Pioneering work, economic factors provide insights into Russian drilling technology

RUSSIAN DRILLING TECHNOLOGIES-1

Dean E. Gaddy
Drilling Editor

• Table 1 - Drilling systems [8,129 bytes]
• Table 2 - Total footage drilled [7,518 bytes]

In Russia and America, individual ingenuity and economic forces have produced a variety of drilling technologies, resulting in the development of disparate drilling systems.

Endeavors by the U.S. Department of Energy, the Gas Research Institute, Sandia Laboratories, and private industry have promoted exchanges of knowledge since the 1980s, and now that the barriers to technology transfer are being lifted, engineers from both countries have the opportunity to exchange knowledge and incorporate the best of both.

The Russian drilling industry, like the Russian space program, has achieved tremendous success in implementing product and process innovations including the first directional (1940s), horizontal (1950s), and multilateral (1950s) wells. In addition, Russian engineers built the first turbodrills, electrodrills, novel drills (lasers, explosives), aluminum drill pipe, downhole electric submersible pumps, and mud hammers.

Industry leaders including Nicolay Baibakov, Mikhail Gusman, Rolen Ioannesyan, Peter Shumilov, Eiub Tagiev, Yakov Gelfgat, and Anatoly Ostrovski not only developed the Russian downhole-motor drilling system but also provided Russia with a technological capability that set world oil-production records.

According to William Maurer, president of Maurer Engineering Inc., long-time advocate of Russian technologies and early promoter of western horizontal drilling technologies, "The Russians are excellent theoreticians and clever inventors. If we could only combine the American ability to implement along with Russian ingenuity, the drilling industry would most certainly benefit."

This first part of a two-part series describes the achievements of Russian engineers in horizontal and multilateral drilling technologies followed by a discussion of the economic differences that led Russian and American drillers to develop dissimilar drilling systems. The second part describes a variety of innovative Russian technologies and provides details on the technical advantages they offer for the drilling process.

A pioneer

In 1941, one of the world's first directional wells-Baku No. 1385-was drilled by Russian drilling engineer Alexander Mikhailovich Grigoryan.¹ This achievement occurred almost 20 years ahead of [intentional] attempts and was the first use of a turbodrill for both the vertical and directional portions of the borehole.

Russian advances in horizontal technology, led by Grigoryan and other Soviet workers, continued into the 1950s without any foreign competition. Jacques Bosio, former deputy research director with Elf Aquitaine, reported that during the 1950s, the Soviets drilled 43 horizontal wells (OGJ, Mar. 21, 1988, p. 71), "a considerable effort with respect to equipment, measurement, and theoretical studies."

Yet Grigoryan's pioneering work into horizontal drilling technology was not his only achievement. In 1953, he drilled the first multilateral well (No. 66-45) in Bashkiria, U.S.S.R., with nine "branches" emanating from parent and subparent well bores (Fig. 1 [98,541 bytes] and Fig. 2 [111,652 bytes]). Grigoryan's work was presented to the Fourth Annual Petroleum Congress in Rome in 1954.

In an interview with OGJ, Grigoryan, who is now in his 80s, said these laterals were sidetracked from an open borehole "without the use of cement bridges or whipstocks." Grigoryan said oil production increased from 44 b/d (offset well production) to 755 b/d for the No. 66-45, proving the economic potential for the technology.

During the 1950s, a typical multilateral well consisted of four to five short branches, up to 500 ft in length. "Drilling a lateral section normally did not require tripping out of the hole to change assemblies, and the entire process for kicking off took only 30-60 min in medium-hard formations," Grigoryan said, "and the design of the window configuration enabled unmistakable insertions of the tools into the laterals without any instruments."

Grigoryan believed that multilateral drilling would increase production and that its cost would decline as technology advanced. In Borislavneft (West Ukraine), an old field that began production in 1914, Grigoryan drilled a multilateral well in 1957 to further advance his theory. The well began producing at 175 b/d; offset wells, located 100-130 ft away, produced only 1-3 b/d. Grigoryan said average well costs were three to five times greater than conventional vertical wells.

Grigoryan also discovered other benefits. During a 1960 multilateral project in Chernomorneft (Black Sea), Grigoryan found that viscous oil production from "branched" wells resulted in "almost pure oil even after years of production;" while offset production "watered out rather quickly." Production rates, as compared to offset wells, increased 7.3-12.5 times, while costs increased 2.0-3.1 times.

In 1969, Grigoryan drilled the deepest horizontal well of his career, located in Markovo, East Siberia. It reached a measured depth of 12,500 ft, including a horizontal interval of 2,070 ft. By the 1970s, Grigoryan had drilled more than 30 multilateral wells in Russia, Tajikistan, and Ukraine.

Published accounts show that European and North American attempts at directional and horizontal drilling, by Elf Aquitaine, Imperial Oil Ltd., Texaco Canada, and ARCO, did not begin until the end of the 1970s and early 1980s.

Elf, respected by western oil companies for its pioneering efforts in directional technologies, did not drill its first horizontal well until 1978, targeting viscous oils in the fractured limestone of the Rospo Mare field (OGJ, Feb. 29, 1988, p. 29).

Grigoryan said Russian technology transfer aided the French in their work. He worked with the Institute Francaise du Petrole in the late 1970s, providing details on the technologies he had developed in the FSU.

