Environment Report 2013

ENVIRONMENT REPORT 2013

7. Appendix A: Well Flow Status Survey Since the Macondo oil spill incident in the Gulf of Mexico during 2010, the UK offshore oil and gas sector, in collaboration with regulators, has extensively reviewed the prevention and response capability in place. Current capability was found to be essentially robust and provides an effective response. Some enhancements were identified and these have been implemented, for example, by constructing a subsea well capping device. An element of this review was to understand whether a significant oil release could occur from wells on production installations. Any well that does not naturally flow oil to the surface, that is it requires assistance to flow, does not have the potential to spill oil. An analysis of the status of all platform wells shows that from the inventory of 5,121 platformwells only 21 are capable of flow rates that could result in a significant oil spill, allowing appropriate preventative and control measures to be put in place. Well Flow Questionnaire All operatorswithplatformwellswere sent a pre-populated spreadsheet containing individual well information from the DEAL Database (now incorporated into UKOilandGasData.com) 18 . The following information was requested for all wells: • Is the well capable of unassisted flow? • Well type – is it an oil, gas or condensate well? • Gas Oil Ratio (GOR) • Specific Gravity

• Well pressure class banded into five categories • Flow rate class (oil) banded into six categories • Flow rate class (gas) banded into six categories

Well Flow Results Information was received for 5,121 wells, representing the total inventory. In response to the first question, on unassisted flow, only 19 per cent (992) of wells on the UKCS are capable of free flow as shown in Figure 15 on page 26, that is, during a blowout, the well is capable of continuing to flow.

Figure 15: Wells Capable of Unassisted Flow

5,000

4,129 (81%)

4,000

3,000

2,000

992 (19%)

1,000

0

No

Yes

Source: Oil & Gas UK

18 Common Data Access Limited (CDA) has streamlined its services by launching a new single gateway for subsurface data that incorporates the previous DEAL database. See www.ukoilandgasdata.com

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