SU458289A1 - Device for radioactive logging - Google Patents

Description

(54) DEVICE FOR RADIOACTIVE COTTAGE

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The invention relates to the exploration of exploration wells by nuclear geophysical methods.

Radioactive logging devices are known using a dual probe measurement system that contains a radiation source and two independent detectors located at different distances from the source. Based on the ratio of the output signals of these detectors, the properties of the studied rocks are judged. Due to the presence of two different-parameter measuring probes of a dual-probe measuring system, it provides more information about the rocks under study than a single probe, and, accordingly, the reliability of research increases.

However, when using a known device, some changes are not monitored, for example, if it is necessary to compare absolute values of intensities independently recorded by two detectors, since (all other things being equal) the signal level from each detector can vary with its detecting properties (if the detector changes or because of its aging). This reduces the accuracy of measurement results and limits.

The possibility of using a known device is limited.

The purpose of the invention is to enhance; measurement accuracy in simultaneous studies of rocks by complex radio methods; 1kt logging.

This is achieved by using one detector in a measuring device, and a dual-probe measuring system is formed

by alternately forcibly changing the position of the shielded source so that at one extreme position of the source one geometrical configuration of the probe is created, corresponding, for example, to the geometry of the X-ray radiometric method,

and in the second, extreme position, a friend, for example, a conventional selective gamma-ray logging probe. At the same time, to record the readings related to measurements with two alternately forming configurations of the measuring probe, the ground chart of the proposed device contains a clock generator synchronously controlling both the drive of the source position changing mechanism and the distribution device, the two-phase outputs through two groups schemes And alternately connect the inputs of two groups of recorders to the outputs of the amplitude analyzer that receives the output signals from the detector. In order for the separate recording of readings to be continuous, the switchgear is also connected with keys that break the discharge circuits of the integrating cells in those recorders whose inputs are disconnected from the amplitude analyzer outputs. The drawing shows a diagram of the proposed device.

The device consists of a depth measuring probe 1 with a radiation source 2 placed in a collimator 3, a hard 4, a screen 5, a detector 6, an electronic circuit 7 and a drive 8 of a mechanism for changing the position of the source. The probe is provided with a clamping device 9. In the device’s ground panel there is an amplitude analyzer 10 that receives signals from the measuring probe and a switchgear 11 controlled by a clock generator 12. The switchgear, B, in turn, controls the actuator 8 and two groups of And 13 and 16, the second inputs of which are connected to the outputs of the analyzer 10, and the outputs of the AND circuits are connected to recorders, for example, counting rate and counting rate ratios. In addition, the switchgear controls the keys 14, connected in series in the circuits of the storage capacitors C with the discharge resistors R, constituting the integrating circuits of the counting rate meters, in which, besides the RC cell, the charging devices 15 are included (in the drawing one counting rate meter).

The device works as follows. At the beginning of the first measurement cycle, the duration of which is specified by the clock generator 12, the switchgear 11 sends a signal to the actuator 8, which rotates the collimator 3 around axis 17 until the collimator takes one of two extreme positions (see drawing) after which it remains in this position until the end of the measurement cycle. The cuts in screen 5 are designed so that in one of these positions a geometric configuration of a conventional selective gamma-gamma logging probe is created, and in the other (see drawing, dashed line), the geometry of X-ray radiometric logging, and in both cases gamma radiation registered by the same detector 6, the signals from which are formed by the electronic circuit 7, and then fed to the input of the amplitude analyzer 10. Simultaneously with the change in the geometry of the probe, the switchgear 11

through a group of circuits, And 13 connects the outputs of the analyzer 10 to the inputs of the first group of recorders, which can serve as parameters of counting rate and ratio. counting rates. They record logging readings performed with the measurement probe geometry fixed during the described cycle. Then, at the beginning of the second measurement cycle, the switchgear sets the collimator to another extreme position through the drive, simultaneously connecting the analyzer outputs through the AND 16 circuit group to the inputs of the second recorder group, and gamma radiation with a different probe geometry is detected. Both cycles periodically alternate as the depth probe moves along the axis of the well in such a way that, with a single probe run, two groups of parameters related to measurements with two geometrical configurations can be recorded simultaneously.

measuring probe.

In order for the separate recording of readings to be continuous, the switchgear 11 simultaneously controls the keys 14, which break the discharge circuits of the integrating cells in those recorders whose inputs are disconnected (pa time of one cycle) from the amplitude analyzer outputs.

Claims (1)

Invention Formula A device for radioactive logging, containing a depth measuring probe, equipped with a clamping device, carrying a gamma-ray source and detector and equipped with an electronic circuit, as well as a ground-based a console consisting of an amplitude analyzer and recorders, for example, meters of counting rate and counting rate ratio, characterized in that, in order to improve measurement accuracy during simultaneous studies of rocks using complex radioactive logging methods, drive in the measuring probe and switchgear with a clock generator and two groups of circuits And, moreover, one from the outputs of the switchgear controlled by a clock generator, is connected to the power supply circuit of the drive, and the other two paraphase outputs of the switchgear are connected respectively to the first inputs two groups of schemes. And, to the second inputs of which the outputs of the amplitude analyzer are connected, and the outputs of the AND circuits are connected to the inputs of the recorders. / 7