A drilling fluid supply device with steady flow delivery

Abstract

The present invention relates to a drilling fluid supply device for steady flow delivery, and relates to the technical field of drilling fluid delivery equipment. A front pre-storage component is connected to the input end of a circulating pump group, and a slow flow module capable of adjustable multi-stage buffering of the pulsating liquid flow outputted by the circulating pump group is arranged at the output end of the circulating pump group. The slow flow module comprises a rear variable capacity slow flow component, a rear multi-stage shunt component and an expansion stabilizing component connected in series in sequence. The rear variable capacity slow flow component absorbs and reduces the liquid flow pressure wave peak in a manner that can perform variable capacity slow release and adjustable energy absorption and vibration reduction on the pulsating liquid flow; the rear multi-stage shunt component completes the shunt pressure reduction of the liquid flow in a manner that can construct a multi-stage shunt channel according to the change of the pulsation intensity of the liquid flow, thereby realizing the secondary pulsation attenuation of the liquid flow. The present invention can buffer the periodically changing pressure fluctuation by constructing an adjustable deformation structure associated with the liquid flow pressure fluctuation, and also realizes the shunt pressure reduction and steady flow delivery of the liquid flow by constructing a multi-stage shunt channel.

Description

Technical Field

[0001] The invention relates to the technical field of drilling fluid delivery equipment, and in particular to a drilling fluid supply equipment with steady flow delivery. Background Art

[0002] As one of the key components of drilling engineering, the drilling mud pump can continuously deliver drilling fluids such as special mud to the bottom of the well during the drilling construction process, so that the continuously circulated drilling fluid can effectively cool the drill bit and transfer the cuttings from the well. As a key equipment of the drilling fluid circulation system, the drilling mud pump can also provide auxiliary driving force for the drilling movement of the downhole drilling tool while cooling the drill bit, so as to achieve auxiliary drilling of the drill bit. When the drilling mud pump is used to drive the drilling fluid, the liquid flow formed by the drilling mud will pulsate with the change of the driving force of the mud pump. The liquid flow pulsation will cause the liquid flow pressure to fluctuate continuously, which seriously affects the continuous and stable supply of drilling fluid. The liquid flow pulsation mainly comes from the movement characteristics of the mud pump's own structure and the particularity of its working environment and transmission medium. The pressure pulsation caused by the flow pulsation of the reciprocating mud pump will cause the pipeline and pump casing to vibrate. This vibration may sometimes produce resonance, and the resonance frequency can be twice or more than the flow pulsation frequency. In addition, due to the pulsation or impact of the liquid in the cavity, the transmission pipeline vibrates, which then excites noise. For reciprocating mud pumps, the pressure fluctuation of the liquid flow can be effectively reduced by slowly releasing the pulsating shock, ensuring the stability of the flow of drilling mud and reducing the working noise and fatigue damage of the equipment.

[0003] At present, the existing pulsation relief method is to install an airbag buffer device at the discharge outlet of the drilling pump, and use the compressibility of the inflatable airbag to alleviate the fluctuation of the discharge pressure of the drilling pump. This method is simple and easy to implement. For example, the patent document with publication number CN105464959A discloses a pump pressure damper, including an upper cavity assembly, a lower cavity assembly and an oil-resistant rubber pad. The lower opening of the upper cavity assembly and the upper opening of the lower cavity assembly are connected by a flange seal. The oil-resistant rubber pad is arranged at the connection between the upper cavity assembly and the lower cavity assembly. The oil-resistant rubber pad separates the upper cavity assembly and the lower cavity assembly, and the upper cavity assembly is filled with damping liquid or damping gas. The oil-resistant rubber pad of the pump pressure damper can deform synchronously with the pressure fluctuation of the liquid flow, thereby reducing the pressure fluctuation and flow pulsation of the drilling mud circulation system pipeline. However, the existing deformable and retractable structures such as airbags cannot adjust their structural strength in real time following the pulsation of the liquid flow, and cannot effectively attenuate the periodic pressure fluctuations. The continuously unchanged elastic parameters provided by the airbag-type buffer structure cannot effectively release the liquid flow at different time points, and it is also very easy to be deformed and damaged due to overwork. In addition, the existing liquid flow pressure buffer device cannot adjust the flow rate of the liquid flow that changes at all times, resulting in the liquid flow pressure flow being unable to obtain sufficient pressure reduction and stable flow through the retractable structures such as airbags, and there are still fluctuations in the flow rate, resulting in the drilling mud flow that eventually flows into the downhole drilling equipment still having periodic flow changes, and the stability of the drilling drive cannot be guaranteed. Summary of the invention

[0004] The purpose of the present invention is to provide a drilling fluid supply device that can buffer periodic pressure fluctuations by constructing an adjustable deformation structure associated with the pressure fluctuations of the liquid flow, and can also realize the diversion, decompression and steady flow delivery of the liquid flow through a multi-stage shunt channel that can change the conduction of the parallel branch by utilizing the pulsating impact of the liquid flow, so as to solve the problem that the existing airbag-type buffer device with a fixed deformation area cannot effectively relieve the continuously fluctuating liquid flow pulsation, especially cannot adjust the adaptability of the structural strength in association with the pressure fluctuation, cannot effectively attenuate the periodic pressure fluctuation, and is also very prone to overwork deformation and damage due to the ever-changing pulsating impact. In addition, it also avoids the defect that the existing liquid flow pressure buffer device cannot adjust the ever-changing flow rate of the liquid flow, resulting in the inability of the liquid flow to obtain sufficient pressure reduction and steady flow through retractable structures such as airbags.

[0005] The technical solution adopted by the present invention is: a drilling fluid supply device with steady flow delivery, including a circulating pump group capable of continuously driving the directional flow of drilling fluid, wherein the input end of the circulating pump group is connected to a front pre-storage component capable of supplying sufficient drilling fluid to the circulating pump group in a pre-storage manner; the output end of the circulating pump group is provided with a slow flow module capable of adjustable multi-stage buffering of the pulsating fluid flow outputted by the circulating pump group, wherein the slow flow module comprises a rear variable capacity slow flow component, a rear multi-stage flow diversion component and a capacity expansion steady flow component which are sequentially connected in series, and the components between the circulating pump group and the rear multi-stage flow diversion component are connected in series. The post-positioned variable volume slow flow component between the flow components absorbs and reduces the pressure peak of the liquid flow in a manner that can perform variable volume slow release and adjustable energy absorption and vibration reduction on the pulsating liquid flow, so that the liquid flow output by the circulating pump group obtains the initial pulsation attenuation; the post-positioned multi-stage shunt component completes the shunt and decompression of the liquid flow in a manner that can construct a multi-stage shunt channel according to the change of the pulsation intensity of the liquid flow, thereby performing secondary pulsation attenuation on the liquid flow output by the post-positioned variable volume slow flow component, and the output end of the multi-stage shunt channel constructed by the post-positioned multi-stage shunt component is connected to the pre-positioned pre-storage component. Its advantage is that the post-positioned variable volume slow flow component and the post-positioned multi-stage shunt component provided in the present application can use different slow release methods to perform dual attenuation and filtering on the flow pulsation of the liquid flow, reduce the impedance of the dynamic transmission of the liquid flow, effectively balance the flow, and control the pressure fluctuation within the allowable range to meet actual needs. Both the post-mounted variable volume slow-flow component and the post-mounted multi-stage diversion component can adapt to the operating conditions according to the pressure fluctuation of the liquid flow, so that both can adapt to different operating conditions at different time points, achieve better vibration reduction and slow-release effects, and meet the needs of actual production.

