Measuring rod and over-drill-bit measurement-while-drilling device thereof

Abstract

The invention discloses a measuring rod and an over-drill-bit measurement-while-drilling device, the measuring rod is provided with at least one expansion jacket along the radial direction, and the expansion jacket is used for forming a sealed space between the expansion jacket and the well bottom after expansion; the measuring rod is provided with a measuring cabin below the expansion jacket, and the measuring cabin is integrated with at least one sensor; a sampling assembly is arranged at the bottom of the measuring rod and used for sampling from the bottom of the well in the sealed space. Sealing in-situ measurement and well bottom sampling of an open hole well section below the drill bit are achieved, on one hand, in-situ measurement can be implemented in an underground sealed space to obtain more accurate stratum parameters, and on the other hand, automatic well bottom sampling can be achieved to facilitate analysis and processing of sampled samples in the later period.

Description

Technical Field

[0001] This invention relates to the field of drilling equipment technology, and in particular to a measuring rod and its through-bit measurement device. Background Technology

[0002] As an important component of uranium resources, sandstone uranium deposits hold an irreplaceable strategic position in the nuclear energy industry chain due to their low mining costs, large resource volume, and suitability for in-situ leaching mining.

[0003] In the mining of sandstone uranium deposits, logging technology is a core means to ensure efficient resource development, optimize mining plans, and reduce environmental risks. However, existing logging techniques suffer from several technical bottlenecks and shortcomings in practical applications, primarily in the accuracy of identifying low-grade uranium deposits, the precision of permeability assessment, and the real-time nature of dynamic monitoring during in-situ leaching. Through-bit logging is a commonly used data acquisition method. It involves transmitting a small-diameter logging instrument through a drill string, passing it through a special through-hole bit into the open hole, thus achieving rapid and efficient data acquisition. There are two methods for through-bit logging data acquisition: one is real-time transmission via a cable connected to the logging instrument, and the other is data reading from a storage port. However, this method places relatively high demands on the instrument's battery, requiring a power supply battery capable of providing power during continuous operation.

[0004] However, existing measurement technologies mounted on drill bit probes still have certain shortcomings in the detection of sandstone uranium deposits. For example, traditional gamma-ray technology is significantly affected by elements such as thorium and potassium, and its sensitivity to low-grade ore bodies with low uranium content is insufficient, leading to resource waste. Relying on indirect inversion models such as resistivity and acoustic wave analysis to calculate permeability results in a high error rate, failing to meet the precise design requirements for leaching fluid injection parameters. Furthermore, bottom hole sampling is limited by the drill bit scenario, making automated sampling difficult and requiring specialized sampling rods, which are complex in structure and cumbersome in operation. Therefore, designing and developing a drill bit-based measurement-while-drilling device and method to achieve in-situ measurement of important parameters such as uranium content and permeability, as well as bottom hole sampling, is of great significance for the efficient mining of uranium resources. Summary of the Invention

[0005] In view of this, the first aspect of the present invention discloses a measuring rod, wherein the measuring rod is provided with at least one expansion sleeve in the radial direction, the expansion sleeve being used to form a sealed space between itself and the bottom of the well after expansion; the measuring rod is provided with a measuring chamber below the expansion sleeve, the measuring chamber integrating at least one sensor; and a sampling component is constructed at the bottom of the measuring rod, the sampling component being used to sample from the bottom of the well within the sealed space.

[0006] In this invention, the measurement chamber integrates a neutron detection component, which is used to measure at least one formation parameter in the sealed space.

[0007] In this invention, the sampling assembly includes an upper cylinder, a lower cylinder, an elastic element, a first one-way switch, and a second one-way switch; the upper cylinder is radially fixedly connected to the bottom of the measuring rod; the lower cylinder is radially movably sleeved on the upper cylinder, and a compressible space is formed between the lower cylinder and the upper cylinder; the elastic element abuts radially between the upper cylinder and the lower cylinder; the first one-way switch is disposed at the bottom of the lower cylinder, and the first one-way switch allows fluid at the bottom of the well to enter the compressible space; the second one-way switch is disposed at the bottom of the upper cylinder, and the second one-way switch allows fluid in the compressible space to enter the measuring rod above the lower cylinder.

[0008] In this invention, the first one-way switch includes a first through hole disposed at the bottom of the upper cylinder and a cover plate covering the first through hole, wherein the cover plate is sealed and pressed against the first through hole by a first elastic telescopic member.

