By Steven Berg, VP Operations, with CAODC
What once started as a heavy tool with a simple open-ended barrel weighted down and hurled into the ground to grab a small amount of dirt has turned into a science that people at the turn of the 20th century could not have envisioned. Their derricks were built of wood and left standing on locations until the weather destroyed them. Steam was needed from multiple boilers to turn the motors that would assist a rig crew in retrieving their open ended mandrel and help hurl it into a hole, hoping to make a few inches of headway into the hardened ground. Eventually they would hit a zone with oil, and through the ingenuity of their time, extract the oil to surface and pool it in above-ground lakes for collection and use as a fuel for engines, heat, or light.
The average sized hole for a cable rig would have been about 6 inches across and roughly 800 feet deep. The amount of earth removed in a well operation would be approximately half the size of a modern dump truck box, which seems insignificant in today’s world. The world needed less fuel when there were only 5 cars for every 1000 people. Compared to today’s numbers of nearly 600 cars per 1000 people, we need significantly higher volumes or oil and gas than what our pioneer forbearers could have foreseen.
With the demand for more oil came the advancement of drilling technologies.
The modern drilling rig fleets are designed using advanced engineering software to ensure fabrication has the lowest impact and cost. The highly mobile and versatile fleet can be deployed with one call, and in many cases can be set up and drilling in one day. The impact of the drilling rig site creates a temporary footprint on the land and over several years the area reverts back to its natural form. The rigs are built more compact and with higher horsepower to ensure fewer trucks are needed to move them, fewer cranes if any at all, and a total reduction of exposure for the public on our highway and secondary road systems.
Modern rigs drill with fluid pumping pressures above 5000 PSI and flow rates in excess of 4 cubic meters per minute (enough to fill an Olympic swimming pool in approximately 12 hours). They transmit torque downward to the custom designed drill bit and it rips the rock apart while the fluid blasts and lubricates all the while carrying the rock fragments to the surface.
Our modern drilling environment demands depths of thousands of meters with extended horizontal sections that permit producing zones to be tapped along their length, creating higher production and better extraction of the resource zone. This can equate to a hole with 3000 meters of vertical depth and 3000 meters of horizontal section which would generate 300,000+ lbs of drill cuttings (approximately 2200 cubic feet) and the fluid would circulate through the well from bottom to top once every 20 minutes.
The advancements in torque technologies (top drives), power distribution (AC drives), drilling fluids, drill bits (polycrystalline diamond compact or PDC), underbalanced and managed pressure technologies (UBD/MPD) and high pressure piping/pumping systems, have created an era where rate of penetration can be predicted and modelled and verified against real-time data. This allows the modern rig to hit targets safely and accurately with increased efficiency.
The next time you stand in front of a modern drilling rig remember the humble roots of the old cable rig and realize that pioneers paved the way to our current modern, efficient, low impact rig fleet, and through the combined knowledge of the industry we have changed our business to be more efficient than anywhere else in the world.