Drilling advances

With more rigs forced to take sabbaticals, and media attention fixated on cost-cutting (read: shedding as many jobs as possible), drilling efficiency of late seems to receive all the play of the kid riding the bench during a game that has become terribly lopsided. Sure, the kid has made tremendous contributions, but that was in yesterday’s game.

To even the score a bit, organizers of June’s IADC Drilling Engineering Committee (DEC) Technology Forum, in Houston, put drilling efficiency front-and-center with eclectic, and largely peer-reviewed, presentations focusing on established and emerging technologies. They were all aimed at illustrating, as a Weatherford engineer pointed out, how “even marginal increases in drilling efficiency can lead to significant savings in field development cost.”

Specifically, he went on to explain how established managed pressure drilling (MPD) techniques, once generally reserved for “drilling the undrillable,” can be equally effective in increasing rates of penetration (ROP) and reducing downtime in the assembly-line approach that characterizes shale drilling. “By having better control over the wellbore, operators can use MPD to optimize ROP,” said Bhavin Patel, a Weatherford International MPD engineer.

Patel said that compared to a conventional drilling methodology, MPD offers a number of advantages in high-rate, unconventional well construction programs. For one thing, closed-loop MPD techniques deliver appreciably better control over equivalent circulating densities (ECD) and, therefore, help corral downhole issues that can lead to non-productive time (NPT). Moreover, he said that by employing MPD, operators can reduce mechanical specific energy (MSE) with more constant drilling parameters, such as mud weight, torque and weight-on-bit (WOB).

“MPD allows for enhanced mud weight management during drilling,” he said. “By keeping a constant mud weight, even in deeper depths, we can drill at higher ROP, and with smaller and less-expensive rigs.”

Patel said MPD techniques are being used on 42 wells, and counting, in Argentina’s Vaca Murta shale, which followed an earlier application in the Haynesville where, he says, overall drilling time on four wells was cut 49%, saving the operator more than $2 million.

Meanwhile, Halliburton’s Akshay Sagar laid out how the company’s integrated Drilling Engineering Solution (DES) helped set new benchmarks in the drilling of a deepwater exploration well offshore Mexico. 

Sagar, the DES business manager, said the complex objectives of the Mexican deepwater wildcat were to deliver a directional well plan through faulted formations comprising unconsolidated sand and shale layers. In addition, the 12 1/4-in. hole was to be enlarged to 20 in. and 16½ in. And, all this had to be accomplished with zero NPT and 100% real-time data acquisition for pore pressure and wellbore stability calculations.

 Sagar said the integrated DES methodology set an area benchmark for building angle and another by delivering a comparative, 65% ROP improvement. 

Deepwater well delivery also was the topic du jour for Ed Adams, senior business development manager for Huisman U.S., who explained the intricacies of the Dutch company’s newest-generation, dual multi-purpose drilling tower, which promises to enhance efficiencies some 30% to cut ultra-deepwater drilling costs. He was followed by Robert Estes, Baker Hughes R&D manager for sensor physics, who presented the results of recent above-ground and vertical well tests of the recently engineered AccuTrak passive magnetic ranging (PMR) service. The PMR, he said, can be applied broadly with measurement-while-drilling tools to improve accuracy, speed and safety, in a variety of applications, especially those with high risks of wellbore collision.

“Cuttings engineering.” Civil engineering principals usually are not part of the mix when discussing technologies for treating and managing drill cuttings. Yet, Blake Scott of Scott Environmental Services, in Longview, Texas, told the DEC that combining cuttings solidification and stabilization technologies with construction disciplines not only helps operators reduce the solid waste stream generated at the wellsite, but it also cuts costs by putting treated cuttings to work as lease roads and drilling pads.

“We not only sequester the (mud) contaminants, but also meet design criteria, so loads are supported, and there are no construction issues to deal with,” he said. “These are competing parameters that we try to make fit, whereas before, solidification was something that was used just to sequester contaminants.”

The engineered cuttings recycling process begins with a sample of a well’s solid waste to determine its geotechnical properties, and the entrained salts, metals and hydrocarbons, to determine the percentage and type of reagents required to meet widely diverse state regulations. 

Though fewer new holes are being constructed these days, Scott said that with multi-well pads, the need for construction integrity does not end when the rig is laid down. “When you start drilling multiple wells off a pad, naturally your traffic increases, and that continues during completion and production. If you build a pad and road correctly, you don’t have to go back and re-work it for completions and production.”   

REFERENCES

1. Grayson, B., B. Patel and H. Gans, “Optimized unconventional shale development with MPD techniques,” presented at the IADC/SPE Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition, San Antonio, Texas, 2013.
2. Wijning, D., “Dual multi-purpose tower engineered to cut ultra-deepwater well delivery costs,” World Oil, April 2015.
3. Hanak, F. C., and R. Estes, “High-speed, continuous single-well magnetic ranging,” SPE paper 173135, presented at SPE/IADC Drilling Conference and Exhibition, London, England, March 17-19, 2015.

About the Authors

Jim Redden

Contributing Editor

Jim Redden is a Houston-based consultant and a journalism graduate of Marshall University, has more than 40 years of experience as a writer, editor and corporate communicator, primarily on the upstream oil and gas industry.