There are many articles talking about the future of oil and gas well drilling. However, as the Chinese philosopher Lao Tzu said 2600 years ago: “A journey of a thousand miles begins with a single step.” Knowledge of the past is a key to understanding the present. So, we would like to use this blog to explore some activities of the earlier pioneers in drilling.
Around 2000 years ago, Chinese in Sichuan province originated deep drilling. The primary motive for deep drilling in China was the search for salt. Even as recently as 1965, 16.5% of China’s salt supplies came from brine pumped out of deep boreholes, making this source of supply second only to sea salt.
The ancient percussive cable drilling system was called “churn”. The derrick had height of ~ 33 ft and all parts of the rig were made from wood (mainly bamboo). A large wooden drum had 16 ft in diameter and was used to perform round trips. Rocking movement of the balancing beam created the percussive impulses on the bit, which sometimes weighted as much as 300 lbs. By alternately lifting this tool and letting it fall, the Chinese achieved a well depth of 2000 ft. Wonder the rate of penetration (ROP)? 2 feet per day! The Orientals were willing to work as long as 3 years to complete a well. This testified the saying: Man who wants pretty nurse must be patient. BTW, Confucius did not say it.
The deep drilling for brine yielded natural gas (primarily methane) from time to time. The boreholes producing methane were known to the Chinese as “fire wells”. So the drilling for natural gas followed and was developed at the same time.
The bamboo tubes were used as pipelines, carrying both brine and natural gas for many miles, sometimes passing under roads and sometimes going overhead on trestles. Among other uses, natural gas was used to heat evaporation pans of brine to make salt: perfect example of killing 2 birds with 1 stone.