Turbine type combined friction reducing tool capable of changing flowing state of drilling fluid
Technical Field
The invention relates to a turbine type combined friction reducing tool capable of changing the flowing state of drilling fluid, belonging to the technical field of drilling tools for oil and natural gas exploitation.
Background
With the continuous exploitation of oil, a large number of long horizontal, large inclination and multi-branch horizontal wells need to be excavated. In the domestic exploitation of long-level, large-inclination and multi-branch horizontal wells, a plurality of problems similar to pressure supporting, drill sticking and drill breakage occur, so that the drilling efficiency is low, the development period is long, the development cost is high, the design requirement of a well trajectory cannot be met, the target rate in a target layer is low, the rock carrying capacity of drilling fluid is low, and the vibration effect is not ideal. This is the major bottleneck that restricts the development of long horizontal, large slope and multi-branch horizontal wells. These problems arise primarily because the friction between the drill string and the borehole wall is greater than that of a vertical well. In the sliding drilling process, the drill string and the well wall are kept in a relatively static state, and the static friction force is larger than the dynamic friction force, so that the larger static friction force can be considered to be converted into the smaller dynamic friction force.
Therefore, the friction force between the drilling tool and the well wall in the long horizontal well section, the large inclination and the multi-branch horizontal well section is reduced, and the key for improving the extended drilling footage of the long horizontal well, the large inclination and the multi-branch horizontal well is realized.
Disclosure of Invention
The invention aims to: in order to overcome the problems of low drilling efficiency, long development period, high development cost, low rock carrying capacity of drilling fluid and non-ideal vibration effect caused by large friction of the conventional unconventional well drilling such as a long-horizontal, large-inclination and multi-branch horizontal well, a turbine type combined friction reduction tool capable of changing the flowing state of the drilling fluid is designed.
In order to achieve the purpose, the technical scheme adopted by the invention for solving the problem is as follows: a turbine type combined friction reducing tool capable of changing the flowing state of drilling fluid is composed of a pull rod, an upper shell A, O-shaped sealing ring A, a limiting ring, an upper shell B, a disc spring, an O-shaped sealing ring B, a shell A, a shell B, a pulse generator, a lower shell, a mandrel, a turbine, a valve A, a sleeve, a valve B and a lower joint, and is technically characterized in that the pull rod is connected with the upper shell B through a spline; the upper shell A, the upper shell B, the shell A, the shell B, the lower shell and the lower joint are connected with each other through threads in sequence; the fluid inlet cone is positioned at the inlet flow channel of the pull rod and is equivalent to a reducing pipe for improving the fluid pressure difference, the quality of the effect of improving the pressure difference is related to the cone angle of the fluid inlet cone and the ratio of the diameter of the small end to the diameter of the large end, and the cone angle is 30 degrees, so the fluid loss coefficient is small, and the pressure difference is improved greatly; the O-shaped sealing ring A is arranged in the upper shell A and is used for sealing a gap between the upper shell A and the pull rod; the limiting ring is positioned in the upper shell B and is axially positioned on the lower end surface of the upper shell A to prevent the pull rod from separating from the shell; the disc spring is arranged between the upper shell B and the shell A, and the pull rod returns by adopting a double-disc spring with a common rectangular section; the O-shaped sealing ring B is arranged in a ring groove at the lower end of the pull rod and is used for applying the pressure of the drilling fluid to the pull rod; the pulse generator is arranged in the shell B, the upper axial end is positioned in the shell A, the lower axial end and the circumferential direction are positioned in the shell B, the drilling fluid generates forward and reverse eddy currents due to the design of a flow passage of the pulse generator, pressure pulses are generated, the structural design of the flow passage is a key for pulse generation, and the pulse frequency generated by the pulse generator can reach 10HZ to 15 HZ; the mandrel is arranged in the lower shell and the lower joint and is positioned at the central and axial positions; the turbine is arranged on the mandrel, the turbine is axially positioned by utilizing a step and a lower joint in the lower shell, the turbine converts linear fluid flow into rotary fluid flow, the rotary fluid flow motion is transmitted to