Survey device for geological survey sampling

Abstract

A surveying device for geological surveying sampling comprises a closed sampling device, a sampling drill rod and a directional drilling mechanism. The closed sampling device adopts a modular design and a double-barrel single-action structure, when the closed sampling device is filled with coal samples, a rubber ball is conveyed to the bottom of a hole by utilizing static pressure water, after the rubber ball reaches the bottom of the hole, the pump pressure is increased, a push rod fixing pin of the closed sampling device is cut off, a push rod moves downwards to drive a shearing closed ball valve to cut off the coal samples, and the coal samples are sealed in sampling barrels; the rapid sealing of the sampled coal sample is realized; a sampling drilling main hole is formed in a coal seam bottom plate, construction branch holes enter a coal seam for sampling, hole sections in the coal seam extend little, the hole forming rate of the hole sections in the coal seam can be increased, in-hole complex conditions such as hole collapse, hole spraying and drill jamming are avoided, and the drilling sampling depth is remarkably increased.

Description

Technical Field

[0001] This invention belongs to the field of exploration equipment technology, and specifically relates to a geological exploration and sampling device. Background Technology

[0002] Geological exploration refers to the investigation and research activities that use various means and methods to explore and detect geology, determine suitable bearing strata, determine the foundation type based on the bearing capacity of the bearing strata, and calculate foundation parameters. It is the investigation and research work that discovers industrially significant mineral deposits during mineral prospecting, in order to ascertain the quality and quantity of minerals, as well as the technical conditions for mining and utilization, and to provide the mineral reserves and geological data required for mine construction design. It involves investigating and researching the geological conditions of rocks, strata, structures, minerals, hydrology, geomorphology, etc. in a certain area. Usually, when conducting geological exploration, surveying equipment is often used to conduct topographic surveys and land surveys.

[0003] Currently, conventional rotary drilling is mainly used for sampling boreholes in coal mines, employing direct methods such as borehole cuttings sampling, casing sampling, and wireline sampling. Borehole cuttings sampling uses a sample container to receive coal slag returned from the borehole to obtain coal samples. Yang Changguang et al., through field tests, concluded that this method is simple and easy to implement. Casing sampling uses casing drilling; after drilling to a predetermined depth, coal samples are obtained through the casing. Ren Haoyang et al., through field application analysis, concluded that this method is suitable for drilling upwards along or across layers, but not for downward drilling. Wireline sampling utilizes a core sampler; a retrieval tool is used to remove the core sample from the borehole to obtain coal samples. Chen Gongsheng developed a ø98 mm wireline core sampling device for underground use, achieving a sampling rate of over 80%.

[0004] Existing sampling technologies meet the basic requirements for sampling in soft and fractured coal seams to a certain extent, but the following problems exist in their application: shallow sampling depth. In underground coal mines, static pressure air from underground pipelines is generally used as the flushing medium. The air supply pressure is low, the slag removal capacity is limited, and the drilling depth is shallow. Existing directional drilling technology for medium-hard coal seams uses water as the flushing medium. When drilling directional holes in soft and fractured coal seams along the coal seam, the disturbance to the borehole wall is large, which easily leads to complex borehole situations such as blowouts, borehole collapses, and stuck drill bits. The drilling depth is also limited, and it is impossible to drill long-distance holes along soft and fractured coal seams. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a geological survey sampling device, comprising: a sealed sampling device, a sampling drill rod, and a directional drilling mechanism; The sealed sampling device adopts a modular design and a double-cylinder single-action structure. When the sealed sampling device is filled with coal sample, the rubber ball is delivered to the bottom of the hole using static pressure water. After the rubber ball reaches the bottom of the hole, the pump pressure increases, shearing the push rod fixing pin of the sealed sampling device. The push rod moves down and drives the shearing sealed ball valve to cut off the coal sample and seal the coal sample in the sampling cylinder, thus achieving rapid sealing of the coal sample. The sampling drill rod adopts a large-diameter spiral drill rod, and the drill rod joint is designed with a large through hole structure to ensure that the rubber ball can pass through smoothly, so as to meet the requirements of closed sampling. The directional drilling mechanism includes a casing section and a directional drilling section. The casing section is enlarged to a set size and the casing is lowered. The drilling trajectory is controlled to be a set distance from the coal floor and extended along the coal mining face. The branch holes are constructed using a forward branching method, with a maximum of 4 branch holes. The two deepest branch holes are used for sealed coring.

