Salt cavern gas storage shaft capable of performing leak detection
By using CCFET comprehensive well logging instruments and tracer detection technology in the salt hole gas storage wellbore, the problem of inaccurate judgment of leakage points in the existing technology is solved, and the precise positioning of leakage points in the wellbore is achieved and the leakage channel is achieved. The detection of the leak plugging operation has increased the success rate.
Patent Information
- Application Number
- CN202323557862.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-26
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2033-12-26
AI Technical Summary
The prior art cannot accurately determine the leakage point location and leakage channel where the sealing of the salt hole gas storage wellbore is unqualified, which affects the success rate of leakage plugging operations.
A system including a wellbore and a CCFET integrated logging instrument was designed. By dividing the wellbore into an inner ring and an outer ring, and setting a ventilation device on the outer ring, the CCFET integrated logging instrument is used to detect the radial gas content of the outer ring, and combining neutrons. Well logging, electromagnetic flaw detection scanning and tracer detection to accurately locate leakage points and leakage channels.
The accurate positioning of leakage points in the wellbore and the detection of leakage channels is achieved, and the success rate and accuracy of leakage plugging operations are improved.
Smart Images
Figure CN222166454U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of salt cavern gas storage wells, in particular to a salt cavern gas storage well capable of leak detection. Background Art
[0002] At present, in order to ensure the sealing of salt cavern gas storage, sealing tests are carried out according to SY / T 7644 "Technical Specifications for Sealing Test of Wellbore and Salt Caverns of Salt Cavern Gas Storage". This test method can determine the sealing of salt caverns and wellbore, but for wells with unqualified sealing, it cannot accurately determine the location of the leak and the leakage channel, and cannot provide accurate data support for on-site plugging operations.
[0003] Therefore, when plugging operations are required in existing wells, the analysis of airtight pressure test data based on existing methods can only roughly determine the possible leakage location, but cannot accurately determine the leakage point location and leakage channel. In the plugging design, it is impossible to determine the plugging method, select the plugging materials and construction technology, etc., which affects the success rate of plugging. Utility Model Content
[0004] The utility model aims at the problem of inaccurate judgment of leakage points in a well in the prior art and provides a salt cavern gas storage wellbore capable of performing leakage detection.
[0005] The utility model provides a technical solution to the above-mentioned technical problems as follows: a salt cavern gas storage wellbore capable of leak detection, comprising a wellbore and a CCFET comprehensive logging instrument, wherein a hollow test pipe string is provided in the middle of the wellbore, the test pipe string is fixed to the top of the wellbore, the test pipe string divides the internal space of the wellbore into an inner ring in the test pipe string and an outer ring between the test pipe string and the wellbore, the bottoms of the inner ring and the outer ring are connected, the outer ring is connected to a ventilation device, brine is provided at the bottom of the wellbore, the CCFET comprehensive logging instrument can be extended into the wellbore and can move in a vertical direction, a first detector is provided in the CCFET comprehensive logging instrument, and the first detector can be used to detect radial gas leakage points of the outer ring.
[0006] The beneficial effect of the utility model is that the wellbore is divided into an inner ring and an outer ring, and the outer ring is connected with a ventilation device, so that air can be ventilated toward the outer ring through the ventilation device, so that more brine in the wellbore can enter the inner ring and the range to be detected in the outer ring is filled with gas. At this time, the CCFET comprehensive logging instrument can be moved for detection to detect the gas content within the radial range of the outer ring to obtain the gas saturation of the corresponding position, thereby judging whether there is a gas leakage and determining and finding the leakage point in the well.
[0007] On the basis of the above technical solution, the present invention can also be improved as follows.
[0008] Further, the first detector is a neutron logging tool.
[0009] The beneficial effect of adopting the above further scheme is that the neutron logging instrument is a neutron-neutron logging (NNK), which can simultaneously record two neutron curves with different source distances when used, and is used to calculate porosity and determine gas aggregate well sections.
[0010] Furthermore, the upper end of the CCFET integrated logging instrument is connected with a logging cable, and is movably extended into the wellbore through the logging cable.
