Qatar Geological Mapping Project - Phase II
Task 4 – SUBSURFACE INVESTIGATION PROGRAM
Activities & Milestones
Downhole Geophysics
- Full Wave Sonic, to identify porosity, rock strength and elasticity (with density log), correction of seismic velocity, fracture and permeability indication in hard rock, location of poor or missing cement behind casing, stratigraphic correlation.
- Gamma Ray, to make lithology correlation between wells, estimation of shale content for advanced log analysis, qualitative permeability indicator for completion decisions.
- Caliper, to identify borehole deviation and drift, borehole volume (derived), true vertical depth (TVD), It is a mechanical log tool that directly measures the diameter of the well.
- Electric Log (SP and Resistivity), used to etermine formation resistivity, resistivity of the units above and below the units whose resistance is measured, formation thickness, resistivity of sludge, resistivity of sludge infestation zone.
- Temperature – Conductivity Log, used to make the fresh and salt water separation from the well walls.
- High Resolution Acoustic Tele-viewer logging (HiRAT-ATV), to study state of borehole wall, joint filler, determination of angle of inclination and azimuth of fractured zones and single joints.
Groundwater Monitoring System
Standpipe Piezometer Installation
For the purpose of monitoring groundwater during and post drilling, the PVC standpipe tubes will be installed in selected boreholes. For the purpose of the groundwater monitoring, electrical sensors will be placed inside the standpipe piezometers. Data from those electrical
sensors will be collected by means of CRD-400 Multipurpose Readout. The measured water pressure data will be taken from sensors and it will be converted into water height.
Laboratory Tests
Laboratory tests will be performed at sufficient quantities of recovered samples as per the project specifications and requirements.
Surfcace Geophysical Surveys
- ERT (Electrical Resistivity Tomography)
- Gravity Survey
- MASW