During the 1980s, Grigoryan was prohibited from advancing his work. "Periodically, and especially in the last years, the powers of the former U.S.S.R. forbade the drilling of such wells." In 1988, Grigoryan emigrated to the U.S., eventually earning citizenship.

Grigoryan's vision of "forthcoming developments in the oil industry, following a path towards the common use of multilateral drilling technology," would not occur until the 1990s. He believes that western companies are developing the wrong technologies and are "...headed down the wrong path. Why are [western] companies still applying whipstock technology, resulting in costly remedial work and wasted effort, when there is a better way?"

Technology pathways

The development of two distinct drilling systems-the Russian downhole motor and American rotary-shows how economic systems can produce different results.

Prior to the dissolution of the Soviet Union, Russian drillers, under pressure to fulfill state quotas, strove to drill as much hole as possible. All nonprivate economic activity was subject to predefined production goals² and profit had no influence over drilling activity.

In the Soviet era, oil provided Russia with its single largest source of hard currency and allowed it to trade with western countries for commodities like wheat. Thus, the maximization of oil production, proportional to aggregate footage, became essential to planning, and Russian drillers designed their systems to meet government objectives.

The state subsidized drilling technologies to maximize cumulative footage, irrespective of capital investment levels, and top-down directives pushed Russian drillers to develop the fastest drilling system possible.

The Soviet strategy produced extraordinary results. In 1988, the FSU drilled 49.1 million m of hole and produced a record 12.48 million b/d of crude oil.^{3 4} It was only after the downfall of communism that FSU production fell behind U.S. and Saudi Arabian production.

American drillers, on the other hand, adhered to another set of economic rules. In the U.S., profits control activity. Thus, American drilling systems were designed to minimize well-construction costs and to drill each foot as cheaply as possible.

Each component of the drilling system formed an integral role in lowering costs. Although one component of the system may be extremely efficient in a particular activity, analogous to the extraordinary penetration rates achieved by the Russian turbodrill, supporting activities (trip time, maintenance) may reduce the system's overall efficiency.

It is the sum of the activities that define cost per foot, and cost-driven activities steered American drillers to develop their own drilling systems. According to Maurer, "these economic differences stimulated the use of downhole motors in Russia" and the rotary system in the U.S.

The U.S.S.R. was the only country to use all three downhole motor systems-turbodrills, electrodrills, positive displacement motors-on a commercial scale (OGJ, Feb. 9, 1998, p. 50). Turbodrills drilled the majority of total footage in the FSU with 83.2% in 1990 and 74.0% in 1985. Rotary drilling, also used on a commercial scale, encompassed 9.3% of total footage in 1990 and 19.6% in 1985.

Comparing capabilities

The Russian turbodrill system has been shown to outperform the American rotary system under certain conditions. According to Mikhail Gelfgat, president of Aquatic Co., a manufacturer and service provider of aluminum drill pipe and downhole motors in Moscow, "When Americans first came to West Siberia [with their rotary drilling systems], they found they could not compete against us in depths up to 1,000 m. Using our high rpm turbodrill and conventional Russian drill bits, they found that our technology was superior."

When drilling shallow formations, the Russians found that trip time becomes less critical in improving cycle time because round-trip time was short. Thus, Russian drillers made as much hole as possible at the top section of the hole (to 2,000 m), disregarding bit life until excessive trip time overtook the time advantages gained through fast penetration rates. At this point, Russian diamond bits, capable of withstanding higher rotational speeds, or retractable drill bits, capable of eliminated drillstring trips, replaced conventional rock bits.

Nevertheless, at greater depths, American rotary drilling technology becomes more efficient than the Russian turbodrilling systems. Drill-bit life became a prime consideration because trip time cuts into drilling costs. "With conventional bits, when you want to drill fast, you must rotate fast," Gelfgat said. Fast rotation shortens bit lift, and with drill-bit technology lagging turbodrilling applications, it does not become cost-effective to drill 400 ft/hr, then have to round trip every few hours.

Russian and American drillers experimented with mixed technologies in West Siberia. "Only in the bottom section, from 2,000-3,000 m, did we find an optimum mix of turbodrills, fluid velocity, and western drill bits that outperformed [former Russian benchmarks]," Gelfgat said.

The problem with turbodrilling technology is that conventional tri-cone rock, button, and PDC bits are not designed to withstand the thermal stress and high impacts that accompany high rotational speeds. "Drill-bit technology has not kept up with turbodrill or other downhole technology [electrodrill]," Gelfgat said, "and that's why western engineers are taking a fresh look at Russian technologies." Over the past 3 years, Russian and American engineers have worked together to improve the performance of PDC bits in combination with turbodrilling and other technologies.

It may be time for western drillers to take a fresh look at Russian technologies; their achievements speak for themselves.

References

1. Novosti Neftyanoy Techniki Bulletin, 1946.
2. Ericson, R.E., "The Classical Soviet-type economy: Nature of the system and implications for reform," J. of Economic Perspectives, Vol. 4, No. 4, p. 11, Fall 1991.
3. International Energy Statistics Sourcebook, PennWell Publishing Co., 7th Ed., September 1997.
4. Neft i Kapital, September 1997, p. 77.

Copyright 1998 Oil & Gas Journal. All Rights Reserved.