SU909646A1

SU909646A1 - Generating device for marine geoelectric prospecting

Info

Publication number: SU909646A1
Application number: SU782702749A
Authority: SU
Inventors: Андрей Эрихович Вишняков
Original assignee: Северо-Морское Научно-Производственное Геолого-Геофизическое Объединение "Севморгео"
Priority date: 1978-12-26
Filing date: 1978-12-26
Publication date: 1982-02-28

Description

Изобретение относится к геофизическим методам разведки, и в частности к электроразведке униполярными импульсами.The invention relates to geophysical methods of exploration, and in particular to electrical exploration by unipolar pulses.

Известно устройство геоэлектроразведки, применяемое в методах вызван- ⁵ной поляризации и становления поля, в котором в питающие электроды подают импульсы тока, а после окончания токового импульса измеряют изменение ₁₀напряжения на приемных электродах ИЗ.Geoelectrical known device used in the methods ⁵ vyzvan- polarization and field establishment, in which the feed current pulses fed to the electrodes, and after the closure of the current pulse measured change in voltage ₁₀ on the receiving electrodes IZ.

Данное устройство непригодно для работы в морских условиях.This device is not suitable for use in a marine environment.

Известны устройства для мррской геоэлектроразведки в движении, со- ,₅стоящие из нескольких поплавков, буксируемых судном, на которых закреплены генераторный и приемные датчики поля С2].Known devices for Mrr geoelectrical exploration in motion, ₅ consisting of several floats towed by a vessel on which the generator and receiver sensors of the field C2 are fixed].

В морских электроразведочных стан- ₂₀цидх используют корабельные или специальные генераторы, обеспечивающие ток до 50-100 А, при этом резко возрастает проблема отвода мощности от генератора в паузах между питающими импульсами.Marine electrical prospecting stations- ₂₀ cidhs use ship or special generators that provide currents of up to 50-100 A, while the problem of power removal from the generator sharply increases in the pauses between supply pulses.

В полном виде установки электропрофилирования с импульсным питающим током помимо питающих электродов содержат также балластную нагрузку и средства коммутации генератора с питающих электродов на балластную нагрузку.In a full form, electric profiling installations with a pulsed supply current, in addition to the supply electrodes, also contain a ballast load and means for switching the generator from the supply electrodes to the ballast load.

Подобная схема применена в серийно выпускаемой электроразведочной станции ЭРС-67. При этом балластная нагрузка выполнена в виде омической нагрузки - проволочного реостата, вынесенного над кабиной, вне станции [3J.A similar scheme was used in the commercially available electric prospecting station ERS-67. In this case, the ballast load is made in the form of an ohmic load - a wire rheostat, carried out above the cab, outside the station [3J.

Недостатком указанного устройства является то, что даже в сравнительно маломощных (50-100 А) станциях объем омической балластной нагрузки приближается к кубометру, а при увеличении токов до тысяч ампер, типичных для морской геоэлектроразведки, объем балластной нагрузки возрастет до 10 и более кубометров и соответственно возрастет занимаемая им площадь, что недопустимо в условиях судна. Кроме того, в условиях судна возрастает пожароопас- ₅ность и опасность поражения электри’·· ческим током.The disadvantage of this device is that even in relatively low-power (50-100 A) stations, the ohmic ballast load volume approaches a cubic meter, and with an increase in currents up to thousands of amperes typical of marine geoelectrical exploration, the ballast load volume will increase to 10 or more cubic meters and, accordingly the area occupied by him will increase, which is unacceptable in a ship. In addition, increases in a vessel ₅ pozharoopas- NOSTA and danger of RE '·· cal shock.