[0006] Furthermore, rotary drilling technology is used for casing section construction. After construction, the casing is installed and the hole is cemented. Then, directional drilling technology is used for directional section construction. The directional drilling tool assembly consists of: directional drill bit, hydraulic screw drill bit, lower non-magnetic drill rod, probe outer tube, drilling measurement device probe tube, upper non-magnetic, integral spiral drilling measurement drill rod, and water supply device. Based on the data from multiple coal-bearing points encountered when the branch hole encounters the coal seam, the coal seam undulation prediction and borehole trajectory design are adjusted to allow the borehole to extend better along the coal seam undulation in the floor.

[0007] Furthermore, before encountering non-core coal seams, fractured and narrow-diameter rock strata, the borehole inclination angle is actively increased to reduce the extension length of the borehole trajectory in unstable strata.

[0008] Furthermore, during sampling drilling, the main drilling parameters are controlled within the range of 50~80 r / min rotation speed, 0.2~0.3 m / min sampling drilling speed, and 1.2~1.5 m drilling depth; the flushing fluid is provided by the downhole static pressure water pipeline.

[0009] The beneficial effects of this invention include: This invention provides a geological survey sampling device, comprising: a sealed sampling device, a sampling drill rod, and a directional drilling mechanism. The sealed sampling device adopts a modular design and a double-cylinder single-action structure. When the sealed sampling device is filled with coal sample, a rubber ball is delivered to the bottom of the hole using static pressure water. After the rubber ball reaches the bottom of the hole, the pump pressure increases, shearing the fixing pin of the push rod of the sealed sampling device. The push rod moves down, driving the shearing sealing ball valve to cut off the coal sample and seal the coal sample inside the sampling cylinder, achieving rapid sealing of the coal sample. The main borehole of the sampling drill is arranged in the bottom plate of the coal seam. The construction of branch holes for coal seam sampling, with less extension of the borehole section within the coal seam, can improve the borehole formation rate and avoid complex situations such as borehole collapse, blowout, and stuck drill bit. This significantly increases the drilling sampling depth, reaching 178m and 238m. At the same time, the application of measurement-while-drilling directional drilling technology can precisely control the extension of the main hole and branch holes along the designed trajectory, making the sampling location controllable. By using a closed sampling method at predetermined locations, the exposed time of the coal samples is short, and the measured gas content is 12.4% and 25.2% higher than that of conventional methods. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the sampling drilling process of a geological survey sampling device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the drilling exploration principle of the present invention. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0013] like Figure 1-2 As shown, this invention discloses a geological survey sampling device, comprising: a sealed sampling device, a sampling drill rod, and a directional drilling mechanism; the sampling borehole and sampling point are designed according to the mine geological data and gas parameter measurement requirements; a comb-shaped sampling directional drilling borehole is constructed using measurement-while-drilling directional drilling technology, with the main borehole located in a stable stratum of the coal seam to be sampled; branch holes are constructed using a "forward-opening" branching method, including exploration branch holes and sampling branch holes; wherein the exploration branch holes are used to explore the undulations of the coal seam while drilling, and the drill is lifted to continue constructing the main borehole after coal is encountered; the sampling branch holes are mainly used as sampling channels, and can also be used to explore the undulations of the coal seam. After drilling to a suitable distance in the coal seam to meet the sampling requirements, the directional drilling tool is pulled out, and a sealed sampling device is lowered. The drilling is then rotated until the sealed sampling device is full of coal samples. The drill is then lifted to conduct a coal sample air tightness test and on-site desorption. After the test is passed, the single fixed-point sealed sampling drilling of the soft coal seam is completed. As needed, the construction of sampling branch holes and sealed sampling are repeated until the fixed-point sealed sampling of all sampling points in the sampling borehole is completed.

