SU1079827A1 - Method of determining the intervals of formation fluid inflow in well - Google Patents

Abstract

METHOD FOR DETERMINING THE INTERVALS OF THE FLOW OF THE PLEASANT FLUSHCHET IN THE WELL, including measuring the temperature in the well, characterized in that, with a chain to increase the reliability of the allocation of intervals of inflow, along with temperature measurements, radial seismic vibrations are measured radially relative to the wellbore, and intervals of inflow of the fluid are recorded, the radially relative to the wellbore is recorded, and the intervals of inflow intervals are measured by radially relative to the wellbore, and the intervals of inflow intervals in the flow curve of the fluid are measured in radial with respect to the wellbore and in intervals of the inflow intervals. the ratio of the amplitudes of low-frequency oscillations, corresponding to temperature measurements, and high-frequency oscillations corresponding to the recorded seism cal vibrations m.sl

Description

The invention relates to the development of a geological survey (} well study) and can be used to distinguish a quantitative assessment and operating intervals of oil and gas wells.

A known method for determining the flow profile of formation fluid in an operating well by introducing an indicator substance with constant costs into the annulus at the wellhead and then measuring the concentration of the indicator substance by a geophysical instrument, the change in which determines the flow profile of formation fluid P.

The disadvantage of the known method is that in the presence of absorptively interbed in the well section, there will be observed a distortion of the recorded curve that is not associated with a change in the intensity of the fluid flow of the operating intervals.

The closest to the invention in terms of its essence and the result achieved is the method for determining the inflow intervals of a reservoir in an active well by measuring the temperature along the borehole 21.

Gas retention when it enters the reservoir into the well is usually accompanied by its cooling (Joule – Thompson effect). As a result of gas output intervals, a temperature anomaly is observed.

The disadvantage of this method is the obligatory presence of a major depression in the formation. In case of low depression on the reservoir, the working interval will not differ in temperature anomaly and will lead to an incorrect interpretation of the curves and an inaccurate selection of the working intervals.

The aim of the invention is to increase the reliability of the allocation of inflow intervals,

The goal is achieved in that, according to the method for determining the inflow intervals of the reservoir ghkid in the well, including temperature measurement in the well, simultaneously with the temperature measurement, longitudinal seismic vibrations are recorded relative to the wellbore, and the inflow intervals of the fluid are determined by the ratio 798272

The amplitudes of the low frequency oscillations, the corresponding temperature measurements, and the high frequency oscillations, the corresponding 5 seismic vibrations.

FIG. a general diagram of the functional blocks that implements the proposed method is presented; FIG. 2RC-borehole thermometer generator 10; in fig. 3 - thermometry registration curves obtained by the known and proposed method.

The method is carried out as follows.

15B, the operating well 1 on the logging cable 2, the complex well device 4, consisting of temperature sensor 5, current 20 of sensor 6 and generator 7, is lowered into the interval of productive gshasta 3. Under the effect of the temperature of the outgoing gas flow, the resistance of thermal sensor 5 changes generator frequency 7, signal with

25 of the frequency generator 7 is fed via cable 2 to the amplifier-demodulator 8, and then to the recorder 9. At the same time, the sensor 6 under the action of the gas flow from the plate, p 3, detects low-frequency oscillations that also modulate the frequency generator 7 and also go to amplifier-demodulator 8 and recorder 9, Power supply is carried out by block 10.

As is known, the downhole part of a TEG type serial thermometer is a frequently controlled RC generator G (Fig. 2). It consists of an amplifier (not shown in the diagram), covered by a positive feedback through a frequency-determining RC-circuit. The latter includes

j two capacitors C and C and resistors R. Thus, by changing the capacitance of the capacitors or the foot-channels of the resistors, or both parameters together, it is possible to control the frequency of the general 0 ° P. The temperature-sensitive resistors R determine the oscillation frequency of the generator, the period of which is linearly dependent on their resistivity, and consequently, on temperature

