Drilling

DRILLING (EN: drilling, coring, boring; DE: Bohren, Bohrarbeit; FR: forage, sondage; ES: perforacion; RU: бурение) is the process of the forming of the mine working with the predominantly circular cross-section, using the method for the destruction of the rocks mainly by the drilling tool (less often by the thermal, hydro-erosional, explosive, and other methods), with the removal of the products of the destruction.

During the drilling, the destruction is conducted throughout the entire area within the bottomhole (non-core drilling), less often only throughout the annular space within the bottomhole for the extraction of the core (see the "Core drilling" article). The diameters of the mine workings, which are drilled, amount to tens of millimetres (blastholes), hundreds of millimetres (drilled wells), and thousands of millimetres (mine shafts). The depth of the drilling is determined by the field of its usage, and amounts to several metres (mostly the blastholes), tens of metres (the boreholes for the placement of the explosive substances, for the fixation of the rocks by cementing, freezing, and so on), hundreds and thousands of metres (the drilled wells, namely, the exploratory wells for water, petroleum, and gas, the operating wells, and others). The process of the construction of the deep drilled wells includes also the fixation of the walls within the barrel by the casing pipes, with the injection of the cement fluid (solution) into the annular gap between the pipes and the walls.

They perform the drilling of the deep drilled wells by the drilling installations, of the blasting wells by the drilling rigs, of the mine shafts by the shaft-tunneling aggregates, of the blastholes by the drilling hammers, drilling augers, and so on. The technical means for the drilling include also the drilling pump or the compressor for the supply of the drilling fluid and gas, drilling pipes, drilling derrick with the block and tackle system, the tool for the destruction of the rock, the equipment for the preparation of the washing fluid, for the cleaning of this fluid of the sludge, and for the degassing of this fluid, the anti-blowout equipment, and the control and measuring apparatuses. The drilling is performed mostly by the mechanical method: the drilling tool directly acts onto the rocks, thus destroying them (see the "Drill bit", and the "Drill crown" articles); during the drilling of the blasting boreholes within the quartz-containing rocks, they use the thermal drilling (by the jet of flame). They sub-divide the mechanical methods for the drilling, according to the method for the action of the tool onto the bottomhole, into the rotary drilling, striking drilling, striking-rotating drilling, and rotary-striking drilling.

According to the type of the rock-destructing tool, which is used, they distinguish the auger drilling, roller-cone drilling, diamond drilling, shot drilling, and so on; according to the type of the drilling machine, they distinguish the perforation drilling, pneumatic striking drilling, hydraulic striking drilling, rotary drilling, turbine drilling, and so on; according to the direction and to the method for the conducting of the drilled wells, they distinguish the cluster drilling, vertical drilling, inclined directional drilling, multi-bottomhole drilling, and so on. The drilling is developed and is specialized for the usage within the three major fields of the mining craft: the extraction of the liquid and gaseous useful minerals, the prospecting and exploration for the useful minerals, the extraction of the hard useful minerals by the blasting method. Such division, which has been formed historically, is very conditional, but it is methodologically convenient for the short description of such very multidimensional concept, as the "drilling".

The drilling for the extraction of the liquid and gaseous useful minerals. There are available the facts, that within China, more than 2 thousand years ago, there were drilled by the striking method the boreholes with the diameter of 12-15 centimetres, and with the depth of up to 900 metres, for the extraction of the salty solutions. They plunged into the borehole the drilling tool (chisel and bamboo rods) on the ropes with the thickness of 1-4 centimetres, which have been twined of the cane. The striking method for the drilling remained the practically single method, till the emergence of the rotary drilling during the end of the 19th century.

Within Russia, the drilling of the first wells refers to the 9th century, and is associated with the extraction of the solutions of the table salt within the Staraya Russa city. Later, the salt extracting enterprises were developed within the Balakhna city (12th century), and within the Solikamsk city (16th century). The emergence of the new methods and technique for the drilling refers to the 19th century, in association with the increasing necessity for the supplying of the large cities with the drinking water. During the 1831, there has been formed within the Odessa city the "Society for the artesian fountains", and there have been drilled 4 wells with the depth of 36-189 metres.