the valve A and the valve B from the turbine through the mandrel, the number of the turbine directly influences the efficiency of converting the linear fluid flow into the rotary fluid flow, and 8 groups of turbines are adopted in the invention; the valve A and the valve B are positioned on the mandrel and positioned through the sleeve and the lower joint, and the hydraulic pulse frequency caused by the change of the flow area generated by the valve group can reach 10HZ to 20 HZ; when the pull rod is positioned at the normal position, the disc spring is in a loose state; when the drilling fluid enters from the upper end of the pull rod and then enters the inlet hole of the pulse generator from the main runner and is accelerated by the accelerating runner, the drilling fluid can flow through the lower runner and the upper runner, however, due to the coanda effect, the drilling fluid only flows along one of the sub-runners, and if the drilling fluid enters from the lower sub-runner and then enters the oil chamber to form a vortex, the suction force generated by the increase of the pressure at the inlet hole can cause the drilling fluid to enter the upper ring runner from the upper return runner, then the drilling fluid flows into the lower turbulence channel from the lower ring flow channel, the drilling fluid at the moment can interfere the liquid flowing out from the accelerating flow channel, the accelerating fluid can turn from the lower turbulence channel to the upper turbulence channel, at the moment, the drilling fluid in the oil liquid chamber flows out from the outlet hole, the drilling fluid in the oil liquid chamber is changed from the clockwise direction to the anticlockwise direction, and the drilling fluid is circulated and reciprocated, and first hydraulic pulse can be generated in the pulse generation; drilling fluid enters a main flow passage from an outlet hole and flows through a turbine to rotate a movable mandrel, so that a valve A is driven to rotate; the valve B is fixed and does not rotate along with the mandrel, so that the change of the flow area is generated, and a second hydraulic pulse is generated at the valve; hydraulic pulse of drilling fluid acts on the pull rod to enable the pull rod to generate axial vibration, and at the moment, the disc spring is in an extension or compression state to enable the pull rod in the limit position to recover; the pressure pulses generated in two times are superposed, the pulse frequency can be stably changed between 20HZ and 30HZ, the flowing state of the drilling fluid is changed, the static friction during drilling is changed into dynamic friction, the friction is reduced, and the drilling speed is increased.
Compared with the prior art, the invention has the beneficial effects that: (1) the invention adopts turbine drive, has the advantages of reliable work, high temperature resistance, small pressure drop and the like, has no radial vibration caused by eccentricity, and can not generate great influence on sensitive elements; (2) the invention utilizes the pulse generator and the valve group to generate two times of pressure pulses, and the two times of pulses are superposed, thereby generating higher pulse frequency and larger pulse amplitude; (3) the main structure of the invention is composed of pure metal parts, no sensitive element to high temperature exists, the invention has the performances of high temperature resistance and wear resistance, the pulse generator has no moving part, the structure is reliable, and the service life is long; (4) the invention has the characteristics of simple mechanism, convenient operation, safety, reliability, strong adaptability, no influence on the structure of the drilling tool and the like, and has very important significance for reducing the friction resistance, improving the drilling speed and prolonging the service life of the drilling tool.
Drawings
FIG. 1 is a schematic structural view of the present invention;
in the figure: 1-pull rod, 2-upper shell A, 3-O-shaped sealing ring A, 4-limiting ring, 5-upper shell B, 6-disc spring, 7-O-shaped sealing ring B, 8-shell A, 9-shell B, 10-pulse generator, 11-lower shell, 12-mandrel, 13-turbine, 14-valve A, 15-sleeve, 16-valve B and 17-lower joint.
FIG. 2 is a schematic diagram of a pulse generator according to the present invention;
in the figure: 201-inlet hole, 202-lower ring flow channel, 203-lower interference flow channel, 204-lower return channel, 205-lower branch flow channel, 206-outlet hole, 207-oil chamber, 208-upper branch flow channel, 209-upper return channel, 210-upper interference flow channel, 211-acceleration flow channel and 212-upper ring flow channel.
FIG. 3 is a three-dimensional schematic diagram of a pulse generator of the present invention;
FIG. 4 is a schematic view of the construction of valve A of the present invention;
fig. 5 is a schematic view of the structure of the valve B of the present invention.
Detailed Description
In order to more clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will now be described with reference to the accompanying drawings.