[0006] According to a preferred embodiment, the post-mounted multi-stage flow diversion component includes a flow guide tube shell, a translational flow diversion mechanism, a deflection and volume retention mechanism and a flow diversion branch pipe, wherein the flow guide tube shell is composed of a plurality of coaxially connected coaxial tube bodies, and the plurality of coaxial tube bodies are each provided with the translational flow diversion mechanism which is coaxial with the coaxial tube body and can undergo relative axial movement, and the flow diversion branch pipe which can be blocked by the translational flow diversion mechanism is also inserted on the side wall of the coaxial tube body; the deflection and volume retention mechanism which can adjust the size of its conducting cross-section according to the liquid flow state is also provided in the translational flow diversion mechanism.

[0007] According to a preferred embodiment, the guide core tube of the translational diversion mechanism is movably inserted into the coaxial tube body in the manner of a coaxial sleeve, and an extended side plate is provided on the outer wall of the guide core tube, which can cooperate with a first limit spring to limit the relative working position of the guide core tube in the coaxial tube body; the extended side plate is movably inserted into a guide groove provided on the inner wall of the coaxial tube body, and the extended side plate can slide back and forth along the grooving direction of the guide groove, and the first limit spring is provided in the groove cavity of the guide groove, which can limit the axial relative position between it and the extended side plate.

[0008] According to a preferred embodiment, the pressure plate of the deflection and quantity protection mechanism is movably embedded on the end face of the tube body of the guide core tube, and is also connected to a linkage rod inserted in the tube body of the guide core tube, and a second limit spring capable of limiting the depth of the pressure plate embedded in the guide core tube is also sleeved on the rod body of the linkage rod; the end of the linkage rod away from the pressure plate is also connected to a rack, and the rack can engage with a gear rotatably positioned in the tube body of the guide core tube by a rotating shaft.

[0009] According to a preferred embodiment, the rotating shaft is rotatably arranged on the guide core tube body in a manner of penetrating the tube cavity of the guide core tube, and a deflection baffle capable of changing the size of the guide cross-section of the guide core tube is arranged on the shaft of the rotating shaft in the tube cavity of the guide core tube; a positioning torsion spring capable of limiting the initial deflection amount between it and the deflection baffle is also arranged on the rotating shaft.

[0010] According to a preferred embodiment, the post-mounted variable capacity slow flow component includes a main shell, an elastic ring body, an annular cover and a variable limiting mechanism, wherein the elastic ring body constituting a deformable shell wall is embedded on the side wall of the main shell, and the annular cover is installed on the outer wall of the main shell in a manner that it forms an annular chamber on the outer side of the main shell and covers the elastic ring body; the variable limiting mechanism capable of changing the deformable area of ​​the elastic ring body is also provided on the outer side of the main shell.

[0011] According to a preferred embodiment, a first inlet pipe and a first outlet pipe are staggeredly arranged on the side wall of the main shell, a single-port pipe body connected to its tube cavity is also installed on the tube body of the first inlet pipe, and a closed cover body is provided at one end of the single-port pipe body away from the first inlet pipe.

[0012] According to a preferred embodiment, the rigid ring plate of the variable limiting mechanism is movably mounted on the main shell body in a manner of being able to cover a portion of the elastic ring body, and the rigid ring plate is connected to the plug body by an inverted U-shaped connecting rod passing through the annular cover shell; the plug body is installed in the single-port tube body in a manner of forming a variable tight cavity in the single-port tube body in cooperation with the closed cover body, and the inverted U-shaped connecting rod is connected to the plug body by passing through the closed cover body.

[0013] According to a preferred embodiment, the pre-tank body of the pre-storage assembly is connected to the inlet end of the circulation pump group through a discharge port; a liquid inlet and a liquid return port connected to the output end of the branch pipe are arranged on the side of the pre-tank body.

[0014] According to a preferred embodiment, the expansion and flow stabilization component includes a rear tank body capable of stabilizing the liquid flow output by the rear multi-stage flow diversion component, and a second inlet pipe and a second outlet pipe staggeredly arranged on both sides of the rear tank body.

[0015] The beneficial effects of the present invention are:

[0016] The pre-storage component provided in the present application can ensure the stability and fullness of the periodic suction of the drilling fluid by the circulating pump group, avoid abnormal supply fluctuations in the drilling fluid flow, and facilitate the subsequent slow flow module to effectively regulate and release the regularly changing pulsating fluid flow. The provision of the pre-storage component can provide supply protection for the equipment to a certain extent and increase the service life of the equipment. The pre-storage component can also simultaneously receive the excess fluid flow diverted, so that part of the drilling fluid diverted due to the pressure fluctuation of the fluid flow can be recycled for a second time, thereby improving the stability and energy saving of the drilling fluid supply.

[0017] The post-variable slow-flow component provided in the present application can absorb, release and resonate the pressure fluctuation of the liquid flow flowing through the chamber by providing an elastic deformation cavity wall structure whose area size can change in correlation with the pressure fluctuation of the pulsating liquid flow, so that the liquid flow gradually tends to be stable, reducing the equipment damage caused by the pulsating impact of the liquid flow and the volatility of the driving force of the drilling system, so that the equipment can supply drilling fluid in a manner with stable pressure and stable flow. The post-variable slow-flow component provided in the present application can adjust its release capacity following the pressure fluctuation of the liquid flow, realize the effective reduction of the pressure fluctuation, and reduce the peak value of the pressure fluctuation of the liquid flow output from it. In addition, when the post-variable slow-flow component completes the initial pulsation attenuation of the liquid flow, the post-multi-stage shunt component provided in the present application can further perform secondary pulsation attenuation on the liquid flow by means of shunt decompression, thereby improving the effectiveness of regulating the smooth delivery of the liquid flow. The post-multi-stage shunt component can further reduce the peak value of the pressure fluctuation of the liquid flow, so that the liquid flow can be continuously and quantitatively output steadily. The rear multi-stage shunt assembly can conduct different numbers of shunt branches according to the pressure fluctuation of the liquid flow to achieve graded pressure reduction of the liquid flow. The graded adjustment driving force of the rear multi-stage shunt assembly is provided by the liquid flow input into it, so that the rear multi-stage shunt assembly can effectively adapt to the pressure fluctuation of the liquid flow, and effectively shunt the continuously changing fluctuation of the liquid flow in a correlation manner to ensure the stability of the liquid flow rate actually transported. In addition, the rear multi-stage shunt assembly can also use the pulsating impact of the liquid flow to adaptively adjust the size of its pipeline cross-section, so that it can reduce the instantaneous flow when the liquid flow pressure increases and the flow rate increases to ensure the unchanged unit flow, achieve a high degree of continuous and stable liquid flow output, and effectively eliminate the fluctuation of the liquid flow. The constant unit flow rate limited by the rear multi-stage shunt assembly realizes the flow stability of the drilling fluid received by the drilling system, ensures the smooth drive of the drilling tool, and avoids excessive wear of the drilling tool caused by the fluctuation of the drilling fluid. In particular, while ensuring the abundance of continuous supply of drilling fluid, it realizes the reduction and transfer of instantaneous excess increments, and also realizes the effective and stable driving of the drilling tool and the buffering protection of the entire equipment system. The post-variable slow-flow component and the post-multi-stage shunt component provided in the present application can utilize different slow-release methods to perform double attenuation and filtering on the flow pulsation of the liquid flow, reduce the impedance of the dynamic transmission of the liquid flow, effectively balance the flow, and control the pressure fluctuation within the allowable range to meet the actual needs. The post-variable slow-flow component and the post-multi-stage shunt component can both change the adaptive working conditions following the pressure fluctuation of the liquid flow, so that the two can adapt to different working conditions at different time points, play a better vibration reduction and slow-release effect, and meet the needs of actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a preferred steady-flow-delivery drilling fluid supply device proposed by the present invention;

