Patent ID: 12234690

DETAILED DESCRIPTION

For a better understanding of the technical features of the present disclosure, a clear and complete description of the embodiments of the present disclosure will be set forth with reference to the drawings. Obviously, the described embodiments are only a part, rather than all, of the embodiments of the present disclosure. All other embodiments derived by persons skilled in the art from the embodiments of the present disclosure without making inventive efforts shall fall within the scope of the present disclosure.

In the embodiments of the present disclosure, the terms ‘first’, ‘second’, etc. are used to distinguish different elements from each other based on appellations, but do not indicate the spatial arrangement, temporal order, or the like of these elements, and these elements should not be limited by these terms. The term ‘and/or’ includes any of one or more of associated listed terms and all combinations thereof. The terms ‘include’, ‘comprise’, ‘have’, etc. refer to the presence of the stated features, elements, components, or assemblies, but do not exclude the presence or addition of one or more other features, elements, components, or assemblies.

In the embodiments of the present disclosure, the singular forms ‘a’, ‘the’ or the like may include the plural form, and should be broadly understood as ‘a type of’ or ‘a category of’ and not limited to the meaning of ‘one’. In addition, the term ‘said’ should be understood as including both singular and plural forms, unless the context clearly indicates otherwise. Furthermore, the term ‘according to’ should be understood as ‘at least partially according to . . . ’ and the term ‘based on’ should be understood as ‘at least partially based on . . . ’, unless the context clearly indicates otherwise. Moreover, the term “a plurality of” means two or more, unless otherwise specified.

The implementations of the embodiments of the present disclosure will now be described with reference to the drawings.

As illustrated inFIG.1, an embodiment of the present disclosure provides an experimental apparatus for rock-breaking by vibration impact, which includes a drill bit10, a confining pressure loading assembly20, a drilling fluid circulation assembly30, a rotary impact assembly40, an axial impact assembly50and a data collection assembly.

As illustrated inFIG.1, the drill bit10is capable of drilling a core sample to simulate a drilling process of a drill bit during an on-site drilling. The drill bit10may be, for example, a Polycrystalline Diamond Compact (PDC) drill bit, which is suitable for drilling rock formations with high hardness. As illustrated inFIG.1, the drill bit10is connected to a drill rod128.

In some embodiments, as illustrated inFIGS.1and2, the confining pressure loading assembly20is capable of applying a confining pressure to a core sample101to simulate a formation confining pressure. Specifically, as illustrated inFIG.2, the confining pressure loading assembly20includes a core cavity102and a liquid outlet116being in communication with the core cavity102. The core cavity102is used for accommodating the core sample101, and the liquid outlet116is used for being connected to the drilling fluid circulation assembly30. The confining pressure loading assembly20is configured to apply pressures to the core sample101located in the core cavity102in three directions perpendicular to each other. In other words, the confining pressure loading assembly20can apply pressures to the core sample101in an X direction, a Y direction and a Z direction which are perpendicular to each other. For example, the confining pressure loading assembly20may be, for example, a true triaxial core holder.

Optionally, as illustrated inFIG.2, the confining pressure loading assembly20includes a plurality of pressing plates103and at least three hydraulic cylinders (i.e., second hydraulic cylinders). The pressing plates103are jointly enclosed to form the core cavity102. The at least three hydraulic cylinders104are used to apply pressures to at least three pressing plates103perpendicular to each other in three directions perpendicular to each other.

Illustratively, as illustrated inFIG.2, the core sample101and the core cavity102are square, and there are six pressing plates103which are jointly enclosed to form the square core cavity102. The pressing plate103at the top of the core sample101(called the top pressing plate103) is provided with a via-hole, through which the core cavity102is being in communication with the outside and the drill bit10can pass to drill the core sample102located in the core cavity102.

In one example, there may be five hydraulic cylinders104respectively connected to five pressing plates103except the top pressing plate103, at the exterior of the core cavity102, so as to drive the five pressing plates103to simultaneously apply pressures to the core sample101in three directions perpendicular to each other, thereby simulating the formation confining pressure.

