SU595498A1 - Device for measuring pressure in well - Google Patents

Description

Depending on the volume of the chamber 2, the device will work either as a pressure gauge or as a thermometer. If this volume will meet the condition - 1 ° h. P - P2

V,

"2Fsil

where Vi is the volume of chamber 1,

01 - coefficient of volume expansion

fluid chamber 1; "2 - coefficient of volume expansion

fluid chamber 2;

FZ is the cross-sectional area of the stem 3 in the gland 5,

/ a - square cross section of the rod 3 in the glands 6 and 7, cm

Then changing the fluid temperature of the chamber 2 liquid, expanding, will push out the rod 3, and its upper end, the exit from chamber 1, will release a volume in it for the fluid expanding in it. In this case, the rod 4 remains stationary. When an external pressure is applied, the rod 3 enters the compensating chamber, squeezing the liquid in it to the pressure of the external environment, simultaneously compressing the liquid and in the measuring chamber 1 to a pressure not equal to the external one. The external pressure in the measuring chamber 1 is established by moving the stem 4, which moves according to the following law:

Vl / o "l- 2

R,

 f.

fl «2

IP - movement of stem 4 at pressurization and ambient temperature; Ft - cross-sectional area

stem 4;

PI is the compressibility factor. fluid in cavity 1;

p2 - compressibility factor

fluid in cavity 2; P - external pressure, kgf / cm; - given above. In the case of operation of the device as a thermometer, the volume of the removable compensating chamber 2 is as follows:

u Vih (

2PZ

When a pressure is applied to the device, the brush 3, compressing the fluid of chamber 2 to the pressure of the external environment, enters the measuring chamber 1, compressing the fluid of this chamber to the same pressure. At the same time, the rod 4 balanced from all sides will remain motionless and will respond only to temperature changes according to the following law:

t.

where / (the movement of the rod 4 when the pressure changes, and the ambient temperature;

t-: ambient temperature, ° С. When this thermometer is connected to the device, the temperature t liquid, expanding, displaces the swab 3 from chambers 2 and 1, thereby freeing part of the volume for the expanding fluid of chamber 1. But the released volume in chamber 1 is not enough for the expanding fluid that is provided by the selection of volume. In view of this expansion, the liquid displaces the brush 4, occupying the required volume. In order for the instrument to function during the selection of fluids, the following relationship should be observed:

- F.

"2P2

Since the pressure is equal to external pressure in all the main components of the invention, the device is manufactured thin-walled, compact.

The invention makes it possible to measure pressure in the order of 1000-1500 kgf / cm and temperatures in the order of 250-300 ° C with full compensation of one of the parameters.

Claims (2)

1. USSR author's certificate No. 457788, cl. E 21B, 47/00, 1970. 2.Isakovich R. Ya. Oilfield measurements and instruments. M., “Nedra, 1966, p. nineteen. - 1Z -15 -11 -w 71 6 -z -3