Sichuan well salt has a long history. According to literature records and expert research, the world-renowned Zhuotong Well in Daying County was founded during the Qingli period of the Northern Song Dynasty, more than 800 years earlier than in the West. Works such as "History of Chinese Drilling Technology", "History of Chinese Science and Technology", and "History of Chinese Well Salt Technology" all call him "the father of world oil drilling" and "the pioneer of mechanical drilling". Compared with Daying County, Zigong's well salt mining is even larger and more famous. During the most prosperous period of the well salt industry in history, there were 1,711 Zhuotong Wells, with an annual salt production of more than 4,000 tons. Now there are still 41 such ancient salt wells in Daying County, distributed within a radius of 6 kilometers. It follows the process of drawing well salt in the Song Dynasty, including drilling, extracting brine, drying brine (filtering brine), and frying salt. The invention of well salt technology led to the emergence of rope-type drilling technology, which enabled the exploitation of natural brine deep underground. Zigong, known as China's Salt Capital, is the birthplace of percussive drilling technology. This technology has gone through the development stages of large shallow wells from the Eastern Han Dynasty to the early Song Dynasty, the transformation period of Zhuotong wells in the Song Dynasty, and the maturity period of small deep wells from the Ming Dynasty to the Qing Dynasty. It has a history of more than 1,900 years. In 1835, the completion of the world's first sea well over a thousand meters deep (1001.42 meters) was an important symbol of the maturity of China's percussive drilling technology, which has promoted the development of drilling technology in the world. Percussive drilling technology includes well drilling, well logging, deflection correction, cavity filling, salvage, and repair of wooden pillars. Its wide application in well salt production has earned Zigong the reputation of "the richest in Sichuan" as early as the Qing Dynasty. In the 28th year of the Republic of China, Zigong was "established as a city because of salt". Today, it has developed into a historical and cultural city with a population of 3.2 million. The salt extraction technique in Zigong City and Daying County has been passed down for nearly a thousand years, and its process is still well preserved, becoming a living fossil of deep well drilling in the world. Practical measures should be taken to protect it. (No pictures yet, welcome to provide.) (No pictures yet, welcome to provide.)