Within the USA, the first well has been drilled for the extraction of the salty solution near the Charleston city within the West Virginia state (1806), the first petroleum from the drilled well has been obtained during the 1826 within the Kentucky state by chance during the prospecting for the brines. During the 1834, the German engineer Eigauzen has proposed to use the shifting pair of sections during the rod-striking drilling. The idea to drop the chisel, which is connected with the rods, has been realized within France by C. G. Kind (1844) and Fabian (1849), who have invented the free falling drilling tool (freifall). During the 1846, there has been successfully drilled by the French engineer Fauvel within Perpignan the well with the cleaning of the bottomhole by the jet of water, which was supplied by the pump from the surface into the hollow rod.

During the middle of the 19th century, the striking manual drilling has started to be displaced by the portable mechanical machine tools. Within Russia, G. D. Romanovskiy has mechanized the works for the first time during the 1859, using the steam powered engine for the drilling of the well near the Podolsk city. Drake has founded during the 1859 (the Pennsylvania state, within the USA) the first well for petroleum, which has been drilled by the machine tool for the striking drilling.

The first well for petroleum within Russia has been drilled during the 1864 near the Anapa city. The development of the technique for drilling is associated with the establishment of the petroleum industry. At the productive petroleum fields of the Baku city, the first steam powered engines have appeared during the 1873, and yet 10 years later, they have replaced the horse power almost everywhere. During the drilling for petroleum, at the first stage, there has got the development the striking method (the drilling with the usage of the rod, rope, and of the fast-striking type with the washing of the bottomhole). During the end of the 80-ies of the 19th century, within the USA, within the New Orleans city (the Louisiana state), there was introduced the rotary drilling for petroleum with the usage of the blade drill bits, and with the washing by the clayish drilling fluid. Within Russia, they have used the rotary method with washing for the first time during the 1902 within the Grozny city for the drilling of the well for petroleum with the depth of 345 metres. Within the Surahani (the Baku city), during the 1901, there has been founded the drilled well for the extraction of gas, and yet one year later, from the depth of 207 metres, there has been obtained the gas, which was used for the heating of the industrial plant. During the 1901, at the productive petroleum fields near the Baku city, there have appeared the first electrical motors, which have replaced the steam powered engines. During the start of the 20th century, within the USA, there has been developed the method for the inclined rotary drilling by the drill bits of the small diameter, for the drilling of the wells with the subsequent widening.

The marine well has been drilled for the first time during the 1897 within the Pacific ocean near the Summerland island (the coastal shelf of the California peninsula, within the USA), and later the drilling at the sea has got the wide distribution. Within the USSR, the coastal shelf drilling has been started during the 1924 (near the Baku city).

During the start of the 20th century, within Russia, there has been created by the Polish engineer V. Wolski the fast-striking bottomhole hydraulic motor (the ram of Wolski), which is the prototype of the modern hydraulic strikers. During the 1924, the Soviet engineers M. A. Kapelyushnikov, S. M. Volokh, and N. A. Kornev have designed the geared turbodrill, which was used till the 1934 during the drilling of the wells with the depth of up to 1000 metres. During the 1935-39, the Soviet engineers P. P. Shumilov, R. A. Ioannesyan, E. I. Tagiyev, and M. T. Gusman have proposed the multi-stage gearless turbodrill, and after this fact the turbine has become the major method for the drilling. During the 1941, they have also developed the method for the inclined directional drilling, with the drill bits of the normal diameter, and without the subsequent widening, which has got the distribution, because it allowed to build several drilled wells on one foundation. During the 1940, there has been drilled within the Baku city the first well by the electrical drill, which has been developed by A. P. Ostrovskiy, and by N. V. Aleksandrov. During the 1941, the Soviet engineer N. S. Timofeev has proposed to use the multi-bottomhole drilling within the stable rocks.

During the start of the 50-ies, according to the proposal by R. A. Ioannesyan, M. T. Gusman, and G. A. Bulakh, there has been drilled within the Makhachkala city for the first time the well of the large diameter (approximately 1 metre) by the reactive-turbine method, which fact has allowed to start the works for the construction of the underground mine shafts.

