Rathlin Answers

This week Rathlin met with 5 local campaigners.  Here are the answers they gave to our written questions.

1. Rathlin has been invited to participate in public meetings and has refused these invitations. Why?

Rathlin has previously hosted public meetings and has declined recent requests as our plans have not changed.

2. What is your definition of fracking?  eg; what pressure?

Hydraulic fracturing involves hydraulic initiation, propagation and propping of the subsurface fracture network for the purpose of producing fluids from a formation. The pressure to be used depends characteristics of the formation and depth requiring hydraulic fracturing to produce fluids.

3. How many wells would you say have been fracked in the UK?

The information available from DECC suggests that hydraulic fracturing has been utilised in around 200 onshore wells in the UK

4. Can you confirm that no horizontal drilling has taken place?

Yes

5. Is there any possibility of horizontal drilling?

Not from these wellbores

6. What depth are your primary targets?

1500-2500m

7. What depth is the shale?

2600-3100m

8. Would you ever describe shale as a conventional reservoir?

No

9. At what depth, and in which formation, are you conducting the mini fall off test?

Bowland Shale. 2600-3100m

10. Could these wells be used for commercial extraction, or will they be abandoned after the tests?

Yes these wells can be used for production for certain conventional reservoirs. Everything below the producing reservoir will be abandoned.

11. How would gas be removed from site, ie; by pipeline?  To households or only commercial?

The gas will be transported by pipeline to be fed into the wholesale gas market via the National Transmission System

12. Rathlin have not undertaken an Environmental Impact Assessment (instead relying on a much weaker Environmental Risk Assessment) to support their Environmental Permit application. Why not?

The ERYC pre-screening assessment, with its consultees, advised that an EIA was not needed due to the temporary nature of the exploratory site.

13. The company has stated that it has no plans to frack at either Crawberry Hill/West Newton. However, the planning application stated their intention to core the Bowland shale. If the coring is successful, how do Rathlin expect the gas to be extracted from the shale if not by fracking?

Both these wells are exploratory wells and as such are to gain as much information about the regional geology as possible. There are no plans to produce from the Bowland Shale.

14. Will they be seeking planning consent and/or permits in the future to carry out hydraulic fracturing?

Possiby but not at either of the existing sites.

15. How can you guarantee that the fracture pressure of the formation has been adequately assessed in order to avoid exceedance?

The fracture gradient will only be determined by the mini fall-off test.

16. Baseline monitoring of the groundwater at Crawberry Hill identify elevated levels of chlorine already and yet Rathlin intend to pump hydrochloric acid through the aquifer (thus potentially increasing risk of further exacerbating the problem).

The chalk aquifer is protected by 5 sets of steel casing and cement to surface and therefore there is no risk of the hydrochloric acid leaching into the cretaceous chalk.

17. Why haven’t Rathlin carried out baseline monitoring of groundwater at West Newton?

The water in the chalk at West Newton is saline and therefore not potable.

18. What medium and long term monitoring testing of the site do Rathlin intend to carry out at both sites to ensure that there is no subsequent contamination?

This suggests there is already contamination. There is not. We will continue to monitor air and water quality where and when the statutory authorities deem necessary, or exceed their requirements.

19. At what facility do you intend to dispose of the produced water from the 'mini fall-off' test?

There will be no water produced from the mini fall-off test

20. How will the produced water be treated, especially if it contains NORM?

Any water produced from conventional formations will be treated at a full licenced facility.

21. Where will the produced water be disposed of?

At a fully licenced facility

22. Where did you dispose of the drilling mud and drill-cuttings that were produced when you originally drilled the wells?

At fully licenced facilities

23. Historically, on how many occasions have you drilled through your primary target (the conventional resource) and continued into the shale or other source rock?

Rathlin have drilled past their primary target to deeper formations in all their wells. Most exploratory wells should drill as far as appropriate to fully explore the geology. It is also customary in producing wells drill past the producing reservoir.

24. Does your parent company, Connaught Oil and Gas, have any history in exploring or producing unconventional hydrocarbons?

Yes

25. You are proposing to conduct a 'mini fall-off ' test on the Bowland shale. Can you describe in lay terms, including volumes, machinery, duration etc what a 'mini fall-off' test involves?

5-10m3 of saline water will be pumped over 5-10 minutes into the formation using a pumping unit on surface. Gauges will be installed at the bottom of the hole and at surface to measure the ’fall-off' ie how long it takes the water to dissipate through the formation, this could be a number of days or weeks.

26. At each site, will the second borehole be targeting the shale gas? And will this subsequently lead to an application for fracking?

No plans for a second well at either site.

27. The process they propose to carry out at both sites consists of the mini fall off tests and the acid wash/squeeze and flow test involve pumping chemicals (including hydrochloric acid) through the aquifers (which, in the case of Crawberry Hill, is within the Groundwater Protection Zone). Rathlin state in their permit application that they will recover all spent acid to the surface. How can Rathlin guarantee that and is there a significant risk that there will be still be significant amounts of chemicals and muds left underground?

Answered in Q16. The amount of hydrochloric acid used is minimal in comparison to the water in the well. When hydrochloric comes into contact with a carbonate the chemical reaction will change it to H20 and salt.

28. Isn't it the case that your planning application had no mention drilling into the shale or conducting a 'mini fall-off' test?

The planning application clearly stated the intention to drill through, and take a core from, the Bowland shale. No testing procedures were outlined due to the exploratory nature of the wells.

29. You're a conventional hydrocarbons company. Why are you now venturing into unconventional hydrocarbons?

Our primary target is a conventional target. It is our duty as an exploration company to fully assess the geology within our licence as far as is convenient.

30. Isn't a 'mini fall-off' test the same of a DFIT or mini-frack?

Companies throughout the industry have many nomenclatures for different operations. Our description of a mini fall-off test is clearly described in our FAQ’s on our website.

31. 45,000 shale gas wells have been drilled in the US. We know that an average shale gas well produces 1billion cubic feet of gas. Producing usable quantities of shale gas in the UK would require very large numbers of wells. Do you acknowledge this fact?

Yes this is potentially correct. Shale gas within the UK is still in infant exploration phase so it is not possible to determine what will be required at this point in time.