SU1643709A1 - Method for productivity testing of gas and gas-condensate wells - Google Patents

Abstract

The invention relates to the development of natural gas fields, as applied to well field research. The goal is to improve the accuracy of determining the filtration resistance coefficients, the characteristics of the productive characteristics of the formations. For this purpose, bottomhole pressure and debits at steady state operating conditions are measured, wells are tested for several (three to five depending on the possible range of flow rates) short-term modes equal to duration Јр (EQ is determined by the time the pressure recovery curve reaches the straight line and averages 4-5% of the time the reservoir pressure was fully restored). Reverse studies are performed, then the well is stopped until the reservoir pressure is fully restored in the drainage zone. Reservoir pressure is measured and repeated studies are carried out in three to five short-term i-th periods. According to the data obtained for the backstop modes, the dependent ib of the drunken pressure oi flow rate and the excitation of this relationship are plotted. . The coefficients of filtration resistance of the two-sided formula of gas inflow to the well are calculated using known formulas, and to improve the accuracy of determining coefficient b, its value is determined as the average for forward and reverse. 2 or 2 tablets. (L with & 4 yo J o with

Description

The invention relates to the gas industry, in particular to well field research to determine the productive characteristics of gas and gas condensate skins.

The aim of the invention is to improve the accuracy of determining the coefficients of filtration resistances that characterize the productivity of wells in studies in short-term modes.

Figure 1 shows the dependences (MPa) on (ge (thousand m3 / day); figure 2 shows the dependence of UP2ia6 / OrKC on QrKc (thousand m3 / day).

Curves 1 and 3 (figure 1) characterize the results of research by the proposed method, and curve 2 - research on stationary filtration modes.

Direct 1, 2, 4 (Fig, 2) characterize the results of research by the proposed method, Direct 3 - studies on stationary filtration modes.

The well survey is carried out as follows.

The bottomhole pressure and flow rate of the established operating mode are measured and a well is tested at several (three-five depending on the possible range of debits) short-term modes equal to the duration of Јр (р is determined by the time the pressure recovery curve returns to the straight section and averages 4-5% of the total recovery time

reservoir pressure). After completion of the return stroke, the well is stopped to fully restore the reservoir pressure, the reservoir pressure is measured, and a direct run study is performed on three to five short-term modes of the same duration V with an increase in flow rate on each subsequent mode.

According to the obtained data, for the back-up modes, a graphical dependence of the PZ on Q (Fig. 1) is constructed, the conditional value of the reservoir pressure of the RPL is determined as a segment cut off on the ordinate axis.

Values of filtration coefficients, resistance in the equation of gas flow and wells

PA PA and “+ bc12 are calculated using the known formulas

numerical processing of research data in stationary modes, and the value of the coefficient b is calculated as the arithmetic mean for the forward and reverse stroke using the formula

.

AR.

Ј 5: 1EI

M ZO -CECM)

N2gQ22i - () 2

- the number of reverse mode, including steady state,

operational; - the number of forward travel modes;

the difference of the squares of the conventional reservoir pressure and the bottomhole pressure in the i-th backward mode, including the operating,

is defined as

gp, conv

cut off axis

ordinate dependence of P-, on () for reversing modes, as shown in figure 1 (MPa);

p2.

pl

P2, 2.1

h: difference of the squares of the measured reservoir pressure and the bottomhole pressure in the 1st mode of forward stroke (MPa2); well production rate at the i-th reverse mode, including operational (thousand .. m3 / day);

.

AR.

Th

N2gQ22i - () 2

well production at the i-th mode of the forward run (thousand m3 / day);

measured reservoir pressure (MPa);

about

five

0

five

chg

ast

bottomhole pressure and flow rate at steady state operation (MPa).

In gabl.1 and figure 2, as an example, the results of field studies of wells 8 — Vuktyl by the proposed method and on long-established modes are presented. The coefficients of filtration resistances determined by the research in an accelerated way on short-term modes are 44 / thousand m3; , 04 10 5 MPa2 (day / thousand m3) 2.

According to the parameters of the long-established modes (1.1X, X), these coefficients have values of 4.27 X1SG2 MPa2. Day / thousand m3; b (., 62 x rW Mia2 (day / thousand m3) 2.

Table 2 presents the main test results for the three wells studied (well 7,8,66 - Vuktyl). Comparison of the productive characteristics determined by the proposed method with the results of well studies in a known manner on stationary modes gives satisfactory convergence.

Claims (1)

The data given in table 2 and figure 2 show a large error in determining the filtration resistance coefficients. Invention Formula The method of determining the productive characteristics of gas and gas condensate wells, including the measurement of bottomhole pressure and flow rate at steady operating conditions, bottomhole pressure and flow rates for short-term unstable Max of the same duration and reservoir pressure in a stopped well with subsequent determination of the reservoir characteristics, characterized in that, in order to improve the accuracy of determining the filtration resistance coefficients characterizing the reservoir performance, measurements of downhole pressure and production rates at unsteady conditions are first performed in reverse with decreasing the flow rate on each afterI - dyude mode, starting with the steady state production, stop the well and measure The reservoir pressure in it is measured, the bottomhole pressure and the flow rate are measured in a straight course with an increase in the flow rate at each subsequent unsteady mode. Reverse Investigation I (exp.) II III IV V VI VII Viii Established Modes jt Nominal reservoir pressure for reverse modes stroke determined by curve 1 in FIG. Table 1 0.0290 0.0333 0.0381 0.0430 7 6 72 72 76 0.46 A, 27 1.96 0.112 4.62 1.64 0.049 1.35 1.39 67.4 56.3 3 21.8 70.3 3 15.8 15.5 100.45 114.44 122.14 0.115 4.04 1.44 2.2 2.6 4.012,5 9.112,1 Rza5 MPa  pl O50 100 150 200 Fy & Rgzod QSHC 0.05 from from about 50 100 150 200 250 Q HCjvc H3 / day Fig 2 250 Qrc thousand / h3 / day