Цель изобретения - экономия производственной площади и улучшение условий техники безопасности. юThe purpose of the invention is to save production space and improve safety conditions. Yu

Поставленная цель достигается тем, что в известном устройстве, содержа-·· щем генератор и блок коммутации, размещенные на судне, балластную нагрузку и. два питающих электрода, разне- is сенных между собой, закрепленных на кабель-тросе вне судна и соединенных один непосредственно с одним полюсом генератора, а другой - через блок коммутации, балластная на- ₂0 грузка выполнена в виде забортной линии, образованной ближним к судну питающим электродом и дополнительным электродом, расположенным симметрично ему относительно линии движения 25 судна вне зоны возможного замыкания, причем дополнительный электрод через коммутатор соединен с генератором.This goal is achieved by the fact that in a known device containing a generator and a switching unit located on the ship, the ballast load and. two feeding electrode is razne- hay each other, mounted on a cable-cable is connected to a vessel and directly from one pole of the generator, and the other - via the switching unit, ballast HA ₂ 0 Booting is designed as a seawater line formed proximal to a vessel a supply electrode and an additional electrode located symmetrically to it relative to the line of movement 25 of the vessel outside the zone of possible short circuit, and the additional electrode is connected through a switch to a generator.

Кроме того, указанный дополнитель- 30 ный электрод выполнен медным. Переходное сопротивление электрода выбирают эквивалентным полному сопротивлению питающей линии.In addition, the specified additional 30th electrode is made of copper. The transition resistance of the electrode is chosen equivalent to the impedance of the supply line.

На чертеже приведена схема предла- ₃₅гаемого устройства.The drawing shows a diagram predla- ₃₅ Guy device.

Устройство содержит трос-кабель 1 длиной 2 км, на конце 2 которого последние . 10-15 м освобождены от всех изолирующих оболочек, а голые жилы 40 кабеля образуют дальний питающий электрод А. Другой конец 3 кабеля через блок 4 коммутации подсоединен к отрицательному полюсу генератора 5 постоянного тока, находящегося на судне 6.The device contains a cable cable 1 with a length of 2 km, at the end of which 2 are the last. 10-15 m are freed from all insulating shells, and bare wires 40 of the cable form a distant supply electrode A. The other end 3 of the cable is connected through the switching unit 4 to the negative pole of the DC generator 5 located on the vessel 6.

II

К другому положительному полюсу генератора 5 подсоединен 10-метровый отрезок кабеля 7, опускаемый с правого борта судна 6 и заканчивающийся электродом В. Кроме того, с левого борта судна 6 В воду опущен отрезок кабеля 8, заканчивающийся дополнительным коротким (5*10 см) медным электродом А¹ , расположенным относительно линии движения судна примерно симметрично электроду В и на расстоянии 10 м, исключающем возможность к.з. Противоположный электроду А¹ конец 9 отрезка кабеля 8 через блок 4 коммутации подключен к тому же отрицательнму полюсу генератора 5. Имеется измерительная линия MN.To the other positive pole of the generator 5 is connected a 10-meter length of cable 7, lowered from the starboard side of the vessel 6 and ending with electrode B. In addition, from the port side of the vessel 6, cable length 8 is lowered into the water, ending with an additional short (5 * 10 cm) copper electrode A ¹ located relative to the line of movement of the vessel is approximately symmetrical to electrode B and at a distance of 10 m, which excludes the possibility of short circuit Opposite the electrode A ^{1, the} end 9 of the cable length 8 through the switching unit 4 is connected to the same negative pole of the generator 5. There is a measuring line MN.

, Устройство в режиме метода становления работает следующим образом., The device in the mode of formation method works as follows.

Через электроды А и В от генератора 5 запитывают линию импульсами прямоугольной формы с амплитудой до 1000А длительностью Ю-ЗОс и такой же паузой. Длительность и пауза импульсов могут быть отрегулированы с помощью блока 4 коммутации. В паузах между импульсами' с помощоь блока 4 коммутации генератор переключают с электрода А на электрод А*. Момент отключения электрода А от генератора синхронизирует измерительную цельна момент начала измерения. Процесс переключения повторяют многократно, суммируя наблюдаемые кривые для увеличения соотношения сигналфон.Through the electrodes A and B from the generator 5, the line is fed with pulses of a rectangular shape with an amplitude of up to 1000 A with a duration of 10–3 ° C and the same pause. The duration and pause of the pulses can be adjusted using the switching unit 4. In the intervals between pulses, using the switching unit 4, the generator is switched from electrode A to electrode A *. The moment of disconnection of the electrode A from the generator synchronizes the measuring whole moment of the start of measurement. The switching process is repeated many times, summing the observed curves to increase the signal-to-signal ratio.

