A hard stratum drilling method based on a water source drilling rig

Abstract

This invention relates to the field of rock drilling technology, and more particularly to a drilling method for hard formations based on a water-source drilling rig. The method includes arranging drilling components and supplying air according to pre-process procedures; adjusting the drilling component rotation speed based on an intake air pressure value greater than a preset intake air value and a reverse air pressure value greater than or equal to a preset reverse air value; responding to an intake air pressure value greater than the preset intake air value, acquiring the drilling speed of the drilling components to determine the mechanical rate of penetration (MRP); and adjusting the initial air pressure based on a MRP deviation rate based on a MRP value less than the preset MRP value; acquiring the torque of the drilling components to determine the actual torque value; and adjusting the subsequent drilling pressure based on a torque deviation rate based on a torque value greater than the preset torque value. This invention comprehensively assesses the cuttings removal capacity and drill bit performance during the impact-breaking and cutting-breaking processes of the rock formation, intelligently controlling the drilling speed to ensure high drilling efficiency.

Description

Technical Field

[0001] This invention relates to the field of rock drilling technology, and more particularly to a drilling method for hard formations based on a water-source drilling rig. Background Technology

[0002] Currently, conventional drilling with water source drilling rigs involves the drill string rotating on the rig's rotary table. The drill string then transmits power to the drill bit to break up the rock at the bottom of the well, forming cuttings. The cuttings are then carried away from the bottom of the well by a circulating flushing fluid driven by a mud pump. This drilling method offers high drilling efficiency and relatively low production costs for softer, less abrasive formations. However, for highly abrasive and hard formations, this method suffers from low drilling efficiency, high safety risks, and high production costs. The air-powered down-the-hole hammer (DHH) process uses compressed air as the power medium to drive a piston inside the DHH hammer to impact the drill bit at high frequency, breaking up the rock. Simultaneously, high-speed airflow carries the cuttings to the surface. This process offers high drilling efficiency for hard formations, but it has significant application limitations, relying heavily on formation stability and being constrained by the capacity of the air compression equipment.

[0003] Chinese Patent Publication No. CN117823046A discloses a magnetic resonance drilling tool and method, belonging to the field of oil drilling rock breaking technology. The drilling tool includes a main shell, a drill bit connector, a central tube, a buffer mechanism, a magnetic telescopic mechanism, and a transmission mechanism. The drill bit connector is connected to the lower end of the main shell. The central tube is located inside the main shell, with its upper end connected to the main shell and its lower end connected to the drill bit connector. An annular cavity is formed between the central tube and the main shell, and the buffer mechanism, magnetic telescopic mechanism, and transmission mechanism are sequentially arranged within the annular cavity from top to bottom. This invention is designed for drilling in hard formations, providing additional impact force to the drill bit. The impact force frequency is close to the natural frequency of the rock, causing rock resonance damage, reducing the difficulty of rock fracturing, forming volumetric fragmentation, and achieving the purpose of improving rock breaking efficiency.

[0004] Therefore, the magnetic resonance drilling tool and method described above have the following problems: it is difficult to combine impact-fractured rock formations with cutting-fractured rock formations, it cannot comprehensively judge the slag removal capacity and drill bit performance during the drilling process, and it cannot guarantee the high efficiency of drilling. Summary of the Invention

[0005] Therefore, this invention provides a drilling method for hard formations based on a water source drilling rig, which overcomes the problems in the prior art that it is difficult to combine impact crushing of rock formations with cutting crushing of rock formations, cannot comprehensively judge the slag removal capacity and drill bit performance during the drilling process, and cannot guarantee the high efficiency of drilling.

[0006] To achieve the above objectives, the present invention provides a method for drilling hard formations based on a water source drilling rig, comprising: Drilling components are arranged and air is supplied according to the preceding process. Based on the obtained air intake pressure value being greater than the preset air intake value, and based on the reverse air pressure value being greater than or equal to the preset reverse air value, the rotation speed of the drilling components is adjusted according to the air intake deviation value. The air intake deviation value is determined based on the air intake pressure value and the preset air intake value. In response to the intake air pressure value being greater than the preset intake air value, the drilling speed of the drilling components is obtained to determine the mechanical drilling speed value, and the initial air pressure is adjusted according to the drilling speed deviation rate based on the mechanical drilling speed value being less than the preset drilling speed value, wherein the drilling speed deviation rate is determined based on the mechanical drilling speed value and the preset drilling speed value. The torque of the drilling components is obtained to determine the actual torque value, and the subsequent drilling pressure is adjusted according to the torque deviation rate based on the fact that the actual torque value is greater than the preset torque value. The torque deviation rate is determined based on the actual torque value and the preset torque value. In response to the air pressure value being greater than the preset air pressure value, and based on the grinding loss index being greater than the preset grinding index, the preset drilling speed value is adjusted according to the grinding deviation rate. Based on the fact that the grinding wear index is less than the ideal grinding index, the initial drilling pressure is adjusted according to the preset drilling pressure adjustment amount. The grinding loss index is determined based on the mechanical drilling speed and the actual torque value, the preset grinding index is determined based on the preset drilling speed and the preset torque value, and the grinding deviation rate is determined based on the grinding loss index and the preset grinding index.

[0007] Furthermore, the process of determining the compliance of chip removal based on the inlet air pressure value includes, Compare the inlet air pressure value with the preset inlet air value to determine the chip removal qualification; In response to the failure of chip removal, and based on the fact that the reverse air pressure value is greater than or equal to the preset reverse air value, the drilling component rotation speed is increased according to the air intake deviation value.

[0008] Furthermore, in response to the failure of cuttings removal, and based on the fact that the reverse air pressure value is less than the preset reverse air value, the drilling pressure is reduced and the drilling component rotation speed is increased according to the preset drilling pressure adjustment amount.

[0009] Furthermore, in response to increasing the drill string speed, the drilling assembly speed is increased to the maximum speed in combination with the drill string speed range.

[0010] Furthermore, the process of determining the qualification of drilling speed based on the mechanical drilling rate value includes, Compare the mechanical drilling rate value with the preset drilling rate value to determine the qualification of the drilling speed; In response to the drilling speed failure determination, the initial air pressure is increased based on the drilling speed deviation rate.

[0011] Furthermore, in response to the fact that adjusting the initial air pressure alone does not meet the drilling speed qualification requirements, the rotation speed of subsequent drilling components is increased based on the drilling speed deviation rate and the current drilling component rotation speed.

[0012] Furthermore, the process of determining the passivation qualification based on the actual torque value includes, Compare the actual torque value with the preset torque value to determine the passivity of the passivation process. In response to passivation failure, the subsequent drilling pressure is reduced based on the torque deviation rate and the current drilling pressure.

[0013] Furthermore, the process of determining the performance qualification of drill bits based on the grinding wear index includes, The performance qualification of the drill bit is determined by comparing the grinding wear index with the preset grinding index. In response to the determination of unqualified drill bit performance, the preset drilling speed and initial drilling pressure are reduced based on the grinding deviation rate.

[0014] Furthermore, in response to the qualification of drill bit performance and based on the fact that the grinding wear index is less than the ideal grinding index, the initial drilling pressure is increased according to the preset drilling pressure adjustment amount.

