by Vera PARAFONOVA, journalist

How can one kill a gas blowout well? Only by its fragmentation (cutting to blocks) and consequent separation using special equipment. Several years ago to conduct remote accident recovery works the members of the State Scientific Center of the Institute of Innovative and Thermonuclear Research (Troitsk) (Rosatom State Corporation) together with the IRE-Polyus Research and Development Association (Fryazino, Moscow Region) suggested a mobile laser up to 24 kW power technological complex MLTK-20 whose coherent (monochromatic) radiation provides remote cutting of heavy-walled elements of emergency oil-gas derricks to pieces. The latest design of physicists passed ground tests and was repeatedly used in elimination of open-gas blowout.

LEADING POSITIONS

The history of the Scientific Center where promising types of lasers are developed today started in 1956 when the Magnetic Laboratory of the USSR Academy of Sciences was organized on the initiative of Acad. Anatoly Alexandrov* in Krasnaya Pakhra (Moscow Region). In 1961 it was incorporated into the Kurchatov Institute

* See: N. Ponomarev-Stepnoi, "At the Head of the Nuclear Branch", Science in Russia, No. 2, 2003; Ye. Velikhov, "Unable to Live Otherwise"; M. Mokulsky, "Rebirth of the Nation's Genetics"; V. Popov, "Scientific Works of Academician Alexandrov", Science in Russia, No. 1, 2013.--Ed.

of Atomic Energy (IAE)*, on whose basis primarily the Plasma Power Engineering Division was created in 1970 and then the IAE branch in 1971 reorganized into the Institute of Innovative and Thermonuclear Research in Troitsk in 1991.

The 1970s are rightfully considered time of the uppermost creative effort of the institute. It was just then that the institute headed by Acad. Yevgeny Velikhov** (from 1971 to 1978) made an advance in a number of sciences such as physics of plasma, laser technology, superconductivity and magnetohydrodynamic (MHD) generators. Today the institute holds leading positions in controlled thermonuclear synthesis, physics of highland low-temperature plasma, plasma power engineering, and physics and technology of high-power gas-discharge lasers. The institute provides fundamental research primarily in safety of atomic power engineering and also introduces technologies based on CO₂, CO, excimer and solid-state lasers into other spheres.

MOBILE LASER

In the 1970s the institute developed a fast-flow CO₂ laser of continuous action with a closed gas-dynamic circuit LT-1, which is introduced into enterprises of 10 industries. It is used for cutting of nuclear fuel elements and used up highly-active parts, welding of elements of the reactor protection system and heat exchangers, surface treatment of blast-furnace tuyeres thus twice increasing their heat stability, hardening of cutting tools and stamping equipment and also cementation of low-carbon steels which extends service life of pile-driving equipment four times.

Comparatively small divergence of CO₂-laser beam allowed orientation of the first plant LT-1 alone to a remote performance of operations. It cut a centimeter layer of concrete in the process of "shelling" (cleaning)

* See: A. Gagarinsky, Ye. Yatsishina, "From a Secret Laboratory to a National Research Center", Science in Russia, No. 2, 2013.--Ed.

** See: V. Shafranov, "Beyond the Pale of What Is Known", Science in Russia, No. 1, 2010.-Ed.

at a distance, welded and cut steel sheets for industry, construction and even cut a stainless pipeline just without rotating a pipe (a laser beam rotated) and gas supply to the cutting area.

Apart from the problems of remote usage of this plant when access to the accident source was hindered, there appeared problems of mobile shifting of this plant to the place of possible accidents for elimination of their consequences. Therefore, already early in the 1990s the institute scientists and engineers took up developing a portable version of high-power laser. Besides, they took account of possible reduction of its weight and size due to utilization of a carbonic acid gas/open air mixture as a working medium in the open cycle.

Just so an idea emerged of developing mobile laser technological complexes based on CO₂ lasers (MLTK) promising for accident recovery and disassembling works in atomic, gas, oil refinery and other industries. They met the basic requirement in such cases, i.e. prompt delivery of the required equipment to any place

by all types of transport (ground, water and air) and its on-line use for elimination of accident problems during dozens of minutes.

The mobile complexes MLTK-5 and MLTK-50 passed field tests already at the end of the 1990s. The first complex was created in 1998 on the basis of a gas-discharge CO₂ laser of closed circuit with pumping by self-sustained discharge and output radiation power 5 kW on a car frame of a container truck semitrailer and could machine large-scale metallurgical, mining, chemical and other equipment. It could also be used in shipbuilding for replacement of several stationary plants and in the mining industry for rock breakup at a distance of up to 30 m from the place of action.