Поперечное поле диполя А* , отделенное от измерительных электродов на 1000 м (порядка 100 длин диполя), не оказывает никакого влияния на измерительную линию MN.The transverse field of the dipole A *, separated by 1000 m from the measuring electrodes (of the order of 100 dipole lengths), has no effect on the measuring line MN.

При использовании длинной подводящей линии (трос-кабель 1) и длинного с большой поверхностью дальнего электрода А суммарное сопротивление определяется сопротивлением трос-кабеля 1 и составляет для кабеля типа КНР-120 около 0,’5 Ом на 2 км. В отрезке кабеля 8 сопротивление самой линии пренебрежимо мало, поэтому ос^· новная часть суммарного сопротивления приходится на переходное сопротивление электрода А¹ , который выполнен коротким (5*10 см) и обладает переходным сопротивлением в те же 0,5 Ом.When using a long supply line (cable-cable 1) and a long one with a large surface of the far electrode A, the total resistance is determined by the resistance of the cable-cable 1 and amounts to about 0, 5 Ohms per 2 km for a cable of the KPP-120 type. In the cable segment 8, the resistance of the line itself is negligible, therefore, the main part of the total resistance falls on the transition resistance of the electrode A ¹ , which is made short (5 * 10 cm) and has a transition resistance of the same 0.5 Ohm.

Опыты’ показывают, что только медный электрод стабильно выдерживает прилагаемые нагрузки. Вследствие сказанного генератор 5 постоянно (за исключением моментов переключения) ⁵⁰ нагружен на одно и то же сопротивление и работает в стабильном режиме. Поверхность палубы освобождается от громоздкого, раскаленного реостата балластной нагрузки. Таким образом, устраняется тепловой источник пожарной опасности. Кроме того, в условиях повышенной влажности и солености находящийся под напряжением реостатExperiments show that only a copper electrode can withstand the applied loads. As a result of this, the generator 5 is constantly (with the exception of the switching times) ⁵⁰ loaded with the same resistance and operates in a stable mode. The surface of the deck is freed from the bulky, hot glow rheostat of the ballast load. Thus, the heat source of the fire hazard is eliminated. In addition, in conditions of high humidity and salinity, a live rheostat

909646 6 представляет двойную опасность и с электрической стороны возможность к.з. и возгорания, а также возможность поражения током персонала.909646 6 is a double hazard and, from the electrical side, the short-circuit capability and fire, as well as the possibility of electric shock to personnel.

