Extraction

Massive rigs reaching to the sky, giant platforms floating in the sea, and beds of sand being dug out by giant machines: these are images that define the practice of petroleum extraction in Canada. Once the exploration is completed, the drilling and extraction companies can move in. Many petroleum companies, like Imperial Oil, contract the actual extraction out. Precision Drilling (http://www.precisiondrilling.com) operates drilling rigs, service rigs and rig-assist snubbing units that complete drilling with controls which many major companies around the world use. Trained workers on the rigs use leading-edge tools and knowledge to extract the product. With the correct tools and information, the drillers know that they could have a “dry hole,” which refers to a well that yields no crude oil or natural gas. They also have to deal with issues such as environmental impacts, safety concerns, equipment problems, remote locations, and rough weather. That is why drilling a well can be called “the moment of truth.”

Onshore drilling begins with the removal of soil; this is called the overburden. Construction also begins with erecting the drilling rig, the mud motor and room, and any other buildings needed for the crew. Until the 1930s, cable tool drilling rigs were used to drill most of the wells in Canada. Today, the most common way of drilling is rotary drilling. The bit is attached to a rotating pipe. The pipe is turned either by a rotating table or a motor that moves up and down on top of the drill rig. Another form of drilling is with a downhole motor where the bit and the motor are attached to a long tube that does not rotate. Mud is added for circulation. Downhole motors are also used with the rotary drilling rigs to drill directional or horizontal holes.

Offshore drilling rigs use the same rigs as onshore drilling rigs. There are important alterations to the rigs, like the platform. The type of platform used depends on the depth that the operation needs to drill to. For example, if the rig is to drill over 2,000 metres, then a dynamically-positioned platform is used. Connected to any platform is a template, an open steel box with holes in it. The template is cemented in place to the sea floor. It contains automatic blowout preventers to seal the well if there are problems or the rig needs to be moved. Cables are used to attach the platform to the template and position the drill pipe in the template and wellbore.