In another example, there may be three hydraulic cylinders104respectively connected to three pressing plates103perpendicular to each other to drive the three pressing plates103to simultaneously apply pressures to the core sample101in three directions perpendicular to each other, so as to simulate the formation confining pressure.

Optionally, as illustrated inFIG.2, the confining pressure loading assembly20further includes a bottom plate130, a barrel132and an upper cover133. The barrel132is fixed on the bottom plate130. The barrel132and the bottom plate130jointly define an internal space with an open top. The pressing plates103and the hydraulic cylinder104are disposed in the internal space. The upper cover133is disposed at the top of the internal space and detachably connected to the barrel132to allow for the pressing plates103and the hydraulic cylinder104to be placed into or taken out of the internal space.

Optionally, as illustrated inFIG.2, the confining pressure loading assembly20further includes a sealing joint129which may be in sealed connection with the upper cover133. The drill rod128passes through the sealing joint129. The liquid outlet116is disposed at the sealing joint129.

Optionally, as illustrated inFIG.2, the confining pressure loading assembly20further includes a pressure sensor105for detecting a pressure applied on the core sample101. For example, there may be three pressure sensors105for detecting the pressures in three directions perpendicular to each other, respectively. For example, the pressure sensors105may be disposed on the hydraulic cylinders104, and the hydraulic pressures of the hydraulic cylinders detected by the pressure sensor105may be considered as the pressures applied on the core sample101.

In some embodiments, as illustrated inFIGS.2and3, the experimental apparatus of the present disclosure further includes a temperature control assembly for heating the core sample101to simulate the formation temperature. The temperature control assembly includes a heating element106for heating the core sample101located in the core cavity102, a temperature sensor107for detecting the temperature of the core sample101, and a controller108electrically connected to the temperature sensor107and the heating element106which are disposed on the confining pressure loading assembly20.

Illustratively, the heating element106may be a heating tube mounted on the pressing plate103. For example, the pressing plate103is provided with a mounting groove in which the heating tube is disposed. Each of the pressing plates103may be provided with a plurality of heating tubes disposed at intervals to realize uniform and rapid heating. Each of the pressing plates103may be provided with a temperature sensor107for detecting the temperature of the pressing plate103, and the temperature of the pressing plate103detected by the temperature sensor107may be considered as the temperature of the core sample101.

Illustratively, the controller108may be a PID temperature control meter, which may receive temperature data from the temperature sensor107and control the heating element106to heat the core sample101based on the temperature data and a temperature set by a user, so that the core sample101is heated to the temperature set by the user.

In some embodiments, as illustrated inFIG.2, the drilling fluid circulation assembly30is capable of simulating a drilling fluid circulation during an on-site drilling. The drilling fluid circulation assembly30includes a drilling fluid outlet109, a drilling fluid inlet110, and a mud pump111connected therebetween. Being driven by the mud pump111, drilling fluid flows into the drilling fluid circulation assembly30via the drilling fluid inlet110and then flows out of the drilling fluid outlet109. The drilling fluid outlet109is in fluid communication with the drill bit10through the drill rod128, and the drilling fluid inlet110is in communication with the liquid outlet116. The mud pump111, the drilling fluid outlet109, the drill rod128, the drill bit10, the core cavity102, the liquid outlet116, the drilling fluid inlet110and the mud pump111are in fluid communication in sequence to form a mud circulation channel. Therefore, the drilling fluid flowing out via the drilling fluid outlet109flows into the drill bit10, and then is sprayed from a nozzle of the drill bit10, flows back upwardly carrying rock debris broken by the drill bit10, then flows out of the confining pressure loading assembly20via the liquid outlet116and flows into the drilling fluid circulation assembly30via the drilling fluid inlet110, and then flows out of the drilling fluid circulation assembly30via the drilling fluid outlet109and enters the drill bit10under the drive of the mud pump111for a next circulation flow.

