Drill bits, the sharp end of the spear in oilfield operations, relentlessly raise the performance bar.

Someone once said that competition inspires innovation. Or something like that. Anyway, you get the idea. If innovation can be measured by record-setting performance - and it certainly seems like a reasonable metric - then drill bit technology is getting innovated at a feverish pace.
For proof, look no further than E&P's Drill Bit Records. The 2005 records will be appearing soon in these pages and on our Web site. The sheer volume of records is one thing, because records can be obtained by every size of every type of bit, times three categories: single-run footage, cumulative footage and rate of penetration (ROP).
But the volume of records is not the whole story. The amount of new records claimed every year is impressive, as is the keen competition to claim them. The numbers in these records don't describe the technology applied in pursuit of their achievement, but that technology is reviewed elsewhere in this issue. For now, let's "mine the data" and see what we find. These nuggets might even win you some bar bets at Crappitos in Houston, the next time you're in the neighborhood.
What is the smallest increment by which a new record has eclipsed an old one? One-tenth of a foot. You're probably thinking, thermal expansion and tensile forces could account for that and more. You would be right, but these factors are constants in most operations. We require supporting data with all record submissions, and these data are resolved to tenths of a foot. They are the numbers we go by.
What are the absolute records in all three of our categories? Note, by the way, that absolute records are not "official" categories. Some formations are easier to drill than others. Official, individual records in each category are a function of bit size and type. Still, it's fun to look at the absolutes, because these numbers are eye-poppers:
The absolute ROP record is 1,901.7 ft/hr (580 m/hr), set by an 81?2-in. pollycrystalline diamond compact (PDC) bit in Malaysia in 2000.
The absolute cumulative footage record, set in Alberta, Canada, in 2003, is 358,307 ft (109,283.6 m), by a 61?4-in. PDC bit, in 166 runs. Average ROP was 165.4 ft (50.4 m). That bit belongs in a museum.
Here's a record that must have made the operator smile. The absolute single-run footage record, set by an 81?2-in. PDC bit in Qatar in 2004, is 24,956 ft (7,611.5 m). ROP during this run was 92.5 ft (28.2 m).
These records may seem like an advertisement for PDC bits. In fact, the top 21 cumulative-footage record holders are PDC bits (from four different companies). It's a different story with absolute ROP. The top 21 record holders here are a mix of almost every bit type: PDC, milled tooth, insert, bicenter and hammer. This is also the case for the top 21 single-run footage record holders. It's interesting to note that the second-place bit in the single-run footage category is an 81?2-in. milled-tooth bit that came up just 631 ft (192.5 m) short of the absolute record.
Of course, not all formations are as accommodating. Sometimes, it's a struggle. So, what are the smallest records held in each category? Keep in mind that, while modest, these records are still hotly contested by the bit manufacturers. It's an indication of what the industry is up against. If you have ever wondered what it's like to drill the world's toughest formations, here's your answer:
The smallest ROP record is 1.7 ft/hr (.5 m/hr), established by a 51?4-in. diamond-impregnated bit in a Kazakhstan field in 2001. Total footage was 292, which must have seemed like an eternity to drill.
The shortest cumulative-run record is held by a 75?8-in. diamond-impregnated bit, which managed 83 ft (25.3 m) in two runs in Glasscock County, Texas, in 1996. This formation possibly had a Rockwell number greater than the face of your titanium driver.
The shortest single-run record is 90 ft (27.4 m), set by a 31?4-in. PDC bit in the United Kingdom in 1998. ROP was 18.8 ft/hr (5.7 m/hr).
What's the oldest record? The oldest E&P bit record of them all was set in 1960, and it's for single-run footage. The record is held by a 133?4-in. milled-tooth bit that drilled 4,676 ft (1,426.2 m) in Lake Maracaibo, Venezuela.
The oldest cumulative-footage record is 7,889 ft (2,406.1 m), set by an 83?4-in. diamond-impregnated bit in Wyoming in 1981.
For ROP, the oldest record is 1969, set by a 14-in. milled tooth bit that drilled 210.5 ft/hr (64.2 m/hr) in the Gulf of Mexico.
As of this writing, there are a total of 1,061 bit records in the three categories. So, who does all this record setting? The records are distributed across the product lines of all the major bit companies. They were set in formations in every major producing area of the world.
Of course, many factors contribute to setting records. But fundamental are the knowledge, skills and resourcefulness of the people who design and build these remarkable tools and the associated systems for conveying them to exactly the right place, miles below the oceans and earth.

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