As shown in fig. 1-5, the turbine-type combined friction-reducing tool capable of changing the flow state of drilling fluid mainly comprises a pull rod 1, an upper shell a2, an O-shaped sealing ring A3, a limiting ring 4, an upper shell B5, a disc spring 6, an O-shaped sealing ring B7, a shell A8, a shell B9, a pulse generator 10, a lower shell 11, a mandrel 12, a turbine 13, a valve a14, a sleeve 15, a valve B16 and a lower joint 17, and is technically characterized in that the pull rod 1 is connected with the upper shell B5 through a spline; the upper shell A2, the upper shell B5, the shell A8, the shell B9, the lower shell 11 and the lower joint 17 are sequentially connected with one another through threads; the fluid inlet cone is positioned at the inlet flow channel of the pull rod 1, is equivalent to a reducing pipe and is used for improving the fluid pressure difference, the quality of the effect of improving the pressure difference is related to the cone angle of the fluid inlet cone and the ratio of the diameter of the small end to the diameter of the large end, and the cone angle is 30 degrees in the invention, so the fluid loss coefficient is small, and the pressure difference is improved greatly; an O-shaped sealing ring A3 is arranged in the upper shell A2 and is used for sealing a gap between the upper shell A2 and the pull rod 1; the limiting ring is positioned in the upper shell B5 and is axially positioned on the lower end surface of the upper shell A2 to prevent the pull rod 1 from separating from the shell; the disc spring 6 is arranged between the upper shell B5 and the shell A8, and the pull rod returns by adopting a double-disc spring with a common rectangular section; the O-shaped sealing ring B7 is arranged in a ring groove at the lower end of the pull rod 1 and is used for applying the drilling fluid pressure on the pull rod 1; the pulse generator 10 is arranged in a shell B9, the axial upper end is positioned in a shell A8, the axial lower end and the circumferential direction are positioned in a shell B9, the drilling fluid generates forward and reverse vortex due to the design of a flow channel of the pulse generator 10, so that pressure pulse is generated, the structure of the flow channel is the key for generating the pulse, and the pulse frequency generated by the pulse generator can reach 10HZ to 15 HZ; the spindle 12 is mounted in the lower housing 11 and the lower joint 17, in a central and axial position; the turbine 13 is arranged on the spindle 12, and is axially positioned by a step and a lower joint 17 in the lower shell 11, the turbine 13 converts the linear fluid flow into the rotary fluid flow, wherein the rotary fluid flow motion is transmitted from the turbine 13 to the valve A14 and the valve B16 through the spindle 12, the group number of the turbines 13 directly influences the efficiency of converting the linear fluid flow into the rotary fluid flow, and the invention adopts 8 groups of turbines; the valve A14 and the valve B16 are positioned on the mandrel 12 through the sleeve 15 and the lower joint 17, and the frequency of hydraulic pulse caused by the change of the flow area generated by the valve group can reach 10HZ to 20 HZ; when the pull rod 1 is positioned at a normal position, the disc spring 6 is in a relaxed state; when drilling fluid enters from the upper end of the pull rod 1, then enters the inlet hole 201 of the pulse generator 10 from the main flow channel, and is accelerated by the accelerating flow channel 211, the drilling fluid can flow through the lower flow channel 205 and the upper flow channel 208, but due to the coanda effect, the drilling fluid only flows along one of the lower flow channels, and here, if the drilling fluid enters from the lower flow channel 205 and then enters the oil chamber 207 to form a vortex flow, the suction force generated by the pressure increase of the inlet hole 201 at this time, the drilling fluid enters the upper ring flow channel 212 from the upper return channel 209 and then flows into the lower flow channel 203 from the lower ring flow channel 202, the drilling fluid at this time can interfere with the fluid flowing out from the accelerating flow channel 211, the accelerating fluid can turn to the upper flow channel 208 from the lower flow channel 205, the drilling fluid in the oil chamber 207 can flow out from the outlet hole 206, the drilling fluid can change from the clockwise direction to the counterclockwise direction in the oil chamber 207, with this cyclic reciprocation, a first hydraulic pulse will occur within the pulse generator 10; drilling fluid enters the primary flow path from the outlet bore 206 and flows through the turbine 13 to rotate the moving mandrel 12, thereby driving the valve a14 to rotate; valve B16 is fixed and does not rotate with the mandrel, thereby creating a change in the flow area, creating a second hydraulic pulse at the valve; hydraulic pulse of drilling fluid acts on the pull rod 1 to enable the pull rod 1 to generate axial vibration, and at the moment, the disc spring 6 is in an extension or compression state to enable the pull rod 1 in the limit position to recover; the pressure pulses generated in two times are superposed, the pulse frequency can be stably changed between 20HZ and 30HZ, the flowing state of the drilling fluid is changed, the static friction during drilling is changed into dynamic friction, the friction is reduced, and the drilling speed is increased.