[0019] Figure 2 It is a structural schematic diagram of a post-positioned variable volume slow flow component of a preferred steady flow delivery drilling fluid supply device proposed by the present invention;

[0020] Figure 3 It is a structural schematic diagram of a post-positioned variable volume slow flow component of a preferred steady flow delivery drilling fluid supply device proposed by the present invention when the fluid flow pressure fluctuation increases;

[0021] Figure 4 It is a structural schematic diagram of a post-positioned variable volume slow flow component of a preferred steady flow delivery drilling fluid supply device proposed by the present invention when the fluid flow pressure fluctuation is reduced;

[0022] Figure 5 It is a structural schematic diagram of a post-mounted multi-stage flow distribution component of a preferred steady-flow delivery drilling fluid supply device proposed by the present invention;

[0023] Figure 6 It is a schematic plan view of a post-mounted multi-stage flow diversion component of a preferred steady-flow delivery drilling fluid supply device proposed by the present invention.

[0024] Reference numerals list

[0025] 1: circulating pump group; 2: front pre-storage component; 3: rear variable volume slow flow component; 4: rear multi-stage flow diversion component; 5: expansion and steady flow component; 11: reciprocating drilling mud pump; 12: liquid supply main pipe; 13: one-way liquid inlet module; 14: one-way liquid outlet module; 21: front tank body; 22: liquid discharge port; 23: liquid inlet port; 24: liquid return port; 31: main shell; 32: elastic ring body; 33: annular cover shell; 34: variable limiting mechanism; 311: first inlet pipe; 312: first outlet pipe; 313: single-port pipe body; 314: closed cover body; 341: rigid ring plate; 34 2: inverted U-shaped connecting rod; 343: plug body; 41: flow guide tube shell; 42: translational diversion mechanism; 43: deflection and quantity retention mechanism; 44: diversion branch pipe; 411: coaxial tube body; 412: deformation joint; 421: flow guide core tube; 422: extension side plate; 423: first limit spring; 424: guide groove; 431: pressure plate; 432: linkage rod; 433: second limit spring; 434: rack; 435: gear; 436: rotating shaft; 437: deflection baffle; 438: positioning torsion spring; 51: rear tank body; 52: second inlet pipe; 53: second outlet pipe. DETAILED DESCRIPTION

[0026] The following is a detailed description with reference to the accompanying drawings.

[0027] The present application provides a steady-flow drilling fluid supply device, which includes a circulating pump group 1, a front pre-storage component 2, a rear variable-volume slow-flow component 3, a rear multi-stage flow diversion component 4 and a capacity expansion steady-flow component 5. In view of the problem that the existing mud pump will produce liquid flow pulsation when driving drilling fluids such as drilling mud due to the limitation of the movement mechanism of the crank push rod structure, it is necessary that the liquid flow corresponding to the instantaneous minimum driving force of the mud pump can meet the supply demand of the drilling work, so as to ensure the sufficiency of the auxiliary driving force continuously supplied by the drilling mud liquid flow. However, due to the existence of liquid flow pulsation, the instantaneous flow of the periodically fluctuating liquid flow at the peak will cause impact and damage to the entire conveying pipeline, and directly flowing into the drilling system will have obvious supply fluctuations, affecting the stability of drilling. Therefore, it is necessary to design a drilling fluid supply device that can effectively release the liquid flow pulsation and reduce the pressure of the liquid flow.

[0028] according to Figure 1 A specific embodiment is shown, in which the circulating pump group 1 can continuously drive the directional flow of drilling fluid. The input end of the circulating pump group 1 is connected to a pre-storage component 2 that can supply sufficient drilling fluid to the circulating pump group 1 by pre-storage. The output end of the circulating pump group 1 is provided with a slow flow module that can adjustably buffer the pulsating liquid flow outputted therefrom in multiple stages. The slow flow module includes a post-positioned variable volume slow flow component 3, a post-positioned multi-stage shunt component 4 and a capacity expansion and stabilizing flow component 5 that are sequentially connected in series. The post-positioned variable volume slow flow component 3 between the circulating pump group 1 and the post-positioned multi-stage shunt component 4 absorbs and reduces the liquid flow pressure peak in a manner that can perform variable volume slow release and adjustable energy absorption and vibration reduction on the pulsating liquid flow, so that the liquid flow outputted by the circulating pump group 1 obtains the initial pulsation attenuation. The post-positioned multi-stage shunt component 4 completes the shunt decompression of the liquid flow in a manner that can adjustably form a multi-stage shunt channel according to the change in the pulsation intensity of the liquid flow, thereby performing secondary pulsation attenuation on the liquid flow outputted from the post-positioned variable volume slow flow component 3. The output end of the multi-stage flow diversion channel constructed by the rear multi-stage flow diversion component 4 is connected to the front pre-storage component 2, so that the excess drilling fluid diverted by the rear multi-stage flow diversion component 4 can be recovered for a second time and driven for a second time by the circulating pump group 1, thereby realizing a continuous and stable equal supply of drilling fluid. The expansion and stabilizing flow component 5 can construct a secondary stabilizing flow cavity, so that it can ensure the real-time abundance of the drilling fluid finally input into the drilling system, and effectively supplement the variable speed fluid flow output by the multi-stage flow diversion component 4 to ensure the stability of the comprehensive continuous supply of drilling fluid.

[0029] The pre-storage component 2 provided in the present application can pre-store drilling fluid that is greater than the single suction amount of the circulating pump group 1. Under the condition of continuous input of drilling fluid, the circulating pump group 1 can obtain sufficient drilling fluid, ensure the stability and abundance of the periodic suction of drilling fluid by the circulating pump group 1, avoid abnormal supply fluctuations in the drilling fluid flow, and facilitate the subsequent slow flow module to effectively regulate and release the regularly changing pulsating fluid flow. When the suction performance of the mud pump is poor, the pressure fluctuations during the suction process are drastic, the pump valve will not be well filled with water, the hydraulic end will emit impact noise, the pump body and the suction pipeline will vibrate, etc., causing the drilling operation to be unable to proceed normally. Therefore, the setting of the pre-storage component 2 can provide supply protection for the equipment to a certain extent and improve the service life of the equipment. The pre-storage component 2 can also receive the excess liquid flow diverted at the same time, so that part of the drilling fluid diverted due to the pressure fluctuation of the liquid flow can be recycled for the second time, which improves the stability and energy saving of the drilling fluid supply.

[0030] The slow flow module provided in the present application can buffer and reduce the pressure fluctuation of the pulsating liquid flow output by the circulating pump group 1 multiple times by cooperating with multiple components, thereby ensuring that the final output flow rate remains unchanged and improving the stability of the liquid flow, so that the driving effect provided by the liquid flow input to the drilling system is continuous and stable, avoiding adverse effects on the drilling effect due to fluctuations in the driving force.