[0015] Furthermore, the pre-process includes, Assemble drilling components based on drill strings, impactors, and down-the-hole hammers, and lower the drilling components to the bottom of the well; Air is supplied to the drilling components based on initial air pressure and initial air volume; The impactor is activated based on the fact that the reverse air pressure value at the wellhead is greater than the preset reverse air value, and the drill string, which is rotating at the initial speed, is fed according to the initial drilling pressure.

[0016] Compared with the prior art, the beneficial effect of the hard formation drilling method based on water source drilling rig of the present invention is that, in the process of impacting and breaking rock formations and cutting and breaking rock formations, the slag removal capacity and drill bit performance during the drilling process are comprehensively judged, and the drilling speed is intelligently controlled to ensure the high efficiency of drilling.

[0017] Furthermore, by combining the impact crushing of rock strata with the rotational cutting of the drill bit, rapid crushing of hard rock strata is achieved. Compared with traditional impact crushing, the cutting crushing after impact crushing can accelerate the crushing speed. The impact-crushed rock strata are then transported by high-pressure airflow, increasing the transport and cleaning speed of rock cuttings. Compared with grinding under drill pressure, the rock strata crushed by impact are easier to break, accelerating the breaking of hard rock strata and the transport of rock cuttings, thereby speeding up the drilling speed and achieving the goal of rapid drilling.

[0018] Furthermore, the quality of chip removal is determined by comparing the inlet air pressure value with the preset inlet air value. This allows for precise monitoring of the high-pressure airflow and understanding of the chip transport capacity. When abnormal chip removal is detected, comparing the reverse air pressure value with the preset reverse air value further identifies the location of blockage in the high-pressure airflow channel and clarifies the cause of the abnormal inlet air pressure value. If the abnormal inlet air pressure value is detected as being caused by partial blockage of the chip, the drill bit speed is increased based on the inlet deviation value. Increasing the drill bit speed enhances the chip transport capacity and accelerates the chip dispersion, allowing the high-pressure airflow to carry the chip out, thus enhancing the high-pressure airflow's effect on the chip removal. The improved transport capacity reduces the blockage of high-pressure airflow by rock cuttings, enabling rapid restoration of normal intake air pressure values ​​in case of abnormalities. This ensures a stable and controllable drilling process and prevents the accumulation of rock cuttings without timely response to abnormal intake air pressure values. This accumulation, without increasing drill bit speed, leads to persistent and aggravated abnormalities in intake air pressure values, ultimately preventing sufficient rock cuttings removal. The resulting accumulation affects drilling speed and efficiency, and repeated breakage of the rock cuttings can also cause wear on the drill bit, increasing economic losses. Rapidly responding to and adjusting abnormal intake air pressure values ​​ensures the quality of drilling operations.

[0019] Furthermore, by further distinguishing abnormal operating conditions where the reverse air pressure value is lower than the preset reverse air value, in cases of severe cuttings blockage or piston jamming: the drill bit speed is increased to the upper limit and supplemented with up-and-down reciprocating motion, while the drilling pressure is reduced according to the preset adjustment amount, so that the drill bit switches from the breaking mode to the clearing mode, dispersing the cuttings to the greatest extent, opening up the slag discharge channel, and quickly restoring the cuttings carrying capacity of the high-pressure airflow; if the abnormality is still not eliminated after adjustment, it can be clearly determined that the impactor piston is jammed, and the drill bit needs to be lifted for inspection in time. This effectively avoids equipment overload and aggravated wear caused by blindly increasing the speed or drilling pressure, significantly reduces the risk of blockage worsening, shortens the fault response time, and ensures the continuity and economy of the deep hole hard rock drilling process.

[0020] Furthermore, by introducing a comparison between the mechanical drilling rate (MRR) and the preset RMR based on an abnormal increase in intake air pressure, precise determination of drilling speed compliance is achieved. When the intake air pressure is abnormal and the MMR is lower than the preset RMR, it is determined that conditions such as cuttings accumulation have substantially affected drilling efficiency. In this case, the initial air pressure is dynamically increased based on the RMR deviation rate. By simultaneously increasing the cuttings carrying capacity and transport speed of the high-pressure airflow, the cuttings removal efficiency is improved, eliminating the root cause of accumulation. This avoids the bottleneck of cuttings removal capacity caused by insufficient air pressure when only adjusting the drill bit speed. Intelligent control of air pressure increment is achieved through the RMR deviation rate, preventing energy waste and equipment load shock caused by blindly increasing pressure, while ensuring a refined response to different degrees of blockage. Rapid and directional air pressure compensation can effectively suppress the continuous deterioration of drilling efficiency, prevent the risk of drill bit wear and impactor failure caused by repeated cuttings breakage, and ensure that the drilling speed quickly recovers to the expected level. Thus, while maintaining smooth cuttings removal, it significantly improves the overall drilling economy and process reliability in hard rock formations.

[0021] Furthermore, when simply increasing the initial air pressure is insufficient to meet drilling speed requirements, a drilling speed deviation rate is introduced to coordinately regulate the drill string rotation speed, achieving joint optimization of air pressure adjustment and mechanical breaking capability. By proportionally increasing the subsequent drill string rotation speed based on the existing speed according to the drilling speed deviation rate, the drill string's ability to perform secondary cutting and rock cuttings dispersion on the impact-broken formation is enhanced. This proactively reduces the rock cuttings accumulation pattern from a mechanical perspective, assisting the high-pressure airflow in improving cuttings carrying efficiency. This effectively overcomes the problems that may arise from simply increasing air pressure, such as partial blockage of the cuttings removal channel or rock cuttings adhesion exceeding the carrying capacity of the high-pressure airflow. Through the coordinated regulation of air pressure and rotation speed, a synergistic cuttings removal mechanism of airflow carrying and mechanical dispersion is formed, which can quickly restore the smooth transport of broken rock cuttings, ensuring the continuous impact efficiency of the down-the-hole hammer on fresh rock formations and the cutting and breaking effect of the drill string. The tiered response and gradual reinforcement control logic avoids stress concentration and energy consumption increases caused by premature and excessive adjustment of a single parameter. It also enables precise reinforcement during the cuttings removal bottleneck period, quickly suppressing drilling efficiency fluctuations caused by repeated accumulation of cuttings, and ensuring the high efficiency, continuity and long-term stability of the drilling process in deep-hole hard rock formations.

[0022] Furthermore, by comparing the actual torque value with the preset torque value, a quantitative judgment standard for the passivity of drill bit passivation was established. When the actual torque value exceeds the preset torque value, it is determined that the drill bit sharpness has decreased beyond expectations, and significant rolling and grinding behavior occurs during rock cutting. At this time, the subsequent drilling pressure is dynamically reduced based on the torque deviation rate. By reducing the feed pressure, the abnormal wear rate of the drill bit is suppressed, avoiding further degradation of cutting ability caused by increased passivation under high drilling pressure conditions. This avoids the situation of drill bit passivation caused by ignoring torque changes, and realizes real-time perception and intelligent response to the degree of passivation. Based on the torque deviation rate and combined with the preset adjustment coefficient, the drilling pressure is finely adjusted. This not only prevents drill bit failure caused by excessive drilling pressure, resulting in abnormal wear or even drill breakage accidents, but also avoids a sharp drop in drilling efficiency caused by premature or excessive reduction of drilling pressure. By proactively controlling the adaptive reduction of drilling pressure during the passivation stage, the effective service life of the drill string can be effectively extended, the stability and controllability of the cutting process can be maintained, and the increase in auxiliary working hours and operating costs caused by frequent drill string removal for inspection or replacement can be reduced. Thus, while ensuring drilling continuity, the economy and safety of drilling in hard formations can be optimized in a coordinated manner.

