Drilling is Established
Contributed by Mark Mau and Henry Edmundson
In spite of early progress in both Azerbaijan and the US, drilling needed to be more reliable, faster and less prone to the vagaries of deep sediments that could stymie the most experienced practitioner. In particular, cable-tool drilling was not working in the soft formations of the southern US.
Rotary Drilling Takes Over
A new approach was required, and it was provided by brothers M.C. and C.E. Baker of South Dakota. Their idea was to rotate the chisel or tool instead of using it as a percussion instrument. In the early 1880s, they developed the first rotary rig and used it to drill shallow water wells in the unconsolidated formations of the Great Plains. By 1895 the Baker brothers were using their rotary method for oilwell drilling, in the Corsicana field of Navarro County, Texas. An early convert to the Baker way of drilling was Captain Lucas at Spindletop. From the beginning, Lucas opted to drill with a steam-driven rotary rig and, in addition, adopted a double-pronged fishtail bit instead of the traditional single-pronged chiseling bit. The combination was a winner.
Spindletop helped promote rotary drilling as a viable alternative. In 1907, Shell began using rotary drilling on a modest scale in Romania, and in the US, rotary drilling gained a reputation for making hole fast in the Gulf of Mexico. Standard Oil of California was impressed by results in Texas and Louisiana, and in 1908, the company hired six drillers from the Gulf Coast and bought three complete rotary outfits to drill the hard formations of California.
Nevertheless, rotary drilling remained a niche activity compared with cable-tool drilling, and Standard Oil of California had to overcome some human as well as technical issues, as the local newspaper Bakersfield Californian noted on May 13, 1909: “The main difficulty with the companies which previously tried the revolving drill, and abandoned it, seems to have been with the drillers. There is a deep-seated jealousy and half-hatred which exists between rotary and standard [cable-tool] driller, much like the feeling between cattlemen and sheepmen, and the standard operators who were put on the rotaries generally neglected the work, while genuine rotary men were hard to find. The Standard [Oil Company of California] seems to like the rotaries, however, and more will probably be added soon.”
Another milestone in rotary drilling technology was the invention of the rotary table and kelly, first used in 1915. The origins of the powered turntable in the middle of the drill floor went back to Spindletop. The primary function of the rotary table was to transmit torque to the drillstring via the kelly, a section of pipe with a square cross-section that slotted through a similar shape on the rotating table.
At first, rotary tables were driven by chain from a sprocket on the hoist, or drawworks. But in 1918, Victor York and Walter G. Black of Standard Oil Company of California were granted a patent for driving the rotary table with a shaft. This innovation guaranteed the ongoing success of the rotary drilling method. By 1930, rotary rigs had replaced cable-tool rigs in most places, except for drilling very shallow wells.
Drilling Mud Makes its Appearance
Another challenge at Spindletop was keeping the hole open. Drilling the unconsolidated mix of sand and clay locally known as gumbo, the sides of the borehole would repeatedly collapse and fill the well with debris and cuttings. Two brothers, Curt and Al Hamill, both drillers at Spindletop in 1900, circulated the gumbo out of the hole with fresh water and shored up the well with wooden casing. But it was a losing battle.
One day, when Al was absent getting wood for shoring up the wells, Curt and workman Peck Byrd made a discovery. Both men noticed that while they were drilling through the gumbo, the fresh water used to clean the hole would become muddy, and this in itself helped stabilize the formation. They therefore decided to muddy up the fresh water before circulating it and see whether this would work even better. To try the idea, Curt Hamill recruited a local farmer, the Reverend John C. Chaney, who was already engaged to periodically clean out the slush pit containing the drilling water.
With the pit empty, Chaney plowed the clay at the bottom of the pit to a depth of about a foot, then filled the pit with water. After that, he drove some of his cattle into the water, walking them back and forth for a few hours until the liquid became thick with mud. The drilling crew then added some water to this viscous mixture. The result not only stabilized the well but also provided enough viscosity to circulate out the cuttings. Thus, with the help of a few cows, the Hamill brothers launched the era of drilling mud.
In Russia, a rotary rig equipped with a drilling mud circulating system—similar to the Spindletop setup— drilled its first well near Grozny in Chechnya in 1902. But rotary drilling was slow to take off in Russia, and indeed, any type of innovation more or less ceased thereafter because of numerous political upheavals such as World War I and the small matter of a revolution.
Derricks and Drawworks
A key breakthrough that cemented the popularity of rotary drilling was the introduction of the standard derrick in 1908 by Lee C. Moore. He had acquired a patent—originally granted to T.A. Neill, a field superintendent for the South Penn Oil Company—on a method of joining steel, tubular sections for constructing derricks. At the time, derricks were built using wood, each time from scratch. Moore’s easy-to-construct tubular sections could be reused, creating a huge efficiency gain. A second major development from Lee C. Moore was his 1937 jackknife cantilever-type drilling mast, which could be erected as a single piece.