[0031] The post-positioned variable volume slow flow component 3 provided in the present application can absorb, release and resonate the pressure fluctuation of the liquid flow flowing through the chamber by providing an elastic deformation cavity wall structure whose area size can change with the pressure fluctuation of the pulsating liquid flow, so that the liquid flow gradually tends to be stable, reduces the equipment damage caused by the pulsating impact of the liquid flow and the volatility of the driving force of the drilling system, so that the equipment can supply drilling fluid in a manner with stable pressure and stable flow. The post-positioned variable volume slow flow component 3 provided in the present application can adjust its release capacity following the pressure fluctuation of the liquid flow, realize the effective reduction of the pressure fluctuation, and reduce the peak value of the pressure fluctuation of the liquid flow outputted from it. In addition, when the post-positioned variable volume slow flow component 3 completes the initial pulsation attenuation of the liquid flow, the post-positioned multi-stage shunt component 4 provided in the present application can further perform secondary pulsation attenuation on the liquid flow by means of shunt decompression, thereby improving the effectiveness of regulating the smooth delivery of the liquid flow. The post-positioned multi-stage shunt component 4 can further reduce the peak value of the pressure fluctuation of the liquid flow, so that the liquid flow can be continuously and quantitatively output steadily. The rear multi-stage shunt assembly 4 can conduct different numbers of shunt branches according to the pressure fluctuation of the liquid flow to achieve graded pressure reduction of the liquid flow. The graded adjustment driving force of the rear multi-stage shunt assembly 4 is provided by the liquid flow input into it. The rear multi-stage shunt assembly 4 can effectively adapt to the pressure fluctuation of the liquid flow, and effectively shunt the fluctuation amount of the liquid flow that changes continuously in a correlation manner, thereby ensuring the stability of the liquid flow rate actually transported. In addition, the rear multi-stage shunt assembly 4 can also use the pulsating impact of the liquid flow to adaptively adjust the size of its pipeline cross-section, so that it can reduce the instantaneous flow when the liquid flow pressure increases and the flow rate increases to ensure the invariance of the unit flow, achieve a high degree of continuous and stable output of the liquid flow, and effectively eliminate the fluctuation of the liquid flow. The constant unit flow rate defined by the rear multi-stage shunt assembly 4 realizes the flow stability of the drilling fluid received by the drilling system, ensures the smooth drive of the drilling tool, and avoids excessive wear of the drilling tool caused by the fluctuation of the drilling fluid. In particular, while ensuring the adequacy of the continuous supply of drilling fluid, the instantaneous excess increment is reduced and transferred, and the effective and stable driving of the drilling tool and the buffering protection of the entire equipment system are also realized. The secondary stabilizing flow chamber formed by the expansion stabilizing flow component 5 provided in the present application can compensate for the flow velocity difference caused by the cross-sectional deviation, and realize the stabilization and slow release of the drilling fluid finally output. The expansion stabilizing flow component 5 can also store a certain amount of drilling fluid to ensure that when the flow at the input end fluctuates, its output end can ensure the adequacy of the supply. The post-variable slow flow component 3 and the post-multi-stage shunt component 4 provided in the present application can use different slow release methods to perform double attenuation and filtering on the flow pulsation of the liquid flow, reduce the impedance of the dynamic transmission of the liquid flow, effectively balance the flow, and control the pressure fluctuation within the allowable range to meet the actual needs.The post-positioned variable volume slow-flow component 3 and the post-positioned multi-stage flow diversion component 4 can both change the working conditions adaptively following the pressure fluctuation of the liquid flow, so that both can adapt to different working conditions at different time points, achieve better vibration reduction and slow-release effects, and meet the needs of actual production.

[0032] Preferably, the circulation pump group 1 includes a reciprocating drilling mud pump 11, a liquid supply main pipe 12, a one-way liquid inlet module 13 and a one-way liquid outlet module 14. Preferably, the reciprocating drilling mud pump 11 is installed in the middle section of the pipe body of the liquid supply main pipe 12, and its variable volume pump body chamber is connected to the pipe cavity of the liquid supply main pipe 12. Further preferably, a one-way liquid inlet module 13 and a one-way liquid outlet module 14 are also provided in the liquid supply main pipe 12, which are respectively located upstream and downstream of the reciprocating drilling mud pump 11, and the two can cooperate with each other to limit the liquid suction direction and liquid discharge direction of the reciprocating drilling mud pump 11 in different movement stages. Further preferably, the reciprocating drilling mud pump 11 can adopt a reciprocating three-cylinder pump, a reciprocating five-cylinder pump, etc. composed of multiple pump body modules in parallel according to needs, so that the reciprocating drilling mud pump 11 can reduce the fluctuation difference through the staggered intermittent alternating operation of the multi-cylinder structure to improve the stability of liquid flow transportation. Specifically, the drilling fluid includes but is not limited to drilling mud. Specifically, the flow pulsation generated by the drilling fluid represented by the drilling mud when forming a liquid flow comes from the periodic change of the working volume of the circulating pump group 1.

[0033] Preferably, the pre-tank body 21 of the pre-storage assembly 2 is connected to the inlet end of the circulation pump group 1 through the discharge port 22. Preferably, a liquid inlet 23 and a liquid return port 24 connected to the output end of the branch pipe 44 are provided on the side of the pre-tank body 21. Specifically, a stirring mechanism capable of continuously stirring the drilling fluid is provided in the pre-tank body 21 to ensure the uniformity of the mixing of the drilling fluid components. The pre-tank body 21 provided in the present application can be used to store part of the drilling fluid whose input amount is greater than or equal to the output amount. When the total amount inputted by the liquid inlet 23 and the liquid return port 24 fluctuates and the instantaneous flow rate is less than the output flow rate, the output flow rate can be compensated to ensure the stability and fullness of the periodic suction of the drilling fluid by the circulation pump group 1, avoid abnormal supply fluctuations in the drilling fluid flow, and facilitate the subsequent slow flow module to effectively regulate and slow release the regularly changing pulsating liquid flow. When the suction performance of the mud pump is poor, the pressure fluctuates violently during the suction process, the pump valve will not be able to fill the water well, the hydraulic end will emit impact noise, the pump body and the suction pipeline will vibrate, etc., causing the drilling operation to be unable to proceed normally. Therefore, the present application sets a sufficiently large pre-storage cavity structure to ensure a stable and sufficient supply of drilling fluid and avoid the disadvantages caused by insufficient suction. The pre-storage cavity formed by the front tank body 21 can also receive the drilling fluid returned by the branch pipe 44 when the liquid flow delivery pressure is too high, ensuring the stability of the continuous supply of drilling fluid and the circulation output of excess drilling fluid.

[0034] like Figure 2 , Figure 3 and Figure 4 As shown, the post-positioned variable volume slow flow component 3 includes a main shell 31, an elastic ring body 32, an annular cover shell 33 and a variable limiting mechanism 34. Preferably, an elastic ring body 32 constituting a deformable shell wall is embedded on the side wall of the main shell 31. Specifically, the elastic ring body 32 can shrink and expand when the pressure in the shell cavity of the main shell 31 changes, thereby changing the actual volume of the shell cavity. The elastic ring body 32 can be a cylindrical structural member formed by a rubber sheet ring. The elastic ring body 32 absorbs the impact force of the liquid flow when the pressure changes by shrinking and expanding, thereby achieving a slow release of the liquid flow pulsation. Preferably, the annular cover shell 33 is installed on the outer wall of the main shell 31 in a manner that it forms an annular chamber on the outer side of the main shell 31 and covers the elastic ring body 32. Preferably, a variable limiting mechanism 34 capable of changing the deformable area of ​​the elastic ring body 32 is also provided on the outer side of the main shell 31.