[0023] Furthermore, by constructing a grinding loss index based on the mechanical drilling rate and actual torque values, and comparing it with a preset grinding index, a quantitative evaluation of the overall performance of the drilling tool was achieved. When the grinding loss index exceeds the preset grinding index, it indicates that the drilling tool is in a severely deteriorated state, with the mechanical drilling rate significantly lower than expected or the actual torque far exceeding the preset range, or even both deteriorating simultaneously. In this case, the preset drilling rate value is dynamically reduced based on the grinding deviation rate, and the initial drilling pressure is reduced simultaneously. By reducing the expected drilling rate and drilling pressure, drilling operations are carried out while ensuring that the drilling tool can still work effectively. This overcomes the limitations of single-parameter control, transforming the drilling rate target and drilling pressure setting from fixed values ​​into dynamic thresholds that adaptively adjust with the degradation of drilling tool performance. This avoids the rapid wear, overheating failure, or even drill string breakage accidents caused by forcibly maintaining the original efficiency target when the drilling tool is severely dulled or worn. By proactively reducing the expected drilling rate and feed pressure, drilling parameters are matched with the actual load-bearing capacity of the drill string. This effectively suppresses the accelerated degradation of drill string performance while ensuring basic drilling continuity, extending the effective service life of the drill string and reducing unplanned hoisting, inspection, and replacement operations caused by sudden drill string failures. This significantly reduces drill string consumption costs and auxiliary time losses. Simultaneously, the construction of the grinding wear index allows for a more comprehensive assessment of drill string performance, coordinating the relationship between drill string performance and drilling speed. This avoids frequent drill string failures caused by excessive pursuit of drilling efficiency, thus enabling more efficient use of the drill string while simultaneously improving drilling efficiency, comprehensively enhancing the safety, economy, and intelligence of the drilling process in hard formations.

[0024] Furthermore, based on the premise that the drill string performance is qualified, an ideal grinding index is introduced to refine the evaluation of the grinding loss index. When the grinding loss index is lower than the ideal grinding index, it indicates that the drill string not only meets the expected performance requirements, but also that the mechanical drilling rate significantly exceeds expectations and the actual torque is significantly lower than the preset value, indicating a performance redundancy. The initial drilling pressure is then proactively increased based on the preset drilling pressure adjustment. This avoids performance redundancy that occurs when the drill string performance exceeds expectations even when it is qualified. By increasing the drilling pressure, drilling efficiency is accelerated, and the excess performance of the drill string is fully utilized. Under ideal conditions with sufficient drill string sharpness, smooth cuttings removal, and low load, the performance redundancy is transformed into a substantial increase in drilling speed by moderately increasing the drilling pressure, thereby shortening the drilling cycle and reducing overall drilling costs. This avoids the waste of high-efficiency conditions caused by insufficient drilling pressure and prevents the risk of equipment overload caused by excessive pressure increase through the limitation of the preset adjustment amount, achieving proactive optimization of drilling efficiency while ensuring safety boundaries. Meanwhile, the introduction of the ideal grinding index has created a multi-level performance evaluation system from unqualified to qualified to excellent, which expands the control of drilling parameters from a single abnormality correction to intelligent optimization control that covers efficiency potential tapping, significantly improving the adaptability and economy of drilling in hard formations. Attached Figure Description

[0025] Figure 1 This is a flowchart of a method for drilling hard formations based on a water source drilling rig according to an embodiment of the present invention; Figure 2 This is a flowchart for determining the chip removal qualification in an embodiment of the present invention; Figure 3 This is a flowchart illustrating the process of determining the qualification of drilling speed according to an embodiment of the present invention; Figure 4 This is a flowchart for determining the performance qualification of drilling tools according to an embodiment of the present invention. Detailed Implementation

[0026] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0027] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0028] Please see Figure 1 As shown, it is a flowchart of the method for drilling hard formations based on a water source drilling rig according to an embodiment of the present invention; This invention provides a method for drilling hard formations using a water-source drilling rig, comprising: Step S1: Arrange the drilling components and supply air according to the previous process. Based on the obtained air intake pressure value being greater than the preset air intake value, and based on the reverse air pressure value being greater than or equal to the preset reverse air value, adjust the drilling component rotation speed according to the air intake deviation value. The air intake deviation value is determined based on the air intake pressure value and the preset air intake value. Specifically, the pre-process includes, Step S11: Assemble the drilling assembly based on the drill string, impactor, and down-the-hole hammer, and lower the drilling assembly to the bottom of the well; Step S12: Air is supplied to the drilling components based on the initial air pressure and initial air volume; Step S13: Based on the fact that the reverse air pressure value at the wellhead is greater than the preset reverse air value, determine to start the impactor and push the drill string rotating at the initial speed according to the initial drilling pressure.

[0029] In this embodiment of the invention, the impact crushing of rock strata by a down-the-hole hammer combined with the rotational cutting of the drill bit achieves rapid crushing of hard rock strata. Compared with traditional impact crushing, the cutting crushing after impact crushing can accelerate the crushing speed. The impact-crushed rock strata are then transported by high-pressure airflow, increasing the transport and cleaning speed of rock cuttings. Compared with grinding under drill pressure by the drill bit, the rock strata crushed by impact are easier to break, accelerating the damage to hard rock strata and the transport of rock cuttings, thereby accelerating the drilling speed and achieving the goal of rapid drilling.

[0030] In this embodiment of the invention, the experimental well section is from 110.09m to 251.67m. A down-the-hole hammer tool consisting of a 325mm diameter hammerhead and a 12-inch impactor is used, with a calibrated air volume of 64m³ / h. 3 The initial air pressure is 1.5 MPa, the drill bit rotation speed is 27 r / min, and the initial drilling pressure is 2 t.

[0031] Please see Figure 2 As shown, it is a flowchart for determining the chip removal qualification in an embodiment of the present invention; Specifically, the process of determining the compliance of chip removal based on the inlet air pressure value includes, Compare the inlet air pressure value with the preset inlet air value to determine the chip removal qualification; In response to the failure of chip removal, and based on the fact that the reverse air pressure value is greater than or equal to the preset reverse air value, the drilling component rotation speed is increased according to the air intake deviation value.

[0032] During the drilling process, the intake air pressure value is obtained by using a multi-parameter drilling parameter instrument. The intake air pressure value is compared with the preset intake air value to determine the qualification of cuttings removal. The multi-parameter drilling parameter instrument is a mature existing technology and is not within the scope of protection of this application.

[0033] If the inlet air pressure value is less than or equal to the preset inlet air value, the chip removal is deemed qualified. If the inlet air pressure value is greater than the preset inlet air value, the chip removal is deemed unqualified. In this embodiment of the invention, after the impactor drives the down-the-hole hammer to complete the formation breaking, a high-pressure airflow blown out from the position of the broken formation under a preset air volume and preset air pressure to assist in the formation breaking. At the same time, during the rotation of the drill bit, the rock cuttings are transported out of the wellbore by the high-pressure airflow from the space between the drill pipe and the well wall, so as to achieve rapid discharge of the rock cuttings. The preset air intake value is determined based on the drilling depth of the experimental well and the effect on the transport of rock cuttings, and the preset air intake value is 1.5 MPa.

