CN101705789B - Hydraulic pulse cavitation jet well drilling method - Google Patents

Abstract

The invention discloses a hydraulic pulse cavitation jet drilling method. The method comprises the following steps: in the drilling operation, converting the continuous and stable liquid flow used to impact the bottom of the well into a pulse resonance flow liquid; injecting the pulse resonance flow liquid into the relatively static liquid at high speed to generate cavitation; and The way of fluctuating pressure impacts the bottom of the well, which reduces the holding effect, improves the ability of the jet to clear and break rocks, and saves drilling costs.

Description

Hydraulic Pulse Cavitation Jet Drilling Method

This application is a divisional application of the patent application submitted to the Patent Office on July 12, 2006, the application number is 200610098598.8, and the title of the invention is "Hydraulic Pulse Cavitation Jet Drilling Device, Method and Drill Bit". the

technical field

The invention relates to a drilling method, in particular to a hydraulic pulse cavitation jet drilling method. the

Background technique

The object of drilling and production technology is the downhole system (from the wellbore to the formation). This kind of object is characterized by small borehole, deep formation, complex downhole conditions, and invisible. Only downhole drilling tools can be closest to the working object. Therefore, if you want to use the new drilling and production technology to perform fine operations on the downhole system, you can only rely on downhole drilling and production tools. The demand for the development of advanced drilling and production technology has triggered the emergence of new downhole drilling and production tools, and the implementation of new drilling and production technology must also rely on downhole drilling and production tools with excellent performance and reliable work, and the innovation of the latter In turn, it will further promote the transformation of drilling technology. the

Traditional drilling methods have always had problems such as low efficiency in energy transmission, conversion, distribution and utilization during the drilling process. Although rotary percussion drilling and downhole booster drilling can increase the ROP to varying degrees, they have not been widely used on site due to their poor life and stability. The pulse jet assisted drilling technology has achieved certain results in the field, but because of its short life, it also has certain limitations. The pulse jet assisted drilling technology mainly generates pulse effects through the action of the pulse nozzle, which is installed on the carcass at the bottom of the drill bit. the

The life of the simple pulse nozzle has certain limitations in the field, and with the increase of the well depth, the hydraulic energy of the drill bit decreases, the confining pressure increases, the cavitation capacity is correspondingly weakened, and the jet impact effect is significantly reduced; the downhole hydraulic propulsion depends on the tool piston. When bit pressure is generated, the effect of hydraulic pulse is not good; the effect of negative pressure pulse of hydraulic pulse circulation valve is good, but the disadvantage is that the structure is complex, and the solid particles contained in the drilling fluid are easy to cause wear to the internal parts of the modulator. the

Contents of the invention

The purpose of the embodiment of the present invention is to provide a hydraulic pulse cavitation jet drilling method, which can improve the bottom hole flow field and the stress state of the bottom rock, reduce the "holding effect", assist rock breaking to increase the ROP, and save drilling costs . the

The embodiment of the present invention provides a hydraulic pulse cavitation jet drilling method, comprising:

Step 1: During the drilling operation, by periodically changing the cross-sectional area of the continuous and stable liquid flow used to impact the bottom of the well, the continuous and stable liquid flow is converted into a pulsed flow liquid; the step 1 is specifically : The continuous and stable liquid flows through the fluid inlet section at the upper end of the body of the hydraulic pulse cavitation jet drilling device and enters the guide part of the hydraulic pulse cavitation jet drilling device, and the pulse of the hydraulic pulse cavitation jet drilling device The generator generates a tangential force to force the impeller inside the pulse generator to rotate at a high speed to change the area of the flow channel, so that the continuous and stable flowing liquid generates pulses to form the pulsed flowing liquid;

Step 2: The pulsating flow liquid amplifies the pulse amplitude and makes it resonate through the pressure feedback of the fluid, and converts it into a pulse resonance flow liquid; the step 2 is specifically: the pulsating flow liquid enters the hydraulic pulse cavitation The self-excited oscillation chamber of the jet drilling device is enlarged and generates fluid resonance in the self-excited oscillation chamber to form the pulse resonance flowing liquid;