Claims

The invention relates to geophysical methods of exploration, and in particular to electrical prospecting by unipolar pulses. A geoelectrical decontamination device is known that is used in methods of induced polarization and field formation in which I apply current pulses to the supply electrodes, and after the end of the current pulse the change in voltage on the receiving electrodes tt3 is measured. This device is unsuitable for operation under marine conditions. There are known devices for exploratory geoelectrical exploration in motion, consisting of several floats mounted by a vessel, on which the generator C2 and receiving sensors C2 are mounted. In marine electrical prospecting camps, shipborne or special generators are used, providing current up to 50-100 A, and the problem of power drainage from the generator in the pauses between the feeding pulses increases dramatically. In full view, the electric profiling equipment with a pulsed supply current in addition to the supply electrodes also contains a ballast load and means of switching the generator from the power electrodes to the ballast load. A similar scheme is applied in the commercially available electrical exploration station ERS-67. At the same time, the ballast load is made in the form of an ohmic load — a wire resistor placed above the cab outside station 33. A disadvantage of this device is that even in relatively low-power (50-100 A) stations the volume of the ohmic ballast load approaches a cubic meter, and with an increase in currents up to thousand amperes typical of marine geoelectrical exploration, the volume of ballast load 330 will increase to 10 or more cubic meters and, accordingly, the area occupied by it will increase, which is unacceptable in the ship. In addition, the fire hazard and the danger of electric shock increase in the ship's conditions. The purpose of the invention is to save production space and improve safety conditions. The goal is achieved by the fact that in the known device, which contains a generator and a switching unit, once the vessel is loaded, a ballast load and two supply electrodes separated from each other, attached to the cable-cable outside the vessel and connected directly to one pole of the generator, and the other - through the switching unit, the ballast load is made in the form of an overboard line formed by a supply electrode and an additional electrode located near the vessel and an additional electrode located symmetrically with respect to the vessel’s line of movement outside the zone possible aamkani, with an additional electrode through the switch connected to the generator. In addition, this additional electrode is made of copper. The contact resistance of the electrode is chosen equivalent to the impedance of the supply line. The drawing shows a diagram of the proposed device. The device contains a cable-cable 1 with a length of 2 km, at the end of which 2 are the last. 10- T5m are freed from all insulating shells, and the bare wires of the cable form the far supply electrode A. The other end of the 3 cable is connected to the negative pole of the DC generator 5 via the switching unit h. Another 10-M pole is connected to the other positive pole. cable section 7, lowered from the starboard of the vessel 6 and ending with electrode B. In addition to the toga, from the left side of the vessel 6 6 water, cable 8 is lowered, ending with an additional short (5-10 cm) copper electrode A located The vessel’s line of motion is approximately symmetrical to electrode B and at a distance of 10 m, which excludes the possibility of a short circuit. The end 9 of the cable section 8 opposite to the electrode is connected via the switching box i to the same negative pole of the generator 5. There is a measuring line MN. The device in the mode of becoming method works as follows. Through the electrodes A and B from generator 5, the line is fed with pulses of rectangular shape with an amplitude of up to 1000A with a duration of 10-AOC and the same pause. The duration and pause of the pulses can be adjusted using the switching unit k. In the pauses between pulses, using the switching unit i, the generator is switched from electrode A to electrode A. The moment the electrode A is disconnected from the generator synchronizes the measuring circuit to the moment the measurement starts. The switching process is repeated many times, summing the observed curves to increase the signal to signal ratio. The transverse dipole A field, separated from the measuring electrodes per 1000 m (in the order of 100 dipole lengths), has no effect on the measuring line MN. When using a long supply line (cable-cable 1) and a long one with a large surface of the far electrode A, the total resistance is determined by the resistance of the cable-cable 1 and is about 0 Ohm for 2 km for cable of the People's Republic of China-120 type. In the section of Cable 8, the resistance of the line itself is negligible, therefore the main part of the total resistance falls on the transition resistance of Electrode A, which is made very compact (cm) and has a transition resistance of the same 0.5 Ohm. Experiments show that only the copper electrode stably withstands the applied load. Due to the aforesaid, generator 5 is constantly (with the exception of the switching points) loaded on the same resistance and operates in a stable mode. The surface of the deck is freed from a bulky, hot glowing ballast. Thus, the heat source of fire danger is eliminated. In addition, under conditions of high humidity and salinity, a rheostat under stress represents a double danger from the electrical side, the possibility and. and ignition, as well as the possibility of electrical shock. Claim Generator for (Jurassic Geoelectromagnetic Survey containing generator and switching unit, placed on the vessel, ballast load and two supply electrodes separated from each other, placed on the cable outside the vessel and connected directly to one generator of the generator and the other through the mutation It is worth noting that, in order to save vessel volume and improve safety conditions, the ballasting load is made in the form of an overboard line formed by the nearest electrodes to the vessel. The additional electrically located symmetrically with respect to the vessel’s line of movement outside the zone of possible closure, the additional electrode being connected via a switching unit to the generator. Sources of information taken into account in the examination 1. USSR author's certificate fT 212388, cl. 01 V 3/02, 1968.

2. For France V 229b5b2, cl. G 01 V 1/38, 1976,.

3. Instructions for electric exploration station ERS-67. TU 25-08-657-70 (prototype).