[0034] The down-the-hole hammer achieves rapid formation breaking through reciprocating continuous impact, the drill bit rotation enables rapid drilling, and the high-pressure airflow transports rock cuttings to ensure the down-the-hole hammer breaks subsequent layers, avoids rock cuttings accumulation which would buffer the impact force, and also prevents accumulated rock cuttings from causing dry grinding of the drill bit, thus affecting the feed of the down-the-hole hammer. When the intake air pressure value is less than or equal to the preset intake air value, it indicates that the high-pressure airflow can flow into the crushing position well without blockage, and transports the rock cuttings from between the drill pipe and the well wall to the surface, completing the rock cuttings transportation, and the cuttings removal is deemed qualified. When the intake air pressure value exceeds the preset intake air value, it indicates that the current high-pressure airflow is abnormal. If there is a blockage in the path of the high-pressure airflow, the chip removal is deemed unqualified. For example, if the intake air pressure value is 1.8MPa, it indicates that the high-pressure airflow is not flowing smoothly. It is necessary to conduct depth detection and judgment to determine the cause of the abnormal intake air pressure value, respond to the current abnormal situation, and avoid aggravating the abnormal situation and affecting the expected drilling objectives.

[0035] When the path of the high-pressure airflow is blocked, the intake air pressure increases. At this time, the reverse air pressure value is obtained and compared with the preset reverse air value. If the reverse air pressure value is greater than or equal to the preset reverse air value, it indicates that the accumulation of rock cuttings is causing poor cuttings removal and blocking the flow of high-pressure airflow, resulting in an increase in the intake air pressure value. The drill speed is increased according to the intake air deviation value. By increasing the drill speed, the rock cuttings transportation capacity is accelerated, the rock cuttings dispersion capacity is accelerated, and the high-pressure airflow carries the rock cuttings out, thereby enhancing the high-pressure airflow's ability to transport rock cuttings and reducing the blockage of the high-pressure airflow by rock cuttings. The preset reverse wind value is determined based on the wind pressure that is still maintained after the initial air intake pressure value is used to transport rock cuttings and in the event of rock cuttings accumulation. Taking an initial air intake pressure value of 1.5 MPa as an example, it is set to 1.0 MPa based on experience. The air intake deviation value equals the air intake pressure value minus the preset air intake value. At this point, the air intake deviation value is 1.8 - 1.5 = 0.3. For every 0.1 MPa increase in the air intake deviation value, the drill string speed increases by 2 r / min. Any increase less than 0.1 MPa is calculated as 0.1 MPa. At this point, the air intake pressure value is 1.8 MPa, and the drill string speed increases to 33 r / min.

[0036] This invention determines the quality of rock cuttings removal by comparing the inlet air pressure value with a preset inlet air value. It accurately monitors the flow of high-pressure airflow, assesses the rock cuttings' transport capacity, and, upon detecting abnormalities, further identifies the blockage location in the high-pressure airflow channel by comparing the reverse air pressure value with a preset reverse air value. This clarifies the cause of the abnormal inlet air pressure value. When partial blockage of the rock cuttings causes the abnormal inlet air pressure value, the drill bit speed is increased based on the deviation value. Increasing the drill bit speed enhances the transport capacity of the rock cuttings and accelerates their dispersion, allowing the high-pressure airflow to carry the rock cuttings out, thus strengthening the high-pressure airflow's effect on the rock cuttings. The improved transport capacity reduces the blockage of high-pressure airflow by cuttings, enabling rapid restoration of normal intake air pressure values ​​in case of abnormalities. This ensures a stable and controllable drilling process and prevents the continuous accumulation of cuttings without timely response to abnormal intake air pressure values. Such accumulation, without increasing drill bit speed, can lead to persistent and aggravated abnormalities in intake air pressure values, ultimately preventing the complete removal of cuttings. The resulting accumulation of cuttings affects drilling speed and efficiency, and repeated breakage of cuttings can also cause wear on drill bits, leading to increased economic losses. Rapidly responding to and adjusting abnormal intake air pressure values ​​ensures the quality of drilling operations.

[0037] Specifically, in response to the failure of cuttings removal, and based on the fact that the reverse air pressure value is less than the preset reverse air value, the drilling pressure is reduced and the drilling component rotation speed is increased according to the preset drilling pressure adjustment amount.

[0038] Specifically, in response to increasing the drill string speed, the drilling assembly speed is increased to the maximum speed in combination with the drill string speed range.

[0039] In this embodiment of the invention, if the reverse air pressure value is less than the preset reverse air value, it indicates that the current slag discharge channel is blocked beyond expectations or the piston of the impactor is stuck, resulting in a large amount of rock cuttings clogging the system. At this time, the drill string speed is increased to the maximum, while driving the drill string to move up and down reciprocally, and the drilling pressure is reduced according to the preset drilling pressure adjustment amount. The drill string speed is usually in the range of 20-40 r / min during drilling. Taking the maximum drill string speed as 40 r / min, the drill string speed is increased from the current 27 r / min to 40 r / min. The preset drilling pressure adjustment amount is empirically set to 0.6-1.0t. Setting the preset drilling pressure adjustment amount to 0.8t avoids insufficient or excessive adjustment. The drilling pressure is adjusted from 2t to 1.2t, reducing the drilling pressure so that the drill string changes its function from breaking rock formations to clearing blockages, thereby ensuring the transport capacity of the high-pressure airflow carrying rock cuttings and preventing the blockage from worsening.

[0040] When the slag discharge channel is blocked, increasing the drill bit speed to the maximum speed can effectively disperse the rock cuttings. Combined with high-pressure airflow, this reduces the blockage of rock cuttings. By driving the drill bit to move up and down, the blockage of rock cuttings is broken up at the concentrated blockage location, further reducing the blockage and restoring the quality of slag discharge by restoring the air pressure value.

[0041] If the reverse air pressure value is still less than the preset reverse air value after the space inside the drill string has completed the up-and-down reciprocating motion, it indicates that the current blockage is caused by the piston of the impactor being stuck. The stuck piston causes the process of exhaust gas being discharged after it is in position to be interrupted. The exhaust gas cannot be discharged when the reciprocating motion of the piston is interrupted, resulting in an increase in the intake air pressure value and the reverse air pressure value being less than the preset reverse air value. At this time, the impactor needs to be removed for inspection.

[0042] This invention further distinguishes abnormal operating conditions where the reverse air pressure value is lower than the preset reverse air pressure value. In cases of severe cuttings blockage or piston jamming, targeted adjustments are made: the drill bit speed is increased to its upper limit and supplemented with reciprocating motion, while the drilling pressure is reduced by a preset adjustment amount. This switches the drill bit from a breaking mode to a clearing mode, maximizing the dispersion of cuttings, opening up the slag discharge channel, and quickly restoring the cuttings-carrying capacity of the high-pressure airflow. If the abnormality persists after adjustment, it can be clearly determined that the impactor piston is jammed, requiring immediate drill string removal and inspection. This effectively avoids equipment overload and increased wear caused by blindly increasing the speed or drilling pressure, significantly reduces the risk of worsening blockage, shortens fault response time, and ensures the continuity and economy of deep-hole hard rock drilling.

