SU655819A1 - Device for hydrodynamic investigations of uncased boreholes - Google Patents

Description

The invention relates to devices for hydrodynamic research of wells.

A reservoir tester is known, which makes it possible to determine the main hydrodynamic parameters: reservoir pressure, effective power of the outgoing part of the reservoir, and approximately the permeability coefficient 1.

The basis for determining the permeability coefficient based on the results of well survey by reservoir testers is based on the equation of the flow of fluid into the tester cylinder, which in the simplest case, when the pressure varies slightly, has the form:

J Lgst | - (Pn-Rb) (1)

W is the average volumetric flow rate of the reservoir fluid;

A is the geometrical coefficient determined by the size and shape of the hole in the shoe, limiting the studied portion of the reservoir;

Hst is the radius of the drain hole;

K-permeability of the reservoir;

and - fluid viscosity;

RPL - reservoir pressure;

P (5 - pressure in the balloon tester.

The average volumetric flow rate of the reservoir fluid, in the case of the whole, the test cylinder is filled only with the formation fluid, is equal to the ratio of the volume of the cylinder to the time of its filling and can be calculated but not always, because the amount of drilling mud that is in the test cylinder when the valve is opened .

 Hr Rb are removed from the recorded pressure change curve in the test cylinder when it is full.

However, the recorded pressure does not always reach the values of reservoir pressure due to the large volume of the cylinder, especially in low permeability formations, when the cylinder does not have time to completely fill.

In addition, the above equation (1) can be used only in the case of

0 fluid inflow according to Darcy's law, i.e., with low depressions, single-phase fluid flow and other assumptions. Determining the permeability coefficient by the result iTci: 1cc, 1dg) va11 and niipoooisau / iii n,: i; i-CT () B with a sufficient for (r) sCiOTOii () conjunction 3ai-py; uieiio, and sometimes impossible.

A device for measuring the nlastic pressure, including the pressure system, is hermetically sealed, pressure sensor, pressure sensor, adjusts the 1.1 valve, and the irregular capacitance with a hollow stem, on which a separating riopHieiib is installed. The device makes it possible to measure with a high accuracy with a high resolution Hpi; .viuoco repeated his intention 2.

However, it is impossible to determine the penetration coefficient of a reservoir with sufficiently accurate (.) Connection with this device, since sampling into the production capacity of the device, this is not a matter of other deirsion.

The aim of the invention is to improve the accuracy of the determined hydrodynamic and physical parameters.

This goal is achieved by the fact that the lower part of the acceptance capacity is made of a smaller diameter than the upper one, and B1) 1stune is made on the middle part of the new stock, limiting and shifting the separation gap.

FIG. 1 is a diagram of the described device; on fng. 2--3 - the position of the device nodes in the process of sampling the formation fluid; pas figs. 4 is a view of the pressure change curve in the receiving container recorded by the remote pressure sensor P1.

The device includes a npemp tank in the form of a stepped cylinder 1, which punch 2 serves as the bottom stop d; 1 J) a3de; n1 piston 3, which divides the bottom capacity into the bottom 4 and top 5 parts. For separation norpsam 3, installed on the hollow flow, there is a cavity 6 with compressed air, the air pressure in which the dust is likely to be airborne. The movement of the separating piston 3 up is limited by the stop 7, n) and what volume of cavity b is made of sign-1te, 1Ы1о larger than the volumes of accepted containers 4 and 5.

The device works as follows.

The device (Fig. 1) is lowered into the cable on the cable 8, the clans 9 are closed, in the lower part 4 of the receiving tank there is air under atmospheric pressure. The pressure sensor 10 and the pressure sensor into the well records pressure. After reaching the specified interval measured (Fig. 2) and the 11 n irrigating system presses the device against the borehole wall, the sealing shoe 12 isolates the test area from the hydrostatic pressure of the liquid, a clan 9 opens. G. by denression from the borehole wall, p drilling mud, it is possible to turn off into the receiving tank

Opening valve 9, occupy some volume 13 in the lower part 4 of the receiving tank. the rest of the dividing 3 is occupied by the primary illumination of the 1st ilast (gtuid.

In e1Oi m () ment, a high depression acts on the aast, as it facilitates cleansing and, as a result, contamination from particles of drilling mud.

After filling with the reservoir fluid) Kchmo volume ----- up to separation 3, the pressure in this volume rises to pressure in cavity 6, and the pressure exceeds that (fng. 3) Hopineifb 3 inter1, up to uior 7, iodine and iodine 1, his istuyat p.stastov of fluid.

At the same time, the top 5 of the iriem capacity, the volume of which is precisely known, is filled with the partial reservoir (}) luid, flowing according to Darcy's law when exposed to ionization deairn due to air pressure in it. 6.

The change in pressure in the disturbed tank is recorded by the pressure sensor 10, an example of the pressure change curves is shown in FIG. 4, where the section “a is iu5.” Is the green pressure underestimated by the lowering of the device into the well, the section “b is the buildup of the hydrostatic pressure of the liquid column, ia1-1-1 of the other well; I | - hydrostatic pressure of the liquid column in the measurement interval, Pj

pressure, f −3 is the pressure at which the upper part 5 of the perturbation tank is filled.

Section 1., -ta corresponds to the time of the flow,; 1, the bottom of 4, vozmu1, akoi1, its capacity, plot (x 1r-i - time of the na-tion of the upper part 1-1 5 of the vozmuntoy capacity. This time is used when calculating the local inflow velocity Frequent fluid.

If there is a sufficient amount of correspondence between the upper part of the disturbing capacitance (; 5 and cavities with compressed air 6, the inflow of the TOBOio fluid into the upper part is 5 of the reservoir capacity and is almost constant at the rate when the formation has a constant denression equal to the difference

) (L

pl

Claims (2)

1. A collection of articles. Geophysical Annunciation. - L .. Nedra vol. 43, 1970. 2. Authors certificate of the USSR LSO 439597, cl. E 21 B 47/06, 1971.