RU2237161C1 - Device for determining behind-column crossflows in a well - Google Patents

Abstract

FIELD: oil and gas extractive industry.

SUBSTANCE: device has infrared radiation sensor, optical system, heat flow modulator and electronic stabilization block for modulator rotation frequency, sensitive element temperature stabilizer and electronic heat-adjustment and heat-stabilization block for sensitive element, block for amplification and conversion of information signal and registering device on the surface. Stabilizer of sensitive temperature element is made in form of thermostat, in which infrared radiation sensor and heat flow modulator are placed, and which is equipped with heating means and inlet port, transparent for infrared radiation. In thermostat, temperature is set and supported at level of upper limit of measured value.

EFFECT: higher precision of detecting of behind-column crossflows.

2 dwg

Description

The invention relates to the oil and gas industry, in particular to devices for determining annular cross-flows in a well above a hydrostatic level.

A device for studying the thermal field of a well is known, including an infrared (IR) radiation sensor, an optical system, a signal modulator, an information signal amplification and conversion unit, and a surface recording device (see USSR AS 203587, IPC E 21 b 47/06 )

The disadvantage of this device is that in the process of measuring temperature in the section of the well, an information signal is generated as a response to the differential temperature

ΔТ = Tob.-Tod.-Th.e.

where tob. - temperature of the measured object;

Tod. - temperature of the modulator blade;

Te - temperature of the sensitive element.

The absence of a thermal stabilization system for the infrared sensor and modulator leads to an error proportional to the change in the temperature of the device, i.e., unreliable estimates of the measurement results.

The closest device to the claimed is a device for studying the thermal field of a well, including an infrared radiation sensor, an optical system, a temperature stabilizer of the sensing element, an information signal amplification and conversion unit, and a recording device on the surface (see application No. 2001106294/03 of 2001.03.05) . However, the operation of this device is time-consuming due to the use of liquid nitrogen, the operating time of the device is limited by the boiling time of liquid nitrogen, which leads to the need to refill the device during the measurement process and is time consuming.

The present invention solves the problem of determining annular flow in the well above the hydrostatic level by non-contact continuous measurement of the infrared radiation of the surface of the wall of the well.

The technical result achieved by the invention is to reduce the time of the measurement operation while reducing costs.

This object is achieved in that the device for determining annulus crossflows in the well, comprising an IR radiation sensor, an optical system, a temperature stabilizer of the sensing element, an information signal amplification and conversion unit, a surface recording device, is additionally equipped with a heat flux modulator, an electronic speed control unit a modulator, an electronic unit for temperature control and thermal stabilization of the sensitive element, while the temperature stabilizer The heating element is made in the form of a thermostat, in which the IR radiation sensor and the heat flux modulator are placed, and is equipped with a heater, an input window transparent to IR radiation, and the temperature is set and maintained in the thermostat at the level of the upper limit of the measured value.

The invention is illustrated in figure 1, which presents a block diagram of a measuring device, and figure 2, which presents a thermogram obtained using the inventive device.

The inventive device contains a geophysical cable 1, a descent device 2, a recording device located on the surface 3, a heater 4, a temperature stabilizer of the sensing element 5, a regulation and thermal stabilization unit 6, a sensitive element 7 of the IR radiation sensor 8, a modulator 9, an IR interruption frequency stabilization unit radiation 10, the optical system 11, the input window of the stabilizer 12, the amplification and signal conversion unit 13.

The device operates as follows.

The descent device 2 is connected by a geophysical cable 1 with a recording device 3 located on the surface. When power is applied, the units included in the device begin to function. In particular, the heater 4 of the stabilizer 5 with the help of thermal control and thermal stabilization unit 6 displays the temperature of the stabilizer 5 to the upper limit of the measured temperature, which provides a given range of measured values. Located in the stabilizer, the sensing element 7 of the IR radiation sensor 8 and the modulator 9 acquire the same temperature, which is maintained at a given level during the entire measurement. The temperature fluctuations of the temperature stabilizer are hardware noise and should be significantly lower than the minimum resolved temperature difference determined by the claimed device. At the same time, the interruption frequency stabilization unit of the modulator 10 outputs the modulator frequency by a predetermined amount. Next, the measuring device is lowered into the well at a constant speed. IR radiation from the inner surface of the well passes through the optical system 11 of the device, is interrupted by the modulator 9, passes through the input window 12 of the stabilizer 5, and enters the sensitive element 7 of the IR radiation sensor 8. The sensitive element 7 of the IR radiation sensor 8 converts the radiation into an electrical signal, which is transmitted to the input of the amplification and signal conversion block 13, in this block the analog signal is amplified and converted into a serial digital code. This code enters through the geophysical cable 1 to the recording device 3 located on the surface. In the recording device 3, it is processed according to a given program and issued to the user in the form of a thermogram. The user of the thermogram, if there is a deviation of the thermogram from the standard geotherm, judges the presence of a casing flow (see Fig. 2), and when determining the equality of the signal at different depths (points 1 and 2 in Fig. 2), he judges the location of the casing flow.

Since the measurement process is carried out with a sampling frequency of at least 4-10 ^-3 s, this circumstance, with an average descent speed of 0.4 m / s, makes it possible to determine the position and extent of the annular flow with a high degree of accuracy. When using a device for non-contact measurement of annular crossflows, preliminary technological work is not required to prepare the well for measurement. The accuracy of measurements is not affected by local defects of the surface of the well, since their angular dimensions are much smaller than the angle of the field of view of the device used, the time of continuous operation of the device is not limited to its design features.

Claims (1)

A device for determining annular crossflows in a well, comprising an infrared radiation sensor, an optical system, a temperature stabilizer of the sensing element, an information signal amplification and conversion unit, a surface recording device, characterized in that it is additionally equipped with a heat flow modulator, an electronic speed control unit modulator, an electronic unit for temperature control and thermal stabilization of the sensitive element, while the temperature stabilizer of the sensitive element This one is made in the form of a thermostat, in which an infrared radiation sensor and a heat flux modulator are placed, and is equipped with a heater and an input window that is transparent to infrared radiation, and the temperature is set and maintained in the thermostat at the level of the upper limit of the measured value.

Images