[0043] Step S2: In response to the intake air pressure value being greater than the preset intake air value, the drilling speed of the drilling component is obtained to determine the mechanical drilling speed value, and the initial air pressure is adjusted according to the drilling speed deviation rate based on the mechanical drilling speed value being less than the preset drilling speed value. The drilling speed deviation rate is determined based on the mechanical drilling speed value and the preset drilling speed value. Please see Figure 3As shown, it is a flowchart for determining the qualification of drilling speed according to an embodiment of the present invention; Specifically, the process of determining the qualification of drilling speed based on the mechanical drilling speed value includes comparing the mechanical drilling speed value with the preset drilling speed value to determine the qualification of drilling speed. In response to the drilling speed failure determination, the initial air pressure is increased based on the drilling speed deviation rate.

[0044] If the intake air pressure value is greater than the preset intake air value, the mechanical drilling rate value is obtained through a multi-parameter drilling parameter instrument. The mechanical drilling rate value is compared with the preset drilling rate value to determine the qualification of the drilling speed. If the mechanical drilling rate is greater than or equal to the preset drilling rate, the drilling speed is deemed to be qualified. If the mechanical drilling rate is less than the preset drilling rate, the drilling speed is deemed unqualified. In this embodiment of the invention, the preset drilling rate value is determined based on the expected drilling efficiency and the current drilling depth. The current experimental well section is 110.09m to 251.67m, with an average drilling efficiency of 6.36m / h. Therefore, a margin is set for the mechanical drilling rate during normal drilling, and the preset drilling rate value is set to 5m / h based on experience. As is well known, different values ​​can also be set according to actual drilling needs. For example, if the actual drilling conditions are similar to those of the experimental well section, the preset drilling rate value can be set to 6m / h. If the actual drilling conditions are more difficult than those of the experimental well section, the preset drilling rate value can be set to 5.5m / h or 4.5m / h.

[0045] During drilling, under the expected conditions, the mechanical rate of penetration (MRP) is under control and drilling is carried out at the expected rate. When the MRP decreases, it may be due to drill bit wear, impactor failure, or cuttings accumulation.

[0046] When the mechanical drilling rate is greater than or equal to the preset drilling rate, it indicates that the current drilling speed has reached the expected drilling speed and can complete the drilling as expected, thus the drilling speed is deemed qualified. For example, if the current mechanical drilling rate is 5.6 m / h, and the mechanical drilling rate is still greater than the preset drilling rate even when the air intake pressure is greater than the preset air intake value, it can meet the expectations. In this case, it is only necessary to adjust the drill string speed according to the air intake deviation value to increase the high-pressure airflow's ability to transport cuttings, restore the cuttings removal capacity, and meet the cuttings removal qualification requirements.

[0047] When the mechanical drilling rate is less than the preset drilling rate, it indicates that the current drilling speed is not up to expectations and there is a problem of deterioration in the drilling process. The drilling speed is judged to be unqualified. For example, the current mechanical drilling rate is 4.8 m / h, which is lower than the preset drilling rate of 5 m / h. The main reason may be the accumulation of rock cuttings. At this time, the initial air pressure is increased according to the drilling speed deviation rate. By increasing the initial air pressure, the ability and speed of the high-pressure airflow to carry rock cuttings are increased, thereby accelerating the transportation capacity of rock cuttings and reducing the accumulation of rock cuttings. Drilling speed deviation rate = (Preset drilling speed value - Mechanical drilling speed value) / Preset drilling speed value; The drilling speed deviation rate at this point is (5-4.8) / 5 = 4%; Adjusted initial air pressure = original initial air pressure × (1 + drilling speed deviation rate) = 1.5 × (1 + 4%) = 1.56.

[0048] This invention, by introducing a comparison between the mechanical drilling rate (MRR) and a preset RMR based on an abnormal increase in intake air pressure, achieves precise determination of drilling speed compliance. When the intake air pressure is abnormal and the MMR is lower than the preset RMR, it is determined that conditions such as cuttings accumulation have substantially affected drilling efficiency. In this case, the initial air pressure is dynamically increased based on the RMR deviation rate. By simultaneously increasing the cuttings carrying capacity and transport speed of the high-pressure airflow, the cuttings removal efficiency is improved, eliminating the root cause of accumulation. This avoids the bottleneck of cuttings removal capacity caused by insufficient air pressure when only adjusting the drill bit speed. Intelligent control of air pressure increments is achieved through the RMR deviation rate, preventing energy waste and equipment load shocks caused by blindly increasing pressure, while ensuring a refined response to different degrees of blockage. Rapid and directional air pressure compensation can effectively suppress the continuous deterioration of drilling efficiency, prevent the risk of drill bit wear and impactor failure caused by repeated cuttings breakage, and ensure that the drilling speed quickly recovers to the expected level. Thus, while maintaining smooth cuttings removal, it significantly improves the overall drilling economy and process reliability in hard rock formations.

[0049] Specifically, in response to the fact that adjusting the initial air pressure alone does not meet the drilling speed qualification requirements, the rotation speed of subsequent drilling components is increased based on the drilling speed deviation rate and the current drilling component rotation speed.

[0050] In this embodiment of the invention, when the drilling speed qualification is determined in the next time, if the mechanical drilling speed value is still less than the preset drilling speed value, the drilling speed is determined to be unqualified. This indicates that adjusting the initial air pressure alone is still not enough to meet the drilling speed qualification requirements. Based on the drilling speed deviation rate and the current drilling component rotation speed, the rotation speed of the subsequent drilling components is increased. It can be understood that increasing the rotation speed of the subsequent drilling components is also increasing the rotation speed of the subsequent drill string.

[0051] For example, if the current drill string speed has been adjusted to 33 r / min, the subsequent drill string speed calculation is as follows: Subsequent drill bit rotation speed = 33 × (1 + 4%) = 34.3 r / min; Further, by increasing the drilling tool's ability to break and disperse the impacted formation, the accumulation of cuttings can be reduced. This aims to quickly restore the high-pressure airflow's ability to transport cuttings, preventing cuttings accumulation from affecting drilling efficiency. By restoring the transport capacity of the broken cuttings, the drilling efficiency is ensured by guaranteeing the impact crushing of the formation by the down-the-hole hammer and the cutting crushing of the formation by the drilling tool.

[0052] When the initial wind pressure is increased alone and still cannot meet the requirements for the qualification of the drilling speed in the embodiments of the present invention, the deviation rate of the drilling speed is further introduced to coordinately regulate the rotation speed of the drill string, realizing the joint optimization of the wind pressure regulation and the mechanical crushing ability. By increasing the subsequent drill string rotation speed in proportion based on the existing rotation speed according to the deviation rate of the drilling speed, the ability of the drill string to perform secondary cutting on the formation after impact crushing and disperse the rock debris is strengthened, and the rock debris accumulation form is actively reduced from the dimension of mechanical action, assisting the high-pressure air flow to improve the chip carrying efficiency. It effectively overcomes the problems that may be faced by simply increasing the wind pressure, such as local blockage of the chip discharge channel or the adhesive force of the rock debris exceeding the carrying capacity of the high-pressure air flow. Through the linkage adjustment of the wind pressure and the rotation speed, a cooperative chip discharge mechanism of air flow transportation and mechanical dispersion is formed, which can quickly restore the smooth migration of the broken rock debris, ensuring the continuous impact efficiency of the down-the-hole hammer on the fresh rock formation and the cutting and crushing effect of the drill string. The hierarchical response and gradually strengthened regulation logic not only avoid the equipment stress concentration and energy consumption increase caused by premature and excessive adjustment of a single parameter, but also can achieve precise reinforcement during the chip discharge bottleneck period, quickly suppressing the drilling efficiency fluctuation caused by repeated rock debris accumulation, and ensuring the high-efficiency continuity and long-term stability of the drilling process in deep-hole hard rock formations.

