LU102416B1 - Core Orienting Device Based on Geomagnetic Field, Coring Device and Sampling Method Thereof - Google Patents

Abstract

The invention discloses a core orienting device based on the geomagnetic field and a sampling method thereof, belonging to the technical field of drilling and coring. The core orienting device comprises a drill bit, core barrels and a core catcher, wherein upper portions of the core barrels are connected with the core catcher and lower portions are connected with the drill bit; the core barrels comprise an outer barrel and an inner barrel; the inner barrel is suspended at the top of the outer barrel; the bottom of the inner barrel is provided with a rotatable disc; and the bottom of the disc is provided with a magnetic needle for indicating directions and an inkpad for marking the directions. According to the core orienting device, the coring direction is determined based on the geomagnetic field.

Description

Core Orienting Device Based on Geomagnetic Field, Coring Device and Sampling Method Thereof

TECHNICAL FIELD The present invention relates to the technical field of drilling and coring, in particular to a core orienting device based on the geomagnetic field, a coring device and a sampling method thereof.

BACKGROUND During drilling and coring, such data as strike and orientation of strata can be provided by oriented coring. Core orienting devices used in the prior art have some shortcomings, such as blurred orientation marks, inaccurate direction and low precision. For example, CN201396092Y discloses a core orienting device, wherein a chemical expansion pipe is connected with a thrust cone to form a whole body. The thrust cone cannot rotate due to the restriction of the upper key of the internal cavity of the chemical expansion pipe and the upper groove of the thrust cone. Pressure is applied by a conventional drill stem, and the pressure is transmitted to the thrust cone to force the chemical expansion pipe to expand longitudinally to squeeze out the instant adhesive in the cavity and to enable the chemical expansion pipe to be glued in the small bore hole. Thereby, the orientation of marks is measured and the orientation of the core is obtained. However, the oriented coring method is complicated in operation process, time-consuming and costly, besides inaccurate orientation and poor implementation effect.

SUMMARY To solve the technical problems in the prior art, the present invention provides a core orienting device based on the geomagnetic field, a coring device and a sampling method thereof, by which the coring direction is determined based on the geomagnetic field, thereby facilitating coring integrity. Coring efficiency is improved, and disadvantages of an existing coring process are overcome.

A first task of the present invention is to provide a core orienting device based on the geomagnetic field.

A core orienting device, comprising a rigid cylinder, a core catcher and a drill bit, wherein the upper portion of the rigid cylinder is connected with the core catcher and the lower portion is connected with the drill bit; the bottom of the rigid cylinder is provided with a rotatable disc, and the bottom of the disc is provided with a magnetic needle for indicating directions and an inkpad for marking the directions.

Preferably, the bottom of the rigid cylinder is connected with the disc through a bearing.

The second task of the present invention is to provide a coring device.

A coring device, comprising an inner core barrel, an outer core barrel and a suspension device, and further comprising the core orienting device according to claim 1 or 2, wherein the core catcher is connected with the inner core barrel, the inner core barrel is connected with the outer core barrel through the suspension device, a suspension bearing is arranged between the suspension device and the inner core barrel, a centralizer is arranged in the inner core barrel, and a back pressure valve device is arranged at the upper portion of the inner core barrel.

Preferably, the inner core barrel is made of seamless steel pipe.

Another task of the present invention is to provide a sampling method of the coring device.

The sampling method of the coring device, comprising the following sequential steps: a. washing the silt deposited in the inner core barrel and cuttings scraped from the shaft wall, cleaning the inner core barrel and the bottom hole, and allowing the drilling fluid to flow out through the back pressure valve device, so as to protect the core from erosion damage during sampling; b. starting coring during which the outer core barrel rotates with the drill bit to provide power continuously, the core keeps moving up with the drilling of the drill bit, and comes into contact with the disc when reaching the core orienting device, so that the inkpad leaves a clear mark on the top of the core and indicates the orientation of the core; c. driving the core to keep moving up with the rotation of the drill bit, enabling the core to enter the inner core barrel through the core catcher, and the drilled core to be stored and protected by the inner core barrel, with the core running through the drill bit, the core orienting device, the core catcher and the inner core barrel, and the disc in a completely open state; d. after core drilling is completed, driving the core catcher to contract, self-lock, clamp and break the core by the friction between the core catcher and the core, enabling the drill bit to be lifted up, the bottom core broken by the core catcher to fall off, and the disc to return to the original position, with the core mainly existing in the inner core barrel; e. protecting the integrity of core samples under the combined action of the core catcher and the core orienting device, with the core kept between the core orienting device, the core catcher and the inner core barrel when the core catcher is not locked tightly and the core is unconsolidated, keeping lifting the drill bit up for coring, and finishing sampling when the drill bit is lifted out of the ground.