Step 3: Inject the pulse resonance flow liquid into a relatively static liquid at high speed to generate cavitation;

Step 4: fluctuate the pressure of the pulse resonance flowing liquid that produces the cavitation phenomenon; generate feedback pressure resonance in the pulse resonance flow liquid that fluctuates in pressure; use the feedback pressure resonance to generate fluid acoustic harmonic resonance to improve The flow rate of the pulse resonance flowing liquid is injected into the relatively static liquid to generate cavitation, causing cavitation damage to the bottom of the well; the pulse resonance flowing liquid impacts the bottom of the well in the form of fluctuating pressure. the

Periodically perturb the cross-section of the above-mentioned continuous and stable liquid flow according to a preset frequency to convert it into a pulsed flow liquid. the

The organ pipe resonant cavity amplifies the pulse resonance flowing liquid flowing into it, and produces fluid acoustic resonance. The high-speed jet of the fluid makes the nozzle outlet jet flow into an intermittent vortex flow, and the vortex flow continues in the high-speed shearing motion. Intensify, so that the jet generates a larger pressure pulse, forming a pulsed jet, and inducing the occurrence of cavitation. the

The hydraulic pulse and cavitation jet coupling modulation mechanism method obtained through the research and analysis of fluid mechanics, combined with the hydraulic pulse and cavitation jet to improve the mechanism of ROP, proposes the hydraulic pulse cavitation jet drilling method of the present invention, wherein , cavitation jet refers to a jet technology that uses the strong impact force generated by the rupture of the cavitation to enhance the jet effect. Most of the liquid jets in the submerged mode produce cavitation. This is because a turbulent vortex is formed in the shear layer between the high-speed jet and the relatively static ambient liquid in the submerged mode, the pressure in the turbulent vortex is low, and a cavitation field is generated in the low-pressure area. The cavitation ring of the jet can not only increase the density of the jet, but also expand the area where the jet is broken and cleaned. the

The hydraulic pulse cavitation jet drilling method provided by the present invention improves the mechanical penetration rate and prolongs the service life by improving the flow field at the bottom of the well and the stress on the rock at the bottom of the well; at the same time, the low-pressure area obtained by the hydraulic pulse method is only limited to the drill bit at the bottom of the well Nearby, the entire annulus is still at overbalanced pressure, which can better ensure the stability of the wellbore wall and ensure downhole safety than the underbalanced drilling method. the

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments. the

Description of drawings

Fig. 1 is the flowchart of the inventive method;

Fig. 2 is the assembly schematic diagram of hydraulic pulse generator of the present invention;

Fig. 3 is the structural representation of guide part of the present invention;

Fig. 4 is the structural representation of impeller in pulse generator of the present invention;

Fig. 5 is the side view of the impeller seat in the pulse generator of the present invention;

Fig. 6 is the plan view of impeller seat in the pulse generator of the present invention;

Fig. 7 is the structural representation of the oscillating nozzle of the present invention;

Fig. 8 is the structural representation of pulse generator body of the present invention;

Fig. 9 is a schematic diagram of the directional nozzle structure of the self-vibrating cavitation nozzle drill bit of the present invention;

Fig. 10 is the bottom view of drill bit of the present invention;

Fig. 11 is the side view of nozzle outlet of the present invention;

Figure 12 is a three-dimensional schematic diagram of a self-vibrating cavitation nozzle drill bit of the present invention;

Fig. 13 is a schematic diagram of the assembly of the hydraulic pulse cavitation jet drilling device and the self-vibrating cavitation nozzle drill bit of the present invention. the

Explanation of reference signs:

1—body; 2—conductor;

3—pulse generator; 4—self-excited oscillation chamber;

5—oscillating nozzle; 6—impeller seat;

7—fluid inlet section; 8—fluid outlet section;

9—impeller; 10—self-vibrating cavitation nozzle drill;

