Name a well were this has occurred during fracking operations. The frack pressure would drop substantially and operations would be suspended. Great consideration is designed into the frack prior to performing it. This design work considers the many 'oil and gas' reservoirs that are water wet (non fresh water - ancient seas) between the target zone and the groundwater. Water production from these wet zones will increase expenses and lower the well reserves. Typical frack height is roughly 100-250 ft above the target zone. By example, if the zone is drilled @ 7500', the frack height may reach 7250'. Fresh water is roughly 50-400' in most of West Texas.Porteroso said:The EPA gives 2 examples of the fluid contaminating nearby groundwater. Are you saying that's not true?kenjon said:Sir- I say this with respect for you as human. Please stop asserting ideas when you don't understand the subject. I'd be happy to converse with you once you have studied it but the propaganda that your attesting to is either not relevant or has no factual basis.Porteroso said:
edit: Fluid definitely escapes its casing, but I posted a quote about it reaching groundwater, was actually looking for information about it reaching the water table.
edit2:I'll admit that I seem to be wrong about it reaching the water table. I have read that in multiple places, and never gone to the trouble of seeing if it was correct or not. It commonly reaches groundwater, not the water table.Quote:
Figure ES-7 illustrates how the vertical separation distance between the targeted rock formation and underground drinking water resources can vary across the United States. The two example environments depicted in panels a and b represent the range of separation distances shown in panel c. In Figure ES-7a, there are thousands of feet between the bottom of the underground drinking water resource and the hydraulically fractured rock formation. These conditions are generally reflective of deep shale formations (e.g., Haynesville Shale), where oil and gas production wells are first drilled vertically and then horizontally along the targeted rock formation. Microseismic data and modeling studies suggest that, under these conditions, fractures created during hydraulic fracturing are unlikely to grow through thousands of feet of rock into underground drinking water resources.
EPA study
The larger point I'm making, about fracking damaging the environment, is still worth making.Quote:
A well with insufficient mechanical integrity can allow unintended fluid movement, either from the inside to the outside of the well (pathway 1 in Figure ES-6) or vertically along the outside of the well (pathways 2-5). The existence of one or more of these pathways can result in impacts on drinking water resources if hydraulic fracturing fluids reach groundwater resources.
EPA study
In this EPA quote, I know of any company that is going to spend millions of dollars fracking down casing that isn't going into the formation that they targeted in the horizontal leg. If issues come up, the frack job will be stopped and the casing repair made. These 'issues' are never near the groundwater supply as casing 'issues' often occur in the horizontal portion of the casing. Groundwater is typically covered by 2--3 strings of casing.
A well can have a small amount of contamination during drilling operations prior to setting casing through the fresh water zones. When drilling initial casing, fresh water is generally required prior to setting the surface casing so this contamination is very minimal - in a lot of cases it probably freshens up the West Texas water.
