferably, the temperature and pressure data in the data storage device correspond one to one according to the release time.

[0014] Preferably, the testing device is lowered into the wellbore of a single well by means of a winch and a slickline.

[0015] Preferably, the pressure gradient is the increase in pressure per 100 meters of depth. For any well section i, the pressure gradient is:

[0016]

[0017] Among them, P i is the pressure value of the i-th well section, P i-1 is the pressure value of the i-1th well section, H i is the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

[0018] Preferably, the temperature gradient is the increase in pressure per 100 meters of depth. For any well section i, the temperature gradient is:

[0019]

[0020] Among them, T i is the pressure value of the i-th well section, T i-1 is the pressure value of the i-1th well section, H i is the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

[0021] Preferably, the method for obtaining well depth data is:

[0022] H

[0023] Among them, Hn is the well depth at point n, tn is the time taken by the test device to run to point n, and v is the running speed of the test device.

[0024] Preferably, a point is measured every 50 m from the wellhead to 300 m, a point is measured every 100 m from 300-1000 m, and a point is measured every 300 m from 1000 m to 6500 m.

[0025] Preferably, the test data on the test device is acquired by playback.

[0026] Preferably, the temperature and pressure data in the temperature and pressure data table correspond one-to-one to the well depth.

[0027] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a temperature and pressure gradient testing method, which involves placing a testing device into a single wellbore at a uniform speed, and pulling the testing device back when the testing device reaches the bottom test point. The testing device does not stop during the entire process, thus solving the problem that traditional steel wire pressure testing requires a stop. The test data on the testing device is then obtained, and the well depth data corresponding to each time point is obtained in combination with the lowering time. Because the testing device descends at a uniform speed, the well depth data is easy to calculate, and a temperature and pressure data table is compiled based on the test data and the well depth data. Finally, the temperature gradient and pressure gradient are calculated based on the temperature and pressure data table. The entire process is simple and convenient, which reduces the testing time and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a downhole temperature and pressure gradient testing method according to the present invention;

[0029] Figure 2 This is a schematic diagram of a vertical well according to an embodiment of the present invention;

[0030] Figure 3 A graph showing the change of temperature and pressure over time measured by the prior art;

[0031] Figure 4 A vertical well depth and temperature curve diagram measured by prior art;

[0032] Figure 5 A vertical well depth and pressure curve diagram measured by prior art;

[0033] Figure 6 The temperature and pressure measured by the present invention are changed with time curves;

[0034] Figure 7 A vertical well depth and temperature curve diagram measured by the present invention;

[0035] Figure 8 This is a vertical well depth and pressure curve measured by the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0039] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0040] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0041] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0043] like Figure 1 The present invention provides a method for testing downhole temperature and pressure gradient:

[0044] S101: placing the testing device into the wellbore of a single well at a uniform speed;

[0045] Specifically, the test device including an electronic temperature and pressure gauge and a data storage device is lowered into the wellbore of a single well at a uniform speed by using supporting equipment such as a winch and a steel wire;

[0046] S102: After the test device reaches the bottom test point, pull the test device back;

[0047] S103: Acquire test data on the test device, and match the time point with the well depth data in combination with the lowering time;

[0048] The temperature and pressure data of the playback test device are the temperature and pressure corresponding to the duration. The temperature and pressure data in the data storage device correspond to the release time one by one. The time is recorded as t1, t2, t3, t4...tn, the temperature data is T1, T2, T3, T4...Tn, the pressure data is P1, P2, P3, P4...Pn, and the temperature and pressure values ​​of each depth point are obtained according to the playback data combined with the time. Since this release is a uniform release, recorded as v, combined with the duration, the well depth corresponding to the duration point can be obtained H1, H2, H3, H4...Hn. The calculation formula for the well depth is:

[0049] H n

[0050] S104 compiles a temperature and pressure data table based on test data and well depth data;

[0051] The temperature and pressure data table is shown in Table 1.