11 - Directional nozzle. the

Detailed ways

Example 1

Fig. 1 is a flow chart of Embodiment 1 of the method of the present invention. The concrete steps of the method for hydraulic pulse cavitation jet drilling are as follows:

Step 101: During the drilling operation, converting the continuous and steady liquid flow used to impact the bottom of the well into a pulsed resonance flow liquid;

Step 102: Injecting the pulse resonance flowing liquid into a relatively static liquid at high speed to generate cavitation;

Step 103: Impacting the pulsed resonance flow liquid that generates cavitation to the bottom of the well in the form of fluctuating pressure. the

In the above preferred embodiment, the pulsating liquid flow can be generated by periodically disturbing the continuous and stable liquid flow according to a preset frequency. the

In the above embodiment, the continuous fluid passes through the resonant cavity to form acoustic resonance, so that the jet flow at the outlet of the nozzle becomes an intermittent vortex flow. In the submerged state, the discontinuity of fluid motion is prone to pressure oscillations, which induce cavitation. In the structure designed by this patent, the rotating impeller can disturb the continuous fluid, enhance the discontinuity of the fluid, and thus enhance the cavitation. the

In the foregoing embodiment, step 103 may be implemented through the following specific steps. Firstly, the pressure of the pulse resonance flowing liquid is fluctuated; secondly, the pressure fluctuation of the pulse resonance flowing liquid is generated to generate feedback pressure resonance; after that, the pressure resonance is used to generate fluid acoustic resonance; finally, the fluid acoustic resonance is improved. The flow velocity of the harmonically resonant pulse resonance flowing liquid makes it inject into the relatively static liquid at high speed to form a shear layer, form a disturbance vortex, and generate cavitation phenomenon. the

Example 2

This embodiment is a process flow of a more detailed solution than that of Embodiment 1. details as follows:

Step 1010: During the drilling operation, converting the continuous and stable liquid flow used for impacting the bottom of the well into a pulse resonance flowing liquid; periodically disturbing the continuous and stable liquid flow according to a preset frequency;

Step 1021: The organ pipe resonant cavity can form acoustic resonance, so that the jet flow at the outlet of the nozzle becomes an intermittent vortex circulation, which induces the occurrence of cavitation;

Step 1022, the rotating impeller can disturb the continuous fluid, enhance the discontinuity of the fluid, thereby enhancing the cavitation;

Step 1031: fluctuate the pressure of the pulse resonance flowing liquid;

Step 1032: Make the pulsed resonant flowing liquid with pressure fluctuations generate feedback pressure resonance;

Step 1033: using the pressure resonance to generate fluid acoustic harmonic resonance;

Step 1034: Increase the flow velocity of the pulse resonance flow liquid with fluid acoustic resonance, and inject it into a relatively static liquid;

Step 104: Introduce the hydraulic pulse cavitation jet into the self-vibrating cavitation nozzle drill bit to form a high-efficiency hydraulic and mechanical combined rock breaking;

Step 105: Short-circuit the self-excited oscillation part with the self-vibration cavitation nozzle bit to improve rock breaking efficiency. the

Example 3

When this embodiment is assembled and used according to Figure 13, the specific steps are as follows:

Step 201, during the drilling operation of the drilling tool, introduce a continuous and stable liquid flow for impacting the bottom of the well;

Step 202, periodically disturbing the continuous and stable liquid flow to form a pulsed flow liquid to increase the impact effect;

Step 203, amplifying the pulsating liquid and causing it to resonate, thus transforming it into a pulsating resonant flowing liquid;

Step 204, by reducing the cross-sectional area of the fluid and accelerating its flow velocity, injecting it into the relatively static ambient liquid at high speed;

Step 205, making the liquid form a turbulent vortex to generate cavitation;

Step 206, flowing the high-speed pulse resonance flow liquid that produces cavitation into the organ pipe nozzle on the drill bit in the form of fluctuating pressure;

Step 207, the cavitation jet is further amplified by the resonance of the organ pipe, and hits the bottom of the well at high speed. the