[0035] When the drilling mud flow is output from the main housing 31, the pulsating impact and pressure fluctuation of the flow can cause the elastic ring body 32 to vibrate, so that the elastic ring body 32 expands and contracts synchronously with the pressure fluctuation, and the elastic ring body 32 can offset the pulsation of the flow through its vibration under the action of the pulsating impact, so as to achieve effective slow release of the pulsating flow. Specifically, the elastic ring body 32 first absorbs the impact expansion force, and then slowly releases it to reduce the flow fluctuation, and the slow release process and the expansion force can offset each other, and the slow release reaction force can again attenuate the shock wave power of the mud flow, so as to ensure the stability of the actual output and rate, and improve the stability of the drilling fluid flow provided to the drilling system.

[0036] Preferably, a first inlet pipe 311 and a first outlet pipe 312 are staggeredly arranged on the side wall of the main shell 31. Further preferably, a single-port tube body 313 connected to its tube cavity is also installed on the tube body of the first inlet pipe 311. Preferably, a closed cover body 314 is provided at one end of the single-port tube body 313 away from the first inlet pipe 311. Specifically, an inflation valve port capable of changing the tube cavity air pressure of the single-port tube body 313 is provided on the closed cover body 314. The inflation valve port can facilitate the filling of pressurized inert gas into the variable tight cavity jointly defined by the single-port tube body 313, the closed cover body 314 and the plug body 343. Specifically, after the pulsating liquid flow enters the main shell 31, the pressure fluctuation of the liquid flow will be attenuated by the elastic elastic ring body 32 and the compressible inert gas, so that the pulsating liquid flow gradually tends to be stable, achieving the effect of pulsating slow release.

[0037] Preferably, the rigid ring plate 341 of the variable limiting mechanism 34 is movably mounted on the main housing 31 in a manner that can cover part of the elastic ring body 32. Further preferably, the rigid ring plate 341 is connected to the plug body 343 through an inverted U-shaped connecting rod 342 that penetrates the annular cover 33, so that the movement of the plug body 343 can drive the rigid ring plate 341 to rise and fall synchronously through the inverted U-shaped connecting rod 342. Preferably, the plug body 343 is installed in the single-port tube body 313 in a manner that forms a variable tight cavity in the single-port tube body 313 in cooperation with the closed cover body 314. Further preferably, the inverted U-shaped connecting rod 342 is connected to the plug body 343 by penetrating the closed cover body 314. Specifically, the plug body 343 can be pushed by the liquid flow when the liquid flow pressure in the lower tube cavity connected to the single-port tube body 313 and the first inlet tube 311 increases, and the plug body 343 moves upward in the single-port tube body 313, so that the volume of the variable tight cavity defined by the single-port tube body 313, the closed cover body 314 and the plug body 343 is reduced, driving the rigid ring plate 341 to move upward, so that the elastic ring body 32 with a larger area is not restricted by the rigid ring plate 341, and the elastic ring body 32 suppresses the impact force of the increased fluid flow by deforming in a larger area. When the liquid flow pressure decreases, the plug body 343 descends under the driving effect of the pressurized gas in the variable tight cavity and the traction effect of the liquid flow in the tight cavity, driving the rigid ring plate 341 to move downward, so that the elastic ring body 32 can achieve pressure-maintaining and slow-release of the liquid flow through a small-area expansion deformation.

[0038] Preferably, the length of the inverted U-shaped connecting rod 342 is associated with the maximum liftable distance of the rigid ring plate 341 , and the maximum liftable distance of the rigid ring plate 341 is limited by setting the length of the rod body.

[0039] Preferably, the annular chamber formed by the annular cover 33 is connected to the tube cavity of the single-port tube body 313 through the external tube body, so that the gas pressure in the inner cavities of the two is equal. When the pressure of the liquid flow increases, the volume of the variable-tight cavity defined by the single-port tube body 313, the closed cover body 314 and the plug body 343 is reduced, and the total volume of the gas in the variable-tight cavity and the gas in the annular chamber is reduced, so that the gas pressure increases. While the elastic ring body 32 effectively releases the gradually increasing liquid flow impact by increasing its deformable area not blocked by the rigid ring plate 341, the gradually increasing gas pressure can increase the load strength, effectively suppress the deformation and vibration of the elastic ring body 32, and further improve the vibration absorption, resonance offset and deformation release of the elastic ring body 32 to the pulsating impact, thereby improving the buffering capacity of the liquid flow pressure peak and the slow release effect on the liquid flow. The present application can utilize the pressure fluctuation of the liquid flow to synchronously adjust the pressure of the gas in the sealed cavity, thereby realizing the increase or decrease of the gas load, and at the same time changing the deformable area of ​​the elastic ring body 32, so that the deformable parameters and deformable area of ​​the elastic ring body 32 can be changed synchronously, thereby realizing the real-time correlation adjustment of the structural strength of the deformable telescopic structure formed by the rear variable capacity slow flow component 3.

[0040] Preferably, variable volume slow release means that the elastic ring body 32 can undergo radial deformation following the pressure fluctuation of the pulsating liquid flow, so that the volume of the cavity of the main shell 31 changes. The deformation of the elastic ring body 32 can buffer and absorb the pressure fluctuation, thereby reducing the liquid flow fluctuation and making the liquid flow gradually stabilize.

[0041] Preferably, adjustable energy absorption and vibration reduction means that the size of the deformable surface area of ​​the elastic ring body 32 can change with the pressure fluctuation of the pulsating liquid flow, and the post-variable flow slowing component 3 utilizes the elastic ring body 32 whose deformable area can change in a correlated manner to absorb the pulsating impact force of the liquid flow, so that the pressure fluctuation of the liquid flow is converted into the expansion deformation of the elastic ring body 32, and the elastic ring body 32 can also vibrate under the action of the pulsating impact, so that the expansion deformation and vibration of the elastic ring body 32 can effectively absorb the pulsating impact force of the converted liquid flow, and the vibration of the elastic ring body 32 can also offset the pulsating impact force of the liquid flow, thereby further reducing the vibration caused by the pressure fluctuation of the liquid flow.

[0042] Preferably, absorbing and reducing the liquid flow pressure peak means that the elastic ring body 32 can absorb the pulsating impact force of the liquid flow through expansion deformation and vibration, so that the fluctuation of the liquid flow is reduced and the peak value of the fluctuation of the liquid flow pressure is reduced.

[0043] like Figure 5 and Figure 6As shown, the post-mounted multi-stage flow diversion assembly 4 includes a flow guide tube shell 41, a translational flow diversion mechanism 42, a deflection and volume retention mechanism 43, and a flow diversion branch pipe 44. Preferably, the flow guide tube shell 41 is composed of a coaxial tube body 411 with multiple sections connected coaxially. Further preferably, a translational flow diversion mechanism 42 coaxial with the coaxial tube body 411 and capable of relative axial movement is provided in each of the multiple sections of the coaxial tube body 411. Further preferably, a flow diversion branch pipe 44 that can be blocked by the translational flow diversion mechanism 42 is also plugged into the side wall of the coaxial tube body 411, so that the multiple translational flow diversion mechanisms 42 distributed with the coaxial tube body 411 can selectively connect the tube cavity of the coaxial tube body 411 with the flow diversion branch pipe 44 to perform a linked graded slow release on the pulsating liquid flow flowing through the flow guide tube shell 41, effectively attenuating the liquid flow fluctuation and outputting a continuous and constant smooth liquid flow. Specifically, graded slow release means that according to the change of the impact force of the pulsation of the liquid flow, one or more coaxial tubes 411 are translated, so that according to the change of the magnitude of the driving force, one or more branch pipes 44 are connected, so that the liquid flow is diverted with a flow change, and the slow release of the liquid flow pulsation is achieved. The graded division of the slow release effect is achieved by changing the number of connected branch pipes 44 in a correlation. Preferably, a deflection and volume retention mechanism 43 is also provided in the translational diversion mechanism 42, which can adjust the size of its conduction cross-section according to the liquid flow state and effectively maintain the conveying flow rate. Specifically, the liquid flow state refers to the actual flow velocity of part of the liquid flow in the guide core tube 421 flowing into the translational diversion mechanism 42. With the change of the flow velocity, the unit flow rate of the liquid flow flowing in the guide core tube 421 will also change. In order to ensure the stability of the unit flow rate, the size of its flow cross-section is reduced when the flow velocity increases, so that the instantaneous flow rate of the liquid flow passing through the guide core tube 421 is reduced and the unit flow rate defined by the instantaneous flow rate and the flow velocity can remain unchanged.