[0009] In this invention, the first one-way switch includes a first blocking ball and a first tapered through hole disposed at the bottom of the upper cylinder and tapering downwards; the first blocking ball blocks the first through hole from top to bottom.

[0010] In this invention, the diameter of the upper cylinder is less than or equal to the diameter of the measuring rod; the radial movement distance of the upper cylinder relative to the lower cylinder is determined according to the number of samples.

[0011] In this invention, the second one-way switch is constructed in the same way as the first one-way switch.

[0012] In this invention, the measuring rod is provided with an inflation hole inside the expansion jacket, and the measuring rod is provided with an inflation channel communicating with the inflation hole in the radial direction.

[0013] In this invention, the measuring rod includes an upper rod, an expansion joint, and a lower rod; the two ends of the expansion sleeve are respectively clamped between the expansion joint and the upper rod and the lower rod.

[0014] Furthermore, a second aspect of the present invention discloses a through-bit measurement device.

[0015] The measuring device includes a drill bit, a drill rod, and a measuring rod;

[0016] The drill pipe is connected to the drill bit; the measuring rod is deployed inside the drill pipe and can extend through the radial through hole of the drill bit along the drilling direction.

[0017] Compared with existing technologies, this invention enables in-situ sealed measurement and bottom hole sampling in the open hole section below the drill bit. On the one hand, it can carry out in-situ measurement in the sealed space downhole to obtain more accurate formation parameters. On the other hand, it can realize automatic sampling at the bottom of the well to facilitate the subsequent analysis and processing of the sampled samples.

[0018] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram of the measuring rod.

[0021] Figure 2 This is a schematic diagram of the expansion joint structure;

[0022] Figure 3 This is a schematic diagram of the sampling component.

[0023] Figure labels: 100, measuring rod; 200, expansion jacket; 300, measuring chamber; 400, sampling assembly; 110, upper rod; 120, expansion joint; 130, lower rod; 210, cylinder; 220, inflation pipe; 410, upper cylinder; 411, limiting baffle; 420, lower cylinder; 421, mesh cover; 422, support leg; 430, compression spring; 441, first one-way switch; 442, second one-way switch. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that in this application, "radial" specifically refers to the direction along the longitudinal axis of the drill pipe, "radial" is the horizontal direction perpendicular to the axis, and "drilling direction" is the positive direction in which the drill bit advances into the depth of the formation.

[0025] This invention discloses a measuring rod 100, which can be applied in drilling-while-drilling (DWD) scenarios. The measuring rod 100 overcomes the technical bottleneck of traditional DWD tools being limited to measurements inside the drill pipe, enabling sealed in-situ measurements and bottom hole sampling in the open hole section below the drill bit. On the one hand, it allows for in-situ measurements downhole to obtain more accurate formation parameters; on the other hand, it enables bottom hole sampling to facilitate subsequent analysis and processing of the sampled data.

[0026] Please refer to Figure 1 In this invention, the measuring rod 100 is radially provided with an expansion jacket 200, a measuring chamber 300, and a sampling assembly 400. The expansion jacket 200 is capable of circumferential expansion and forms a contact seal with the downhole sidewall, creating a sealed space between the expansion jacket 200, the downhole sidewall, and the well bottom. The measuring chamber 300 is located below the expansion jacket 200 and integrates multiple sensors to measure one or more formation data within the sealed space. Simultaneously, the sampling assembly 400 is located at the bottom of the measuring rod 100 and can sample liquids or solid-liquid mixtures at the well bottom within the sealed space.

[0027] Furthermore, Figure 1 The measuring rod 100 is shown to include an upper rod 110, an expansion joint 120, a lower rod 130, and a sampling assembly 400. The upper rod 110 has a standard threaded interface at its tip for connecting a transition rod section or external equipment. The upper rod 110, expansion joint 120, lower rod 130, and sampling assembly 400 are each constructed with a through radial bore. All the radial bores combine to form an internal channel.

[0028] In this invention, the expansion joint 120 comprises a titanium alloy cylinder 210 and an expansion jacket 200 surrounding the cylinder 210. The expansion jacket 200 is constructed from a mesh skeleton woven from titanium alloy wires and a neoprene rubber injection-molded sheath. A sealed cavity is formed between the cylinder 210 and the expansion jacket 200. The cylinder 210 has an inflation port communicating with an internal channel. The inflation port is connected to an external gas device via an inflation pipe 220 disposed in the internal channel. The external gas device inflates the space between the cylinder 210 and the expansion jacket 200 through the inflation pipe 220 and the inflation port. After inflation, the expansion jacket 200 expands circumferentially away from the cylinder 210 until it is in close contact with the downhole sidewall. External gas equipment can sense pressure changes within the inflation pipe 220. When the pressure increase rate within the inflation pipe 220 is detected to decrease significantly, it indicates that the expansion jacket 200 is in contact with the downhole sidewall. When the pressure increase rate within the inflation pipe 220 is detected to be too slow or stops, it indicates that the expansion jacket 200 is in close contact with the downhole sidewall and forms a seal.