Optionally, as illustrated inFIG.2, the drilling fluid circulation assembly30further includes a mud tank112and a desander113which are connected between the drilling fluid inlet110and the drilling fluid outlet109. The mud tank112is used for accommodating drilling fluid, and the desander113is used for removing solid impurities such as gravel and rock debris in the drilling fluid.

Illustratively, in a flowing direction of the drilling fluid, the desander113, the mud tank112and the mud pump111are connected in sequence. Therefore, the drilling fluid entering the drilling fluid circulation assembly30via the drilling fluid inlet110is purified by the desander113and then enters the mud tank112. Being driven by the mud pump111, the drilling fluid in the mud tank112flows out of the drilling fluid circulation assembly30via the drilling fluid outlet109and enters the drill bit10.

The desander113may be, for example, a cyclone desander, which separates solid impurities from the drilling fluid on the principle of hydraulic cyclone separation. Alternatively, the desander113may be a vibrating screen.

The mud pump111may be, for example, a submersible pump.

In some embodiments, as illustrated inFIG.1, the rotary impact assembly40is capable of applying a rock-breaking torque and a circumferential impact load to the drill bit10to drive the drill bit10to break the core sample101.

The rotary impact assembly40includes a hydraulic rotary motor114connected to the drill rod128and a hydraulic swing motor115connected to the drill rod128. The rock-breaking torque and the circumferential impact load applied by the rotary impact assembly40can be transferred to the drill bit10through the drill rod128, and a Weight on Bit (WOB) and an axial impact load applied by the axial impact assembly50are transferred to the drill bit10through the drill rod128, so as to drive the drill bit10to drill the core sample.

Specifically, the hydraulic rotary motor114is capable of applying a torque in a first direction (i.e., a rock-breaking torque) to the drill rod128, so as to drive the drill rod128and the drill bit10to rotate in a first direction, which is clockwise or counterclockwise.

Specifically, the hydraulic swing motor115is configured to alternately apply a torque (i.e., an impact torque) in the first direction and a torque (i.e., an impact torque) in a second direction to the drill rod128. The second direction is clockwise or counterclockwise and is opposite to the first direction.

When the hydraulic swing motor115applies the impact torque in the first direction to the drill rod128, the rotation of the drill bit10in the first direction will be accelerated. When the hydraulic swing motor115applies the impact torque in the second direction to the drill rod128, the rotation of the drill bit10in the first direction will be decelerated. The time interval between alternately applying the torque in the first direction and the torque in the second direction by the hydraulic swing motor115is short, and the time duration for which the hydraulic swing motor115applies the torque in the first direction and the time duration for which the hydraulic swing motor115applies the second direction are also short, thereby driving the drill bit10to apply an instantaneous circumferential impact to the core sample101.

The alternating frequency at which the hydraulic swing motor115alternately applies the torque in the first direction and the torque in the second direction, and the time durations for which the hydraulic swing motor115applies the torque in the first direction and the torque in the second direction may be set according to actual needs.

The hydraulic swing motor115may be connected to a pumping station, which provides an energy source to the hydraulic swing motor115by supplying oil. The hydraulic swing motor115is a hydraulic actuator with an output shaft that can swing reciprocally. The hydraulic swing motor115may be a vane swing motor or a piston swing motor. The working principle of the vane swing motor is that the vanes of the motor are driven by pressure oil to drive the output shaft to swing reciprocally. The working principle of the piston swing motor is that the piston of the motor is driven by pressure oil to move linearly to drive the output shaft to swing. The hydraulic swing motor115may be controlled by an electro-hydraulic servo valve. Upon receipt of a control instruction from a control system, the electro-hydraulic servo valve controls the hydraulic swing motor115to operate by controlling the flowrate and the direction of the hydraulic oil.

In this embodiment, the hydraulic swing motor115cooperates with the hydraulic rotary motor114to accelerate and decelerate the drill rod128at a certain frequency on the basis of the hydraulic rotary motor114driving the drill rod128to rotate, so as to achieve a dynamic and varying impact of the circumferential torque, thereby obtaining the circumferential impact force and impact frequency required by the experiment.

In this embodiment, the hydraulic rotary motor and the hydraulic swing motor are available from the prior art, and the specific structures thereof will not be described in detail.

