Drilling advances

While the accountants are keenly aware of the budget-busting time wasted, dealing with lost circulation, stuck pipe and the like, what about the undetected inefficiencies that occur during routine operations and never leap out from the morning report? Pinpointing this unseen lost time, and taking corrective measures, could deliver considerable savings to shale drillers when projected across an entire rig fleet.

Therein lies the impetus behind an automatic, drilling performance measurement system, designed to determine the rig state at every point of the well. Dr. Eric Maidla, president and co-owner of TDE Petroleum Data Solutions, said that the independent, data-generated, quality control process isolates so-called invisible lost time by quantifying in real time, or at least near-real time, crew, rig and directional drilling performance. He said the resulting data  can be used to optimize efficiency and safety, thereby leading to tremendous savings in drilling time and costs.

Maidla dissected the methodology in his presentation, “How to continue to lower drilling costs in shale drilling after that steep learning curve,” during the quarterly technology forum of the IADC Drilling Engineering Committee (DEC), formerly the Drilling Engineering Association (DEA). Heavy on unconventional drilling advances, the one-day Houston confab also got the lowdown on the latest entrant to the pad drilling rig fleet; new-generation PDC bit technology; and how aluminum drill pipe is increasing both rig capabilities and motor-driven horizontal drilling rates.

In a nutshell, he said the process includes hundreds of key crew performance indicators (KPIs) that cover every aspect of normal, daily operations, including rotating, sliding, tripping and everything in-between. By way of illustration, he cited a KPI of slip-to-slip connection time for different crews on the same rig, performing the same job and under identical conditions. An analysis of the events arising during tower operation clearly shows the performance of each crew. “No crew should be doing anything different from the other,” he said. “Everybody should be doing it consistently, the same way, every time. If the crew on one tower performed more efficiently than the crew on the other tower, that’s an indication that perhaps one crew needs additional training.”

By acting on four KPI’s, for example, and extrapolating the results over a 25-rig fleet, a firm conceivably could save upwards of $13 million/year, he said. Maidla stressed that while normal morning reports efficiently document atypical events, they are unable to get a fix on the hidden issues in routine operations. “People are very good at describing problems, but not routine operations,” he said. “The morning report appears to present a lot of information, but actually there’s no information, whatsoever. It just shows that you drilled from this depth to that depth, and here are the parameters you used. It doesn’t explain the parameters you should be using.”

Rigs, bits, pipe. Meanwhile, just when you thought that the unconventional drilling rig fleet had reached its saturation point, along comes two-year old Independence Contract Drilling, Inc., of Houston and its new, aptly named Shale Driller walking rig. Ed Jacob, executive V.P. and COO of the new drilling contractor, described the 1,500-hp AC design as an “integrated, multi-directional walking system, designed to optimize pad drilling.”

Jacob told the DEC that nine Shale Driller rigs are now on location in the Permian basin, with another under construction and seven more newbuilds on the books for next year. “The rig has four walking shoes, with each operating independently of the others. This enables us to move the rig around to where we don’t necessarily need a wellbore in a straight line,” he said. “It can go forward, or sideways, and can literally walk around itself. The rig was designed specifically to manufacture wellbores in an efficient way, and one that is economical.” He said the Shale Driller also is equipped with a bi-fuel package that saves roughly $1,500/day in fuel costs, while reducing emissions.

Efficiency and economy, likewise, can be used to define today’s application and formation-specific PDC drill bits, says Dan Scott, senior technical advisor for Baker Hughes. He explained that advanced PDC cutter and bit designs, including dual-chamfer geometry and friction-reducing polishing, are setting new durability and drilling performance standards in complex shale wells. He pointed out a number of applications, where one new-generation PDC bit effectively replaced multiple earlier versions to drill high-angle curves and long-reach laterals in single runs. “Today, using one bit under surface, to TD, is a real possibility,” he said.

Going forward, Scott said the PDC bit could become integral to automated drilling systems by gathering real-time data on formation responses.

The shale-centric forum also heard from Jeff Lehner, technology general manager for Alcoa Oil and Gas, who used “lighter, faster and stronger” to spell out how advances in high strength-to-weight, aluminum alloy drill pipe are elevating efficiencies in horizontal drilling programs. He said field results on mud motors have shown composite drill strings, featuring aluminum drill pipe, delivering an average 25% reduction in torque, resulting in ROP that is 43% higher in the sliding mode and a surprising 8% faster while rotating. “Using aluminum drill pipe with steerable mud motors could be a viable option for rotary steerable systems,” he said.

Compared to steel, Lehner claims aluminum alloy drill pipe has demonstrated high strength-to-weight ratios, equivalent to 160-ksi yield-strength steels, but typically 30% to 50% lighter. Consequently, he said, field data show aluminum drill pipe increasing the depth capabilities of the smaller rigs used to drill many wells in the Marcellus and Utica shale plays.