[0011] The beneficial effect of adopting the above further solution is that the CCFET comprehensive logging instrument is connected and turned on through the logging cable, which has good stability and strong reliability.
[0012] Further, the CCFET integrated logging instrument is located within the inner circle.
[0013] The beneficial effect of adopting the above further solution is that the CCFET comprehensive logging instrument is located in the middle of the wellbore, which facilitates the detection of various radial positions.
[0014] Furthermore, at least three circles of casing are radially arranged on the outer edge of the wellbore, and an electromagnetic flaw detection scanning logging instrument is arranged in the CCFET comprehensive logging instrument.
[0015] The beneficial effect of adopting the above further solution is that the electromagnetic flaw detection scanning logging instrument can detect whether the casing has deformation, holes and corrosion, so as to determine whether the leakage is caused by damage to the casing string.
[0016] Furthermore, a cement filling layer is provided on the outer periphery of each casing; three circles of casing are provided outside the wellbore and are divided into a guide tube, a surface casing and a production casing from the outside to the inside, and the guide tube, the surface casing and the production casing are coaxially arranged.
[0017] The beneficial effect of adopting the above further solution is that the electromagnetic flaw detection scanning logging instrument can simultaneously detect the annular cement filling layer to obtain the cement filling situation and determine whether there is a leakage point in the cement layer.
[0018] Furthermore, the tops of the inner ring and the outer ring are respectively connected to a first pressure gauge and a second pressure gauge.
[0019] The beneficial effect of adopting the above further solution is that the air pressure of the outer ring can be detected by the first pressure gauge, and the hydraulic pressure of the inner ring can be detected by the second pressure gauge, so as to assist in judging the leakage condition.
[0020] Furthermore, the gas introduced by the ventilation device is nitrogen.
[0021] The beneficial effect of adopting the above further scheme is that the nitrogen has good stability.
[0022] Furthermore, a tracer is mixed in the nitrogen and an atmospheric sampler is provided on the top outer side of the wellbore.
[0023] The beneficial effect of adopting the above further scheme is that the atmosphere sampler can sample the atmosphere from the top of the wellbore, and then detect it through an ultra-high resolution mass spectrometer to determine whether the tracer is detected, thereby determining whether there is a leak at the top of the wellbore.
[0024] Furthermore, the tracer is SF6.
[0025] The beneficial effect of adopting the above further solution is that it facilitates auxiliary detection. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a schematic diagram of a wellbore of a salt cavern gas storage reservoir capable of leak detection according to the utility model;
[0027] Figure 2 The utility model is a schematic diagram of the detachable part of the wellbore of the salt cavern gas storage reservoir capable of leak detection.
[0028] In the accompanying drawings, the components represented by the reference numerals are listed as follows:
[0029] 1. CCFET integrated logging instrument; 2. Test pipe column; 3. Inner ring; 4. Outer ring; 5. Brine; 6. Logging cable; 7. Conduit; 8. Surface casing; 9. Production casing; 10. First pressure gauge; 11. Second pressure gauge; 12. First gate valve; 13. Second gate valve; 14. Cement filling layer. DETAILED DESCRIPTION
[0030] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0031] Example 1
[0032] like Figure 1 A salt cavern gas storage wellbore capable of leak detection comprises a wellbore and a CCFET comprehensive logging instrument 1, a hollow test pipe string 2 is provided in the middle of the wellbore, the test pipe string 2 is fixed to the top of the wellbore, the test pipe string 2 divides the internal space of the wellbore into an inner ring 3 in the test pipe string 2 and an outer ring 4 between the test pipe string 2 and the wellbore, the bottoms of the inner ring 3 and the outer ring 4 are connected, the outer ring 4 is connected to a ventilation device, brine 5 is provided at the bottom of the wellbore, the CCFET comprehensive logging instrument 1 can be extended into the wellbore and can move in a vertical direction, a first detector is provided in the CCFET comprehensive logging instrument 1, and the first detector can be used to detect gas leakage points radially of the outer ring 4.