[0053] Step S3, obtain the torque of the drilling assembly to determine the actual torque value, and based on the actual torque value being greater than the preset torque value, regulate the subsequent drilling pressure according to the torque deviation rate, where the torque deviation rate is determined according to the actual torque value and the preset torque value; Specifically, the process of determining the passivation qualification according to the actual torque value includes, Compare the actual torque value with the preset torque value to determine the passivation qualification; In response to the passivation being unqualified, reduce the subsequent drilling pressure according to the torque deviation rate in combination with the current drilling pressure.

[0054] The actual torque value can be obtained through a multi-parameter drilling parameter instrument, or the actual torque value of the drill string can be obtained through a torque sensor arranged at the connection between the drill string and the power device, that is, the actual torque value of the drill tool or the drilling assembly. Compare the actual torque value with the preset torque value to determine the passivation qualification; If the actual torque value ≤ the preset torque value, determine that the passivation is qualified; If the actual torque value > the preset torque value, determine that the passivation is unqualified; In the embodiments of the present invention, the preset torque value is determined by setting a margin according to the torque value corresponding to the initial state of the drill tool. For example, the torque value corresponding to the initial state of the drill tool is 10 kN·m, and according to experience, the preset torque value is taken as 12 kN·m, giving the torque value corresponding to the drill tool still being able to reach the expected state after experiencing expected wear and passivation during long-term use.

[0055] During drilling, the down-the-hole hammer is driven by impact force to break the formation. The rotation of the drill string cuts the broken formation. When the drill string is in the expected dulling state, it still maintains sufficient sharpness to cut the rock formation. Under the preset torque value, the rock formation is cut and dispersed. However, when the dulling of the drill string exceeds the expected state, the rotation of the drill string changes from cutting the rock formation to a situation of partial abrasion. The friction increases, the cutting ability of the rock formation decreases, and a greater torque is required to complete the breaking of the rock formation. When the actual torque value is less than or equal to the preset torque value, it indicates that the current drill bit's sharpness can still complete the rock formation breaking as expected under the expected torque condition, and complete the transportation of rock cuttings under the high-pressure airflow, thus the passivation is deemed qualified; for example, if the current actual torque value is detected to be 11.5 kN·m, it indicates that the current drill bit has wear and passivation after long-term use, and the sharpness has gradually decreased, but it can still reach the expected state and meet the expected drilling requirements.

[0056] When the actual torque value is greater than the preset torque value, it indicates that when the drill bit is used to break the rock layer after impact crushing, the drill bit is not sharp enough, so there is already a process of crushing and grinding when cutting the rock layer. A larger torque is required to achieve the expected drilling speed, and the passivation is deemed unqualified. At this point, it is necessary to reduce the drilling pressure according to the torque deviation rate to avoid excessive drilling pressure, which would accelerate the wear of the drill bit beyond the expected position and aggravate the passivation of the drill bit. By reducing the drilling pressure, the pressure of the drill bit during feeding can be reduced, thereby suppressing the passivation rate of the drill bit. Torque deviation rate = (actual torque value - preset torque value) / preset torque value; For example, the current actual torque value is 12.4 kN·m, which indicates that the wear condition of the drill bit has exceeded expectations. Under the condition of meeting the current drilling requirements of the drill bit, the actual torque value required exceeds the preset torque value, and the sharpness of the drill bit decreases. Torque deviation rate = (12.4-12) / 12 = 3.3%; At this point, the drilling pressure needs to be reduced according to the torque deviation rate. The drilling pressure adjustment rate is set to twice the torque deviation rate. At this point, the drilling pressure is reduced by 6.6%, and the reduced drilling pressure is 1.87t. As is well known, the drilling pressure adjustment rate can also be set according to different drilling conditions, different drilling tools, different preset torque values, and different actual situations.

[0057] This invention establishes a quantitative standard for determining the passivity of drill bit passivation by comparing the actual torque value with a preset torque value. When the actual torque value exceeds the preset torque value, it is determined that the drill bit sharpness has decreased beyond expectations, and significant rolling and grinding behavior occurs during rock cutting. At this time, the subsequent drilling pressure is dynamically reduced based on the torque deviation rate. By reducing the feed pressure, the abnormal wear rate of the drill bit is suppressed, avoiding further degradation of cutting ability caused by increased passivation under high drilling pressure conditions. This avoids the situation of ignoring drill bit passivation associated with torque changes, and achieves real-time perception and intelligent response to the degree of passivation. Based on the torque deviation rate and combined with a preset adjustment coefficient, the drilling pressure is finely adjusted. This prevents drill bit failure caused by excessively high drilling pressure, resulting in abnormal wear or even drill breakage accidents, while also avoiding a sharp drop in drilling efficiency due to premature or excessive reduction of drilling pressure. By proactively controlling the adaptive reduction of drilling pressure during the passivation stage, the effective service life of the drill string can be effectively extended, the stability and controllability of the cutting process can be maintained, and the increase in auxiliary working hours and operating costs caused by frequent drill string removal for inspection or replacement can be reduced. Thus, while ensuring drilling continuity, the economy and safety of drilling in hard formations can be optimized in a coordinated manner.

[0058] Step S4: In response to the air intake pressure value being greater than the preset air intake value, and based on the grinding loss index being greater than the preset grinding index, the preset drilling speed value is adjusted according to the grinding deviation rate. The grinding loss index is determined based on the mechanical drilling speed and the actual torque value, the preset grinding index is determined based on the preset drilling speed and the preset torque value, and the grinding deviation rate is determined based on the grinding loss index and the preset grinding index.

[0059] Please see Figure 4 As shown, it is a flowchart for determining the performance qualification of drilling tools according to an embodiment of the present invention; Specifically, the process of determining the performance qualification of drill bits based on the grinding loss index includes comparing the grinding loss index with the preset grinding index to determine the performance qualification of drill bits. In response to the determination of unqualified drill bit performance, the preset drilling speed and initial drilling pressure are reduced based on the grinding deviation rate.