[0014] The main sampling borehole is located in the coal seam floor at a certain distance from the coal seam. However, the undulation of the coal seam in the mine is generally not accurately known. To avoid the main borehole accidentally entering the coal seam, the undulation of the coal seam should be explored during the drilling of the sampling borehole. The method for exploring the coal seam undulation during drilling is as follows: adopting a "forward" branching method, actively increasing the borehole inclination at certain intervals (50~80m), and constructing exploration branch holes closer to the coal seam; when the feed pressure decreases and the drilling speed increases during the drilling of exploration branch holes, and coal slag is returned from the borehole opening, it is confirmed that the exploration branch hole has encountered the coal seam; using the coal-encounter data from multiple exploration branch holes, the actual coal seam inclination is calculated, and the changes in coal seam undulation in the borehole extension direction are predicted. The trajectory of the main borehole, the location of the sampling point, and the trajectory of the sampling branch holes are optimized and adjusted to achieve precise control of the borehole trajectory during drilling.

[0015] To improve the drilling efficiency of exploration branch holes and the sampling success rate of sampling branch holes, the coal-encounter angle should vary depending on the type of branch hole. When constructing exploration branch holes, the borehole inclination should be actively increased before encountering the coal seam to ensure the branch hole encounters coal at a larger angle. After encountering coal, the main hole should be constructed immediately to reduce ineffective drilling progress. A larger coal-encounter angle also improves the removal of drill cuttings. When constructing sampling branch holes, the borehole inclination should be actively decreased before encountering the coal seam to ensure the branch hole encounters coal at a smaller angle. After encountering coal, the hole should be drilled a certain distance before being removed and a sealed sampling device replaced for sampling drilling. This ensures the sampling branch hole effectively extends within the coal seam, prevents it from penetrating the coal seam, and allows sufficient drilling distance for sampling, thereby improving the success rate of sampling drilling.

[0016] The sampling borehole extends a long distance through the coal seam floor. To improve the borehole depth, drilling efficiency, and drilling safety, a "mechanical + hydraulic" high-efficiency slag removal technology was proposed. This technology combines the advantages of hydraulic slag removal and mechanical slag agitation. Based on hydraulic slag removal suspending and transporting finer drill cuttings to the borehole opening, a combination of shaped drill bits (shaped drill rod + spiral non-magnetic drill rod + spiral screw drill bit) is used for rotary mechanical slag agitation. This grinds and stirs the coarser drill cuttings deposited at the bottom of the borehole, reducing the deposition of coarse particles. This allows the flushing fluid to promptly transport the drill cuttings to the borehole opening, preventing stuck holes, buried drill bits, and other complex borehole conditions. This achieves efficient drilling of the sampling borehole using the "mechanical + hydraulic" high-efficiency slag removal principle.

[0017] Conventional sampling devices cannot quickly seal and preserve coal samples during bottom-of-hole sampling, resulting in prolonged exposure time and affecting the accuracy of gas parameter measurements. In sealed sampling, once the device is filled with coal sample, hydrostatic water is used to propel a rubber ball to the bottom of the borehole. Upon reaching the bottom, the pump pressure increases, shearing the fixing pin of the sealed sampling device's push rod. The push rod then moves downward, shearing the sealing ball valve to cut off the coal sample and sealing it within the sampling cylinder, achieving rapid sealing of the coal sample. This mechanical method of rapid sealing reduces the coal sample exposure time and prevents gas escape during drill lifting and sample sealing, thus making gas content test results more accurate and reliable.

[0018] Coal samples are quickly sealed using a ball-throwing method and then stored in a sealed sampling tube. The sampling tube serves both as a sealing device for the coal sample and as a means to collect in-situ desorbed gas from the coal sample underground. The sampling tube is retrieved by drilling, and the content of desorbed gas is initially determined at the coal mine construction site using a gas parameter measuring device. The desorbed gas content of the underground coal sample is Q1. The coal sample is then brought to the surface, where the desorbed gas content before crushing is measured as Q2. The coal sample is then crushed, and the amount of desorbed gas during and after crushing is measured as Q3. Therefore, the desorbed gas content Q of the coal sample can be calculated as follows:

[0019] The equipment for directional drilling of fixed-point closed sampling in fractured and soft coal seams mainly includes directional drilling rigs, mud pumps (trucks), screw drills, measurement-while-drilling systems, directional drill rods, and drill bits.

[0020] The closed sampling device uses small-diameter equipment with a modular design and a double-cylinder single-action structure. It is easy to disassemble and maintain, and is very convenient to match and connect with various drilling rigs, drilling tools, mud pumps, gas desorption instruments and other equipment. The core sampling process is simple to operate and can accurately, completely and quickly extract high-quality coal samples.