Example 4

Fig. 2 is a schematic diagram of assembly of the present invention. Fig. 2 is a preferred embodiment of the device of the present invention, as shown in Fig. 2, comprises a cylindrical body 1, and one end of this body is provided with fluid inlet section 7, and the other end is provided with fluid outlet section 8, and fluid inlet section 7 and the fluid outlet section 8 are sequentially matched with a guide part 2 that makes the flow direction of the fluid deviate, a pulse generator 3 that makes the continuous fluid generate pulses, and a self-excited oscillation part that makes the pulsed fluid resonate; the guide One end of the flow part 3 is provided with an inlet, and the other end is provided with an outlet. The outlet and the inlet are arranged eccentrically, and the area of the outlet is smaller than the area of the inlet; 9. The blades of the impeller 9 are aligned with the outlet of the guide part 2; the self-excited oscillating part is provided with a through fluid channel, which is composed of a plurality of flow channels with successively decreasing cross-sectional areas. The flow channel with the largest area is set at the end where the self-excited oscillation part is connected to the pulse generator. The device can generate strong pulsating vortex circulation and impact the bottom of the well in the form of fluctuating pressure. The lower end of the device is connected to the drill bit, and the upper end is directly connected to the downhole dynamic drilling tool (or drill collar). It is easy to use and install. At the same time, the lower part has a step that can be matched with the drill collar, and the upper part has a retaining ring groove. This design not only meets the technical requirements but also greatly simplifies the structure, greatly enhancing its safety and reliability. the

The hydraulic pulse cavitation jet drilling device of the present invention is to enter the guide part 2 through the fluid inlet section 7 at the upper end of the body 1 through the continuously flowing drilling fluid in the drill collar (or downhole power drilling tool) during the drilling process, A tangential force is generated on the pulse generator 3 to force the internal impeller 9 to rotate at a high speed to change the area of the flow channel, so that the continuously flowing drilling fluid generates pulses and then enters the self-excited oscillation chamber 4, where the pulsed drilling fluid flow is amplified and generated Fluid resonance, when it enters the resonant nozzle 5 through the exit contraction section of the self-excited oscillation chamber 4, pressure fluctuations are generated, and this pressure fluctuation is reflected back to the resonant cavity to form a feedback pressure oscillation. When the frequency of the pressure fluctuation is consistent with the frequency of the resonant cavity When they are consistent, the feedback pressure oscillation is amplified, thereby generating fluid acoustic resonance in the self-excited oscillation chamber 4, high-speed fluid jet flow, and strong pulsating vortex circulation in the fluid outlet section 8, impacting the bottom of the well in the form of fluctuating pressure, Improve the flow field at the bottom of the hole, reduce the "holding effect" and improve the ability of the jet to clear and break rock, thereby increasing the ROP. The realization of cavitation is realized through the self-excited oscillation nozzle, and the purpose of impeller rotation is to generate pulses, so that the drilling fluid entering the self-excited oscillation cavity becomes an active disturbance. The vortex ring grows continuously during the high-shear movement, which makes the jet generate a large pressure pulse, forming a pulse jet, which is transmitted to the bottom of the well through the drill bit, thereby greatly improving the erosion and cleaning capabilities of the jet. On the one hand, a pulse jet is formed at the nozzle outlet of the drill bit to improve the jet’s ability to clear and break rock; on the other hand, due to the pressure pulsation generated by the hydraulic pulse device, a low-pressure zone can be formed near the drill bit, which can reduce the pressure of the annular liquid column on the rock at the bottom of the well. Its mechanism is similar to that of underbalanced drilling, which can greatly increase the drilling speed, but the low pressure zone obtained by the hydraulic pulse method is only limited to the vicinity of the bottom hole bit, and the entire annular space is still overbalanced. It can better guarantee the stability of well wall and underground safety. the

Fig. 3 is a schematic structural view of the flow guiding part of the present invention. As shown in Fig. 2 and Fig. 3, the deflector 2 described in the present invention is a slope channel, which changes the flow direction of the drilling fluid, and generates a tangential force on the impeller of the pulse generator 3 to force the impeller 9 to rotate, through Changing the angle of the slope flow path changes the size of the tangential impact force of the drilling fluid flow on the impeller, and at the same time, the raised part below is convenient for installation and positioning. the