[0060] The grinding loss index is constructed by obtaining the mechanical drilling speed value and the actual torque value. The grinding loss index is compared with the preset grinding index to determine the performance qualification of the drill bit. If the grinding wear index is less than or equal to the preset grinding index, the drill bit is deemed to be of qualified performance. If the grinding wear index is greater than the preset grinding index, the drill bit performance is deemed unqualified. In this embodiment of the invention, the grinding wear index is set to G, the preset grinding index is Gi, the mechanical drilling speed is X, the preset drilling speed is Xi, the actual torque is T, and the preset torque is Ti. G = (Xi / X) × (T / Ti); For example, the current mechanical drilling speed is 4.8 m / h, and the actual torque is 12.4 kN·m; G=(5 / 4.8)×(12.4 / 12)=1.076; The preset grinding index is determined based on experience after adjusting for torque and drilling speed under expected conditions. Gi = K × (Xi / X) × (T / Ti), where K is a correction coefficient used to adjust the calculation result of (Xi / X) × (T / Ti) according to the actual drilling conditions and different drill string requirements, so as to meet the comprehensive evaluation of drill string performance. The value range of K is usually 0.8 to 1, and it is set to 1 based on experience. It is used to correct the calculation result of (Xi / X) × (T / Ti). Under the expected conditions, Xi≤X, T≤Ti, and the maximum value of (Xi / X) × (T / Ti) is 1. Therefore, the preset grinding index is set to 1. When the grinding wear index is less than or equal to the preset grinding index, it indicates that the current mechanical drilling speed exceeds the preset drilling speed or the actual torque is less than the preset torque. Only one direction of abnormality needs to be adjusted to determine that the drill bit performance is qualified. When the grinding wear index is greater than the preset grinding index, it indicates that the current mechanical drilling rate is much less than the preset drilling rate or the actual torque is much greater than the preset torque, or both occur at the same time. The performance of the drill bit is severely degraded, affecting drilling operations, and the drill bit performance is judged to be unqualified. At this point, the preset drilling speed value needs to be reduced according to the grinding deviation rate to prevent damage to the drill string caused by excessive pursuit of drilling speed. By reducing the preset drilling speed value, the grinding wear index can be reduced when the grinding wear index is constructed next time. At the same time, the speed adjustment range when increasing the subsequent drill string speed is reduced, as well as the adjustment range of the initial drilling pressure is reduced, thereby reducing the drilling speed, slowing down the wear and dulling of the drill string, extending the service life of the drill string, preventing the drilling process interruption caused by rapid failure of the drill string, and replacing the drill string when drilling can still be completed while making reasonable use of the drill string, thus reducing the decrease in drilling speed.

[0061] The grinding deviation rate = (grinding wear index - preset grinding index) / preset grinding index; Grinding deviation rate = (1.076-1) / 1 = 7.6%, The reduced preset drilling speed value = original preset drilling speed value × (1 - grinding deviation rate); The reduced preset drilling speed = 5 × (1 - 7.6%) = 4.62; At the same time, the initial drilling pressure is reduced based on the grinding deviation rate. Reduced initial drilling pressure = original initial drilling pressure × (1 - grinding deviation rate); The reduced initial drilling pressure = 2 × (1 - 7.6%) = 1.85; By reducing the preset drilling speed and initial drilling pressure to regulate the drilling speed, the excessive pursuit of drilling speed can lead to rapid wear of the drill string and waste of the drill string. This ensures the continuity and integrity of the drilling process while making reasonable use of the drill string, and prevents frequent interruptions and replacements of the drilling process due to unreasonable use of the drill string.

[0062] This invention achieves a quantitative evaluation of the overall performance of drilling tools by constructing a grinding loss index based on mechanical drilling rate and actual torque values ​​and comparing it with a preset grinding index. When the grinding loss index exceeds the preset grinding index, it indicates that the drilling tool is in a severely deteriorated state, with the mechanical drilling rate significantly lower than expected or the actual torque far exceeding the preset range, or even both deteriorating simultaneously. In this case, the preset drilling rate value is dynamically reduced based on the grinding deviation rate, and the initial drilling pressure is reduced simultaneously. By reducing the expected drilling rate and drilling pressure, drilling operations are carried out while ensuring that the drilling tool can still work effectively. This overcomes the limitations of single-parameter control, transforming the drilling rate target and drilling pressure setting from fixed values ​​into dynamic thresholds that adaptively adjust with the degradation of drilling tool performance. This avoids the rapid wear, overheating failure, or even drill string breakage caused by forcibly maintaining the original efficiency target when the drilling tool is severely dulled or worn. By proactively reducing the expected drilling rate and feed pressure, drilling parameters are matched with the actual load-bearing capacity of the drill string. This effectively suppresses the accelerated degradation of drill string performance while ensuring basic drilling continuity, extending the effective service life of the drill string and reducing unplanned hoisting, inspection, and replacement operations caused by sudden drill string failures. This significantly reduces drill string consumption costs and auxiliary time losses. Simultaneously, the construction of the grinding wear index allows for a more comprehensive assessment of drill string performance, coordinating the relationship between drill string performance and drilling speed. This avoids frequent drill string failures caused by excessive pursuit of drilling efficiency, thus enabling more efficient use of the drill string while simultaneously improving drilling efficiency, comprehensively enhancing the safety, economy, and intelligence of the drilling process in hard formations.

[0063] Step S5: Based on the fact that the grinding wear index is less than the ideal grinding index, adjust the initial drilling pressure according to the preset drilling pressure adjustment amount.

[0064] Specifically, in response to the qualification of drill bit performance and based on the fact that the grinding loss index is less than the ideal grinding index, the initial drilling pressure is increased according to the preset drilling pressure adjustment amount.

[0065] In this embodiment of the invention, when the grinding wear index is less than or equal to the preset grinding index, the grinding wear index is further compared with the ideal grinding index to determine the qualification level of the drill bit performance. The ideal grinding index is determined by empirically correcting the torque and drilling speed under the expected conditions, in the same way as determining the preset grinding index. At this time, the ideal grinding index is used to determine whether the grinding wear index is qualified, and K is set to 0.8.

[0066] If the grinding wear index is greater than or equal to the ideal grinding index, it indicates that the current drilling speed meets expectations and does not exceed expectations, there is no redundancy in drilling speed, and the current initial drilling pressure remains unchanged. If the grinding wear index is less than the ideal grinding index, it indicates that the current drilling speed is far exceeding the expected drilling conditions. In addition, when the drilling speed exceeds expectations, the sharpness of the drill bit is also within the expected range. The dulling of the drill bit is excessive. The initial drilling pressure can be adjusted according to the preset drilling pressure adjustment amount to speed up the drilling efficiency, shorten the drilling period, ensure the rapid completion of drilling operations, and save resources.

[0067] This invention, based on the premise that the drill string performance is qualified, further introduces an ideal grinding index to refine the evaluation of the grinding loss index. When the grinding loss index is lower than the ideal grinding index, it indicates that the drill string not only meets the expected performance requirements, but also that the mechanical drilling rate significantly exceeds expectations and the actual torque is significantly lower than the preset value, indicating a performance redundancy. The initial drilling pressure is then proactively increased according to the preset drilling pressure adjustment amount. This avoids performance redundancy that occurs when the drill string performance exceeds expectations despite being qualified. By increasing the drilling pressure, drilling efficiency is accelerated, and the excess performance of the drill string is fully utilized. Under ideal conditions of sufficient drill string sharpness, smooth cuttings removal, and low load, the performance redundancy is transformed into a substantial increase in drilling speed by moderately increasing the drilling pressure, thereby shortening the drilling cycle and reducing overall drilling costs. This avoids the waste of high-efficiency conditions caused by insufficient drilling pressure and prevents the risk of equipment overload caused by excessive pressure increase through the limitation of the preset adjustment amount, achieving proactive optimization of drilling efficiency while ensuring safety boundaries. Meanwhile, the introduction of the ideal grinding index has created a multi-level performance evaluation system from unqualified to qualified to excellent, which expands the control of drilling parameters from a single abnormality correction to intelligent optimization control that covers efficiency potential tapping, significantly improving the adaptability and economy of drilling in hard formations.