The present invention has the following advantageous technical effects: According to the present invention, the sampling direction is determined by arranging a directional magnetic needle at the bottom of the disc, which is easy to 0102610 operate and reliable in performance. Meanwhile, the disc is connected with the bottom of the rigid cylinder through a bearing. At the beginning of coring, the core orientation is determined by the magnetic needle located at the bottom of the disc. When the drill bit starts coring, the core keeps moving upward. When the core comes into contact with the disc, the inkpad leaves a mark on the top of the core for indicating the orientation of the core samples under the combined action of the weight of the bearing and the disc. At the end of sampling, the disc is closed to protect the coring integrity.

so that the coring effect is good and the coring efficiency is improved.

When the core orienting device is used for sampling in the coring device, the solid disc with a certain weight capacity at the bottom of the core orienting device and the bearing for controlling the opening and closing of the disc can ensure that the core samples do not slip out. The core samples are kept between the core orienting device, the core catcher and the inner core barrel when the core catcher is not locked tightly and the core samples are unconsolidated. The integrity of the core samples is protected under the combined action of the core catcher and the core orienting device, avoiding the coring tool from slipping out. The core drill keeps lifting up, and the sampling is finished when the core drill is lifted out of the ground.

BRIEF DESCRIPTION OF THE FIGURES The present invention will be further described with reference to the accompanying drawings: Fig. 1 is a structural diagram of a coring device of the present invention.

Fig. 2 is a structural diagram of a core orienting device of the present invention.

Fig. 3 is a structural diagram of the bottom of a disc of the present invention.

Fig. 4 is a schematic diagram of the disc in a rotating state of the present invention.

In the figures: 1. drill bit, 2. core orienting device, 3. core catcher, 4. inner core barrel, 5. centralizer, 6. outer core barrel, 7. back pressure valve device, 8. suspension bearing, 9. suspension device, 10. rigid cylinder, 11. spring bearing, 12. disc, 13. magnetic needle, 14. inkpad.

DESCRIPTION OF THE INVENTION The present invention discloses a core orienting device based on the geomagnetic field, a coring device and a sampling method thereof. The present invention will be described in detail in combination with preferred embodiments for clear understanding of the advantages and technical solution of the present invention.

As shown in Figs. 1-3, the core orienting device of the present invention comprises a rigid cylinder 10, a core catcher 3 and a drill bit 1, wherein the upper portion of the rigid cylinder is connected with the core catcher 3 and the lower portion is connected with the drill bit 1; the bottom of the rigid cylinder is provided with a rotatable disc 12, and the bottom of the disc is provided with a magnetic needle 13 for indicating directions and an inkpad 14 for marking the directions. Preferably, the bottom of the rigid cylinder is connected with the disc through a spring bearing 11 to realize rotation.

The coring device of the present invention is composed of a core orienting device 2, an inner core barrel 4, an outer core barrel 6, a centralizer 5, a back pressure valve device 7, a suspension bearing 8 and a suspension device 9, wherein the upper portion of the core orienting device is connected with the core catcher 3, the core catcher 3 is connected with the inner core barrel 4, the diameter of the inner core barrel 4 is larger than that of the core samples, the inner core barrel 4 is connected with the outer core barrel 6 through the suspension device 9, and the suspension

& LU102416 bearing 5 & arranged between the suspension device § and the inner core barre! 4 io sind ensure that the inner barrel dass not rotate with the outer barret & centralizer 8 io aranged in the inner core barrel 4 fo prevent the core from bending and deformation; the upper porlion à provided with the back pressure valve device 7 which can prevent the core from erosion from washing fluid and ensure Suid in he inner bare! tv be discharged: the lower portion of fie core crentîing device © 15 connected with the driff bit 1, and the bottom of the core orienting device à is provided with solid disc 17 capable of rotating up and down, and the solid dise 12 has a contain weight and can bear à certain pressure, tie solid disc 13 is fixed at the bottom of the sald eyfinder 10 through the spring bearing 11, and the dameter af the gid eylinder 10 is sighiiy larger than that of the coring sample: the main function of the spring bearing 11 is io control the opening and closing of the solid dise 12) and the boftom of the solid disc 12 is inaid with a magnetic nesdle 13 which can rotate freely and determine directions based on the geomagnetic field, and a marking inkpad TA for marking the directions.

The sampling method of the coring device of the present invention comprises the following stop: washing the sit deposiiad in he nner core barre! and cutings sovapsd from the shaft wall with à large amount of ciroufeting driling fuid, cleaning the inner core barres and the bottom hola, and allowing the drilling Suid to fee oui Brough the back pressure valve device 7, so as to profent the core from erosion damage during sampling. At the beginning of coring, te magnetic nesdie 13 for indicating directions automatireïy determines the orientation of the core samples according to the direction of the guomagnetio Feld at the sampling site. When the cri DUT starts Core, the outer core hare! & rotates with the dill bit 1 to provide power continucusly, the core moves up continuously with the drilling of the drill bit, and comes into contact with the solid disc 12 at the bottom of the core orienting device when reaching the core orienting device 2. Under the combined action of the spring bearing 11 controlling the opening and closing of the solid disc and the solid disc 12 with a certain weight, the inkpad 14 leaves a clear mark on the top of the core for indicating the orientation of the core samples.

