These images may provide some insight into what’s in store for the Delaware Basin, particularly the southern region of that basin. The composite image shows acreage leased by three of eight oil & gas producers in the basin, predominantly covering Reeves, and portions of Pecos, Jeff Davis, and Brewster counties – some 700,000 acres. The recent “find” announced by Apache Corp is included here, along the Reeves-Jeff Davis northeastern county line. The second image is the geographic extent of the Delaware Basin itself, included as an overall reference.
What you’ll see as this play develops should be alarming. The usual development of this kind of play involves multi-well pads, and bores with multiple, stacked laterals. A typical four-well pad completion will use 1,000,000 bbl. of water (42,000,000 gallons) over about a two week period. The flow-back operation will generate contaminated water, some of which is recovered, and potentially recycled. The remainder has to be either treated for disposal, or disposed of through deep-well injection (this is what is causing earthquake activity in North Texas and Oklahoma).
Someone has to put in take-away capacity for tens of thousands of barrels of crude oil, and NGL’s – pipelines, as well as the gathering lines from the well heads. Since this is primarily a rich, wet gas play, most of the production will be natural gas, and condensates (NGL), and some oil. And some water – depending on a variety of factors, tens to hundreds of thousands of barrels in an operating month – a good average for these formations is about 100,000bbl/month, or about 4,200,000 gallons of produced water, that comes back up with the stream. That contaminated water has to be hauled out…
There will be flaring activity during drilling and completion, less once the field is in production, as technically flaring gas wells is illegal under RCT and TCEQ/EPA rules. That is not to say there will be no flaring once the field is in production. Emergency shut-in of a well, compressor station, etc. all typically result in flaring, as do maintenance activities.
Since this is classified as a sour gas play (rich, wet gas often has a high H2S content), there will have to be one, or more gas plants capable of removing the sulfur from the stream, and drying the gas – gas plants of this type produce molecular sulfur, which is usually transported out in molten form by tanker, either truck or rail. Depending on the market conditions, the sulfur can be sold for industrial purposes (used in fertilizer, rubber, etc.) When the market is down, the producer either has to store the sulfur, or pay to have it hauled out – neither is a good thing.
Today’s 3D seismology, and petri-geology techniques are pretty good, but they are not perfect. What is happening underground, given the idiosyncratic nature of the geology and formations can be unpredictable. A bore excursion, a frack-out, a hidden fault that connects to other structures, like the water table, fluid migration, and other factors can, and does cause groundwater contamination. One of the existing 19 wells is adjacent to Balmorhea Lake… imagine the eventual web of horizontal bores permeating southern Reeves County, and the potential risks.
The greater concern is the level of industrialization related to developing an oil & gas play of this magnitude. While all eight producers holding lease interests in the region are likely over-stating the reserves, in some cases probably substantially, to try and prop up their shaky business by inflating stock prices, the impact on the region will be tremendous, even if only a fraction of this is developed and brought into production.
Notice the significant lease block in southeastern Brewster County, and its proximity to Big Bend National Park. The impacts include increased sky-glow, threatening the region’s dark skies, reduced air quality, due to combustion by-products from rig and site power, fugitive emissions, and flaring, water demands, and potential contamination of groundwater resources, increased dust from traffic on unpaved lease roads, wear & tear on county and state roads from oilfield traffic, increases in vehicle accidents, including fatalities, increased crime, and corresponding increased demands on area public safety, EMS and fire resources.
This is what the region has to look forward to, if development of these unconventional oil & gas resources proceeds in the Big Bend.