Fig. 4 is a schematic structural view of the impeller 9 in the pulse generator of the present invention. Fig. 5 is a side view of the impeller seat in the pulse generator of the present invention. Fig. 6 is a top view of the impeller seat in the pulse generator of the present invention. The pulse generator 3 described in the present invention comprises the impeller 9 and the impeller seat 6 of the positioning impeller, changes the flow path area by changing the impeller blade radius of the impeller 9 to change the pulse amplitude, and changes by changing the impeller blade number of the impeller 9 pulse frequency. the

FIG. 7 is a schematic structural view of the oscillating nozzle 5 of the present invention. It can be seen from Fig. 6 that the sectional area of the oscillating nozzle 5 is much smaller than that of the self-excited oscillating chamber 4, so that the fluid jet becomes an intermittent vortex ring. the

Fig. 8 is a schematic diagram of the structure of the pulse generator body of the present invention. In the embodiment of the above-mentioned device, the fluid inlet section 7 of the body 1 may be in the shape of a cylinder or a truncated cone with a large outside and a small inside. the

In the embodiment of the above device, the shape of the inlet of the flow guide part 2 and the shape of the outlet of the flow guide part may be rectangular or circular. the

In the embodiment of the above device, the end face of the guide part 2 combined with the pulse generator 3 is also provided with an inlet for snapping into the pulse generator, and the outlet of the guide part 2 is aligned with the impeller 9 Positive convexity. the

In the embodiment of the above-mentioned device, the cross-sectional shape of the multi-stage flow channel provided in the self-excited oscillation part may be circular or polygonal. the

The continuous, stable and high-speed drilling fluid enters the guide body to generate tangential force on the impeller in the impeller assembly, forcing the impeller to rotate at high speed to generate pulse disturbance. By changing the radius of the impeller blade to change the area of the flow channel to change the pulse amplitude, by changing the impeller of the impeller The number of blades is used to change the pulse frequency; then it enters the self-excited oscillation chamber on the upper part of the oscillating nozzle, where the pulsed drilling fluid flow is amplified and generates fluid resonance, and a strong pulsating vortex circulation is generated at the outlet, impacting the bottom of the well in the form of fluctuating pressure, Improve the flow field at the bottom of the hole, reduce the "holding effect" and improve the ability of the jet to clear and break rock, thereby increasing the ROP. the

Example 5

Fig. 9 is a schematic diagram of the directional nozzle structure of the self-vibrating cavitation nozzle drill bit of the present invention. Fig. 10 is a bottom view of the drill bit of the present invention. The organ tubular resonant cavity can form acoustic resonance, so that the jet flow at the outlet of the directional nozzle 10 becomes an intermittent vortex circulation, which induces cavitation; at the same time, the outlet of the nozzle 10 is bent at a certain angle, and the self-vibrating cavitation nozzle bit 11 chip tooth Cooperate, as shown in Figure 11; the nozzle 10 is a built-in type, and its structure is shown in Figure 9, to achieve hydraulic-mechanical combined rock breaking. The nozzle adopts directional installation to form a combined hydraulic and mechanical rock breaking method, which improves the rock breaking effect of the drill bit and rock cleaning at the bottom of the well. Fig. 12 is the three-dimensional schematic diagram of the self-vibrating cavitation nozzle drill bit designed and processed. the