[0021] The sampling drill pipe uses a large-diameter auger drill pipe with a triangular helical structure to enhance slag removal mechanically, thus improving slag removal efficiency in drilling through soft coal seams. The drill pipe joint requires a large-diameter through-hole design, with an overall internal diameter of at least 20mm to ensure the rubber ball can pass through smoothly, meeting the requirements for sealed sampling. Large-diameter triangular auger drill pipe.

[0022] The directional drilling consists of a casing section and a directional section. The casing section is enlarged to ø193mm, and a 9m ø146mm casing is installed. The directional section has a diameter of 105mm, and the drilling trajectory is controlled to be 1~1.5m away from the coal floor. It extends along the strike of the coal mining face, with a main borehole depth of ≥300m. The branch boreholes are constructed using a "forward" branching method, with ≥4 branch boreholes. The two deepest branch boreholes are used for sealed coring, and the other branch boreholes are used for coal seam undulation exploration.

[0023] The main supporting equipment for directional drilling includes an ø89mm sealed sampling device, a ZDY4000LD(C) type fully hydraulic directional drilling rig, a YHD2-1000(A) mining measurement while drilling system, a BLY260 / 9 type mud pump truck, an ø73mm hydraulic screw drill bit, an ø73mm integral spiral measurement while drilling drill rod, an ø73mm large diameter triangular spiral drill rod, an ø105mm directional drill bit, and an ø98mm core drill bit.

[0024] First, rotary drilling technology was used to construct the casing section. After the construction was completed, the casing was installed and the hole was cemented. Then, directional drilling technology was used to construct the directional section. The directional drilling tool assembly was: ø105mm directional drill bit + ø73mm hydraulic screw drill bit + ø76mm lower non-magnetic drill rod + ø76mm probe outer tube (with YHD2-1000T(A) measurement-while-drilling device probe installed inside) + ø76mm upper non-magnetic drill bit + ø73mm integral spiral measurement-while-drilling drill rod + ... + ø73mm integral spiral measurement-while-drilling drill rod + ø73mm water feeder. Finally, core drilling was carried out when constructing the two branch holes. The core drilling tool assembly was: ø98mm core drill bit + ø89mm sealed sampling device + ø73mm large diameter triangular spiral drill rod + ... + ø73mm large diameter triangular spiral drill rod + ø73mm water feeder.

[0025] The main borehole reached a depth of 301m, and four branch boreholes were successfully constructed, with a total drilling depth of 532m. During drilling, based on data from multiple coal-bearing points encountered in the branch boreholes, adjustments were made to the predicted coal seam undulations and the borehole trajectory design. This allowed the borehole to extend better along the coal seam undulations in the floor, which was beneficial for controlling the sampling point location. Before encountering non-coring coal seams, fractured and narrow-diameter rock strata, the borehole inclination angle was actively increased to reduce the extension length of the borehole trajectory in unstable strata, thereby improving drilling safety. Fixed-point sealed sampling was conducted in the 3rd and 4th branch boreholes, obtaining coal samples at depths of 178m and 238m, respectively.

[0026] Considering the lag in the return of drill cuttings from the bottom of the borehole to the borehole opening, before the sampling branch borehole approaches the target core coal seam, the drilling speed should be appropriately reduced to observe whether coal dust appears in the return cuttings at the borehole opening, thus preventing the borehole from penetrating the coal seam.

[0027] During sampling drilling, the main drilling parameters are controlled within the range of 50~80 r / min rotation speed, 0.2~0.3 m / min sampling drilling speed, and 1.2~1.5 m drilling depth. The flushing fluid is supplied by the downhole static pressure water pipeline to avoid excessive water pressure and volume, which could affect the sampling quality.

[0028] Gas content testing and analysis of coal samples were conducted after fixed-point sampling of the soft coal seam. The gas contents of samples obtained at depths of 178m and 238m were 9.05 m³ / t and 10.08 m³ / t, respectively. The average gas content measured in this area of ​​the mine using conventional methods is approximately 8.05 m³ / t. It can be seen that the gas content obtained by fixed-point, sealed sampling is 12.4% and 25.2% higher than that obtained by conventional methods, respectively, providing more accurate gas data for the mine.