Optionally, the drill rod128is provided with a torsion angle measuring instrument140, which is located between the hydraulic rotary motor114and the hydraulic swing motor115and connected to the drill rod128. When the hydraulic rotary motor114drives the drill rod128to rotate, the torsion angle measuring instrument140rotates synchronously with the drill rod128. When the hydraulic swing motor115applies an instantaneous impact torque to the drill rod128, the instantaneous impact torque causes an instantaneous tiny circumferential impact displacement of the drill rod128, or in other words, the instantaneous impact torque causes an instantaneous tiny impact rotation angle of the drill rod128, and the value of the impact rotation angle can be measured by the torsion angle measuring instrument140.

Optionally, the experimental apparatus of the present disclosure further includes a torque sensor141for measuring a torque of the drill rod128and a rotational speed sensor142for measuring a rotational speed of the drill rod128. The torque of the drill rod128is the sum of the torques applied to the drill rod128by the hydraulic rotary motor114and the hydraulic swing motor115.

Illustratively, the torque sensor141is a non-contact torque sensor, and the rotational speed sensor142is a non-contact rotational speed sensor, so that the torque sensor141and the rotational speed sensor142can be mounted at positions aligned with the drill rod128without rotating with the drill rod128. For example, the torque sensor141and the rotational speed sensor142are mounted on a housing of the hydraulic swing motor115.

Optionally, as illustrated inFIG.1, the hydraulic rotary motor114and the hydraulic swing motor115are supported by a platform, and actuating parts of the hydraulic rotary motor114and the hydraulic swing motor115are fixedly connected to the drill rod128to apply a rotation torque and an impact torque to the drill rod128.

In some embodiments, the axial impact assembly50is capable of applying a WOB and an axial impact load to the drill bit10to drive the drill bit10to break the core sample101.

The axial impact assembly50includes a hydraulic cylinder118(i.e., a first hydraulic cylinder), a servo linear actuator117and a connector119. The servo linear actuator117is connected to the drill rod128, and a piston rod of the hydraulic cylinder118is connected to the servo linear actuator117.

The hydraulic cylinder118is capable of applying a thrusting force to the drill rod128in a third direction. The third direction is towards the core sample101and parallel to an axial direction of the drill rod128. Since the hydraulic cylinder118is connected to the drill rod128through the servo linear actuator117, the thrusting force generated by the hydraulic cylinder118is applied to the drill rod128through the servo linear actuator117. The thrusting force applied by the hydraulic cylinder118provides the WOB to the drill rod128and the drill bit10, and drives the drill rod128and the drill bit10to move towards the core sample101.

The servo linear actuator117is capable of alternately applying a thrusting force in the third direction and a tensile force in a fourth direction to the drill rod128. The fourth direction is opposite to the third direction and parallel to the axial direction of the drill rod128.

When the servo linear actuator117applies the thrusting force in the third direction to the drill rod128, the axial drilling of the drill bit10in the third direction will be accelerated. When the servo linear actuator117applies the tensile force in the fourth direction to the drill rod128, the axial drilling of the drill rod128in the third direction will be decelerated. The time interval between alternately applying the thrusting force in the third direction and the tensile force in the fourth direction by the servo linear actuator117is short, and the time duration for which the servo linear actuator117applies the thrusting force in the third direction and the time duration for which the servo linear actuator117applies the tensile force in the fourth direction are also short, thereby driving the drill bit10to apply an instantaneous axial impact to the core sample101.

The servo linear actuator117can apply controllable thrusting force and tensile force to the drill rod128, and the axial impact load applied to the drill rod128by the servo linear actuator117is controlled by controlling the amplitude of the servo linear actuator117, thereby controlling the axial impact force of the drill bit10on the core sample101.

The servo linear actuator117may be connected to a pumping station, which provides an energy source to the servo linear actuator117by supplying oil. The servo linear actuator117may be controlled by the electro-hydraulic servo valve. Upon receipt of a control instruction from a control system, the electro-hydraulic servo valve controls the servo linear actuator117to operate by controlling the flowrate and the direction of the pressure oil, so that the servo linear actuator117can generate linear and varying reciprocating force, thereby obtaining the axial impact force and impact frequency required by the experiment.

