SU1281665A1 - Well-testing apparatus - Google Patents

Abstract

The invention relates to the oil and gas industry and improves the accuracy of formation parameters determination. The device includes a support shank 1, installed in the lower part of the laser channel (LC), filter-2, packer 3, shut-off valve -A. Along the length of the LC, reference elements (OM) 6 are installed at intervals from each other in the form of pipes with a diameter different from the LC section. Into the well, the device runs on the pipes. 5. The calculated intersp.

Description

The shafts of the ER 6 installation depth are determined by the formula, 583s (/ t, where dH is the depth interval of the installation of the ER 6, m; o (d is the distance between filter 2 and the upper ER 6, m; m is the number of the ER 6 ; n is the sequence number (bottom) of the ER 6. The length of the time interval for filling the interfacial sections (MS) with liquid is determined by the indications of the manometer being lowered into the well during the inflow and the average values of flow rates are calculated as the ratio of the capacity of each MS to the corresponding time interval The device 7 measures the rate of change of the bottomhole pressure. The moments of the passage of the ER 6 fluid level are determined by breaking the monotony of the change in velocity. 3 Il.

one

The invention relates to the oil industry and can be used for testing and testing oil and gas wells.

The purpose of the invention is to improve the accuracy of determining the parameters of the flippers.

Figure 1 shows the proposed device; Fig. 2 is a diagram of the Yu-bottomhole pressure variation (t); Fig. 3 is a diagram of the rate of change of bottomhole pressure (t).

The well testing device includes support shank 1, filter 2, packer 3, shut-off valve 4.

The device is lowered into the well on pipes 5 having a diameter of 73 mm. As the reference elements 6, meter sections of pipes having a diameter of 89 mm are used. Measurement of pressure and rate of change of bottomhole pressure is carried out by the device 7;

into the cable hole. I

Consider the operation of the device on

test well example.

The number of reference elements 6 is chosen equal to,. Interval 30

the depths of the installation of elements L is 1000 m. For the reference point of the adopted maximum depth of

HO 1500 m. Calculated depths of installation of reference elements are determined by the formula

and-0,6

dN 1,583 &, (1)

where AI is the depth interval set- 40 ti

reference points, m;

L is the distance between the filter and the upper reference element, m;

m is the number of reference elements; n - serial number (bottom)

reference element. The formula is based on the following.

i

Experience of using in practice

methods for interpreting flow curves in calculation formulas which include the current time between readings taken from the resulting diagrams, shows that, although the reference elements can be set at any intervals, it is desirable for the quality of data processing to be done, so that the intervals between readings are not too different from each other. In this case, the scatter of points is reduced when plotting the resulting graph in semi-logarithmic coordinates. Since it is known that, most often, the process of changing the flow rate when testing wells is determined by an exponential relationship, it is proposed to set the intervals for the installation of benchmarks based on the exponential relationship, namely, using formula (1).

The actual values of the depth intervals uHj, obtained by assembling the nodes of the column of the test instrument, and, accordingly, the volumes of the interfacing sections V, may differ somewhat from the calculated ones.

The tests are carried out as follows.

In the well down the layout of the test tool, before

put in fig. I, after which a test packer is made, the fountain equipment is mounted with a lubricator suspended on the hook of the subsurface, the remote device is lowered to the bottom and the mouth is sealed.

The tool is unpacked and, using a compressor connected to the pipes, completely displace the water from the tubing with circulation through the filter.

Then re-packaged and bleed air-. from the pipes, as a result of which a depression of 150 kgf / cm is transmitted to the packer (full) ..

The inflow process is monitored according to the readings of the remote device with a recording on the photo recorder tape. After 2 hours (after raising the level 10 m above the upper reference element), the shut-off valve is closed and the pressure recovery curve (HPC) is recorded.

At the end of the test, the production is unpacked and the well is circulated through the filter. Then the instrument is lifted, the wellhead is dismantled and the tool is raised.

As a result of testing with a remote device, two charts were registered:

 a) changes in the bottomhole pressure PJ f (t) (Fig. 2); .

b) the rate of change of the downhole

pressure -; - - f (t) (fig.Z). at

 The diagrams of Amme (Fig. 2) denote the following areas:.

a - the descent of the device; . b - decrease of the level of liquid in the tubing with the help of a compressor;

c - packer;

d - air release from tubing;

e - inflow curve (KP);

f - pressure recovery curve (HPC) ;,

g - opening the shut-off valve;

h - unpacking;

k - topping-up and displacement of the flat water from the pipes;

1 - lifting device.