However, the Achilles heel of the new rotary drilling rigs was the drawworks, the central winch system that lowered and lifted the drillstring. By 1930, the drawworks had evolved from single-speed (1910) to two-speed (1920) and then to four-speed. It had grown to a considerable size and typically consisted of 70 or more distinct parts that had to be carefully dismantled and rebuilt each time the rig was moved.
Hu Harris, head of the drill-tools division of the Texas-based Humble Oil and Refining Company, recalled the problems: “In those days it took three to five men two days or more to set up the drawworks and about the same time to tear it down. Another objectionable feature to erecting the drawworks on each well was that the parts, especially the brakes, were not always assembled properly. Drawworks brakes were the source of considerable complaint and if they were not installed correctly, there was always the danger of injuring the driller. Also, in dismantling the drawworks and moving to another location many of the small parts were lost or misplaced.” Harris decided to design a drawworks with fewer pieces. By assembling the shafts, chains and guards as a unit, he created a drawworks with just a few large parts saving days between rig moves. Harris’s idea was immediately copied by others, and by 1934 rig manufacturers were systematically building unitized drawworks.
From Fishtail to Tricone Bits
As rotary drilling took off, attention turned to the drill bit. The traditional fishtail bit that Lucas used was proving unreliable when drilling hard formations. The solution was found by one of the many engineer-entrepreneurs who journeyed south to ride the oil boom in southeast Texas. This young man in his 20s had let go a career in the lead and zinc mining industry in Joplin, Missouri, to try his luck in oil. His name was Howard Hughes Sr.
All things mechanical fascinated Hughes. In his youth he spent hours tinkering with watches, clocks and engines of every sort “to see what made them go,” remembered his brother Rupert. Hughes recognized the need for a completely new drill bit for the rotary rig. Visiting a machine shop in 1907, in Sour Lake, Texas, where some conventional drilling tools were being repaired, he noticed a grinder with two outer wheels moving in one direction and an inner wheel moving in the opposite direction. Hughes figured this type of contrary motion might work for drilling, and in subsequent experiments eventually came up with a two-cone rock cutting tool that, rather than scraping against the formation like a fishtail bit, actually crushed and ground the rock. Early experiments enabled Hughes to successfully file for a US patent. In 1909, Hughes, together with his longtime business associate Walter Sharp, formed the Sharp-Hughes Tool Company, renamed Hughes Tool Company in 1912, to market and develop the new bits.
Meanwhile, wells were being drilled deeper, and it became increasingly difficult to gain smooth passage up and down the hole. In 1917, Hughes and his engineers came up with the idea of adding a reamer, a large-diameter sub placed some way above the bit, with cutters to keep the hole in gauge. By the time Hughes died prematurely of a heart attack in January 1924, there were 73 patents to his name, all connected with rotary drilling. Hughes’s innovative rock bits had a near monopoly in the early days and made his only son, the eccentric business magnate and aviator Howard Hughes Jr., one of the wealthiest men on earth.
During the Depression in the early 1930s, Hughes Tool continued to stay ahead of the competition. In 1932, Hughes Tool commercialized staggered teeth and cantilevered bearing shafts to make the hole faster and cheaper. These minor improvements lead to Hughes Tool’s most famous innovation, the tricone bit. Bit producers had long been striving to find an alternative to the standard two-cone model. The two-cone bit had problems in gumbo or shale, which caused the cones to ball up or lock. Many bit manufacturers were experimenting with four cones, except Hughes Tool. Their new bit came with three cones mounted centrally with teeth that intermeshed and self-cleaned. Substantially outdrilling the two-cone bit, without balling up, the tricone bit soon won acceptance in West Texas, and in 1933 Hughes Tool was granted a US patent. The tricone bit set the standard for developing even faster drill bits through the 1930s and 1940s.
By this time, oilfield engineers had a forum for exchanging ideas and technical news. In 1871, the American Institute of Mining Engineers (AIME) was founded in Pennsylvania, and by 1913 a standing committee on oil and gas was created to provide a professional home for them. Later, this evolved in a semi-autonomous Petroleum Division that was renamed the Society of Petroleum Engineers (SPE) in 1957. From a handful of members, the society has mushroomed to several thousand members.
This entry is based on Groundbreakers: The story of oilfield technology and the people who made it happen, by Mark Mau and Henry Edmundson. You can find the book at Groundbreakers / Fast-print.net.