The turbine 13 converts linear fluid flow to rotary fluid flow, wherein rotary fluid flow motion is transferred from the turbine 13 through the spindle 14 to valve a14 and valve B16.
The first pulse frequency generated by the pulse generator 10 can reach 10HZ to 15HZ, the pressure pulse frequency generated by the valve A and the valve B can reach 10HZ to 20HZ, and the pulse frequency can reach 20HZ to 30HZ after the two pulses are superposed.
The turbine type combined friction resistance reducing tool capable of changing the flowing state of the drilling fluid has the following specific working process:
when drilling fluid enters from the upper end of the pull rod 1 and passes through the fluid inlet cone, the pressure difference is increased, the speed is increased, the drilling fluid enters the inlet hole 201 of the pulse generator 10 from the main runner, after the drilling fluid is accelerated by the accelerating runner 211, the drilling fluid can flow through the lower runner 205 and the upper runner 208, but the drilling fluid only flows along one of the sub-runners due to the coanda effect, if the drilling fluid enters from the lower runner 205 and then enters the oil liquid chamber 207 to form a vortex, at the moment, the pressure of the inlet hole 201 is increased to generate suction, the drilling fluid enters the upper ring runner 212 from the upper return runner 209 and then flows into the lower ring runner 203 from the lower ring runner 202, at the moment, the drilling fluid interferes with the liquid flowing out from the accelerating runner 211, the accelerating fluid can be turned to the upper runner 208 from the lower runner 205, at the moment, the drilling fluid in the oil liquid chamber 207 flows out from the outlet hole 206, and the fluid circulates and reciprocates, a first hydraulic pulse will occur within the pulse generator 10; drilling fluid enters the primary flow path from the outlet bore 206 and flows through the turbine 13 to rotate the moving mandrel 12, thereby driving the valve a14 to rotate; valve B16 is fixed and does not rotate with the mandrel, thereby creating a change in the flow area, creating a second hydraulic pulse at the valve; hydraulic pulse of drilling fluid acts on the pull rod 1 to enable the pull rod 1 to generate axial vibration, and at the moment, the disc spring 6 is in an extension or compression state to enable the pull rod 1 in the limit position to recover; the pressure pulses generated in two times are superposed, the pulse frequency can be stably changed between 20HZ and 30HZ, the flowing state of the drilling fluid is changed, the static friction during drilling is changed into dynamic friction, the friction resistance is reduced, and the drilling speed is improved
The tool has stronger axial vibration capability, and can effectively solve the problems that the drilling fluid has low rock carrying capability, unsatisfactory vibration effect, longer development period and higher development cost and cannot meet the design requirement of well trajectory. If the tool is placed near the drill bit, the strong axial pulsation of the tool can reduce the axial vibration intensity of the drill bit and improve the uniform contact time of the drill bit and the rock, thereby improving the mechanical drilling speed; the axial vibration can effectively destroy the rock debris bed formed in the horizontal section and can prevent drill jamming; the control precision of the well depth track can be improved, the smoothness of the track is improved, and drilling steps caused by instability of a drilling tool face are effectively reduced.
The above-mentioned embodiment is only a preferred technical solution of the present invention, and should not be construed as limiting the present invention. The scheme is a protection range. The embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict. The protection scope of the present invention is defined by the claims, and includes equivalents of technical features of the claims. I.e., equivalent alterations and modifications within the scope hereof, are also intended to be within the scope of the invention.