Example 6

Fig. 13 is a schematic diagram of the assembly of the hydraulic pulse cavitation jet drilling device and the self-vibrating cavitation nozzle drill bit of the present invention. The self-vibrating cavitation nozzle drill bit 11 is short-circuited with the lower end of the hydraulic pulse cavitation jet drilling device, and used together to further enhance the cavitation effect of the fluid and improve the rock-breaking ability. The preferred embodiment is specifically as follows: step 1 is to introduce a continuous and stable liquid flow for impacting the bottom of the well during the drilling operation of the drilling tool; step 2 is to periodically disturb the continuous and stable liquid flow to form a pulsed flow of liquid , to increase the impact effect; step 3 is to amplify the pulsed flow liquid and make it resonate, so it is transformed into a pulse resonance flow liquid; step 4 is to reduce the cross-sectional area of the fluid, speed up its flow rate, and make it high-speed Inject into a relatively static environmental liquid; step 5 is to make the liquid form a turbulent vortex to produce cavitation; step 6 is to flow the high-speed pulse resonance flow liquid that produces cavitation into the organ pipe on the drill bit in the form of fluctuating pressure Nozzle; step 6 is to further amplify the cavitation jet through the resonance of the organ pipe, and hit the bottom of the well at high speed. the

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be The scheme shall be modified or equivalently replaced without departing from the spirit and scope of the technical scheme of the present invention. the

Claims (5)

1. a hydraulic pulse cavitation jet well drilling method is characterized in that, comprises the steps:

Step 1: in drillng operation, the area of the cross section of the flow of liquid through being used in the continous-stable that impacts the shaft bottom produces cyclically-varying, and the liquid flow of said continous-stable is changed to effect of Fluid Pulsation liquid; Said step 1 is specially: the fluid intake section of the flow of liquid of said continous-stable through the body upper end of waterpower pulse cavitation jet well drilling device gets into the diversion division of said waterpower pulse cavitation jet well drilling device; Impulse generator generation tangential force to said waterpower pulse cavitation jet well drilling device forces the inner impeller of said impulse generator to rotate the change flow area at a high speed; Make said continous-stable flowing liquid produce pulse, form said effect of Fluid Pulsation liquid;

Step 2: said effect of Fluid Pulsation liquid is exaggerated and produces resonance, converts the pulse resonance working fluid into; Said step 2 is specially: said effect of Fluid Pulsation liquid gets into the self-oscillation chamber of said waterpower pulse cavitation jet well drilling device, amplifies and generation fluid resonance at said self-oscillation chamber, forms said pulse resonance working fluid;

Step 3: said pulse resonance working fluid is injected at a high speed in the static relatively liquid, produced cavitation phenomenon;

Step 4: make the pressure of the said pulse resonance working fluid that produces said cavitation phenomenon produce fluctuation; Make the said pulse resonance working fluid of pressure oscillation produce feedback pressure resonance; Utilize said feedback pressure resonance to produce the humorous resonance of fluid sound, improve the flow velocity of said pulse resonance working fluid, inject in the static relatively liquid, produce cavitation, make the shaft bottom produce cavitation erosion; Said pulse resonance working fluid impacts the shaft bottom with the mode of surge pressure.

2. hydraulic pulse cavitation jet well drilling method as claimed in claim 1 is characterized in that, also comprises after the said step 4:

Step 5: introduce self-vibration cavitating nozzle drill bit to waterpower pulse cavitation jet, in order to form efficient waterpower, the broken rock of mechanically combining.

3. hydraulic pulse cavitation jet well drilling method as claimed in claim 2 is characterized in that, also comprises after the said step 5:

Step 6: self-oscillation chamber and self-vibration cavitating nozzle bit sub, in order to improve efficiency of breaking rock.

4. hydraulic pulse cavitation jet well drilling method as claimed in claim 1; It is characterized in that; In the said step 1, the detailed process that the liquid flow of said continous-stable is changed to effect of Fluid Pulsation liquid is: according to predefined frequency the cross section of the flow of liquid of said continous-stable is carried out periodic disturbance.

5. hydraulic pulse cavitation jet well drilling method as claimed in claim 1; It is characterized in that said step 3 is specially: the said pulse resonance working fluid that the organ pipe resonator will flow into wherein amplifies, and produces the humorous resonance of fluid sound; Said pulse resonance working fluid is injected at a high speed and is formed the fluid high-speed jet; Make the jet expansion jet become interrupted collar vortex stream, said collar vortex stream goes from strength to strength in the high shear campaign, makes said jet expansion jet produce bigger pressure pulse; Form pulsing jet, bring out cavitation and take place.

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