ATMOSPHERIC ENERGY

In 1992-2000 by order of OAO Gazprom the TRINITI scientific center developed MLTK-50 on the basis of a pulse-periodic electroionization CO₂ laser of open circuit and radiation power up to 50 kW. In 2002 the following persons were granted the RF Government bonus for this work: the institute scientists and engineers Vladimir Vostrikov, Valery Gavrilyuk, Alexander Krasyukov, Valery Kuznetsov, Valery Naumov, Vladimir Cherkovets, Leonid Shachkin, Vladimir Shashkov and their colleagues from the Yefremov Research Institute of Electrophysical Equipment (St. Petersburg), the Raspletin Almaz Science and Technology Association and the Gazobezopasnost company (Moscow).

Freshness of the idea when developing the complex was based on utilization of surrounding atmospheric air with addition of 5 percent carbonic acid gas as the main working medium. Laser beam was brought to the atmosphere through a special gas-dynamic seal and directed to an object by mirrors of a forming guidance telescope. The plant installed at a distance of up to 80 m from the object could cut metal structures and reinforced concrete during accident recovery works at atomic power stations and oil and gas wells, eliminate consequences of earthquakes and other natural disasters, dismantle ships including atomic ships and submarines to metal scrap, clean coastlines from oil products after oil spillage and water surface from oil film. MLTK-50 was installed on two serial car semitrailers, and the layout of its equipment weighing less than 50 t allowed railway transportation.

In October of 2000 in the course of field acceptance tests the complex proved useful in cutting fragments of gas fittings with over 100 mm diameter and up to 20 mm wall thickness at a distance above 50 m. The laser beam broke through a 5 m flame. At the next stage it cut gas pipes of 250 mm diameter and metal structures up to 50 mm thick. Its energy (radiating wavelength 10.6 mem) was transported to a distance of 20-70 m in the atmosphere passing through 6 m firefront. Fragmentation and removal of the damaged gas equipment in the mouth of a gas well shooting out flame ended successfully. The gasmen were not satisfied only with the weight and size characteristics of this complex.

YTTERBIUM LASER

Early in the 21st century compact high-power optical fiber laser sources appeared in laser technology. It has become clear that similar systems with fiber-optic delivery of energy (distance up to 300 m) successfully fit in the institute's concept of creation of multifunctional mobile MLTK. Finally, the series of fiber plants

suggested by IRE-Polyus Research and Development Association (Fryazino) allowed the institute specialists to create a mobile complex family of a new generation.

The first complex MLTK-2 of 2 kW power based on ytterbium laser was created by order of Rosatom state corporation. It solved one of the difficult problems in atomic power engineering associated with the end of service life and removal from service of nuclear objects, namely, fragmentation of parts and units and multiple reduction of their radiation and ecological danger. Due to high productivity, possibility of remote handling of works and reduction of a volume of secondary radioactive wastes liable to disposal laser technologies provide substantial advantage in such cases as compared with conventional chemical methods.

The mobile complex MLTK-2 operates in national industry almost for 10 years and demonstrates excellent technical characteristics in remote cutting of metal structures up to 20 mm thick at a distance of dozens of meters from the test object. During breaks in technological tasks with a visit to the dislocation site this complex is used for commercial precision cutting of metal sheets of different thickness (up to 14 mm). Besides its constituent three blocks 3 m long and weighing 970 kg can be transported by any delivery vehicle. Upon arrival the set-up time of the complex is less than 10 minutes.

The complex MLTK-3 is also good for dismantling of construction structures by using three laser sources of 1 kW power. It consists of seven equipment modules each not exceeding 100 kg and working independently.

BEAM-LIQUIDATOR

The complex MLTK-20 developed at the institute in 2010 in cooperation with the IRE-Polyus Research and Development Association (Fryazino), ETAN-Promgaz (Moscow), Sistema Research and Production Center (Moscow), Vavilov Optico-Physical Laboratory (St. Petersburg) and other organizations to order of the Gazprom Gazobezopasnost company is one of the latest developments of the RF SSC TRINITI. Continuous ytterbium laser emission sources each of 8 kW power with a cooling system are installed in three out of the four container blocks of less than 2 t each (to compare with 48 t MLTK-50). Laser emission is brought from each source to a forming telescope installed in the fourth container block by a fiber-optic route up to 90 m long. The guidance, positioning and control systems of the complex are also installed here.

Such layout (modular structure) allows usage of laser blocks not only as a part of MLTK-20 but also separately depending on a pattern of operations. The four-block assembly can provide guidance of a 24 kW laser beam to any given zone, for example, cutting of metal structures at a distance of up to 70 m. The setup time of the complex in field conditions does not exceed half an hour at a continuous operational life of the main equipment. The cutting speed reaches 2 m/h and depends on metal thickness. Besides, the complex output power can be increased by attachment of additional container blocks.

