Rathlin Energy is planning up to 90 weeks of 24-hours-a-day drilling at one of its wellsites in East Yorkshire.

The company is seeking to triple the width of West Newton-A in Holderness and carry out production for up to 20 years.

The scheme, which aims to add another six wells to the existing two, was revealed last week.

More details have now been published online in a screening request report submitted by Rathlin Energy to East Riding of Yorkshire Council. The council has ruled that an environmental impact assessment is not needed.

The screening request report has revealed:

• The pad would be expanded to 3.46ha
• 12 construction and 12 security staff would be employed during expansion
• 30 heavy goods vehicles (HGVs) would visit the site each day during 12 weeks of site construction – equivalent to 1 journey leg every 12 minutes for 12 hours
• A drilling rig up to 55m tall would be used on the six new wells
• Additional sidetracks could be drilled for all six wells
• Drilling is forecast to last a total of 90 weeks, 24 hours per day
• Wells would be treated with acid before production
• If wells did not flow, they will be treated with nitrogen gas for 1-5 days
• Up to 330,000,000 standard cubic feet of waste gas could be burned during well testing
• Well testing is expected to take 1-2 years
• If approved, the site would store up to 490 tonnes of crude oil
• 20-25 tankers would visit the site every day during 20 years of production – equivalent to up to one journey leg every 15 minutes for 12 hours, including Sundays and bank holidays

Phases of work

According to the screening report, there would be 10 main phases of work:

Testing of existing wells: 12 weeks + 1 week mobilisation/demobilisation

Wellsite expansion: 12 weeks + 2 weeks mobilisation/demobilisation

Drilling conductor pipes: 4 weeks per well + plus 4 days per mobilisation/demobilisation (total 24 weeks drilling + up to 4 weeks mobilisation/demobilisation)

Drilling wellbores: 15 weeks per well + 2 weeks mobilisation/demobilisation (total 90 weeks drilling + up to 12 weeks mobilisation/demobilisation)

Well treatment/cleaning: 4 weeks per well + 2 weeks mobilisation/demobilisation (total 24 weeks treatment + up to 12 weeks mobilisation/demobilisation)

Well testing: 1-2 years

Delivery of processing equipment: 6 weeks

Production: 15-20 years

Decommissioning: 11 weeks per well + 2 weeks mobilisation/demobilisation (total 66 weeks decommissioning + up to 12 weeks mobilisation)

Restoration and after care: 5 years+

New equipment

The document has details of the processing equipment that would be added to West Newton-A if the site went into production:

• phases separator/treater
• bath heater
• flow lines above ground
• secondary containment bunds
• concrete foundations
• incinerator(s)/vent stack
• propane storage
• knock-out pot
• storage tanks for crude oil and formation water
• HGV unloading bays
• gas generators.

Environmental impact assessment “not needed”

East Riding of Yorkshire Council has ruled that the proposal did not require an environmental impact assessment.

The council’s principal development management officer, Matthew Sunman, said the proposal would “not have the potential to have significant adverse impact on the environment within the meaning of the 2017 regulations”.

He said estimated production at West Newton-A was below the threshold for an EIA of 500 tonnes of oil per day and 500,000 cubic metres of gas. The company had estimated it would store up to 490 tonnes of crude oil on site, Mr Sunman said, and produce an estimated 170,000 cubic metres of gas per day.

He said:

“It is likely that the proposals effects would be limited to the local area and the impacts mitigated against”.

Rathlin Energy said it planned to generate power for the site from waste gas during production. But it said up to 330 million standard cubic feet of waste gas could be burned in a flare or incinerator during well testing.

As part of the scheme, the two existing wells would also be treated with acid to improve flows and then tested. Lateral or deviated wells may also be drilled off them.

Rathlin said heavy traffic to the site was not expected to have a significant effects. It described HGV traffic numbers during the wellsite extension and production as “moderate”. It also said the development would “not result in a significant adverse effect to either health or quality of life to even the closest receptors to the development”.

The company said:

“Amenity could be compromised by noise, odour, vibration, light-spill or glare. In addition, the outlook from a residential properties, private garden or viewpoint could be adversely impacted by operational development. Given the relative remoteness of sensitive receptors, the limited number of viewpoints which overlook the wellsite, the effects of the Proposed Development upon amenity are not likely to be significant.”

The company said the proposal could potentially cause “adverse effects” to surface and ground water. But it said because of mitigation measures the residual effects were “likely to be minor”.

• Rathlin Energy has said it will carry out a community consultation on the scheme before submitting a planning application. DrillOrDrop will follow the proposal through the planning system.