Oil/gas drilling is used the down-hole safety check
Technical field
The utility model relates to a kind of oil/gas drilling and uses underground equipment, and particularly a kind of oil/gas drilling is used the down-hole safety check, in the oil/gas drilling process, prevent the pit shaft inner fluid along drill string inside to well head backflow.
Background technique
At present, as interior blowout prevention instrument, at normal drilling well circulation time, wash the down-hole safety check open and realize normal circulation by drilling fluid with the down-hole safety check for the situ of drilling well multiselect.In case drilling fluid stops circulation time, automatic, the quick closedown of safety check ability, thus reach the purpose that prevents that the pit shaft inner fluid from refluxing.Guarantee the down-hole safety check safe and reliable with have the key in enough life-spans and be: guarantee that 1. sealing system is reliable; 2. avoid the inner member erosion; 3. safety check switch resetting-mechanism is flexible.
Summary of the invention
The purpose of the utility model is exactly the above-mentioned defective that exists to existing technology; Provide a kind of oil/gas drilling to use the down-hole safety check; Can avoid effectively that the key components and parts erosion is serious, Returnning spring mechanism collapse and sealing are prone to the problem that lost efficacy; And simple in structure, be convenient to manufacturing, installation, maintenance, switch is flexible.
Its technological scheme is: mainly be made up of valve body, spool gland, seal assembly, spool, Returnning spring, valve seat, valve body all has connecting thread up and down, and the spool gland outside is the trapezoidal thread structure; There are runner and center hole in the centre, is installed on the top of valve body, and seal assembly is compressed by the spool gland and is positioned in the valve body; Cooperate with spool; Valve seat is installed on the body cavity bottom, and the bottom of described spool is provided with Returnning spring, and Returnning spring is installed between valve seat and the spool.
Above-mentioned spool by last axle, lower shaft, and conical surface forms, last center hole that is installed on the spool gland is interior, lower shaft is installed in the valve seat, conical surface cooperates with seal assembly.
The beneficial effect of the utility model is: Returnning spring is away from swiftly flowing drilling fluid passage; And realized the spacing of spool through the cooperation of valve seat upside step surface spool leave from office terrace; Prevent the generation of the overvoltage damage of Returnning spring, effectively increased the operating life of easily damaged parts Returnning spring.
Description of drawings
Accompanying drawing 1 is the structural representation of the utility model;
Accompanying drawing 2 is plan views of the valve seat of the utility model;
Among the last figure: valve body 1, spool gland 2, seal assembly 3, spool 4, Returnning spring 5, valve seat 6.
Embodiment
In conjunction with accompanying drawing 1-2, the utility model is done further to describe:
The utility model mainly is made up of valve body 1, spool gland 2, seal assembly 3, spool 4, Returnning spring 5, valve seat 6; Valve body 1 all has connecting thread up and down; Spool gland 2 outsides are the trapezoidal thread structure, and there are runner and center hole in the centre, are installed on the top of valve body 1; Be used to locate seal assembly 3, spool 4 placed in the middle, the drilling fluid flow channels is provided simultaneously; Seal assembly 3 is compressed by spool gland 2 and is positioned in the valve body 1, cooperates with spool 4, and valve seat 6 is installed on valve body 1 intracavity bottom, and the bottom of described spool 4 is provided with Returnning spring 5, and Returnning spring 5 is installed between valve seat 6 and the spool 4.
Wherein, spool 4 by last axle, lower shaft, and conical surface forms, last center hole that is installed on spool gland 2 is interior, lower shaft is installed in the valve seat 6, conical surface cooperates with seal assembly 3.
Basic principle is: when the turn on pump circulation time is carried out on ground; The power of drilling fluid forces spool descending; The Returnning spring pressurized; The conical surface of spool separates with seal assembly, forms the drilling fluid flow channels, and this moment, drilling fluid was through the annular space of annular space, spool and valve body between runner, the spool conical surface and the seal assembly of spool gland and the drilling fluid flow channels normal circulation of valve seat outer end; When the termination of pumping of ground, drilling fluid no longer includes power, Returnning spring provides elastic force to make spool up, the conical surface of spool contacts with seal assembly is tight, the sealing of drilling fluid flow channels, thus realize preventing the purpose of the backflow of drilling fluid.