By Joanne Liou, associate editor
Horizontal drilling has been around for more than 25 years, yet the extent and intensity to which horizontal wells with extended lateral sections are being drilled today bring new challenges to industry. While these are not the most technical wells ever drilled, “we’re seeing all kinds of variability in the way people drill these wells and the way they handle well control,” said Jeff Flaherty, Senior VP of US Land Operations for Helmerich & Payne (H&P). “We take it 90°, and gravity is not your friend; it’s your foe. It’s a different ball game throughout the shales,” particularly in relation to well control. Mr Flaherty spoke at a plenary session focusing on unconventional resources on 5 March at the 2014 IADC/SPE Drilling Conference in Fort Worth, Texas.
The industry is now perforating production zones that can run 10,000-ft or longer, which means that drilling contractor engineers must be engaged in horizontal well control. “There are hydrocarbons, and they will go to the path of least resistance. Companymen may not understand a lot of it, and we see people trying to kill wells in the lateral section,” Mr Flaherty said. “Make sure when you pull up into the vertical portion that this well is dead. Kill it and circulate bottoms-up once, twice to make sure you have the gas out of the wellbore.”
The intensity of unconventional operations is also placing more pressure on drilling contractors’ equipment and personnel. Batch drilling, for example, is working equipment, such as drillstrings and mud pumps, to their limits, while equipment maintenance has to be redefined to keep pace. “We can’t do it the way we used to,” he said. Unconventional operations also are taking a toll on people, especially in remote areas where crews may work 14-day shifts, 12 hrs/day. “When you batch-drill, it’s happening in a rapid-fire occasion. You’re doing nothing but drilling and running casing. Fatigue sets in,” he noted.
The industry is still in the early stages of understanding the long-term costs of unconventional operations, particularly from the perspective of drilling contractors. As their equipment is run longer and people are working harder, the costs for contractors to operate are only going up. “Ultimately, as service providers, our costs go up. We calculate daily costs, but it’s a long-term capital cost,” Mr Flaherty said.