Guest post: Save the Fylde – keep the earthquake safety limit at 0.5

A poor guest blog from the invariably inaccurate Mike Hill

Well-demolished by the lady expert Judith Green in comments (along with some by Ken Wilkinson;
She writes
Mr Hills guest post seems to suggest that he’s a complete charlatan. Maybe he could take time from all of his advising to such eminent bodies to clarify a few points in his article:-

1) “To be clear I did not set the limit but did review the value with the DECC and have first hand knowledge of the debate that took place.”

Could Mr Hill tell us which experts that he discussed this with and whose opinions he heard at “first hand”?

2) “But after long discussions and some mathematical modelling,”

Could Mr Hill give some details of the mathematical modelling? I for one would like direction on which mathematical models can be used to predict induced-seismicity.

3) “the science and engineering that led to the introduction of the 0.5 ML”
Could Mr Hill provide some indication of which science and engineering experts contributed to this decision and whether or not they’re respected by others in their field of expertise?

4) “To raise the seismic threshold now has no basis in science or engineering. It will reduce safety and could lead to a catastrophic incident.”

Could Mr Hill provide an example of where such a catastrophic accident has occurred previously? Given that over 2 million frackjobs have been conducted, one would assume that if such a catastrophic incident was likely to occur then there would be evidence for such an occurrence within the pool of knowledge that has being built on this subject.

5) “The cement surrounds the steel tubes inside the borehole (casing) and it fills the gap between the casing and the borehole wall – the actual rocks that have been drilled through. It is the only thing that is stopping (to date) up to 11.5 million litres of fracking waste from vertically migrating up the side of the borehole. It can do this in the annulus between the cement and the casing and can move up to the higher areas and eventually the aquifer.

Why would fluid move upwards against gravity? The reason is twofold. Firstly it is understood by hydrogeologists that fracking fluids are less dense than surrounding formation fluids and hence rise; and secondly the pressures during and immediately after fracking are huge (in the range 2,000 – 15,000 psi). The fracking fluid will find the path of least resistance. Due to repeated and increasing energy earthquakes, the gap around the casing and between the cement and the formation wall could have increased.”

Could Mr Hill explain how the huge pressure would push 11.5 million litres of water to the surface? Surely as an engineer he knows that water is very incompressible and that a very small amount of water would be forced to the surface due to decompression. If he’s thinking about the gas pushing the water from >2km maybe he could explain how this would happen given the mobility ratio of brine and gas. Also, could he provide a model as to how density driven advection in a microannulus could result in significant movement of fracking fluid to the surface?

6) “But annular pressure is a very crude tool. It will tell an operator if well integrity is lost – but an entire string of cement must have failed before you will know anything. As you typically only have three strings in an entire well then this represents a very significant failure before you are aware of it. Annular pressure checks on their own are not enough to guarantee well integrity.”

Could Mr Hill provide an example of such a failure mechanism in a shale gas well with the same design as those of the wells at PNR

7) “As a Chartered Engineer, heavily involved in this topic for a long period, I feel it would be reckless to raise the 0.5ML limit. To do so would be putting the public of the Fylde at even greater risk of severe damage to health and the environment than they already are. The 0.5ML limit is there for a reason and that reason has not changed. Safety must always take precedence over commercial viability.”

Given Mr Hill’s complete ignorance of this subject, do he really think he should be chartered as an engineer?

DRILL OR DROP?

Save the Fylde slogan

Chartered Electrical Engineer, Michael Hill, stood as an independent candidate in the 2015 general election on a “Save the Fylde” ticket, highlighting his concerns about the fracking industry. In this guest post, he argues that his message seems more relevant now than ever as he makes the case why the safety limit on fracking-induced earthquakes should not be altered.

View original post 1,372 more words

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