GPS CONTROL NETWORK FOR OML 103 WITHIN THE JURISDICTION OF IJAWS IN ONDO, EDO AND DELTA STATES

 

The project was a purely seismic operation and was focused on the GPS Control Network for OML 103 in the jurisdiction of Ilaje and Ijaw communities of part of Edo, Delta and Ondo States. The area of the prospect was 351km².The order of this survey job was second order survey whose scope included; reconnaissance, monumentation, field observation, data processing, map plotting/ printing and report writing. Reconnaissance was the preliminary survey carried out to familiarize ourselves with the site of the project and to know how to arrange best in carrying out the survey operation.

Monumentation which was the casting of pillars/monuments of position points that later constituted the control points used in the entire operation (seismic). The casting of these pillars/monuments was special because of the nature of the sites of the project, each monuments consisted of metallic pipe, 1.5m long driven 0.9m into the concrete at ration 3:2:1 of sharp sand, crushed stone and cement. The concrete cast (in situ) is 0.6 m inside the ground and 0.4 m above the ground levels thus allowing the pipe to provide 0.2 m above the concrete for firmness and stability.

During the field operation, six geodetic dual frequency GPS receivers on L1 and L2 bands were employed in the execution of this project using different method in seismic static mode. The data obtained were processed using Leica Geomatic Office Combine (LGOVER 6.0) software package and the misclosine errors were expressed “loop by loop”. The map was drawn at a scale of 1:100000 using AutoCad 2010 version.

The map so produced was used throughout the seismic operations by; surveyors, drillers, seismists etc. to find their directions while performing their operation.