[0029] Furthermore, Figure 2The expansion jacket 200 is shown as a cylinder open at both ends. The upper rod 110 and lower rod 130 have a central inner groove and a central outer groove with stepped cross-sections at their ends facing the cylindrical body. The end of the cylinder 210 facing the upper rod 110 and lower rod 130 is threaded to the central inner groove, and the outer periphery of the end is pressed against the inner wall of the central outer groove to achieve a compression seal and fixation of the expansion jacket 200.

[0030] Preferably, a sealing gasket is provided between the end of the cylinder 210 facing the connecting section and the central inner groove to enhance the sealing strength of the connection between the upper rod 110, the lower rod 130 and the expansion joint 120.

[0031] Furthermore, when the two ends of the expansion sleeve 200 are laterally clamped by the upper rod 110, the lower rod 130 and the cylinder 210, their ends bend towards the center line of the cylinder 210 and are longitudinally clamped between the upper rod 110, the lower rod 130 and the cylinder 210, forming a tighter contact surface. This also effectively disperses stress, prevents the clamped ends of the expansion sleeve 200 from shifting or being damaged under expansion, and improves the stability and reliability of the expansion sleeve 200.

[0032] Furthermore, the lower rod 130 integrates a measurement chamber 300, which is equipped with a neutron detection assembly. The neutron detection assembly includes a neutron generator, a neutron detector, and a gamma detector. The neutron generator emits a neutron beam. The neutron detector and the neutron generator are radially spaced (preferably with a spacing of approximately 150 mm). A neutron signal filter (such as a cadmium / boron screen) can be installed at the front end of the neutron detector to selectively absorb fast neutrons and hyperthermal neutrons, primarily detecting thermal neutrons. A neutron signal amplifier can also be integrated to amplify the thermal neutron count signal to a recognizable threshold. The gamma detector is used to detect gamma rays and preferably integrates a multi-channel pulse amplitude analyzer capable of identifying and stripping characteristic gamma spectral peaks of elements such as uranium, thorium, and potassium. Simultaneously, the measurement chamber integrates processing circuitry. The processing circuitry controls the sensor operation (e.g., controlling the neutron generator emission, setting the detector sampling interval to ≤10 cm), and collects and stores raw data from the neutron detector and gamma detector (such as thermal neutron count rate, gamma spectrum, temperature, etc.). Furthermore, the processing circuitry can perform real-time or post-processing on the acquired raw data. For example, it can calculate neutron porosity (φ_N) using the thermal neutron count rate; and use gamma-ray spectral data, combined with neutron porosity (φ_N), to invert the formation uranium content (U) and C using a neutron-gamma multivariate regression model. U =a·R γ +b·φ N +c retrieves the uranium content, where GR is the gamma count rate, and a, b, c are regression coefficients obtained through experimental calibration; stores the calculated formation parameters (such as permeability K, porosity φ, uranium content U, etc.).

[0033] Furthermore, the stored raw data can be retrieved from the measuring rod after drilling is completed and read by an external computer via an interface. The internal sensors of the measuring cabin can be arranged in a radially layered layout to optimize space utilization and signal acquisition.

[0034] Preferably, the measurement chamber is encapsulated within a cylindrical shell that is resistant to high pressure (≥70MPa) and high temperature (≥150℃), and the various sensors and their arrays are integrated inside. The sensors in the measurement chamber can be arranged in a radially layered layout.