[0044] As the pressure of the liquid flow increases, its flow rate will also increase synchronously. Therefore, the liquid flow will cause a greater impact on the pipeline, and the unit flow rate of the liquid flow will also increase, causing the total amount of drilling fluid received by the final drilling system in a certain period of time to increase, and not remain at a constant order of magnitude. In order to improve the stability of the liquid flow output, the present application diverts the drilling fluid through a post-mounted multi-stage diversion component 4, so that the incremental flow of the liquid flow is effectively diverted, ensuring that the flow rate of the drilling fluid actually output from the drilling system remains unchanged. The unit flow rate refers to the total volume of the liquid flow flowing through a specific pipe section in a certain period of time. When the flow rate of the aforementioned liquid flow changes and the pipe section through which the liquid flow flows remains unchanged, the total amount of drilling fluid flowing through the position of the pipe section increases, forcing the drilling system to receive more drilling fluid in the same unit time, resulting in the drilling fluid chamber of the drilling system being pressurized and filled. The post-multi-stage diversion component 4 provided in the present application can reduce the flow rate and liquid flow pressure by diversion, and at the same time, reduce the pipe cross-section driven by the liquid flow pressure, so that the passage cross-section defined by the pipe becomes smaller, forcing the instantaneous flow rate of the liquid flow to decrease, so that the unit flow composed of the collection of several instantaneous flow rates within a certain period of time can be effectively maintained at a stable value, thereby achieving continuous stability of the liquid flow supply and effectively eliminating the fluctuation of the liquid flow.

[0045] Preferably, the change in pulsation intensity means that the pressure of the liquid flow is continuously changing periodically, causing its pulsation impact force to change all the time. The post-multi-stage shunt assembly 4 provided in the present application can change the working position of the coaxial tube body 411 and the translation shunt mechanism 42 according to the magnitude of the pulsation impact force, so that the shunt branches 44 corresponding to different coaxial tube bodies 411 are connected, and the shunt pressure relief with variable flow size is realized. In addition, the synchronous change of the working position of the translation shunt mechanism 42 can also limit the minimum flow cross-section of different sizes, so as to ensure the invariance of the unit flow and the smooth output of the liquid flow.

[0046] Preferably, a deformable joint 412 is further provided on the inlet side of the pipeline constructed by the multiple coaxial tubes 411. The deformable joint 412 can adapt the shape of the flow channel cross section, so that the liquid flow can act more effectively on the translational diversion mechanism 42 when the pressure fluctuates, and use the impact force generated by the pressure fluctuation to open the diversion channel and change the size of the flow channel cross section, thereby ensuring the stability of the liquid flow delivered to the drilling system.

[0047] Preferably, the multi-stage shunt channel refers to a shunt channel defined by a plurality of mutually parallel shunt branches 44 arranged on a plurality of coaxial tube bodies 411 connected in series. The plurality of shunt branches 44 are gradually opened in the process of increasing the liquid flow pressure, and different numbers of translational shunt mechanisms 42 are driven according to the magnitude of the liquid flow pressure, so that different numbers of shunt branches 44 are turned on. Specifically, the shunt branches 44 gradually increase the amount of liquid flow they shunt by means of graded superposition conduction, ensuring that in the process of increasing the liquid flow pressure, the flow delivered to the expansion and stabilization assembly 5 by the coaxial tube body 411 at the end station remains unchanged.

[0048] Preferably, the shunting pressure reduction means that the liquid flow is shunted through the shunting branch pipe 44 as a shunting branch by constructing a shunting branch parallel to the main channel defined by the lumen of the coaxial tube body 411, thereby reducing the pressure of the liquid flow further transported through the lumen of the coaxial tube body 411. It should be particularly noted that the shunting branch pipe 44 can only shun when the pressure of the liquid flow received by the coaxial tube body 411 is too large and forces the coaxial tube body 411 to translate. The shunting is not continuous and uninterrupted, but can be intermittent shunting following the pressure fluctuation of the liquid flow.

[0049] Preferably, the translational diversion mechanism 42 includes a guide core tube 421, an extension side plate 422, a first limit spring 423 and a guide groove 424. Preferably, the guide core tube 421 of the translational diversion mechanism 42 is movably inserted into the coaxial tube body 411 in the form of a coaxial sleeve. Specifically, in order to facilitate the installation and function execution of the deflection and quantity retention mechanism 43, the guide core tube 421 is set to a tube body with a polygonal cross section, preferably a tube body structure with a square outer contour section and a tube cavity section. Further preferably, an extension side plate 422 is provided on the outer side wall of the guide core tube 421, which can cooperate with the first limit spring 423 to limit the relative working position of the guide core tube 421 in the coaxial tube body 411. Preferably, the extension side plate 422 is movably inserted into the guide groove 424 provided on the inner wall of the tube of the coaxial tube body 411. Specifically, the extension side plate 422 can slide back and forth along the slotting direction of the guide groove 424. Preferably, a first limit spring 423 capable of limiting the axial relative position between the guide groove 424 and the extended side plate 422 is provided in the groove cavity of the guide groove 424. Specifically, a plurality of extended side plates 422 are arranged circumferentially and spaced apart on the outer wall of the guide core tube 421. Preferably, the first limit spring 423 is installed in the groove cavity of the guide groove 424 in a manner parallel to the guide groove 424. Specifically, one end of the first limit spring 423 is connected to the inner end wall of the guide groove 424, and the other end of the first limit spring 423 is connected to the extended side plate 422, which defines a connection relationship in which the extended side plate 422 can be elastically displaced in the guide groove 424. Further preferably, the first limit spring 423 and the guide groove 424 are arranged circumferentially and spaced apart on the inner wall of the coaxial tube body 411 in the same manner as the extended side plates 422. Further preferably, the inner end wall of the guide groove 424 connected to the first limit spring 423 is capable of transverse displacement along its axial direction, thereby adjusting the initial relative position of the extended side plate 422 in its groove cavity. Preferably, sealing rings capable of filling the sleeve gap between the coaxial tube body 411 and the guide core tube 421 are embedded on the inner walls on both sides of the guide groove 424. Specifically, the guide core tube 421 can be axially translated under the impetus of the liquid flow filled in the coaxial tube body 411, so that the first limit spring 423 is compressed, thereby connecting the flow inlet of the branch pipe 44 blocked by the guide core tube 421 with the tube cavity of the coaxial tube body 411, and part of the liquid flow flows into the branch pipe 44, thereby realizing the diversion of the liquid flow and reducing the impact force of the liquid flow. The guide core tube 421 blocks the passage of the excess liquid flow difference while continuously delivering a fixed amount of liquid flow, and utilizes the excess liquid flow difference to push it to move laterally, so that the diversion branch tube 44 blocked by it is connected to the lumen of the coaxial tube body 411, and the excess liquid flow difference can be discharged through the diversion branch tube 44, thereby realizing the diversion of the liquid flow and ensuring the stability of the liquid flow output.

