March 15, 2020

Directional drilling has come a long way since its origins. First directional drilling techniques were set up very early with the development of modern drilling before the end of the 1800’s. As the drillers were able to drill deeper wells, downhole accidents such as loosing part of the drill string, became costly operations. It appeared more economical to deviate the well from its natural vertical trajectory rather than to move the drilling rig and start a new project from scratch. Uncontrolled directional drilling started with the basic sidetrack technique using the first directional downhole tool – the whipstock. Whipstocks trimmed from hardwood round timbers were used in the early days. More sophisticated types, permanent and retrievable, came to the oilfield followed by the knuckle joint.
The acid bottle technique, developed in the late 1800s in South African diamond mines to survey boreholes, became in the 1920s, the first method to be utilized solely for measuring inclination. A glass bottle filled with acid was lowered into the borehole where the acid would settle at an angle in the bottle lying parallel to the angle of inclination. After some time, the acid etched the glass, which allowed calculation of the wellbore’s inclination at a given depth. In the 1920s, Totco developed the mechanical drift recorder, which could only measure borehole inclination but was more accurate than the acid bottle and other early techniques.
In 1926, Sun Oil enlisted Sperry Corporation to use gyroscopic-based technology to make survey instruments for accurately measuring borehole inclination and direction.
In 1929 H. John Eastman introduced the first magnetic single-shot and multi-shot instruments, which measured both inclination and direction. He was awarded a patent the following year.
Records from two wells drilled in Huntington Beach, California, in 1930 are the first records from directionally controlled boreholes drilled from an onshore location to oil/gas deposits under the ocean.
But the need for controlled directional drilling technology came to light in Conroe, about 40 miles north of Houston, in 1933.
A blowout occurred in a field owned by Humble Oil Company of Conroe. A gas kick from a high-pressure zone ignited, and the entire rig was engulfed in flames. After many months and attempts to bring the fire under control, other nearby rigs had to be closed down and the entire field was threatened. Although the fire was eventually put out, oil continued to flow into the lake. The only way to manage this was to drill another well to relieve the pressure.
On November 12, 1933, Eastman and company arrived on location of Humble Oil & Refining’s relief well, approximately 400 ft from the crater lake. They set the first whipstock at 1400 ft. The well successfully deviated from vertical and reached the target formation on January 7, 1934. Humble brought in steam-powered pumps to flood the reservoir with brine, killing the well at the first attempt. Finally, nearly a year after the initial blowout of Madeley No.1, the Conroe Oilfield had been brought back under control.
The Eastman Oil Well Surveying Co’s reputation exploded after they successfully killed the well. In the coming decades, Eastman would be immortalized as the father of directional drilling.
In 1930, a French inventor named René Moineau discovered the principle of the progressive cavity pump which led to the development of downhole positive displacement motors (PDMs). PDMs would eventually become the most effective and commonly used deviation tools in the industry. However, whipstocks would remain the primary steering mechanism for directional drilling until the mid-1950s. The first modern downhole drilling mud motors were designed and manufactured by Dyna-Drill in 1958.
(Source: IADC/K. Grieser/AOGHS/History of Oil Well Drilling/JE Brantly – Image: Conroe lake and E. John Eastman)