Onshore Extraction Development
There are three broad stages of development activity
These are exploration; appraisal and production
Not all sites will go through all three stages
Whilst each site will be different depending on its geology and its geographical location, it is possible to group the general development process into three broad stages of activity. It is important to note that stage 1 and 2 could be a continuous process and that not every site will go through all the stages below.
Stage 1 – Exploration
This normally begins with an operator seeking the planning consent to drill a well. These wells are designed to be data gathering wells which will take samples of rock in order to collect vital geological information about the potential oil and gas layers of interest.
Typically, operational activity at an exploration site spans two to four months. The site is normally vacated after that.
Stage 2 – Appraisal
After examining the data taken during the exploration phase, operators will usually decide to test the well before making a decision about whether it will be commercially viable.
Depending on the geology, this stage may involve carrying out one or more hydraulic fracturing (fracking) procedures. This will usually involve an additional planning consent and a full environmental impact assessment.
Operations on the surface typically last between four and six months, but with on-site activity lessening the longer the testing goes on.
Stage 3 – Production
Once the operator has worked out whether the development is commercially viable, the operator will apply for planning consent for a full production site and a Field Development Plan (FDP) will be submitted to the Oil and Gas Authority (OGA).
The size of a production pad will depend upon location and the specific geology but will normally be about two hectares (five acres) in size.
At this stage, the additional infrastructure will be constructed. For example, this includes any pipelines which are needed, subject to further planning applications. Once drilling has been completed, activity on the surface will lessen greatly as wells start to produce natural gas.