[0050] Preferably, a sealing ring capable of preventing drilling fluid from being poured in is also provided in the groove cavity of the guide core tube 421 accommodating the pressure plate 431 and the linkage rod 432. Preferably, the elastic coefficient of the first limit spring 423 corresponding to the guide core tubes 421 arranged in series in sequence is a gradient change. In the case where the guide core tube 421 close to the inlet side is translated and the branch pipe 44 opened by it cannot achieve sufficient diversion and pressure reduction, the guide core tube 421 downstream thereof is translated in the same direction, and the downstream guide core tube 421 is connected to achieve synchronous operation of multiple guide core tubes 421, and the multi-stage parallel guide core tube 421 is used to achieve sufficient diversion and pressure reduction of the liquid flow. Specifically, the present application can set two or more translational diversion mechanisms 42 according to needs, forming a larger number of branch pipes 44 corresponding to the translational diversion mechanism 42, so as to facilitate sufficient diversion and pressure reduction of liquid flows of different pressures in stages. Further preferably, a pressure-resisting column is provided on the outflow end face of the flow-guiding core tube 421 at the upstream position, so that the pressure-resisting column can assist in pushing the flow-guiding core tube 421 at the downstream position to translate when the pressure overload is large and the upstream flow-dividing branch tube 44 cannot fully divert and reduce the pressure, thereby increasing the flow volume of the diverted liquid. Specifically, when the flow-guiding core tube 421 at the upstream position translates excessively and still cannot fully divert and reduce the pressure, it can effectively push the flow-guiding core tube 421 at its downstream position to translate synchronously, connect the flow-dividing branch tube 44 blocked by the flow-guiding core tube 421 at the downstream position, thereby increasing the diversion volume.

[0051] Preferably, the deflection and quantity-keeping mechanism 43 comprises a pressure plate 431, a linkage rod 432, a second limit spring 433, a rack 434, a gear 435, a rotating shaft 436, a deflection baffle 437 and a positioning torsion spring 438. Preferably, the pressure plate 431 of the deflection and quantity-keeping mechanism 43 is movably embedded on the end face of the tube body of the flow guiding core tube 421. Further preferably, the pressure plate 431 is also connected to the linkage rod 432 inserted in the tube body of the flow guiding core tube 421. Specifically, the linkage rod 432 is movably inserted in the tube body of the flow guiding core tube 421 in a manner parallel to the axial direction of the flow guiding core tube 421. Further preferably, a second limit spring 433 capable of limiting the depth of the pressure plate 431 embedded in the flow guiding core tube 421 is also sleeved on the rod body of the linkage rod 432. Preferably, a rack 434 is also connected to the end of the linkage rod 432 away from the pressure plate 431. Further preferably, the rack 434 can mesh with the gear 435 rotatably positioned by the rotating shaft 436 in the tube body of the guide core tube 421, and when the rack 434 is axially translated, the gear 435 and the rotating shaft 436 are driven to deflect. Preferably, the rotating shaft 436 is rotatably arranged on the tube body of the guide core tube 421 in a manner of penetrating the tube cavity of the guide core tube 421. Preferably, a deflection baffle 437 capable of changing the size of the guide cross section of the guide core tube 421 is arranged on the shaft of the rotating shaft 436 in the tube cavity of the guide core tube 421. Further preferably, a positioning torsion spring 438 capable of limiting the initial deflection amount of the rotating shaft 436 and the deflection baffle 437 is also arranged on the rotating shaft 436. The pressure plate 431 provided in the present application is located on the inlet side end face of the flow guiding core tube 421. When the hydraulic pressure at the inlet end of the flow guiding core tube 421 is enhanced, the pressure plate 431 gradually retracts into the flow guiding core tube 421 under the impact of the liquid flow pressure, and the pressure plate 431 drives the linkage rod 432 and the rack 434 to synchronously translate axially. The rack 434 drives the rotating shaft 436 and the deflection baffle 437 to deflect through the gear 435 meshing with it, so that the size of the lumen cross section of the flow guiding core tube 421 changes, ensuring that the output flow rate can remain unchanged when the flow velocity of the liquid flow changes, and ensuring the stability of the drilling mud flow received by the drilling system. When the pressure of the liquid flow decreases, the rotating shaft 436 and the deflection baffle 437 can be driven by the positioning torsion spring 438 to rotate back, and the lumen cross section of the flow guiding core tube 421 is increased again, so that the instantaneous flow rate of the liquid flow with a reduced flow velocity in the flow guiding core tube 421 increases, ensuring that the unit flow rate remains unchanged. At the same time, the impact force of the liquid flow on the pressure plate 431 is reduced, and the pressure plate 431 performs a restoring motion under the restoring force of the second limit spring 433 , so that it partially moves out of the guide core tube 421 .

[0052] The deflection and volume retention mechanism 43 provided in the present application can effectively ensure the constancy of the unit flow rate, realize the stability of the flow rate of the drilling fluid received by the drilling system, ensure the stability of the drilling tool drive, and avoid excessive wear of the drilling tool caused by the fluctuation of the drilling fluid. In particular, while ensuring the abundance of the continuous supply of drilling fluid, the instantaneous excess increment is reduced and transferred, and the effective and stable driving of the drilling tool and the buffer protection of the entire equipment system are also realized.

[0053] Preferably, a one-way valve is provided in the branch pipe 44 to realize the directional discharge of part of the liquid flow flowing out of the branch pipe 44 and used for diversion and pressure reduction. Further preferably, a diversion drive unit can be provided in the branch pipe 44 as required to directional drive the drilling fluid periodically intermittently injected into its lumen.

[0054] Preferably, the expansion and flow stabilization component 5 includes a rear tank body 51 capable of performing variable volume flow stabilization on the liquid flow output by the rear multi-stage flow diversion component 4, and a second inlet pipe 52 and a second outlet pipe 53 offset on both sides of the rear tank body 51. Further preferably, the horizontal height of the second inlet pipe 52 is higher than the horizontal height of the second outlet pipe 53. Preferably, a baffle structure can be selectively offset in the rear tank body 51, the main shell 31 and the front tank body 21, and the baffle can buffer the pressure peak, change the flow direction of the medium, and resonate with the mud to absorb the impact vibration of the liquid flow. Further preferably, a vibration generating unit is provided on the baffle, so that the natural vibration frequency of the baffle can be adjusted according to demand, thereby ensuring the effectiveness and applicability of vibration compensation.

[0055] When the actual conduction cross section of the multi-stage flow splitter 4 changes with the actual flow rate, its unit flow rate remains unchanged. However, due to the deviation of the cross-sectional ratio between it and the standard pipeline of the drilling system, the secondary steady flow cavity formed by the rear tank 51 is used to compensate for the flow rate difference caused by the cross-sectional deviation, so as to achieve steady flow and slow release of the final output drilling fluid. The rear tank 51 can also store a certain amount of drilling fluid to ensure that when the flow at the input end fluctuates, the output end can ensure sufficient supply.