With the rotation of the drill bit, the core keeps moving up and enters the inner core barrel 4 through the core catcher 3, and a centralizer 5 is arranged in the inner core barrel 4 to ensure that the core is not deformed or bent. The drilled core is stored and protected by the inner barrel. At this moment, the core samples run through the drill bit 1, the core orienting device 2, the core catcher 3 and the inner core barrel 4, and the solid disc 12 is in a completely open state.

When the drill tool is slowly lifted up after coring and drilling, the core catcher 3 contracts, locks itself, clamps and breaks the core due to the friction with the core samples. When the drill tool is lifted up, the bottom core samples broken by the core catcher 3 fall off, and the solid disc 12 at the bottom of the core orienting device 2 returns to the original position under the action of the spring bearing 11. The whole process is shown in Fig. 4, and the core mainly exists in the inner core barrel 4 at this moment. With the continuous lifting of the drill tool, the core tends to slide down due to the weight of the core samples or unconsolidated core samples, and the core catcher 3 is not locked tightly. At this moment, the core samples are guaranteed not to slip out under the action of the solid disc 12 with a certain weight capacity at the bottom of the core orienting device 2 and the spring bearing 11 for controlling the opening and closing of the solid disc 12. In the case that the core catcher 3 is not locked tightly and the core samples are unconsolidated, the core samples are kept between the core orienting device 2, the core catcher 3 and the inner core barrel 4. Under the combined action of the core catcher 3 and the core orienting device 2, the integrity of the core samples is protected and the coring tool is prevented from slipping out. The core drill keeps lifting up, and the sampling is finished when the core drill is lifted out of the ground.

The core orienting device 2 is mainly arranged between the drill bit 1 and the core catcher 3. The main principle of the implementation method is to determine the coring direction based on the geomagnetic field through the magnetic needle 13 and calibrate the direction by using an inkpad 14. Meanwhile, under the combined action of the rigid cylinder 10 and the solid disc 12 with a certain weight and bearing capacity connected with the spring bearing 11, the coring integrity is guaranteed, the coring efficiency is improved, and the dual effects of orientation and protection are achieved.

It should be noted that any equivalent or obvious modification made by those skilled in the art under the teaching of the specification should fall within the protection scope of the present invention.

Claims (5)

1. A core orienting device, characterized by comprising a rigid cylinder, a core catcher and a drill bit, wherein the upper portion of the rigid cylinder is connected with the core catcher and the lower portion is connected with the drill bit; the bottom of the rigid cylinder is provided with a rotatable disc, and the bottom of the disc is provided with a magnetic needle for indicating directions and an inkpad for marking the directions.

2. The core orienting device according to claim 1, characterized in that the bottom of the rigid cylinder is connected with the disc through a bearing.

3. A coring device, comprising an inner core barrel, an outer core barrel and a suspension device, and characterized by further comprising the core orienting device according to claim 1 or 2, wherein the core catcher is connected with the inner core barrel, the inner core barrel is connected with the outer core barrel through the suspension device, a suspension bearing is arranged between the suspension device and the inner core barrel, a centralizer is arranged in the inner core barrel, and a back pressure vaive device is arranged at the upper portion of the inner core barrel.

4. The coring device according to claim 3, characterized in that the inner core barrel is made of a seamless steel pipe.

5. A method for using the coring device according to claim 3 or 4, characterized by comprising the following sequential steps: a. washing the silt deposited in the inner core barrel and cuttings scraped from the shaft wall, cleaning the inner core barrel and the bottom hole, and allowing the drilling fluid to flow out through the back pressure valve device, so as to protect the core from erosion damage during sampling; b. starting coring during which the outer core barrel rotates with the drill bit to provide power continuously, the core keeps moving up with the drilling of the drill bit, and comes into contact with the disc when reaching the core orienting device, so that the inkpad leaves a clear mark on the top of the core and indicates the orientation of the core;

c. driving the core to keep moving up with the rotation of the drill bit, enabling the core to enter the inner core barrel through the core catcher, and the drilled core to be stored and protected by the inner core barrel, with the core running through the drill bit, the core orienting device, the core catcher and the inner core barrel, and the disc in a completely open state;

d. after core drilling is completed, driving the core catcher to contract, self-lock, clamp and break the core by the friction between the core catcher and the core, enabling the drill bit to be lifted up, the bottom core broken by the core catcher to fall off, and the disc to return to the original position, with the core mainly existing in the inner core barrel; and e. protecting the integrity of the core samples under the combined action of the core catcher and the core orienting device, with the core kept between the core orienting device, the core catcher and the inner core barrel when the core catcher is not locked tightly and the core is unconsolidated, keeping lifting the drill bit up for coring, and finishing sampling when the drill bit is lifted out of the ground.