Disclosure of Invention
The invention aims to provide an underground card measuring system provided with a fiber grating sensing device, which comprises an underground instrument and a ground instrument, wherein the underground instrument comprises a cable joint, a fiber magnetic positioning sensing device, a fiber torsion sensing device and a blasting device;
the fiber magnetic positioning device comprises a substrate material and fiber gratings uniformly wound on the surface of the substrate material and used for detecting the running state of the downhole instrument;
the optical fiber torsion sensing device is wound on the drill rod mandrel in a crossed manner through an optical fiber grating and is used for acquiring the drill rod torsion;
arranging a first centralizer at the upper end of the drill rod, and arranging a second centralizer at the lower end of the drill rod; the first centralizer and the second centralizer centralize the drill pipe by applying opposing forces.
Preferably, the downhole tool comprises a weighted rod and a spring anchor, the spring anchor being divided into an upper spring anchor and a lower spring anchor.
Preferably, the base material is a columnar magnetostrictive material.
Preferably, the surface instrumentation comprises a signal collection device and an armored cable, the armored cable connecting the cable joints.
Preferably, the fiber bragg grating is wound on the drill rod mandrel in a crossed manner, and the crossed winding manner is clockwise winding and anticlockwise winding.
Preferably, the blasting device comprises an ignition control device, a power optical fiber and an optical fiber connector.
Preferably, the ignition control device comprises a laser, a laser focusing lens and a coupler;
the optical fiber connector comprises an isolating film and a medicine cavity; the power optical fiber is connected with the isolation film.
The invention provides an underground card measuring system provided with a fiber grating sensing device, which is wound on a drill stem mandrel in a fiber grating crossing mode to measure the torque of a drill stem, thereby realizing more accurate card measuring requirements.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
Detailed Description
The objects and functions of the present invention and methods for accomplishing the same will be apparent by reference to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The nature of the description is merely to assist those skilled in the relevant art in a comprehensive understanding of the specific details of the invention.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar parts, or the same or similar steps.
The embodiments of the present disclosure are exemplified in the examples herein, and the descriptions mentioned about the devices, structures, sensing devices, cables, base materials, and connection means, etc., should be understood easily by those skilled in the art and all the implementations can be conceived.
Fig. 1 is a schematic structural diagram of a downhole card-measuring system equipped with a fiber grating sensing device according to the present invention, and fig. 2 is a schematic fiber grating laying diagram of the downhole card-measuring system according to the present invention. The surface instrument comprises a signal collecting device 101(201) and an armored optical cable 102(202), wherein the armored optical cable 102(202) is connected with the cable joint 104, and the signal collecting device 101(201) is in information transmission with the downhole instrument through the armored optical cable 102 (202). The underground instrument acquires the position information of the stuck point of the drill rod, transmits the signal to the ground instrument, and the ground instrument analyzes the signal and then adjusts the drill rod to obtain the specific stuck point position in the well.
Specifically, in an embodiment, the downhole tool comprises a cable connector 104, a fiber optic magnetic positioning sensing device 103, a fiber optic torsion sensing device 105, and a blasting device 108 (210).
The cable connector is passed downhole to interconnect with downhole tools, and in some embodiments, the cable connector 103 is connected to the upper end of the fiber optic magnetic positioning device 103. In this embodiment, the cable connector 104 is connected to the lower end of the fiber magnetic positioning device 103.
The fiber magnetic positioning device comprises a base material 203 and a fiber grating 204a uniformly wound on the surface of the base material, wherein the base material 203 is a magnetic telescopic material and can be a column shape convenient for winding the fiber grating in some embodiments; in other embodiments, the shape of the block may be rectangular. The optical fiber positioning device 103 is used for detecting the running state of the downhole instrument.
The underground drill pipe comprises a mandrel and a sleeve, a fiber bragg grating 209 extending from an armored optical cable 102(202) is connected with a fiber torsion sensing device 105, the fiber torsion sensing device 105 is wound on a drill pipe mandrel 205 in a crossing mode through a fiber bragg grating 204b, the fiber bragg grating 204b is wound on the drill pipe mandrel 205 in the crossing mode to be used as a sensor for acquiring the torque of the drill pipe, and the crossing winding mode is clockwise winding and anticlockwise winding. The fiber bragg grating wound clockwise and the fiber bragg grating wound anticlockwise are stressed differently to generate strain when the drill rod is subjected to torsional deformation, and the strain of the two optical fibers is subjected to differential operation to obtain accurate drill rod torque.
A first centralizer 106(206) is arranged at the upper end of the drill rod, a second centralizer 107(207) is arranged at the lower end of the drill rod, the first centralizer and 106(206) the second centralizer 107(207) centralizes the drill rod by applying opposing forces. The armored fiber optic cable 102(202) extends out of the power fiber 208, which is connected to the blasting device (108) 210.
In some embodiments, the downhole tool should further include a weighted rod and a spring anchor, the spring anchor being divided into an upper spring anchor and a lower spring anchor.
As shown in fig. 3, the schematic diagram of the blasting device of the downhole card-testing system of the present invention includes an ignition control device, a power fiber 302 and a fiber connector 303;
the ignition control device comprises a laser 301, a laser focusing lens 304 and a coupler 305;
the optical fiber connector 303 comprises an isolation film 306 and a medicine cavity 307; the power fiber 302 is connected with the isolating membrane 306, and the explosive cavity 307 is filled with explosive for blasting.
Laser output by the laser 301 is focused by the laser focusing lens 304, and the focused laser is coupled by the coupler 305 and transmitted to the isolation film 306 through the power optical fiber 302 to detonate the explosive in the explosive cavity 307, so as to loosen the clamping point of the underground drill pipe. In some embodiments, the laser power output by laser 301 is determined based on geological conditions, and location of the stuck point. In some embodiments, the laser power may be a few milliwatts; in other embodiments, the laser power may be several watts.
FIG. 4 shows a schematic winding diagram of the fiber grating of the fiber magnetic positioning device of the downhole card-measuring system according to the present invention. In this embodiment, a cylindrical magnetic stretching material is taken as an example to describe the fiber grating magnetic positioning device, and the fiber grating 402 is uniformly wound on the surface of the magnetic stretching material 401, preferably, in a spiral winding manner. The distance between the windings of the fiber grating is not a limitation of the present invention.
When the fiber grating magnetic positioning device passes through different inner diameters of different underground pipe columns, the magnetic telescopic material is deformed, so that the fiber grating is deformed in a telescopic manner. The invention can more accurately correct and position the depth of the underground instrument in a spiral winding mode.
FIG. 5 shows a schematic fiber grating wrap around the core of a drill pipe of the downhole sonde system of the present invention. The fiber bragg grating 502 is wound on the inner mandrel 501 of the underground drill rod in a crossed mode to serve as a torsion sensor for measuring a clamping point, and the fiber bragg grating wound clockwise and the fiber bragg grating wound anticlockwise both adopt a spiral type uniform winding mode. When the drill rod is twisted and deformed, the fiber bragg grating wound clockwise and the fiber bragg grating wound anticlockwise are stressed differently to generate strain, and the strain of the two optical fibers is subjected to differential operation to obtain accurate drill rod torque.
The invention provides an underground card measuring system provided with a fiber grating sensing device, which is wound on a drill stem mandrel in a fiber grating crossing mode to measure the torque of a drill stem, thereby realizing more accurate card measuring requirements.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.