In this embodiment, the servo linear actuator is available from the prior art, and the specific structure thereof will not be described in detail.

Optionally, the hydraulic cylinder118is provided with a displacement sensor143for measuring the displacement of the piston rod of the hydraulic cylinder118.

Optionally, the servo linear actuator117is provided with a magnetostrictive displacement sensor144for measuring the tiny axial displacement of the servo linear actuator117caused by the axial impact of the servo linear actuator117.

In this embodiment, the servo linear actuator117is connected to the drill rod128through the connector119. The connector119may be an end bearing, which can transfer the axial forces applied by the servo linear actuator117and the hydraulic cylinder118to the drill rod128, without transferring the torque applied to the drill rod128by the hydraulic rotary motor114to the servo linear actuator117and the hydraulic cylinder118, thereby reducing the circumferential friction exerted on the drill rod and avoiding the inaccuracy of the measured torque or the deviation of the experimental data.

Optionally, a pressure sensor145is connected between the servo linear actuator117and the connector119to measure the WOB.

In some embodiments, as illustrated inFIG.4, the experimental apparatus of the present disclosure further includes a servo controller121and a constant pressure servo pumping station122. The servo controller121is configured to receive measurement data collected by the torsion angle measuring instrument140, the torque sensor141, the rotational speed sensor142, the displacement sensor143, the magnetostrictive displacement sensor144and the pressure sensor145, and a user instruction, and configured to send a control signal according to the measurement data and the user instruction. The user instruction may be received from a computer or any other terminal. The constant pressure servo pumping station122is configured to receive the control signal and control the hydraulic swing motor115, the hydraulic cylinder118and the servo linear actuator117according to the control signal. The constant pressure servo pumping station122is electrically connected to the hydraulic rotary motor114to control the rotation of the hydraulic rotary motor114. The constant pressure servo pumping station122is electrically connected to the hydraulic cylinder104to control the action thereof.

In some embodiments, as illustrated inFIG.4, the experimental apparatus of the present disclosure further includes a terminal device123, which is in communicative connection with the confining pressure loading assembly20, the drilling fluid circulation assembly30, the data collection assembly and the servo controller121. The terminal device123can receive and process the data sent by the confining pressure loading assembly20, the drilling fluid circulation assembly30and the data collection assembly, and can send a user instruction to the servo controller121. For example, the terminal device123is a computer.

Specifically, as illustrated inFIG.4, the terminal device123is in communicative connection with the pressure sensor105of the confining pressure loading assembly20, the temperature sensor107of the temperature control assembly, the mud pump111of the drilling fluid circulation assembly30, and the data collection assembly.

Optionally, the measurement data collected by the torsion angle measuring instrument140, the torque sensor141, the rotational speed sensor142, the displacement sensor143, the magnetostrictive displacement sensor144, and the pressure sensor145may be sent to the servo controller121directly or through the terminal device123.

In some embodiments, as illustrated inFIG.1, the experimental apparatus of the present disclosure further includes a fixed bracket124, a movable bracket, a hydraulic cylinder126(i.e., a third hydraulic cylinder) and a locking device127. The movable bracket is disposed on the fixed bracket124and movable in the axial direction. The hydraulic cylinder118, the hydraulic rotary motor114, and the hydraulic swing motor115are mounted on the movable bracket, so as to be supported by the movable bracket.

As illustrated inFIG.1, the hydraulic cylinder126is connected to the fixed bracket124and the movable bracket125, respectively, for driving the movable bracket125to ascend and descend in the axial direction, so as to adjust the height of the movable bracket125, thereby adjusting the height of the drill bit10. For example, by decreasing the height of the drill bit10, the drill bit10inserts into the core cavity102to drill the core sample101, and by increasing the height of the drill bit10, the drill bit10moves out of the core cavity102, so that the core sample101in the core cavity102can be taken out or replaced.