[0068] After drilling a single drill string section, a foaming agent solution prepared in the correct proportion is injected into the air line between the air compressor and the drill string using a foam pump. This foam is propelled to the bottom of the hole by the airflow and then carries rock cuttings back to the surface through the annular gap between the drill string and the borehole wall. The rock cuttings are encapsulated in foam and return from the wellhead as a moist, viscous mud-like substance, completely eliminating dust and promoting green construction. This achieves dust control and environmental protection goals. The foaming agent solution includes stabilizers and anti-collapse agents. The foam forms a thin, viscoelastic foam filter cake on the borehole wall, effectively preventing moisture loss from the borehole wall, supporting the borehole wall, and preventing its peeling and collapse. The foam has higher viscosity and lower density, easily pushing and carrying larger and heavier rock cuttings back, maintaining a clean bottom hole even at low annular return velocities. After the foaming agent returns from the wellhead, the drill string is pulled up and the drill string is added, ensuring that the drilling assembly can proceed with deeper drilling.

[0069] After drilling through the hard formation, the actual torque value suddenly decreased while the mechanical drilling rate increased rapidly, indicating that the formation with high water content had been reached. This suggests that the formation was not hard at this point, and the drilling method was changed to gas lift reverse circulation to drill to the designed well depth. After drilling into the water-bearing formation, if the simultaneous drilling method of impact crushing and cutting crushing is continued, it will be ineffective because there is no hard rock layer to crush the rock during impact, resulting in the ineffectiveness of impact. The efficiency of cutting crushing by the drill string and removing rock cuttings by high-pressure airflow is much lower than that of the gas lift reverse circulation drilling process. Therefore, the more effective gas lift reverse circulation process was switched to for subsequent drilling.

[0070] In this embodiment of the invention, a down-the-hole hammer tool combining a 325mm diameter hammerhead and a 12-inch impactor was used in the experimental well section from 110.09m to 251.67m, with an air volume of 64m³. 3 Under the parameters of 1.5 MPa initial air pressure, 27 r / min drill speed, and 2 t initial drilling pressure, the average drilling efficiency is 6.36 m / h.

[0071] Compared with conventional drilling technology, conventional drilling technology, in the well section from 109.53m to 251.25m, using a conventional drill bit with a diameter of 311.1mm and with process parameters of pump pressure of 4MPa, displacement of 32L / s, rotation speed of 63r / min and drilling pressure of 10t, has an average drilling efficiency of 1.47m / h.

[0072] The comparison shows that the drilling efficiency of the water source drilling rig in the hard formation of the present invention is increased to 4.3 times that of the original drilling efficiency, which can complete the drilling task faster and more efficiently when drilling in hard formations.

[0073] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A drilling method for hard formations based on a water source drilling rig, characterized in that, include, Drilling components are arranged and air is supplied according to the preceding process. Based on the obtained air intake pressure value being greater than the preset air intake value, and based on the reverse air pressure value being greater than or equal to the preset reverse air value, the rotation speed of the drilling components is adjusted according to the air intake deviation value. The air intake deviation value is determined based on the air intake pressure value and the preset air intake value. In response to the intake air pressure value being greater than the preset intake air value, the drilling speed of the drilling components is obtained to determine the mechanical drilling speed value, and the initial air pressure is adjusted according to the drilling speed deviation rate based on the mechanical drilling speed value being less than the preset drilling speed value, wherein the drilling speed deviation rate is determined based on the mechanical drilling speed value and the preset drilling speed value. The torque of the drilling components is obtained to determine the actual torque value, and the subsequent drilling pressure is adjusted according to the torque deviation rate based on the fact that the actual torque value is greater than the preset torque value. The torque deviation rate is determined based on the actual torque value and the preset torque value. In response to the air pressure value being greater than the preset air pressure value, and based on the grinding loss index being greater than the preset grinding index, the preset drilling speed value is adjusted according to the grinding deviation rate. Based on the fact that the grinding wear index is less than the ideal grinding index, the initial drilling pressure is adjusted according to the preset drilling pressure adjustment amount. The grinding loss index is determined based on the mechanical drilling speed and the actual torque value, the preset grinding index is determined based on the preset drilling speed and the preset torque value, and the grinding deviation rate is determined based on the grinding loss index and the preset grinding index.

2. The drilling method for hard formations based on a water source drilling rig according to claim 1, characterized in that, The process of determining the compliance of chip removal based on the inlet air pressure value includes: Compare the inlet air pressure value with the preset inlet air value to determine the chip removal qualification; In response to the failure of chip removal, and based on the fact that the reverse air pressure value is greater than or equal to the preset reverse air value, the drilling component rotation speed is increased according to the air intake deviation value.

3. The drilling method for hard formations based on a water source drilling rig according to claim 2, characterized in that, In response to the failure of cuttings removal, and based on the fact that the reverse air pressure value is less than the preset reverse air value, the drilling pressure is reduced and the drilling component rotation speed is increased according to the preset drilling pressure adjustment amount.

4. The drilling method for hard formations based on a water source drilling rig according to claim 3, characterized in that, In response to increasing the drill string speed, the drilling assembly speed is increased to the maximum speed, taking into account the drill string speed range.

5. The drilling method for hard formations based on a water source drilling rig according to claim 1, characterized in that, The process of determining the qualification of drilling speed based on the mechanical drilling rate value includes: Compare the mechanical drilling rate value with the preset drilling rate value to determine the qualification of the drilling speed; In response to the drilling speed failure determination, the initial air pressure is increased based on the drilling speed deviation rate.

6. The drilling method for hard formations based on a water source drilling rig according to claim 5, characterized in that, In response to the fact that adjusting the initial air pressure alone does not meet the drilling speed qualification requirements, the rotation speed of subsequent drilling components is increased based on the drilling speed deviation rate and the current drilling component rotation speed.

7. The drilling method for hard formations based on a water source drilling rig according to claim 1, characterized in that, The process of determining the passivation qualification based on the actual torque value includes: Compare the actual torque value with the preset torque value to determine the passivity of the passivation process. In response to passivation failure, the subsequent drilling pressure is reduced based on the torque deviation rate and the current drilling pressure.

8. The method for drilling hard formations based on a water source drilling rig according to claim 1, characterized in that, The process of determining the performance qualification of drill bits based on the grinding wear index includes the following steps: The performance qualification of the drill bit is determined by comparing the grinding wear index with the preset grinding index. In response to the determination of unqualified drill bit performance, the preset drilling speed and initial drilling pressure are reduced based on the grinding deviation rate.

9. The drilling method for hard formations based on a water source drilling rig according to claim 8, characterized in that, In response to the drill bit performance qualification determination, and based on the fact that the grinding wear index is less than the ideal grinding index, the initial drilling pressure is increased according to the preset drilling pressure adjustment amount.

10. The method for drilling hard formations based on a water source drilling rig according to claim 1, characterized in that, The pre-process includes, Assemble drilling components based on drill strings, impactors, and down-the-hole hammers, and lower the drilling components to the bottom of the well; Air is supplied to the drilling components based on initial air pressure and initial air volume; The impactor is activated based on the fact that the reverse air pressure value at the wellhead is greater than the preset reverse air value, and the drill string, which is rotating at the initial speed, is fed according to the initial drilling pressure.

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