[0035] Furthermore, Figure 3 The sampling assembly 400 of the present invention includes an upper cylinder 410, a lower cylinder 420, a compression spring 430, a first one-way switch 441, and a second one-way switch 442. The upper cylinder 410 and the lower rod 130 are connected radially by threads. The second one-way switch 442 is located at the bottom center of the upper cylinder 410. The lower cylinder 420 is located below the upper cylinder 410 and is radially movable and sleeved with the upper cylinder 410, forming a compressible space between the lower cylinder 420 and the upper cylinder 410 that changes according to the relative distance between the upper cylinder 410 and the lower cylinder 420. The first one-way switch 441 is located at the bottom center of the lower cylinder 420. A compression spring 430 capable of radial elastic expansion and contraction is disposed within the compressible space. In its initial state, the compression spring 430 maintains the upper cylinder 410 and the lower cylinder 420 at a maximum radial separation. The first one-way switch 441 allows fluid (liquid or solid-liquid mixture) to flow unidirectionally from the compressible space into the internal channel of the measuring rod 100 above the inner cylinder when a pressure difference exists. The second one-way switch 442 allows fluid (liquid or solid-liquid mixture) to flow unidirectionally from the bottom of the well into the compressible space when a pressure difference exists. Therefore, during the process of the measuring rod 100 contacting the bottom of the well, the lower cylinder 420 contacts the bottom of the well first, the upper cylinder 410 continues to move downward, the compression spring 430 is gradually compressed, the compressible space shrinks radially and generates high pressure, the first one-way switch 441 opens under the high pressure of the compressible space, and the original gas in the compressible space enters the internal space or channel of the measuring rod 100 through the first one-way switch 441 until the high pressure of the compressible space is eliminated, and the first one-way switch 441 closes. During the process of removing the measuring rod 100, under the combined action of the compression spring 430 and the weight of the lower cylinder 420, the lower cylinder 420 and the upper cylinder 410 gradually move away from each other, the compressible space gradually expands and generates negative pressure, the second one-way switch 442 opens under the negative pressure of the compressible space, and at least part of the fluid (liquid or solid-liquid mixture) at the bottom of the well is drawn into the compressible space until the negative pressure of the compressible space is eliminated, and the second one-way switch 442 closes.

[0036] Based on this, in this invention, when the measuring rod 100 passes through the drill bit into the open hole section and reaches the bottom of the well, the lower cylinder 420 first contacts the bottom of the well. Under the action of the measuring rod 100 and its own gravity, the upper cylinder 410 moves downward relative to compress the compression spring 430, compressing the compressible space and forming a high-pressure environment. The gas or liquid originally present in the compressible space enters the internal channel of the measuring rod 100 through the first one-way switch 441, at which point the high-pressure environment in the compressible space is released. At this time, the external gas equipment inflates the expansion jacket 200 and seals it with the downhole sidewall to form a sealed space. The integrated sensor in the measuring chamber 300 measures the formation parameters within this sealed space. Subsequently, the inflation of the expansion jacket 200 is released, the measuring rod 100 finishes measurement and is lifted back into the drill bit. During the lifting of the measuring rod 100, the upper cylinder 410 moves upward relative to the compression spring 430, releasing the compression of the compression spring, thus expanding the compressible space and creating a negative pressure environment. The liquid or solid-liquid mixture that was originally present at the bottom of the well enters the compressible space from the bottom of the well through the second one-way switch 442 and is stored there. At this time, the fluid in the compressible space will be taken out for sampling from downhole along with the measuring rod 100.

[0037] Furthermore, this invention can achieve multiple cumulative bottom hole samplings by repeatedly raising and lowering the measuring rod 100. Each time the measuring rod 100 is raised and lowered, the gas, liquid, or solid-liquid mixture at the bottom of the well enters the compressible space, and the gas, liquid, or solid-liquid mixture in the original compressible space enters the internal channel of the measuring rod 100, thereby improving sampling efficiency.

[0038] Furthermore, the lower cylinder 420 is provided with at least two limiting baffles 411 on the outer periphery of the end near the lower rod 130. The limiting baffles 411 can contact the upper end of the lower cylinder 420 when the upper cylinder 410 moves radially relative to each other, so as to limit the relative radial movement distance between the upper cylinder 410 and the lower cylinder 420.

[0039] Furthermore, the bottom of the lower cylinder 420 includes a mesh cover 421 and several support legs 422. The bottom of the mesh cover 421 is sealed, and several sample inlet holes are provided laterally to prevent solid objects such as sand at the bottom of the well from blocking the second one-way switch 442. The support legs 422 are used to support the lower cylinder 420 and protect the mesh cover 421, preventing the mesh cover 421 from being damaged by radial compression.

[0040] Preferably, the first one-way switch 441 includes a first blocking ball and a first tapered through hole disposed at the bottom of the upper cylinder 410 and tapering downwards. The first blocking ball blocks the first through hole from top to bottom. The second one-way switch 442 has the same structure as the first one-way switch 441. Therefore, the first one-way switch 441 and the second one-way switch 442 are activated only when the lower pressure is greater than the upper pressure.