[0056] Preferably, drainage ports are provided at the bottom of the rear tank body 51 and the main housing body 31 to facilitate the external discharge and cleaning of residual mud during shutdown.

[0057] The present invention is not limited to the above optional implementation modes. Anyone can derive other various forms of products under the enlightenment of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope of the claims of the present invention fall within the protection scope of the present invention. Those skilled in the art should understand that the specification of the present invention and its drawings are illustrative and do not constitute limitations on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. Throughout the text, the features guided by "preferably" are only an optional method and should not be understood as having to be set. Therefore, the applicant reserves the right to abandon or delete the relevant preferred features at any time.

Claims

1. A steady-flow drilling fluid supply device, comprising a circulating pump group (1) capable of continuously driving the directional flow of drilling fluid, characterized in that: The input end of the circulation pump group (1) is connected to a pre-storage component (2) capable of supplying a sufficient amount of drilling fluid to the circulation pump group (1) in a pre-storage manner; The output end of the circulation pump group (1) is provided with a slow flow module capable of adjustable multi-stage buffering of the pulsating liquid flow outputted therefrom, wherein the slow flow module comprises a post-positioned variable capacity slow flow component (3), a post-positioned multi-stage flow diversion component (4) and a capacity expansion and flow stabilization component (5) which are sequentially connected in series. The post-positioned variable volume slow flow component (3) between the circulation pump group (1) and the post-positioned multi-stage flow splitting component (4) absorbs and reduces the pressure peak of the liquid flow in a manner that can perform variable volume slow release and adjustable energy absorption and vibration reduction on the pulsating liquid flow, so that the liquid flow output by the circulation pump group (1) obtains the initial pulsation attenuation; The post-positioned multi-stage flow diversion component (4) completes the flow diversion and decompression of the liquid flow in a manner that a multi-stage flow diversion channel can be constructed according to the change in the pulsation intensity of the liquid flow, thereby performing secondary pulsation attenuation on the liquid flow output by the post-positioned variable capacity slow flow component (3), and the output end of the multi-stage flow diversion channel constructed by the post-positioned multi-stage flow diversion component (4) is connected to the pre-positioned pre-storage component (2).

2. The steady flow delivery drilling fluid supply equipment according to claim 1, characterized in that: The post-mounted multi-stage flow diversion assembly (4) comprises a flow guide pipe shell (41), a translational flow diversion mechanism (42), a deflection and volume retention mechanism (43) and a flow diversion branch pipe (44), wherein: The flow guide tube shell (41) is composed of a plurality of coaxially connected coaxial tube bodies (411), and the plurality of coaxial tube bodies (411) are each provided with a translational flow diversion mechanism (42) coaxial with the coaxial tube body and capable of relative axial movement, and the side wall of the coaxial tube body (411) is also plugged with a flow diversion branch pipe (44) capable of being shielded by the translational flow diversion mechanism (42); The deflection and quantity-maintaining mechanism (43) is also provided in the translational flow-dividing mechanism (42) and is capable of adjusting the size of its conducting cross section according to the state of the liquid flow.

3. The steady flow delivery drilling fluid supply equipment according to claim 2, characterized in that: The flow guiding core tube (421) of the translational flow dividing mechanism (42) is movably inserted into the coaxial tube body (411) in the manner of a coaxial sleeve, and an extension side plate (422) is provided on the outer side wall of the flow guiding core tube (421) and is capable of cooperating with a first limit spring (423) to limit the relative working position of the flow guiding core tube (421) in the coaxial tube body (411); The extended side plate (422) is movably inserted into a guide groove (424) provided on the inner wall of the coaxial tube body (411), and the extended side plate (422) is capable of reciprocatingly sliding along the groove direction of the guide groove (424). The first limiting spring (423) is arranged in the groove cavity of the guide groove (424) and is capable of limiting the axial relative position between the first limiting spring (423) and the extension side plate (422).

4. The steady flow delivery drilling fluid supply equipment according to claim 3, characterized in that: The pressure plate (431) of the deflection and volume retention mechanism (43) is movably embedded in the end surface of the tube body of the flow guiding core tube (421), and is also connected to a linkage rod (432) inserted in the tube body of the flow guiding core tube (421), and a second limit spring (433) capable of limiting the depth of the pressure plate (431) embedded in the flow guiding core tube (421) is sleeved on the rod body of the linkage rod (432); One end of the linkage rod (432) away from the pressure plate (431) is also connected to a rack (434), and the rack (434) can mesh with a gear (435) rotatably positioned by a rotating shaft (436) in the tube body of the guide core tube (421).

5. The steady flow delivery drilling fluid supply equipment according to claim 4, characterized in that: The rotating shaft (436) is rotatably arranged on the body of the flow guiding core tube (421) in a manner of penetrating the tube cavity of the flow guiding core tube (421), and a deflection baffle (437) capable of changing the size of the flow guiding cross section of the flow guiding core tube (421) is arranged on the shaft of the rotating shaft (436) located in the tube cavity of the flow guiding core tube (421); The rotating shaft (436) is also provided with a positioning torsion spring (438) capable of limiting the initial deflection amount between the rotating shaft (436) and the deflection baffle (437).

6. The steady flow delivery drilling fluid supply equipment according to claim 5, characterized in that: The post-positioned variable volume slow flow assembly (3) comprises a main housing (31), an elastic ring body (32), an annular cover (33) and a variable limiting mechanism (34), wherein: The elastic ring body (32) constituting a deformable shell wall is embedded on the side wall of the main shell (31). The annular cover (33) is mounted on the outer wall of the main housing (31) in such a manner that it forms an annular chamber on the outer side of the main housing (31) and covers the elastic annular body (32); The variable limiting mechanism (34) capable of changing the deformable area of ​​the elastic ring body (32) is also provided on the outside of the main housing (31).

7. The steady flow delivery drilling fluid supply equipment according to claim 6, characterized in that: A first inlet pipe (311) and a first outlet pipe (312) are staggeredly arranged on the side wall of the main shell (31); a single-port pipe body (313) communicating with the lumen of the first inlet pipe (311) is also mounted on the pipe body of the first inlet pipe (311); a closed cover body (314) is arranged at one end of the single-port pipe body (313) away from the first inlet pipe (311).

8. The steady flow delivery drilling fluid supply equipment according to claim 7, characterized in that: The rigid ring plate (341) of the variable limiting mechanism (34) is movably mounted on the main housing (31) in a manner capable of covering a portion of the elastic ring body (32), and the rigid ring plate (341) is connected to the plug body (343) via an inverted U-shaped connecting rod (342) penetrating the annular cover (33); The plug body (343) is installed in the single-port tube body (313) in a manner of forming a variable tight cavity in the single-port tube body (313) in cooperation with the closed cover body (314), and the inverted U-shaped connecting rod (342) is connected to the plug body (343) by penetrating the closed cover body (314).

9. The steady flow delivery drilling fluid supply equipment according to claim 8, characterized in that: The front tank (21) of the front pre-storage assembly (2) is connected to the inlet end of the circulation pump group (1) via a liquid discharge port (22); A liquid inlet (23) and a liquid return port (24) connected to the output end of the branch pipe (44) are provided on the side of the front tank body (21).

10. The steady flow delivery drilling fluid supply equipment according to claim 9, characterized in that: The volume expansion and flow stabilization component (5) comprises a rear tank body (51) capable of stabilizing the flow of liquid output by the rear multi-stage flow diversion component (4), and a second inlet pipe (52) and a second outlet pipe (53) staggeredly arranged on both sides of the rear tank body (51).

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