[0033] The beneficial effect of this embodiment is that by dividing the wellbore into an inner circle 3 and an outer circle 4, and the outer circle 4 is connected with a ventilation device, air can be ventilated into the outer circle 4 through the ventilation device, so that more brine 5 in the wellbore can enter the inner circle 3 and the range to be detected in the outer circle 4 is filled with gas. At this time, the movable CCFET integrated logging instrument 1 can be used for detection to detect the gas content within the radial range of the outer circle 4 to obtain the gas saturation at the corresponding position, thereby judging whether there is a gas leakage and determining and finding the leakage point in the well.
[0034] Based on the above embodiment, if the gas saturation is greater than 0, it is considered that there is a gas leak at that location.
[0035] Example 2
[0036] Preferably, based on Example 1, the first detector is a neutron logging instrument.
[0037] The beneficial effect of adopting the preferred solution in the above embodiment is that the neutron logging tool is a neutron-neutron logging (NNK) tool, which can simultaneously record two neutron curves with different source distances for calculating porosity and determining gas aggregate sections.
[0038] Example 3
[0039] Preferably, on the basis of Embodiment 1-2, the upper end of the CCFET integrated logging instrument 1 is connected to a logging cable 6, and can be movably extended into the wellbore through the logging cable 6.
[0040] The beneficial effect of adopting the preferred solution in the above embodiment is that the CCFET integrated logging instrument 1 is connected and turned on through the logging cable 6, which has good stability and strong reliability.
[0041] On the basis of the above embodiment, the CCFET integrated logging instrument 1 is connected by a logging cable 6 and lowered into the wellbore. A blowout preventer and a blowout preventer are installed at the wellhead. In the logging state, the blowout preventer is opened, and the dynamic sealing device on the upper part of the blowout preventer allows the cable to pass up and down, so that the high-pressure gas in the well will not escape. The movement of the CCFET in the wellbore can be controlled by lifting and lowering the logging winch.
[0042] Example 4
[0043] Preferably, based on embodiments 1-3, the CCFET integrated logging instrument 1 is located in the inner circle 3 .
[0044] The beneficial effect of adopting the preferred solution in the above embodiment is that the CCFET comprehensive logging instrument 1 is located in the middle of the wellbore, which facilitates the detection of various radial positions.
[0045] Example 5
[0046] Preferably, on the basis of embodiments 1-4, at least three circles of casing are radially arranged on the outer side of the wellbore, and an electromagnetic flaw detection scanning logging instrument is arranged inside the CCFET comprehensive logging instrument 1.
[0047] The beneficial effect of adopting the preferred solution in the above embodiment is that the electromagnetic flaw detection scanning logging instrument can detect whether the casing has deformation, holes and corrosion, so as to determine whether the leakage is caused by damage to the casing string.
[0048] Example 6
[0049] Preferably, on the basis of Example 5, a cement filling layer 14 is provided on the outer periphery of each casing; three circles of casing are provided outside the wellbore and are divided into a guide tube 7, a surface casing 8 and a production casing 9 from the outside to the inside, and the guide tube 7, the surface casing 8 and the production casing 9 are coaxially arranged.
[0050] The beneficial effect of adopting the preferred solution in the above embodiment is that the electromagnetic flaw detection scanning logging instrument can simultaneously detect the annular cement filling layer 14 to obtain the cement filling situation and determine whether there is a leakage point in the cement layer.
[0051] Example 7
[0052] Preferably, on the basis of embodiments 1-6, the tops of the inner ring 3 and the outer ring 4 are respectively connected to a first pressure gauge 10 and a second pressure gauge 11 .
[0053] The beneficial effect of adopting the preferred solution in the above embodiment is that the air pressure of the outer ring 4 can be detected by the first pressure gauge 10, and the hydraulic pressure of the inner ring 3 can be detected by the second pressure gauge 11, so as to assist in judging the leakage condition.
[0054] On the basis of the above embodiment, a first gate valve 12 is provided between the first pressure gauge 10 and the wellbore; one end of the second pressure gauge 11 is connected to the top of the wellbore, and the other end is connected to a second gate valve 13 .