[0052] Table 1 Temperature and pressure data

[0053] well deep Corresponding temperature Corresponding pressure H1 T1 P1 H2 T2 P2 H3 T3 P3 … … … <![CDATA[ H ]]> Tn <![CDATA[ Pn ]]>

[0054] S105: Calculate temperature gradient and pressure gradient based on temperature and pressure data table

[0055] Calculate the temperature and pressure gradient (temperature and pressure increase per 100 meters deep), that is, for any well section i, the pressure gradient is

[0056]

[0057] Among them, P i is the pressure value of the i-th well section, P i-1 is the pressure value of the i-1th well section, H i is the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

[0058] For any well section i, the temperature gradient is:

[0059]

[0060] Among them, T i is the pressure value of the i-th well section, T i-1 is the pressure value of the i-1th well section, H iis the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

[0061] Example:

[0062] Testing process:

[0063] 1. As Figure 2 As shown, Well A in a gas field is a vertical well with a depth of 7640m, a perforation section of 7540m-7624m, and a medium depth of 7582m. The test requirements designed according to the previous method are: measure a point every 50m from the wellhead to 300m, measure a point every 100m from 300-1000m, measure a point every 300m from 1000m to 6500m, and measure a point every 100m in the section below 6500m near the medium depth. The final test position is near 7624m. The test process speed is 40m / min, and each stop time is 6 minutes.

[0064] 2. Under this requirement, there are 44 test stop points, the instrument lowering speed is 40m / min, the instrument lifting speed is 50m / min, the final test depth is 7600m, and the calculation time T1 = number of measuring points × stop time + lowering time + lifting time = 44×6 + 7600 / 40 + 7600 / 50 = 606min.

[0065] 3. After adopting the technical solution of the present invention, no stop point is required, and the calculated time T2 = lowering time + lifting time = 7600 / 40 + 7600 / 50 = 342 minutes. The test time is shortened to 342 minutes.

[0066] Table 2 Comparison of the results of this technology and previous technologies in the test of Well A

[0067] project Time required for previous technology (testing only) Time required for this technology (testing only) Save time Stop 264 minutes (44 points) 0 minutes 264 Lowering and lifting the instrument 342 minutes 342 minutes 0 Duration 606 minutes 342 minutes 264

[0068] Data Results

[0069] Using the previous technology, the pressure gauge was taken out to play back the temperature and pressure data, and the curve of temperature and pressure changing with time was obtained, as shown in Figure 3 As shown in the figure, by identifying the step direct reading depth in the figure, the temperature and pressure data are sorted out.

[0070] Table 3 Temperature and pressure data measured by previous technology

[0071] well deep pressure temperature well deep pressure temperature 0 77 25 3700 90.431 59.57 50 77.195 27 4000 91.68 68.4 100 77.363 22 4300 93.469 76.11 150 77.555 15 4600 93.606 78.2 200 77.768 13 4900 94.689 82.81 250 77.91 7 5200 96.032 87.88 300 78.134 5.13 5500 97.57 94.6 400 78.54 7 5800 98.75 97.44 500 78.815 8.35 6100 99.265 101.87 600 79.31 10.62 6400 100.488 106.88 700 79.527 11.76 6500 100.79 108.55 800 79.912 13.92 6600 101.684 114.18 900 80.267 15.57 6700 101.857 112.56 1000 80.73 16.3 6800 102.16 113.56 1300 81.966 22.75 6900 102.875 117.99 1600 82.952 26.56 7000 102.9 117.6 1900 84.334 30.97 7100 103.128 120.7 2200 85.272 38.5 7200 103.424 120.96 2500 86.125 43.5 7300 104.083 121.91 2800 87.5 46.2 7400 104.158 127.28 3100 88.842 53.01 7500 104.825 129.75 3400 89.818 57.8 7600 105.424 128.44

[0072] Through the gradient table, the relationship curve between temperature and pressure and corresponding well depth is drawn, such as Figure 4 and Figure 5 As shown, according to the gradient calculation formula, the temperature gradient of Well A is calculated to be 1.71℃ / 100m and the pressure gradient is 0.37MPa / 100m.

[0073] Using this technology, take out the pressure gauge and play back the temperature and pressure data, and also get the curve of temperature and pressure changing with time, as shown in Figure 6 As shown in the figure, the difference is that the curve obtained by this technology is a smooth curve without steps. Since the test process is a uniform lowering process, the data is derived, the well depth is obtained based on the product of the duration and the lowering speed, and the temperature and pressure data are sorted out.

