The Basics of Oil Well Drilling: From testing for oil to tricone drill bits

 

The world consumes more than 90 million barrels of oil every day , says the CIA World Factbook, and odds are no matter where you live, you’re dependent on systems that burn oil for energy, heating, transportation, or some other mundane facet of daily life. Everyone knows oil is drilled out of the ground—some even know about extraction details like tricone bits—but how does the whole drilling process actually work? This article aims to outline the basic steps that go into drilling for oil, everything from preparing a site to choosing materials for tricone drill bits.

Selecting A Well Site: Luck be a lady… and science be a lady too!

Before you can start polishing the tricone bits and getting ready to drill, you need to locate a site and prepare it for drilling. Geologists are in charge of finding a site, using tools like a Thumper Truck, a large truck that slams the ground with heavy weights, causing shock waves that can be measured. And of course a geologist’s best friend, explosives. Detonated after using a tricone bit to drill a set distance into the ground, the shock waves are again measured.

Preparation: All about selecting the right tricone drill bit for the job

After any legal issues surrounding rights to drill on the land are sorted out, the area is prepared for drilling by clearing away and leveling the surrounding land. Water is essential to the drilling process, so depending on the terrain, a tricone or fixed cutter bit is used to drill a water well. After that, the crew must dig several holes for the rig, including a large “cellar” where they can work around the actual drilling location. This space can be used for fitting drill bits, working with the drill string, or any gauge protection needed for the drill bits. The exact type of bit depends on the rock formations at the site. Soft rock formations call for mill-tooth tricone bits. Medium rock formations can be drilled with a mill-toothed tricone bit as well, but on many occasions it’s better to go with a TCI tricone bit (Tugsten Carbide Insert). Lastly hard rock formations certainly call for a TCI tricone drill bit. Tricone bits can be used with either sealed or open bearings depending on the intended depth.

Drill baby drill!

Once the site has been found and prepared and all the equipment is ready to go it’s time to start drilling. The tricone drill bit, the collar and the pipe are placed in the hole, and drilling begins. When the tricone bit hits a preset depth, it is taken out and a hole casing is cemented into place to protect the structural integrity of the hole. Once the cement has hardened, the tricone bit is inserted to the prior depth once again, and drilling resumes. This process of removing the tricone bit, extending the casing may need to be repeated several times. Once the desired depth is reached the tricone bit’s job is done and it’s time to test for oil in the well. Usually a small carefully controlled explosive is lowered and the well casing is intentionally breached at the target depth to allow oil to fill the well. A small tube is lowered down to test if oil had been found—if oil is found the crew will set up extraction, if not the tricone bit comes out again and drilling resumes. Tricone bits can drill at extraordinary speeds compared to conventional drill bits so it’s always critical to ensure safety when drilling with tricone bits. From the tip of the tricone to the top of the well everything is inspected for safety. And that’s how oil is extracted to be used in everything from cars to plastics to residential heating! Learn anything that surprised you? We sure did.

Click for a list of Tricone Bits.