All About PDC Drill Bit

Directional drilling has been gaining significant popularity as a technique to get otherwise hard to access natural gas or oil embedded in shale. It does this by controlling the path of the wellbore by manipulating the angleofthetricone or PDC bit, as opposed to simply drilling straight down. Directional drilling will continue to see expanded use in North America, where many of the easiest to access deposits are no longer viable, and more difficult to access reserves are increasingly being turned to. Directional drilling is limited to oil or gas drilling, however, as the difficulties and costs associated with it make it unfeasible for any smaller scale project. This article aims to provide a general overview of the two main kinds of directional drilling and the adaptions made to tricone bits to better enable it.Checkout http://ulterra.com/ for more info.

The Directional Drilling Process-By definition, directional drilling involves any attempt to intentionally divert the path of the wellbore. This is almost always done to access otherwise difficult to reach deposits, such as under a lake or mountain. Usingatricone or PDC bit the wellbore first goes straight down to a predefined depth. This functions as the so-called "kick off point" from which the path of the wellbore will divert. At this point the bit will usually be changed to a specially engineered tricone that can run on an independent motor. The idea behind this is to have a bit that can rotate to drill under its own power, without any rotation required from the drill string. Thus, when the drill is pointed at the desired angle the force needed to progress through the rock formation comes from the rotation of the tricone or PDC bit and the Weight On Bit provided by the drill string. In addition to the special motorized tricone, directional drilling also requires special equipment to measure the progress while drilling. A professional directional driller is essential, and they will require exact knowledge about the progress of the drill bit when determining course.

Rotary Steerable System Drilling and Advances in Tricone and PDC Bits. A Rotary Steerable System (RSS) is the newest development in directional drilling. It allows for further steering of the bit whilethedrillsting is still rotating and providing force. This negates the need for a motor powering the drill bit itself, and reduces the potential areas of failure or mishap. Traditionally tricone bits have been the go to choice for directional drilling because they are more easily steerable, although this capacity has recently expanded to PDC bits as well. Rotary Steerable Systems use detailed data on the position of the bit, collected while drilling, to send commands to the bit from the surface. Generally they will either send carefully controlled variations in the mud column, or variations in the drill string rotation, to send a message to the tool powering the tricone or PDC bit. This process, while more complicated than conventional directional drilling, offers significant advantages. Additionally, as the steering can be carefully controlled from the surface it allows for more controlled wellbores with smoother surfaces and greater complexity.