[0074] Table 4 Temperature and pressure data measured by the present invention

[0075] well deep pressure temperature well deep pressure temperature 0 77 25 3700 90.542 62.9 50 77.184 27 4000 91.8 69.2 100 77.367 22 4300 92.867 73.1 150 77.549 15 4600 94.02 79.12 200 77.734 13 4900 94.983 83.3 250 77.9175 7 5200 96.188 88.4 300 78.098 5.1 5500 97.405 94.6 400 78.472 6.84 5800 98.228 100.34 500 78.86 8.5 6100 99.631 103.7 600 79.232 10.38 6400 100.424 108.8 700 79.569 12.11 6500 101.115 111.8 800 79.92 13.84 6600 101.486 114.18 900 80.339 15.21 6700 101.589 113.23 1000 80.69 17.1 6800 102.16 116.28 1300 81.745 22.23 6900 102.599 119.37 1600 82.872 27.68 7000 102.69 119.7 1900 83.954 32.3 7100 102.915 119.99 2200 85.096 37.84 7200 103.28 123.12 2500 86.25 42.5 7300 104.083 124.1 2800 87.276 48.44 7400 104.306 128.02 3100 88.377 52.39 7500 104.75 128.25 3400 89.41 58.48 7600 104.74 130.72

[0076] Through the gradient table, the relationship curve between temperature and pressure and corresponding well depth is drawn, such as Figure 7 and Figure 8 shown.

[0077] According to the gradient calculation formula, the temperature gradient of Well A is calculated to be 1.70℃ / 100m and the pressure gradient is 0.37MPa / 100m.

[0078] Comparison of the two results:

[0079] Table 5 Comparison of temperature and pressure gradient results of two technologies

[0080]

[0081] Comparing the new technology with the original technical means, from the test process and final results of obtaining the temperature and pressure gradient of Well A, this technology takes a short time during the test, and the final results are not significantly different from the original technology that requires a stop point. It has the advantages of short cycle, low cost, and effectively reduces the labor intensity of operators on the well test site and reduces the workload of operating equipment. At the same time, it can obtain accurate and reliable temperature, pressure and gradient data.

[0082] Although the embodiments of the present invention are described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative and instructive, rather than restrictive. Under the guidance of the specification, a person skilled in the art can also make many forms without departing from the scope of protection of the claims of the present invention, all of which belong to the scope of protection of the present invention.

Claims

1. A downhole temperature and pressure gradient testing method, characterized in that: include: The test device is placed into the wellbore of a single well at a uniform speed; After the test device reaches the bottom test point, pull back the test device; Obtain the test data on the test device, and match the time point with the well depth data in combination with the lowering time; Prepare temperature and pressure data tables based on test data and well depth data; Calculate the temperature gradient and pressure gradient based on the temperature and pressure data table.

2. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The testing device comprises an electronic temperature and pressure gauge and a data storage device.

3. A downhole temperature and pressure gradient testing method according to claim 2, characterized in that: The temperature and pressure data in the data storage device correspond one to one according to the lowering time.

4. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The testing device is placed into the wellbore of a single well by means of a winch and a steel wire.

5. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The pressure gradient is the increase in pressure per 100 meters of depth. For any well section i, the pressure gradient is: Among them, P i is the pressure value of the i-th well section, P i-1 is the pressure value of the i-1th well section, H i is the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

6. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The temperature gradient is the increase in pressure per 100 meters of depth. For any well section i, the temperature gradient is: Among them, T i is the temperature value of the i-th well section, T i-1 is the temperature value of the i-1th well section, H i is the well depth value of the i-th well section, H i-1 is the well depth value of the i-1th well section.

7. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The method for obtaining the well depth data is: H n Among them, H n is the well depth at point n, t n is the time taken by the test device to run to point n, and v is the running speed of the test device.

8. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: A point is measured every 50m from the wellhead to 300m, a point is measured every 100m from 300-1000m, and a point is measured every 300m from 1000m to 6500m.

9. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: Acquire test data on the test device by playback.

10. A downhole temperature and pressure gradient testing method according to claim 1, characterized in that: The temperature and pressure data in the temperature and pressure data table correspond to the well depth one by one.

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