T 2iTRoC (, oct To i-cttl, oscillation period; Td - oscillation period at temperature Cp; resistance of thermometer p. Connecting in parallel with capacitors C and C 2 converter P of the receiver seismic, made in the form of an adherent capacitor of variable capacitor C and C ) it is possible to control the oscillation period of the generator in a linear manner depending on the oscillations of the wellbore. In this case, the oscillation period of the generator can be expressed by the formula T 2nRo (l4oi, t) cll ± p), where X is the displacement of the inert mass of the seismic receiver from the average reading; P is the constant of the converter of the characteristic of the capacitance change depending on the n displacement of the inert mass; bi is the temperature coefficient of resistance of the thermo arm; t is the ambient temperature; С - capacitor capacitance. Since the oscillation frequency of the generator is of the order of 3300 Hz, while driving (tires capacity C, and C equal to 0.066 microfarad each, choose the capacity of each section to convert 500 microfarads. The capacity of the converter section with an average (zero) seismometer At a maximum plate input, the capacitance is 500 pF, at a pnumming of 10 pF. When the converter capacity changes from maximum to minimum deviation, the oscillation frequency of the generator is 24.7 Hz, which is sufficient for registering 1 Example: A downhole thermo | meter of TEG type with a seismic sensor unit attachment with a capacitive transducer is lowered into the borehole. After connecting the borehole device D to the carnage, cable 2 is supplied with a stabilized voltage of 250 VDC. position 7 20 and. Set the required recording scale of the temperature curve. The recording scale from the seismic sensor is set in such a way that with a maximum oscillation (25 Hz) of the glare of the galvanometer It is 5 cm on the scale of the recorder. Thus, the recording scale corresponds to 8 Hz per 1 cm. Recording is done when the instrument is lowered. In the interval of the reservoir, the temperature sensor 5 (FIG. 1), reacting to the temperature of the outgoing gas flow, changes the frequency of the generator 7 and the signal for changing the frequency of the generator enters the surface of the cable 2 to the recording device 9. At the same time, the seismic sensor 6 with the capacitive transducer oscillation 1 marks the transverse oscillations created by the outgoing fluid. These oscillations move the inertial mass of the seismic sensor, as which the moving sections of the variable capacitor C and C2 are used (Fig. 2). When the converter capacity changes from the maximum to the minimum deviation of the oscillation frequency of the generator, it is about 25 Hz, which is sufficient for the registration by the ground control panel. The signal from the seismic sensor is recorded together with the curve of the thermogram, superimposed on which, marks the areas of the outgoing fluid causing the device to oscillate. The inflow interval of the reservoir fpkida is determined as follows (Fig. 3). Gas is passed to formations A, B, D, gas is not supplied to formation B, water is supplied to formation D. Curve II, shown in FIG. 3, is registered by a known prototype method. Curve 12 expresses the proposed method. Curve 11 shows the general pattern of the deviation of the curve towards decreasing temperatures due to the throttle effect resulting from the pressure drop. Separately, each interlayer in the thermometry curve I1 does not differ, and reservoir D does not react at all to the influx of water, and only lisch records its temperature from the fluid level and below.

On curve 12 of the total thermoelectric effect, the intervals of gas-producing formations (formations A, B, D) are recorded by negative temperature anomalies and relatively large amplitudes of seismic waves.

The drainage interval (d (recorded at relatively high amplitudes of seismic oscillations) and, due to the influx of formation fluid into the well, is a positive temperature anomaly.

From the analysis of curves 1–1 and 12, it can be seen that the curve expressing the cumulative effect of thermal and seismic oscillations makes it possible to increase the reliability of studies. Economic efficiency from the use of the proposed method arises due to the SKOHOMiiH time required to isolate the water-cut interval in the active gas well with its stopping, pushing the solution

and subsequent geophysical surveys.

In this case, the injection of the solution, the rise of tubing and geophysical surveys in one well is about 1,250 rubles.

Annually, the costs of determining the flow profile of 50 wells amount to 1250x50 72500 rubles.

In addition, when carrying out these works, the wells stand idle on average for about J mon. With an average daily production rate of 100 thousand meters a day, gas losses for each well due to simple wells are 100 thousand X 30 days x 50 SCR. 150000 thousand.

With a commercial gas price of 1 thousand m 0.9 rubles. the cost of gas is 150000x0.9 "134000 rub. The economic effect will be 72500 rubles. + 134000 rubles. 206400 rub. in year.

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Claims (1)

METHOD FOR DETERMINING THE INTERSERVES OF THE FLOW FLUID FLOW IN THE WELL, including measuring the temperature in the well, characterized in that, in order to increase the reliability of the identification of the inflow intervals, longitudinal seismic oscillations radial to the wellbore are recorded along with the temperature measurement, and the intervals of the inflow of the fluid are determined by the ratio of the amplitudes of low-frequency oscillations corresponding to temperature measurements and high-frequency oscillations corresponding to recorded seismic oscillations Niyama.