Angus Energy’s new plans to test for oil at its Balcombe site in West Sussex have been published.
The new proposal, validated yesterday (26/8/2020), seeks permission for a one-year test. It stresses the importance of oil for energy and as an industrial feedstock and argues that any impacts would be “minor adverse”, “temporary and reversible”.
A consultation on the application runs until 28 September 2020.
Angus Energy said the well test was needed to “further understand the viability of extracting hydrocarbons in the future”.
It said the Lower Stumble site in Balcombe had the “potential to make a positive contribution” to UK energy supply and energy security”.
The site was considered a “sweet spot” in the Weald Basin, the company said, and was “the most appropriate site in West Sussex to accommodate this type of development”.
The application estimated the development would create or support up to four permanent and up to 33 temporary jobs.
Latest bid to test
The proposal is the latest of four applications to test the Balcombe-2z well, drilled by Cuadrilla in 2013.
But so far, the only test carried out was for seven days in 2018 and was inconclusive. For most of the past seven years, there has been no work at the site.
The previous test application, published in October 2019, was opposed by Balcombe Parish Council and 535 organisations and individuals, including Frack Free Balcombe Residents’ Association, Sussex Wildlife Trust and CPRE.
West Sussex County Council planners recommended refusal, saying three years of testing would “establish a continued presence of industry which is not appropriate to the area”. They also said the application did not pass tougher planning hurdles required for a major development in an area of outstanding natural beauty (AONB). The developer has to show there are exceptional circumstances to support the scheme and that it is in the public interest.
Angus said the new application was “modest and temporary” and the site would be an “unobtrusive presence”.
The proposal had “sufficient merits to justify development” in the High Weald AONB, the company said.
A previous well, Balcombe-1, was drilled at Lower Stumble in 1986 and Angus makes the case that the site had been “subjected to oil and gas exploration for over 30 years”.
But the planning history reveals that for much of this time the site was used instead for forestry storage. The total duration of drilling and testing at Balcombe amounts to less than a year, in short periods during 1986-7, 2013 and 2018.
Work and impacts
Angus said it planned to carry out testing work at Balcombe in four phases over a period of 18 months.
Operations would begin by removing wellbore fluids to establish whether there was dry oil in the well. If oil was confirmed, the company would install a new impermeable membrane across the active part of the site to meet current regulations.
A 55-week extended well test would follow to provide information about flow rates, hydrocarbon composition and the likely volume of formation water. The well would then be shut in and either be plugged and abandoned or a new application submitted for production.
Angus said it had three contingency options to improve oil flow rates: nitrogen lifting, acid wash and installation of a bridge plug (see more information below).
According to the application, the well test would use a flare, measuring nearly 14m tall, to burn any waste gases. Other equipment listed included a linear rod pump or pump jack, coiled tubing unit, tanks, generators and pipework.
Angus Energy acknowledged there was potential for noise disturbance from the flare and plant on site. But it said planners had previously considered that noise could be “adequately controlled by conditions requiring monitoring, and remediation if levels are exceeded”.
Lower Stumble is acknowledged to be in “a sensitive area”. It is surrounded by ancient woodlands and there are sites of special scientific interest nearby. The application said the surrounding area was considered to be of high value for foraging and commuting bats. But the site itself has a low value, the company said.
The previous planners’ report on the three-year flow test concluded: “the proposal is acceptable in terms of its potential impact on ecology”.
The impact on the landscape was considered to be ““locally minor adverse” and “negligible” beyond 0.5km.
Heavy goods vehicles (HGVs) will be brought through Balcombe village to the site. Angus Energy quoted the planners’ previous conclusions that “the increase in HGV traffic would not be significant in highways terms, and would not result in an unacceptable impact on highway safety, or a severe impact on the road network”.
The company said its previous plans could have an impact on air quality but these would be controlled by an environmental permit. The potential impact from increased vehicles was not considered to be significant, it added.
Angus said a hydrogeological risk assessment concluded there was “a very low likelihood of groundwater impact” from the flow test. This would be monitored and managed during the work and as part of decommissioning, it said.
DrillOrDrop will follow the application through the planning system and report on comments to the proposals
Work phases and contingencies
Phase 1: Removal of wellbore fluids
Angus said it intends to pump out previously used drilling fluids to ascertain whether there is dry oil in the well.
Equipment: linear rod pump or pump jack, surge tanks, low pressure separator, pipework and manifold, oil and waste storage tanks, pressurised tank for fluid export and vapour recovery, generator and welfare unit.
Duration: Up to 4 weeks
Working hours: 24 hours/7 days a week for wellbore activities. Mobilisation: 7am-7pm Monday-Friday, 8am-1pm Saturdays.
Maximum daily two-way lorry movements: 16
Analysis period: Well suspended for several weeks to 3 months
Phase 2: Pad membrane
Site-wide impermeable membrane has to be installed to meet oil and gas standards. The membrane is intended to isolate spills and contamination from the well test.
- Remove existing 300m granular platform surface material, existing polypropylene geo-grid and existing geotedxtile
- Screen existing granular material if required
- Construct V-type perimeter containment ditch
- Install high density polyethylene (HDPE) impermeable membrane anchor berm around the active area of the wellsite
- Install 2mm HDPE impermeable membrane across active area of wellsite and perimeter containment ditch
- Additional polypropylene geo-grid installed above the HDPE membrane
- 300m compacted granular material laid above geotextile
Duration: 8 weeks
Working hours: 7am-7pm Monday-Friday, 8am-1pm Saturdays.
Maximum daily two-way lorry movements: 14
Phase 3: Extended well test
Equipment: Test separator unit, data acquisition and reporting system, pipework and manifolding package, surface emergency shut down system, choke manifold, surge tank, oil and waste storage tanks, linear rod pump, flare unit, coil tubing unit and injector head, nitrogen tanks and convertor, hydrochloric acid wash tanks, vapour recovery tank.
Contingency options to improve flow rates:
- Nitrogen lift – pumping nitrogen from the surface into the wellbore to lift liquids to the surface
- Acid wash – pumping hydrochloric acid at 15% concentration into the well to remove scale or other deposits from well perforations and well-completion components and to restore natural porosity of the formation.
- Installation of bridge plug – isolate sections of formation which are producing water rather than hydrocarbons
Duration: 55 weeks plus 2 weeks for each contingency
Working hours: 24 hours/7 days.
Maximum daily two-way lorry movements: 16
After reviewing the data, Angus Energy said it would shut in the well and move to phase 4 or submit a new planning application for oil production
Phase 4: Plug and restore site
- Removal of surface plant and equipment
- Plugging – injecting cement into the wellbore to prevent the unintended release of fluids
- Site restoration
Duration: 4 weeks for plugging and decommissioning; 8 weeks for site restoration
Working hours: plugging and decommissioning – 24 hours/7 days; restoration – 7am-7pm Monday-Friday, 8am-1pm Saturdays.
Maximum daily two-way lorry movements: 12
- West Sussex County Council has set itself a deadline of Wednesday 25 November 2020 to decide the application. Details