[0055] Example 8
[0056] Preferably, based on Examples 1-7, the gas introduced into the ventilation device is nitrogen.
[0057] The beneficial effect of adopting the preferred solution in the above embodiment is that the nitrogen has good stability.
[0058] Example 9
[0059] Preferably, based on Example 8, a tracer is mixed in the nitrogen, and an atmospheric sampler is provided on the outside of the top of the wellbore.
[0060] The beneficial effect of adopting the preferred scheme in the above embodiment is that the atmospheric sampler can sample the atmosphere from the top of the wellbore, and then detect it through an ultra-high resolution mass spectrometer to determine whether the tracer is detected, thereby determining whether there is a leak at the top of the wellbore.
[0061] Example 10
[0062] Preferably, based on Example 9, the tracer is SF6.
[0063] The beneficial effect of adopting the preferred solution in the above embodiment is that it facilitates auxiliary detection.
[0064] After nitrogen is introduced, the direction of the gas flow can be divided into two situations: 1. No leakage, the gas is confined in a space and will not flow; 2. If there is a leakage, the gas will flow along the leakage channel.
[0065] The leak detection method is: inject high-pressure nitrogen mixed with a certain amount of tracer into the outer ring 4, and then observe the changes of the first pressure gauge 10 and the second pressure gauge 11 within 24 hours. If the change trend of the two gradually tends to zero, and the change of the gas-liquid interface does not exceed 1m, the gas seal is determined to be qualified; if one of the two judgment conditions is not met, there is a leak. At this time, the CCFET instrument can be used to detect the gas saturation in the cement sheath. If the test result shows that there is gas in the cement sheath, it means that there is a leakage channel in the cement sheath; if there is no gas in the cement sheath, then the gas leaks through the formation; at this time, with the detection of the tracer, it can be determined whether the underground gas has leaked to the ground. If the tracer result detected on the ground is higher than the background value, it means that it has leaked to the ground; otherwise, there is no leakage.
[0066] The reason for setting a "1m" allowable value is that the allowable value of 1m is required according to the provisions of SY / T 7644-2021 "Technical Specifications for Sealing Test of Wellbore and Salt Caverns of Salt Cavern Gas Storage". Considering that the brine 5 is in direct contact with the open hole section, the formation has a certain permeability. Under the action of pressure, a small part of the brine 5 will enter the formation. The standard stipulates that if the drop does not exceed 1m, the sealing of the formation is considered to be qualified.
[0067] Among them, the "background value" is the "base value". Before the tracer test was carried out in this area, other wells may have used this tracer, or there may be a small amount of leakage when the tracer was filled into the detection medium nitrogen, so there will be a certain concentration of tracer in the nearby air. This concentration is the "background value". Before the airtightness test, the tracer concentration in the air should be determined, and a reasonable tracer concentration should be selected for testing based on this value to make a distinction.
[0068] like Figure 1 and Figure 2 After the measurement is completed, the CCFET integrated logging instrument 1 and the logging cable 6 are taken out and the logging is completed; wherein, the CCFET integrated logging instrument 1 and the logging cable 6 can be reused for the measurement of multiple wells.
[0069] The CCFET comprehensive logging instrument 1 is in the shape of a long strip and may have a plurality of logging short sections. Each logging short section has a corresponding detection radius, and thus needs to be moved in the test string 2. The parameters of the corresponding position can be obtained by moving to any position.
[0070] When detecting tracers, the principle is as follows: underground gas storage micro-leakage monitoring technology is to adsorb and enrich gas tracers from the surface atmosphere, and adsorb and enrich gas tracers from the surface facilities of the cavity of the adjacent underground salt cavern gas storage, and then use low-temperature freezing online adsorption technology, large-volume low-temperature freezing enrichment direct sampling technology and ultra-high accuracy gas tracer detection technology to detect gas tracers. The detection limit of this method is 2.5×10 -16 L / L. The technical process adopted in this application is: collecting surface air through an atmospheric sampler, using a molecular sieve adsorption column; using online gas thermal desorption technology, using a self-developed multi-atmosphere pyrolysis / thermal desorption furnace; using large-volume low-temperature frozen enrichment injection technology, and performing detection and analysis through an ultra-high resolution mass spectrometer.
