SU1654512A1 - Device for determining drill pipe string axial compressive forces - Google Patents

Abstract

The invention relates to well control means. The purpose of the invention is to increase the efficiency of the device by eliminating the influence of the ambient temperature. The device contains a cup 2 connected to the sub 1, in which the nozzle 5 is located. In the latter there is a cylinder 8 with a piston 16 and a rod 17. The upper part is cylindrical with § 27

Description

pa 8 is located in the sub 1. Glass 2 has a camera 13 with a measuring unit. In the lower part of the cylinder 8, an additional chamber 21c is made by the measuring unit 22, communicated with the internal cavity of the cylinder 8. The piston 16 with the rod 17 is made with a through axial channel 20 communicated with the chambers 13

and 21. With a change in temperature, the volume of fluid enclosed in chamber 13 will change, changing pressure. After the descent of the column to a predetermined depth, a shutter speed is made for a set of temperature conditions. After that, the device is raised or lowered from the column pipe. 1 il.

The invention relates to well control tools and is intended to measure compressive forces.

The aim of the invention is to increase the efficiency of the device by eliminating the influence of the ambient temperature.

The drawing shows a device for determining axial compressive forces.

The device consists of a cup 2 connected to the sub 1 with an inner annular protrusion at the bottom 3, on which a thrust collar 4 is mounted for free movement upwards, with a rigidly fixed branch pipe 5 for connecting the lower movable part of the column 6 with the aid of a sleeve 7. A cylinder 8 with an outer annular protrusion 9 is freely suspended on the anvil bushing 4, the channel 10 connects the internal cavity 11 of the cylinder 8 with the internal pipe space, and the channel 12 connects the working cavity 11 with the chamber 13, to which the measuring node is connected in Ideal depth gauge 14, sealing the lower cavity is carried out by the sealing element 15. The piston 16 with the rod 17 through the spring 18 with an outer annular protrusion 19 is pressed against the lower end of the sub 1. Inside the piston 16 and the stem 17 there is a through axial passage 20 through which pressure is transferred to an additional chamber 21 formed at the bottom of the cylinder 8 and an additional measuring unit 22. The tightness is provided by an elastic element.

The device works as follows.

To measure the axial compressive forces, the device joins the casing and descends into the well to a predetermined depth with topping up the fluid. With an increase in the buoyancy force, the lower part of the cylinder 6 freely suspended on the thrust sleeve 4 will lift and push the cylinder 8, which, moving upwards relative to the fixed piston 16, will separate the internal cavity 11 of the cylinder 8 from the in-tube space and from the chamber 13. In this case the pressure gauge 22 registers pressure from buoyancy. In the insulated chamber 13, the pressure change after the overlap of the channel 12 does not depend on the buoyancy force and is determined only by the temperature change in the barrel. With a change in temperature, the volume of liquid

The prisoner in this chamber will change by changing the pressure, which will be fixed by a pressure gauge 14. After the column has been lowered to a predetermined depth, an exposure is made to set the temperature conditions. Thereafter

lifting or lowering the device from the column pipe.

The determination of compressive forces acting on the cross section of pipes at the installation site of the device is determined as follows.

in a way.

In the diagram, recorded by the upper instrument, the corresponding pressure value is determined along the time axis. Since the device records the total pressure from

three factors: the hydrostatic pressure inside the column, the pressure due to the axial load and the pressure due to the change in temperature, then the target value will be determined from the expression

P (P06sc- Rstzh -Pt) S ,.

where Ptot is the pressure registered by the upper instrument;

Rst.zh. - internal pressure in the column at the depth of installation of the device;

Pt is the pressure due to the change in temperature in the lower instrument;

S is the piston area,

The force acting on the lower end of the column is determined from the expression

F Fe + gKy + j.

where F is the axial force in cross section at the depth of installation of the device;

dku - the weight of the column below the device; j - the weight of the fluid in the column.

51654512

Since the change in axial load wilted glass, located in a glass

the length of the column occurs along the linear pipe, placed on the pipe of the maximum magnitude of the shoe cylinder, the piston installed in the cylinder

(bottom) of the column to the cross section with a numerical value with a rod, the upper part of which is measured by a rezmeniem, it is possible to determine its size5 in the sub, a camera with a meter in any section of pipes located in a glass by the dependent node, Fr. - j, is that. for the purpose of raising where Rb is the force acting on the bottom of the column; - the weight of the column below is considered to eliminate the effect of temperature

10 environment, in the lower part of the cylinder is the weight of the fluid in the pipes. An additional chamber is made with

measuring unit, communicated with enut Formula of invention by the cavity of the cylinder, and the piston with

The device for determining the axial shafts is made with a through axial clamping force of the drill string 15 connected to the chamber and supplemented with a pipe containing connected to a translating chamber.

Claims (1)

Claim A device for determining the axial compressive forces of a drill string, containing a nozzle connected to an adapter, a nozzle located in the nozzle, a nozzle mounted in the nozzle, a piston with a rod installed in the nozzle, the upper part of which is coupled to the adapter, a chamber with a measuring unit located in the nozzle, o which means that. In order to increase the efficiency of the device by eliminating the influence of ambient temperature 10, an additional chamber with a measuring unit, connected with the internal cavity of the cylinder, is made in the lower part of the cylinder, and a piston with a rod is made with a through axial channel connected to the camera and additional camera.