The amended ECC No. APP 3664 is required by the Proponent (MEL Oil and Gas Exploration (Namibia) (Pty) Ltd with respect to the addition of 1174.32 km long of new seismic survey lines to the already approved 330.84 km long and bringing the total proposed survey lines for PEL 93 to 1505.16 km. During the seismic survey, the generated seismic wave travels into the earth and get reflected by various rock layers of the subsurface formations and returns to the surface where it is recorded by receivers called geophones which are like microphones. The proposed 2D seismic survey will use the Vibrator as the energy sources and will utilise wireless receivers that will allow for greater line offsets. The centred vibrating metal plates from the Vibroseis truck will generate acoustic / sound waves that will penetrate deep into the ground below the survey line and bounced off the various subsurface rock layers. The wireless receivers that will be installed along the survey lines at between 5 – 10 m station intervals will measure the returning sound / acoustic wave. The resultant product following complex processing is a vertical sonic cross-section of the subsurface beneath the survey line showing the geological materials (de-risked geological sub-model). The interpreted 2D seismic survey data sets is used to find specific drilling locations where potential reservoirs within the AOI oil or gas may be trapped in sufficient commercial quantities. Vibroseis trucks especially the recently designed broadband units have greater advantage in energy spectrum control as this can be done with much ease. The force applied to the ground can be monitored and adjusted in real time. Hence the effective usage of Vibroseis in urban areas. With enhanced mechanical and hydraulic components and shaker redesign, latest Vibroseis such as the Nomad 65 with similar specs to the Explorer 360 has a superior performance of optimised broadband acquisition by bringing down the sweep start’s frequency at full drive from 7 to 5.4Hz. Therefore, the time spent in emitting the very low frequencies from 1Hz can be significantly reduced, with a positive impact on crew production and cost. New technologies in Vibrioses such as the Nomad 65 will facilitate the recording of an extra low frequency bandwidth that has proved to be very beneficial for vertical resolution and seismic inversion. The implementation of the proposed 2D ground survey programme can be divided into the following fice (5) stages: 1. Planning and mobilisation (Pre-survey preparation, field scouting and mapping of buffers and offsets along proposed survey lines). 2. Base camp and fly-camp sites setups and operations. 3. Widening of tracks by pruning vegetation overgrowth and tracks levelling as may be applicable. 4. Actual survey operation (data acquisition), and. 5. Demobilisation and closure (Survey completion). The proposed survey will be undertaken along the already existing roads, farm fences and tracks and already disturbed areas. In consultations and with the approval of the landowners / local community, very limited new cutlines may be created to either straighten a survey line or create new access as may be required. A typical survey track will need a space opening along the survey line (track) of about three meters (3 m) wide.
Prpject status REVIEW IN PROGRESS
Ministry of Environment and Tourism
Department of Environmental Affairs
(+264 -61) 284 2701 (T)
(+264-61) 240 339 (F)