SU832516A2 - Well-loging photodetector - Google Patents

Description

(54) CARTRIDGE PHOTO REGISTRATOR

to an increase in the number of measuring channels and inconvenience in the interpretation of logs from diagrams.

The purpose of the invention is to expand the functionality of the logging photo recorder, simplify its scheltl and reduce the number of curves when registering one parameter that changes in a wide dynamic range.

The goal is achieved by adding an exponential voltage source block to the photo recorder, the input of which is connected to one of the outputs of the scanner, and the inputs are connected to the other inputs of the comparators block.

Figure 1 shows the functional diagram of the device; 2-4 are timing diagrams explaining the operation of the device.

The logging recorder contains an electron-beam tube 1, lens 2, photosensitive tape 3, tape mechanism 4, scanning unit 5, exponential voltage source block 6, comparators block 7, combining unit 8, coincidence circuit 9, sources 10 of recorded signals, control unit 11 .

The device works as follows.

The inputs of the comparator block 7 From the outputs of the sources, 10 recorded signals, receive time varying or constant signals to be recorded (in Fig. 2, curves 12-15 for the case of recording four independent parameters). Scanning unit 5 operates only in the horizontal scanning mode. At that, from one of the outputs of the sweep unit 5, the sawtooth voltage is applied to the horizontal deflecting plates of the cathode ray tube 1, and from the other output of the sweep unit 5 at the moment sweep starts, a rectangular pulse appears that triggers the exponential voltage source unit 6 signals varying in time according to a given exponential law. From the outputs of block 6 of sources of exponential voltage, signals are fed to the other inputs of block 7 of comparators. At the moments of coincidence of the input signal levels with the levels of the signals produced by block 6 of the sources of exponential voltage (in Fig. 2, the intersection of curves 12-15 with curve 16, which is an exponent), short pulses appear at the output of the commator 7. (C), which, through the coincidence circuit 9 and the combining unit 8, are fed to the modulating electrode of the electron-beam tube 1. On the screen of the electron-beam tube 1, there are observed light points located on one straight line in an amount equal to the number of recorded parameters (figure 4). Since the scanning of the beam and the comparison of the recorded signals with the exponential voltage is carried out synchronously using the same sawtooth generator of the scanning unit 5, the position of each point on the screen of the electron-beam tube 1 is determined by the value of the recorded parameter and the longframe detection scale specified by the block b sources of exponential stress. If it is necessary to register any parameter on a linear scale, the signal from the output of scanner unit 5, mine unit 6 of exponential voltage sources, is fed to those inputs of comparators unit 7, to the second inputs of which sources of signal 10 are recorded on a linear scale. The image from the screen of the electron beam tube 1 through the lens 2 is projected onto the photosensitive tape 3, evenly moved in front of the lens 2 by means of a tape mechanism 4. Each light with a dot on the screen of the electron beam tube 1 displays a curve reflecting the change in the recorded parameter on the photosensitive tape. Since the scan frequency of unit 5 can be chosen sufficiently high compared with the speed of movement of the photosensitive tape 3, for example, 1020 kHz, the recorded parameter is displayed on the photosensitive tape 3. In the form of a continuous curve.

The control unit 11, which is, for example, a set of multivibrators with different duty cycle and pulse duration, the inputs of which are connected to the inputs of the coincidence circuits 9, is intended for convenience of decoding the logging diagrams, since the various curves on the sensitive tape 3 are recorded as a sequence of dots, short and long strokes, a combination of dots and strokes, etc.

In block 6, several sources of exponential voltage can be provided, for example, several exponential voltage generators using the principle of charging and discharging electrical capacitance to enable recording of various parameters with a different logarithmic scale module.

Thus, the introduction of an additional block into the photo recorder

sources of exponential voltage allows its functionality to be expanded, namely, to record geophysical parameters on a logarithmic scale, which allows recording parameters varying in a wide dynamic range, such as apparent electrical resistivity of rocks, etc., through a single measuring channel of the photo recorder.

Expanding the functionality of a logging photo recorder provides a certain economic effect by reducing the number of recorder measurement channels used in parallel to record, with different sensitivity, a parameter varying over a wide dynamic range (up to 10); exclusion from the composition of geophysical measuring systems of special logarithmic blocks, converters, used to record electric logging curves on a logarithmic scale; reducing the number of curves on the chart tape, reflecting the change of ONE and the same registered parameter, which leads to an increase in efficiency and a decrease in the interpretation error; shorten the time needed to interpret the logging curves obtained using equipment having a logarithmic transformation characteristic, e.g.

gamma density meters, gamma thickness gauges / neutron carriage instruments, due to the fact that the transformation function of the measuring system as a whole (including the well part, ground part and recorder with a logarithmic scale) has a linear relationship.

Claims (3)

1.Love I.I. and Chukin V.T. Instrumentation and equipment for geophysical methods for investigating wells. M., Nedra, 1978, p. 6-32. 2. Authors certificate of the USSR W 307180, cl. E 21 47/00, G 01 V 1/13, 1969. 3. Copyrights certificate CCClp 661484, cl. G 01 V 13/00, G 01 O 15/32, 1977. f2