Energy issues

I pen this at the end of a fairly busy week that included three days in attendance at the Society of Petroleum Engineer’s Annual Technical Conference and Exhibition in Dallas. As usual, the conference and exhibition were very well done, and the chance to catch up with old friends, and make new ones, was exhilarating. But this year’s event also took me down memory lane.

West Texas sand. The event featured a substantial focus on fracturing, which included several frac sand providers. I stopped at one provider’s booth, which included a display of small bottles of sand. It was my thought that the bottles of sand were probably to hand out to the passing audience, much like the pens, koozies and tally books that lie in piles on the front tables of most booths. I asked if the sand was from the sand hills of West Texas. I was told it was. I asked if I might take a bottle. There was some hesitancy. The booth person said they really weren’t for distribution and, anyway, why would I want one. I told him that I spent hours rolling down those very sandhills as a child growing up in West Texas. In fact, I said, I probably rolled down the actual sand in the bottles in the display. I got a sympathetic look and a bottle of sand. I’m not sure what I will do with it, but it does bring back good memories.

It was only a couple of days later that I was reminded of a worsening plight for sand miners. As discussed in this column several times before, the Permian basin of West Texas is booming, to put it mildly. It now accounts for about 30% of the 11 MMbopd produced in the U.S. Unfortunately, that boom has produced a plethora of production potential through expanded drilling programs, far more, in fact, than the existing export systems can handle. The result is a huge increase in drilled-but-uncompleted (DUC) wells. The U.S. Department of Energy (DOE) estimates that the number of DUC wells in the Permian basin increased more than 40% from January through August of this year. The large increase in DUC wells collided with a marked increase in demand for sand, beginning in 2016, accompanied by an equally large increase in sand mining in the Permian basin. The resultant oversupply has led to dramatic decreases in sand prices. The current downturn in demand has led to the shutting-in of five sand mining plants in the U.S. Midwest, where the sand quality is better, and the price higher.

The answer to this problem, of course, is the expansion of the oil and gas export system that carries Permian basin production to refining and marketing. Solutions are in progress, but their completion is not in the near future.

Progress in methane detection. The National Energy Technology Laboratory (NETL), a division of DOE, is working to locate and quantify methane leaks in the U.S. natural gas infrastructure. Transmission and distribution lines are typically well recorded and regulated. However, fewer inspections are required for small-diameter gathering lines, which are less likely to be mapped or recorded. These gathering lines are of interest to NETL researchers, as leaks from gathering lines are not as well characterized.

The first challenge is locating gathering pipelines—both active and inactive—by finding the endpoints of the lines, which usually are wells and processing stations. The latter are well-marked on maps, but individual wells are sometimes not well-marked. A previous NETL study that focused on finding oil and gas wells explored the efficacy of aerial surveys by helicopter versus ground surveys by utility terrain vehicles (UTVs), either using powerful magnets or methane detection equipment. Aerial magnetic surveys were determined to be the most accurate, economical and time-effective method to locate steel-cased wells in large areas.

NETL Technology Portfolio Lead Natalie Pekney, Ph.D., said that finding wells is often easier than locating gathering pipelines, because wells are oriented vertically and generate an obvious magnetic “bull’s-eye.” Meanwhile, gathering systems run horizontally, produce a weaker magnetic signal, and may be made of plastic or other materials that are undetectable using magnets.

Well finding is important, because many early wells drilled in the U.S. were not sealed properly when they were abandoned, creating pathways for liquids and gases to rise to the surface or flow underground. Poorly sealed wells can contaminate sources of drinking water, release harmful gases and threaten subsurface energy-related activities—including hydraulic fracturing, EOR and carbon storage. Leaking pipelines may also pose some of these threats, so as NETL has refined effective well-finding techniques, research has transitioned to locating gathering lines and characterizing any leakage from those lines.

To extend the impact of site studies and surveys like NETL’s helicopter work, another NETL team uses geospatial data analytics and modeling to provide useful information about the U.S. natural gas pipeline network. For instance, data analyses have highlighted patterns, in regions prone to incidents, that can lead to severe injury or explosions from excavation damage—in regions experiencing rapid development—and corrosion in offshore environments, such as the Gulf of Mexico.

Researchers are now working to determine the possible factors that impact methane leak rates for gathering pipelines, including age, region of the country, and pipeline materials. Several environmental variables are also measured or recorded, as they can impact the integrity of the pipeline and influence the dispersion of methane into the atmosphere from a leak. Researchers also are working to improve methane detection methods, as sensor altitude, sample rates and more can affect leak detection. Additional information from NETL can be found at https://www.netl.doe.gov/newsroom/news-releases/. 

About the Authors

William J. Pike

World Oil

William J. Pike has 47 years’ experience in the upstream oil and gas industry, and serves as Chairman of the World Oil Editorial Advisory Board.