The first full-scale tests of MLTK-20 were carried out in May of 2011 in the Dosang Training Center of

Gazprom (Astrakhan Region). One may state that it was its first world demonstration. For the first time the complex was transported on the car semitrailers at a large distance (1,000 km) by Russian spring roads. During the tests the complex cut gas fittings of blowout wells with 50 mm thick walls to fragments at a distance of 40 m. It took place in the presence of several dozens of specialists from Russia, the CIS and foreign countries. But the first full-scale test of MLTK-20 was conducted in July of 2011. Having covered above 5,000 km of national roads the complex was delivered to a gas field of the Yamalo-Nenets Autonomous Area. Let us point out that the high-power laser facilities developed at the TRINITI Scientific Center for elimination of accident consequences were used for the first time in the world.

BLOWOUT WELLS

On July 12, 2011, an open gas blowout took place as a result of explosion at drilling on the West-Tarkosalinsk gas field (Purovsky District, Yamalo-Nenets Autonomous Area). Four days later MLTK-20 was delivered by motor transport to the place of accident. The derrick damaged elements (above 240 t of metal) blocked the well mouth and hindered elimination of the accident and conducting of the stipulated for such cases recovery work. The laser complex was to cut massive steel parts of the damaged structure, make free and cut off a flow pipe flange. Formally such wells were "shot" by means of artillery guns which turned also rather valuable and expensive equipment into a scrap heap. But this was not our case. Though MLTK-20 operated under extreme conditions (high-power thermal radiation of the gas flame prevented from advancing nearer than 70 m) the heaps of metal structures were removed and the flange was cut off. Thereafter the gasmen plugged by their own means the gas blowout which carried to the atmosphere almost 20 mln rubles daily. The total time of laser radiation generation due to a reliable operation of MLTK-20 was over 30 hours.

On August 19, 2013, an accident took place on the Samburg oil-gas condensate field (Yamal Peninsula) 150 km to the north of Novy Urengoy. The institute specialists promptly loaded a laser complex on board of a transport airplane IL-76 and sent it to the place of accident. On the next day the laser complex set to work. The situation was complicated by the fact that in contradistinction to the previous well, which was not yet put into operation, that one was already functioning. Therefore, the work had to be done with utmost care. The thermal radiation from the powerful flame of about 10 m diameter did not allow to deliver the equipment closer than 60-70 m. Nevertheless, MLTK-20 after 2.5 days of practically uninterrupted operation managed to cut off 9 out of 12 elements of the oil-gas fittings, namely, a blowout preventer flange of the wellhead, which allowed the artillerymen to easily remove an upper part of the locking device without damaging the basic equipment and clear the route of the gas flow vertically upwards.

LASER-ASSISTED PILOTING OF SHIPS

It was planned to use the gas-discharge MLTK-50 also for cleaning of a water surface from a thin "rainbow" of oil film difficult to be removed by other means. This is especially the case today. In the period of industrial and technological development of the Arctic Regions where active construction of drilling rigs for development of oil and gas off-shore and shelf deposits is under way, there arise problems, in particular, of protection of the marine environment and coastal belt from oil- and gas-condensate contamination. Therefore, Gazprom company as a main developer of natural resources in the region takes an active interest in a reli-

able and trouble-free operation of the Arctic offshore oil fields and development of promising technologies of prevention and elimination of liquid hydrocarbon accidental spills in the regions of severe climatic and ice conditions.

At present by agreement with Gazprom, the TRINITI Scientific Center is already carrying on an approbation of the method of laser combustion of oil. The crux of the matter lies in search for an efficient remote thermal method of oil spill elimination in the conditions of shore and drifting (pack) ice depending on weather and ice factors. Physicists already now suggest setting fire to an oil film from a distance of hundreds of meters by using a reaction of the conventional combustion mechanism. According to them first a small volume of oil shall be heated till it starts evaporating, then a laser-induced spark shall

burn it and afterwards insignificant residues of a "tar" film shall be collected.

It was intended to carry on such works already in the 1990s by the laser complex MLTK-50. But there were too many sceptics at that time. Now, after the carried out experiments, there are practically no such people left. During a week the specialists covered a surface of ice cubes with oil and tried to clean it by laser radiation. This method helped destroy even that oil film, which was covered with a 10 cm layer of snow. True, the process took place under - °C. But in the Arctic Regions temperatures are different--around -50-60 °C. Therefore, in the near future we shall develop modes of operation of a laser complex which will meet the permafrost conditions.

The institute staff members are already concerned about a next step in using mobile complexes as they can become indispensable in ship piloting. Since 2000, transportation by sea is becoming more and more popular as well as development of the Northern Sea Route--the shortest from Europe to Asia. In the context of the marked growth of transport operations there is an increased need in the atomic icebreaker fleet. How can we make their trips easier in ice conditions? The Troitsk specialists suggest reduction of ice strength by laser. The tests have proved that from a distance of 50 m it is easy to obtain vertical cuts, but horizontal cuts are more difficult to get. But this is also a matter of the near future. You know, atomic icebreakers generate sufficient amount of electric power, so a part of it can be used for operation of a laser unit.

Illustrations supplied by the TRINITI Scientific Center