Taking into account that in the diagram of the pressure change in the JJ-E channel of the well at the moment of transition of the liquid level from the channel with one cross section (therefore, with one specific capacity) into the channel with another section

j

(i.e., with a different specific capacity) are noted) in the form of a sharp change in the slope of the curve of change in bottomhole pressure over time (Fig. 2), and

chart

dP

-at dependencies

FROM t to u

These points are singled out as local jump-like peaks corresponding to the violation of the monotony of the change in the speed function (Fig. 3). When decoding diagrams, it is possible to determine the time intervals corresponding to the passage of the level of reference elements, i.e. the intervals t, t, t ... t, during which the corresponding interrebar sections of the tubing string are filled.

The average flow rates for the specified time intervals with known volumes, sections of the elevator channel V, located between the reference elements, are determined by the formula

25

  (l / s)

,

(2)

V u .t where gf is the average debit for the time interval;

full volume of the interfamily section;

the time interval during which the fluid level in the elevator channel of the well passes the distance from one reference element to another;

serial number of the interperture section;

n 40

45

50

55

V.

/ V –v

 h. l-rp

- capacity of the elevator channel

on

where

section from one reference element

to another;

Vp is the capacity of the elevator canal at the installation site of the reference element included in this interfacing section. I

Average weights

liquid column for each interfiber section are calculated depending on the change in hydrostatic pressure using the formula

. (where 4P is the increment of the bottomhole pressure with the filling of a regular / interfamily section having a height of &Krvtp;

uPf, is determined by the RP (f) diagram.

The advantage of the proposed well testing technology is the ability to determine the flow rate; according to one downhole tool, located under the tester fitting, i.e. without using a second pipe gauge. In this case, the flow rate is determined not by the change in hydrostatic pressure in the elevator channel, but by the volumetric method — by the time of fluid filling of individual sections of the elevator channel, the volume of which is known between adjacent reference elements, and the time of filling each section is determined by the depth diagram pressure gauge. An important circumstance is that with this testing technology for determining the flow rate it is not for the child to know the proper weight of the fluid or its density. Moreover, the device allows quickly, without conducting additional geophysical studies, to determine the specific gravity of the fluid by the formula linking the height of the liquid column, the hydrostatic pressure and the specific gravity of the liquid, using the values of the hydrostatic pressure measured from the depth chart. At the same time, the accuracy of measuring downhole pressure when determining the flow rate by the volumetric method does not matter, since the hydrostatic pressure value is not included in the flow rate calculation formula, which is an important additional positive effect of using the device.

In addition, in cases where the sensitivity of the downhole gauge is not sufficient to produce noticeable changes in the pressure diagram P, f (t), it is proposed to additionally measure the rate of change

bottomhole pressure -; - f (t).

at

Another advantage of this device is the possibility of an approximate estimate of the gas flow rate and phase composition of the inflow. This is very important when testing gas-bearing or oil-and-gas-bearing formations, when a gas, falling into the pipes of a plastospray, begins to push a pack of fluid over it, which, like

It is usually poured into pipes as the tester descends into the well. At the same time, the flow of gas does not cause a perceptible increase in hydrostatic pressure, and therefore the process

The downhole gauge diagram is represented as a region close to horizontal, however, as the level of the liquid approaches the detector element, the height of the stack of liquid propelled by the gas changes, and after the passage of the clamp element returns to its original value. This allows you to remove the time needed to calculate the gas flow rate from the manometer chart. one

Thus, the device, in contrast to the known, allows measuring the flow rate not only in oil and gas

5 water wells, but also in gas wells.

Claims (1)

Invention Formula A device for testing wells, containing a lift channel with a filter in the lower part and fixed reference elements along its length, a manometer for measuring bottomhole pressure, 5 chths, in order to improve the accuracy of determining the parameters of formations, it is equipped with a device for measuring the rate of change of bottomhole formation pressures, while the reference elements are made in the form of pipes with a cross section that is different from the section of the elevator channel, and are set at intervals determined by the formula. t ro.S & H 1, 583 .. e, t where dN is the interval of installation of the reference elements, m; LP — distance between the filter 50 and the upper reference element, m; m is the number of reference elements; n is the sequence number (bottom) of the reference element. 0 0 45 io f 2 ty t ig tg (Rig.y.