Specifically, as illustrated inFIG.1, the hydraulic cylinder126is disposed in the axial direction, with one end connected to the fixed bracket124and the other end connected to the movable bracket125. The hydraulic cylinder126drives the movable bracket125to ascend and descend by extending or shortening in the axial direction. There may be two hydraulic cylinders126opposite to each other and disposed at an interval to drive the movable bracket125to ascend and descend steadily. The constant pressure servo pumping station122is electrically connected to the hydraulic cylinder126to control the action thereof.

As illustrated inFIG.1, the locking device127is connected to the movable bracket125for releasably locking the movable bracket125with the fixed bracket124. For example, after the movable bracket125is adjusted to a preset height, the movable bracket125is locked with the fixed bracket124through the locking device127, so as to carry out subsequent experimental operations. When it is necessary to adjust the height of the movable bracket125, the locking device127unlocks (releases) the locking of the movable bracket, so that the hydraulic cylinder126drives the movable bracket125to ascend and descend until the movable bracket125reaches another preset height.

For example, the locking device127is a locking hydraulic cylinder, which locks the movable bracket125by means of hydraulic locking, so as to ensure that the movable bracket125will not move or crawl during the experiment, and achieve stable and reliable locking. The constant pressure servo pumping station122is electrically connected to the locking hydraulic cylinder to control the action thereof.

In some embodiments, as illustrated inFIG.1, the fixed bracket124includes a base1241and a plurality of supporting posts1242fixed on the base1241. Each of the supporting posts1242is disposed in the axial direction. The movable bracket125includes a plurality of supporting platforms1251disposed at intervals in the axial direction and connected in sequence for supporting the hydraulic cylinder118, the hydraulic rotary motor114, and the hydraulic swing motor115, respectively. Each of the supporting posts1242passes through the plurality of supporting platforms1251. Therefore, being driven by the hydraulic cylinder126, the plurality of supporting platforms1251are guided by the supporting posts1242to ascend and descend in the axial direction. At least one of the supporting platforms1251is connected to at least one of the supporting posts1242through the locking device127, so that the locking device127can lock the supporting platforms1251with the supporting post1242.

For example, as illustrated inFIG.1, there are three supporting platforms1251disposed at intervals from top to bottom. The hydraulic cylinder118is supported by the uppermost supporting platform1251, the hydraulic rotary motor114is supported by the middle supporting platform1251, and the hydraulic swing motor115is supported by the lowermost supporting platform1251.

For example, there are four locking devices127and four supporting posts1242. The four supporting posts1242are arranged as a rectangle, and the four locking devices127are disposed at the four corners of the middle supporting platform1251, respectively, so as to lock the supporting platform1251with the four supporting posts1242, thereby realizing stable and reliable locking.

Optionally, as illustrated inFIG.1, the top surface of the base1241of the fixed bracket124is provided with a plurality of guide rails139disposed in parallel at intervals. A bottom surface of the bottom plate130of the confining pressure loading assembly20is provided with tracks131fitted with the guide rails139, so that the confining pressure loading assembly20can be slidably fitted with the base1241, thus facilitating moving the confining pressure loading assembly20onto or out of the base1241, and facilitating the mounting or removing of the core sample101.

In one example, the guide rail139is an elongated groove, and the track131is a bump that can be fitted with the groove.

In another example, the guide rail139is an elongated bump, and the track131is a groove that can be fitted with the bump.

Optionally, both the base1241and the bottom plate130are provided with a plurality of positioning holes. Therefore, after the confining pressure loading assembly20is moved onto the base1241, bolts are mounted in the positioning holes to fix the base1241and the bottom plate130, so as to avoid the deviation of the confining pressure loading assembly20during the experiment.

Described above is merely exemplary embodiments of the present disclosure, and is not meant to limit the present disclosure. Various modifications and variations may be made to the present disclosure by those skilled in the art. Any modifications, alternations, improvements, etc., made by those skilled in the art without departing from the concepts and principles of this disclosure shall fall within the scope of the claims.