[0029] Multi-branch closed-loop sampling drilling technology has the following advantages: the main sampling borehole is located in the coal seam floor, while the branch boreholes enter the coal seam for sampling. This results in less borehole extension within the coal seam, improving the borehole formation rate and avoiding complex situations such as borehole collapse, blowouts, and stuck drill bits. It also significantly increases the sampling depth, reaching 178m and 238m. Furthermore, the application of measurement-while-drilling (MWD) directional drilling technology allows for precise control of the main borehole and branch boreholes along their designed trajectories, ensuring controllable sampling locations. The closed-loop sampling method at predetermined locations results in shorter coal sample exposure times, leading to a 12.4% and 25.2% increase in gas content compared to conventional methods.

[0030] Based on the analysis of the problems existing in conventional sampling drilling technology, key drilling technologies such as precise control of drilling trajectory and efficient slag removal by "mechanical + hydraulic" were developed. Key equipment was selected and matched, and the advantages of long-distance closed coring technology were integrated to form a multi-branch sampling drilling technology for coal seam floor boreholes. It has significant advantages such as large sampling depth, controllable sampling position, and high sampling and testing accuracy. It can provide technical support for long-distance gas parameter determination in fractured and soft coal seams, gas drainage borehole engineering design, and drainage effect evaluation.

[0031] A field test of multi-branch sampling drilling technology for the bottom plate of fractured and soft coal seams was carried out in a certain mine. A sampling directional borehole with a main hole depth of 301m was constructed, and two fixed-point sealed samplings were completed. Coal samples were successfully collected, with a maximum sampling depth of 238m. The measured gas content was 12.4% and 25.2% higher than that of conventional methods, which improved the accuracy of coal seam gas parameter testing.

[0032] The main drilling process parameters for sampling drilling are controlled within the following ranges: rotation speed: 50~80 r / min, sampling drilling speed: 0.2~0.3 m / min, drilling depth: 1.2~1.5 m. The flushing fluid is supplied by the underground static pressure water pipeline to avoid excessive water pressure and volume, which could affect the sampling quality. This can provide parameter guidance for sampling drilling in broken and soft coal seams.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A geological survey sampling device, characterized in that, include: Sealed sampling device, sampling drill rod and directional drilling mechanism; The sealed sampling device adopts a modular design and a double-cylinder single-action structure. When the sealed sampling device is filled with coal sample, the rubber ball is delivered to the bottom of the hole using static pressure water. After the rubber ball reaches the bottom of the hole, the pump pressure increases, shearing the push rod fixing pin of the sealed sampling device. The push rod moves down and drives the shearing sealed ball valve to cut off the coal sample and seal the coal sample in the sampling cylinder, thus achieving rapid sealing of the coal sample. The sampling drill rod adopts a large-diameter spiral drill rod, and the drill rod joint is designed with a large through hole structure to ensure that the rubber ball can pass through smoothly, so as to meet the requirements of closed sampling. The directional drilling mechanism includes a casing section and a directional drilling section. The casing section is enlarged to a set size and the casing is lowered. The drilling trajectory is controlled to be a set distance from the coal floor and extended along the coal mining face. The branch holes are constructed using a forward branching method, with a maximum of 4 branch holes. The two deepest branch holes are used for sealed coring.

2. The geological survey sampling device as described in claim 1, characterized in that, Rotary drilling technology was used for casing section construction. After the casing was completed, it was installed and cemented. Then, directional drilling technology was used for directional section construction. The directional drilling tool assembly consisted of: directional drill bit, hydraulic screw drill bit, lower non-magnetic drill rod, probe outer tube, measuring while drilling probe tube, upper non-magnetic, integral spiral measuring while drilling drill rod, and water supply device. Based on the data from multiple coal-bearing points encountered when the branch hole encountered the coal seam, the coal seam undulation prediction and borehole trajectory design were adjusted to make the borehole extend better along the coal seam undulation in the bottom plate.

3. The geological survey sampling device as described in claim 1, characterized in that, Before encountering non-core coal seams, fractured and narrow-diameter rock strata, the borehole inclination angle is actively increased to reduce the extension length of the borehole trajectory in unstable strata.

4. The geological survey sampling device as described in claim 1, characterized in that, During sampling drilling, the main drilling parameters are controlled within the range of 50~80 r / min rotation speed, 0.2~0.3 m / min sampling drilling speed, and 1.2~1.5 m drilling depth; the flushing fluid is supplied by the downhole static pressure water pipeline.

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