During the start of the 60-ies, within the USA, Harrison has used the gerotor screw pump by Moineau for the creation of the voluminous motor, which they are using for the curving of the well during the inclined directional drilling. Within the USSR, for the drilling of the wells for petroleum and gas, since the end of the 60-ies, there is used the gerotor motor with the screw pair drive with significantly greater quantity of the taps, which fact allows to increase the torque, and to decrease the frequency of the rotation. They drill by this motor the entire well, instead of only the places of its curving (see the "Screw bottomhole motor" article).

Within the USA, there has been drilled during the 1975 by the rotary method one of the deepest wells within the world, namely, with the depth of 9583 metres (see the "Super-deep drilling" article). Within the USSR, according to the "Upper mantle of the Earth" scientific programme, there is planned to drill several wells with the depth of up to 15 kilometres. The drilling of the first such well has been started on the Baltic shield by the turbodrills (by the 1981, the depth has reached 11 kilometres).

The modern drilling of the wells for petroleum and gas is characterized by the increase of the depth of drilling, and by the steep increase of the total volumes of the drilling. The average depths of the wells within the USA during the operational drilling amount to approximately 1300 metres, and during the exploratory drilling amount to approximately 1700 metres; within the USSR, the average depths of the wells during the operational drilling amount to approximately 1900 metres, and during the the exploratory drilling amount to approximately 3000 metres. The major volumes of the drilling within the USSR are accounted for the turbine drilling (approximately 80% of the total length of drilling, during the 1975-78). There are planned the increase of the quantity of the rotary drilling, and the expansion of the usage of the gerotor motors. Within the US, the major method for the drilling for petroleum and gas is the rotary method; there is expected to increase the percentage of the drilling by the bottomhole motors. The major directions for the perfecting of the drilling are associated with the improvement of the designs for the drill bits, motors, drill columns, with the increase of the penetration by the drill bit per plunge, with the usage of the effective washing solutions for the drilling fluid, with the automation for the process of the drilling, with the improvement of the designs of the wells, and with the improvement of the quality of their fixation.

The prospecting and exploration for the hard useful minerals. The development of the exploratory drilling for the hard useful minerals is associated with the invention of the diamond drill by the Swiss person J. Lesho (1862). During the 1899, there has been proposed the shot drilling by the American engineer Davis. Within the USSR, the shot drilling has been used during the 1927-28 by the Soviet scientists V. M. Kreiter and B. I. Vozdvizhenskiy for the core drilling, which fact has allowed to replace the diamond drilling within the strong erupted and metamorphic rocks by this method. During the 1928-29, within the USSR, there was started the production of the drilling machine tools with the advancement by the lever, for the rotary core drilling at the depth of 300-500 metres; since the 1947, there were created the machine tools with the advancement by the differential lever, the multi-speed machine tools for the depth of 300-2000 metres, the self-propelled drilling installations. Since the 1960, there were started the works for the mastering of the hydraulic striking drilling (L. E. Graf, A. T. Kiselev, D. I. Kogan), which fact has ensured the significant increase for the performance of the hard-alloy core drilling. There was radically perfected the diamond drilling (F. A. Shamshev, I. A. Utkin, B. I. Vozdvizhenskiy, S. A. Volkov, and others), the quantities of which for the searches for the deposits of the useful minerals were increasing. During the exploration of the steeply dipping ore bodies, when they drill several boreholes for the transversing of them at various horizons, they use the directional multi-bottomhole drilling, which is conducted with the help of the deflecting devices, which are installed within the borehole at various depths. The exploratory drilling for the hard useful minerals is performed mostly by the rotary method, which accounts for approximately 80% of the length of the boreholes, which have been drilled; within the limited quantities, there are used the striking-rotary, hydraulic striking, auger, vibratory, and other methods for the drilling. The works in the field of the exploratory drilling are directed onto the ensuring of the preservation of the core, which is extracted from the great depth, and onto the development of the apparatuses, and of the reliable methods, for the testing of the rocks. The perfecting of the technique and technology of the exploratory drilling for the hard useful minerals is associated with the introduction of the drilling by the tools with the removable core-receiving devices, of the hydraulic striking drilling, of the core-less drilling with the usage of the lateral drilling soil-carriers, and is associated with the complete automation of the entire process of the drilling.

