Development phase
The development phase consists of all works related to developing exploitation wells, building specific installations, collecting pipes and sewer lines and of the necessary utilities for the extraction, processing, storage, transportation and transit of oil (according to the Petroleum Law no. 238/2004).
The development phase begins on the date of the approval of the exploitation project, based on confirmed reserves and statement of commercial use of the deposit.
The development phase for shale gas includes the following main steps:
1. Development and preparing the site, activity that includes development and site preparation involving construction of roads, mining and drilling equipment.
2. Vertical drilling at several thousand meters (1.000 - 4.000m), in which there are shale formations.
3. Horizontal drilling starting the end of the vertical well, when the vertical well is at the depth where the shale layer is disposed. Horizontal drilling is performed along the length of the layer of shale, sometimes with more horizontal wells in opposite directions, over a distance of 1.000-2.000 m, so that the drilled well crosses as many cracks.
4. Hydraulic fracturing of shale formations, using a fracturing fluid formed of 99.5% water and 0.5% sand and chemical additives. Hydraulic fracturing is the method through which, within the geological layers with tiny flow properties (very low permeability) and where there is natural gas, there are made very small cracks that allow their capture. Through these cracks there will be drained / collected the natural gas accumulated in these rocks. (See Annex I - hydraulic fracturing procedure)
5. Recycling or disposal of water waste which has been used in the hydraulic fracturing and any naturally occurring water which is brought to the surface.
6. Building the collecting pipelines and utilities.
The transition from the development phase to the exploration phase is done for each location (well-pad), when wells are drilled at the location, equipped and fracked and surface infrastructure, including connection to the main pipeline or to the final consumer is completed.
The transition to the exploration phase is approved by the National Agency for Mineral Resources and can be done only after obtaining the environment permit and after securing the conditions for capture of oil and sewage.
Annex I – Hydraulic fracturing (Source Unconventional gas: Potential energy market impacts in the European Union - Joint Research Centre)