[0071] When testing the cement ring of the cement filling layer 14, the position of the CCFET comprehensive logging instrument 1 is not fixed. To detect the cementing quality of a certain well section, the instrument needs to move within the well section. Perform pipe string testing and obtain the MID-S&T curve to perform cementing diagnosis and calculate the density of multiple layers of cement outside the pipe and the cement stone filling rate. When testing the casing damage, just like testing the cement filling layer 14, the CCFET comprehensive logging instrument 1 moves in the vertical direction and uses the electromagnetic flaw detection scanning logging MID-S to check the casing damage and wall thickness corrosion.
[0072] The CCFET comprehensive logging tool 1 is a combined instrument. The full name of CCFET in English is Casing Cement Formation Evaluation Tool.
[0073] The wellbore of the present application has multiple layers of casing, and the relationship between the casing and the cement ring is: the casing depth is different in each drilling, and as the number of drillings increases, the size of the casing becomes smaller and the depth of the casing becomes deeper; the cement ring is the cement stone formed by the solidification of cement slurry after cementing. If it is in the overlapping casing section, the cement ring is between the casing, but if it is in the open hole section, the cement ring is between the casing and the formation.
[0074] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0075] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0076] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0077] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.
[0079] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.
Claims
1. A salt cavern gas storage wellbore capable of leak detection, characterized in that: The invention comprises a wellbore and a CCFET integrated logging instrument (1), wherein a hollow test pipe string (2) is provided in the middle of the wellbore, wherein the test pipe string (2) is fixed to the top of the wellbore, wherein the test pipe string (2) divides the internal space of the wellbore into an inner ring (3) within the test pipe string (2) and an outer ring (4) between the test pipe string (2) and the wellbore, wherein the bottoms of the inner ring (3) and the outer ring (4) are connected, wherein the outer ring (4) is connected to a ventilation device, wherein the CCFET integrated logging instrument (1) can be extended into the wellbore and can be moved in a vertical direction, wherein a first detector is provided inside the CCFET integrated logging instrument (1), wherein the first detector is used to detect a radial gas leakage point of the outer ring (4).
2. The leak-detectable salt cavern gas storage wellbore according to claim 1, characterized in that: The first detector is a neutron logging tool.
3. The leak-detectable salt cavern gas storage wellbore according to claim 1, characterized in that: The upper end of the CCFET integrated logging instrument (1) is connected to a logging cable (6), and can be movably extended into the wellbore through the logging cable (6).
4. The leak-detectable salt cavern gas storage wellbore according to claim 1, characterized in that: The CCFET integrated logging instrument (1) is located inside the inner circle (3).
5. The leak-detectable salt cavern gas storage wellbore according to claim 1, characterized in that: At least three circles of casing are radially arranged outside the wellbore, and an electromagnetic flaw detection scanning logging instrument is arranged inside the CCFET comprehensive logging instrument (1).
6. The leak-detectable salt cavern gas storage wellbore according to claim 5, characterized in that: A cement filling layer (14) is provided on the outer periphery of each casing space; three circles of casing are provided outside the wellbore and are divided into a guide tube (7), a surface casing (8) and a production casing (9) from the outside to the inside; the guide tube (7), the surface casing (8) and the production casing (9) are coaxially arranged.
7. The leak-detectable salt cavern gas storage wellbore according to claim 1, characterized in that: The tops of the inner ring (3) and the outer ring (4) are respectively connected to a first pressure gauge (10) and a second pressure gauge (11).
8. The leak-detectable salt cavern gas storage wellbore according to any one of claims 1 to 7, characterized in that: The gas introduced into the ventilation device is nitrogen.
9. The leak-detectable salt cavern gas storage wellbore according to claim 8, characterized in that: The nitrogen is mixed with a tracer, and an atmospheric sampler is arranged on the outside of the top of the wellbore.
10. The leak-detectable salt cavern gas storage wellbore according to claim 9, characterized in that: The tracer is SF6.