The drilling of the blastholes and blasting boreholes. The drilling of the blastholes by the machine has been developed by the German mechanic G. Gutman (1683); the development of this drilling is associated with the creation of the drilling machines by the Austrian engineer Gainshing (1803), and by the English mechanic Travel (1813). They have used the piston drilling machines for the striking drilling of the blastholes (these machines have been proposed by the engineer Sommeye) for the first time during the laying of the tunnel within the Alps mountains, which fact has dramatically decreased the duration of the construction. Since the middle of the 19th century, the drilling of the blasting boreholes within the open pit mines is performed by the powerful drilling hammers, which are installed onto the tripods.

During the start of the 20th century, there was introduced the rotary drilling of the blastholes within the soft rocks by the electrical drilling augers. During the start of the 20-ies, at the open pit mines within the USA, there have been used for the first time the striking-rope drilling machine tools. Within the USSR, this method was used during the 30-60-ies, and was the major method for the drilling of the vertical boreholes with the diameter of 150-300 millimetres within the rocks with the strength, which is greater than the average strength. They have started to use the auger drilling within the USSR since the 1939. During the 1943, at the Bogoslovsk open pit coal mines (at the Urals mountains), there has been tested the first machine tool for the rotary drilling on the tracked chassis.

During the 1947, within the USA, there has been tested at the open pit mines one of the first machine tools for the drilling of the blasting boreholes by the roller-cone drill bits. Within the USSR, the works on the roller-cone drilling have been started during the 1956. During the 60-ies, there have been created the mass-produced roller-cone machine tools for the drilling of the vertical and inclined boreholes with the diameter of 214-320 millimetres. The powerful machine tools for the roller-cone drilling have turned out to be the most effective and economical for the drilling of the strong rocks.

The deep blasting boreholes instead of the blastholes have been used for the breaking of the ores for the first time during the 30-ies within the USSR for the underground mine workings on the Kola peninsula and within the Krivoy Rog city. Since this time, there started to be created the machines for the underground drilling of the boreholes with the diameter of 60-150 millimetres, and with the depth of 10-40 metres. Since the middle of the 30-ies, there was developed the method for the rod drilling of the blasting boreholes by the powerful drilling hammers, which fact has allowed to introduce the mass breaking of the ore within the underground development of the ore deposits. During the end of the 30-ies, at the underground mines of the Krivoy Rog city, there has been successfully introduced the multi-machine drilling of the deep boreholes. During the 1938, there has been proposed by the Soviet engineer A. K. Sidorenko the drilling by the submersible drilling hammers, which were entering into the borehole, following the advancing bottomhole. During the 1949-50, at the Altai mountains, within the underground mine workings, there have been tested for the first time the machine tools with the submersible pneumatic strikers, the rotation of which is perfromed from the surface through the drilling column (S. P. Yushko). During the 1954, within the USSR, there has been created the machine tool with the submersible pneumatic striker, which is working using the air-water mixture (see the "Pneumatic-striking drilling" article), for the drilling of the boreholes with the diameter of 105 millimetres, with the depth of up to 40 metres. The introduction of the high-performance machine tools of this type has allowed to widely distribute the effective breaking of the ore by the deep boreholes, by which boreholes there are drilled within the USSR 50 - 60% of the total amounts of the drilling for the extraction of the ores by the underground method. Since the 1950, there are created for the underground extraction the self-propelled drilling machine tools, with the powerful pneumatic and hydraulic drilling hammers, with the long-stroke automatic advancers, for the drilling of the blasting boreholes, with the diameter of 50-70 millimetres, and with the depth of up to 30 metres. Since the 50-ies, there were conducted the works on the fire drilling of the boreholes within the strong quartz-containing rocks. The drilling of the blasting boreholes at the open pit mines within the USSR is performed mostly by the roller-cone method (approximately 70%, 1981), there is also used the auger drilling (approximately 20%). During the underground development of the coal deposits, there has the greatest distribution the drilling by the drilling hammers, and by the electrical drilling augers; of the ore deposits, by the drilling hammers, by the submersible pneumatic strikers, and by the roller-cone drill bits.