Overview of Diamond Drill Tools

Diamond drill bits are widely used for exploration, drilling, and extraction in geology, hydropower engineering, metallurgy, coalfields, petroleum, and construction engineering. Compared with traditional steel and hard alloy drill bits, diamond drill bits have a series of advantages such as high drilling efficiency, good drilling quality, low drilling cost, light equipment, easy operation, and fewer accidents.

 

The earliest record of using diamond as a drilling tool for rock drilling dates back to 1751, when natural diamond was manually embedded into a drilling tool similar to a drill bit; Around 1860, the first diamond drilling rig was developed, greatly increasing the mechanization of drilling. Afterwards, diamond drill bit manufacturing and drilling technology were successively adopted and rapidly developed by some developed countries such as the United States; Around 1945, people began to study the use of powder metallurgy to manufacture diamond drill bits and achieved success. At the same time, high-speed drilling technology also emerged, and since then, diamond, especially fine-grained diamond, has been increasingly used in drilling. The emergence of synthetic diamonds in the 1950s further promoted the development of drill bits; According to incomplete statistics, 60-80% of the total drilling work in some developed countries at that time was completed by diamond drill bits. From 1960 to 1967, diamond drill bits accounted for 20-30% of rotary drilling footage in the United States. In 1975, the drilling volume of geological rock cores reached about 5.5 million meters; The total drilling depth of diamond drill bits used by the former Soviet Union in 1967 was about 1.2-1.5 million meters, about 2 million meters in 1969, and about 4.8 million meters in 1970.

 

In the early 1970s, diamond polycrystalline and composite disc (PDC) drill bits were developed. In 1973, the American Christensen Company collaborated with G.E Company to develop PDC drill bits, which were later widely used in petroleum, geological exploration, or drilling. The famous Geoset drill bit is a hard matrix drill bit made by powder metallurgy using triangular or polygonal diamond crystals, which are densely arranged on the drill edge in the form of corn kernels; The Stratapax drill bit embeds polycrystalline or composite pieces in the drill bit body in a watermelon peel stripe or spiral blade distribution pattern, and exerts a shearing effect on the rock with the cutting edge perpendicular to the processing direction. It is suitable for drilling soft and medium hard rocks, with a drilling efficiency of 40-60cm/min and a drill bit life of even over 4000 meters. The Syndrill series drill bits from De Beers are also similar to the Stratapax drill bits.

 

 

The research and application of diamond drill bits in China started relatively late (in the mid-1960s), but developed rapidly. In the 1970s, they were widely used in industries such as metallurgy, geology, coalfields, and petroleum. Especially in the petroleum sector, the research, introduction, and application of diamond drill bit manufacturing and drilling technology have been emphasized for a long time, and have achieved good results. For example, in 1972, Shengli Oilfield used domestically produced synthetic diamond polycrystalline three scraper drill bits (only suitable for softer formations), and one drill bit drilled the highest level of 2858.56 meters, realizing the wish of drilling one well with one drill bit. According to incomplete statistics, Shengli Oilfield shared about 3500 PDC drill bits during the 1980s and 1990s, with a cumulative drilling depth of about 7 million meters and an average drilling depth of about 2000 meters per bit.