[0041] In some embodiments, the first one-way switch 441 includes a first through hole disposed at the bottom of the upper cylinder 410 and a cover plate covering the first through hole, the cover plate being sealed and pressed against the first through hole by a first elastic telescopic member.

[0042] Preferably, the diameter of the upper cylinder 410 is less than or equal to the diameter of the measuring rod 100; the radial movement distance of the upper cylinder 410 relative to the lower cylinder 420 is determined according to the sampling quantity requirements.

[0043] Furthermore, this invention discloses a through-bit measurement-while-drilling device. The through-bit measurement-while-drilling device includes a drill bit, a drill rod, and a measuring rod 100. The drill rod is connected to the drill bit; the measuring rod 100 can extend through a radial through-hole of the drill bit along the drilling direction.

[0044] Furthermore, the measurement-while-drilling device of this invention also includes a plug rod and a core rod. The plug rod is installed inside the drill pipe and drills synchronously with the drill string assembly of the drill pipe and drill bit during drilling. The plug rod can maintain the closure of the axial through hole of the drill bit during drilling. The combination of the core rod with the drill pipe and drill bit enables the function of a core drilling rig. During drilling, the core rod is installed inside the drill pipe and cooperates with the drill bit and its axial through hole to complete the core sampling operation during drilling. It is worth mentioning that the plug rod, core rod, drill pipe and drill bit and other components of the measurement device of this invention and their installation relationship can directly use existing technology, such as the outer tube and inner tube assembly of the S75 wireline coring drill. The dimensions of the existing components only need to ensure that the measuring rod 100 can pass unobstructed through the inside of the drill pipe and the axial through hole of the drill bit into the open hole section.

[0045] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A measuring rod, characterized in that, The measuring rod is provided with at least one expansion sleeve in the radial direction, and the expansion sleeve is used to form a sealed space between itself and the bottom of the well after expansion; The measuring rod is provided with a measuring chamber below the expansion jacket, and the measuring chamber integrates at least one sensor; The bottom of the measuring rod is equipped with a sampling component for sampling from the bottom of the well within a sealed space.

2. The measuring rod according to claim 1, characterized in that, The measurement chamber integrates a neutron detection component, which is used to measure at least one formation parameter in the sealed space.

3. The measuring rod according to claim 1, characterized in that, The sampling assembly includes an upper cylinder, a lower cylinder, an elastic element, a first one-way switch, and a second one-way switch; The upper cylinder is fixedly connected to the bottom of the measuring rod radially; The lower cylinder is radially movably sleeved onto the upper cylinder, and a compressible space is formed between the lower cylinder and the upper cylinder; The elastic element abuts radially between the upper cylinder and the lower cylinder; The first one-way switch is located at the bottom of the lower cylinder, and the first one-way switch allows fluid at the bottom of the well to enter the compressible space; The second one-way switch is located at the bottom of the upper cylinder, and the second one-way switch allows fluid in the compressible space to enter the measuring rod above the lower cylinder.

4. The measuring rod according to claim 3, characterized in that, The first one-way switch includes a first through hole disposed at the bottom of the upper cylinder and a cover plate covering the first through hole. The cover plate is sealed and pressed against the first through hole by a first elastic telescopic member.

5. The measuring rod according to claim 3, characterized in that, The first one-way switch includes a first blocking ball and a first tapered through hole disposed at the bottom of the upper cylinder and tapering downwards; The first sealing ball blocks the first through hole from top to bottom.

6. The measuring rod according to claim 3, characterized in that, The diameter of the upper cylinder is less than or equal to the diameter of the measuring rod; The radial movement distance of the upper cylinder relative to the lower cylinder is determined by the number of samples.

7. The measuring rod according to claim 3, characterized in that, The second one-way switch has the same construction as the first one-way switch.

8. The measuring rod according to claim 1, characterized in that, The measuring rod has an inflation hole inside the expansion jacket, and the measuring rod has an inflation channel in the radial direction that communicates with the inflation hole.

9. The measuring rod according to claim 1, characterized in that, The measuring rod includes an upper rod, an expansion joint, and a lower rod; The two ends of the expansion sleeve are respectively clamped between the expansion joint and the upper rod and the lower rod.

10. A drilling-while-drilling measurement device, characterized in that, The measuring device includes a drill bit, a drill rod, and a measuring rod as described in any one of claims 1 to 9; The drill pipe is connected to the drill bit; the measuring rod is deployed inside the drill pipe and can extend through the radial through hole of the drill bit along the drilling direction.

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