In this book, the World Energy Commission (WEC) examines the exploration for hydrocarbons in Angola from the early 1900s when the first well was drilled. The petroleum geology chapter includes geological maps of Angola and regional geological evolution and basin information. The reservoir geometry section discusses surface seismic methods and interpretation, structural dip and faults, and well testing objectives and methods. A section on formation evaluation offers an in-depth discussion of porosity and lithology, resistivity modeling, permeability, and fracture characterization. The final chapter on completion and production methods highlights cementing and evaluation techniques used in Angola basins, testing hardware, on-site fluid analysis, saturation monitoring, and corrosion monitoring. (352 pages)
Geological maps of Angola are presented, along with the history of exploration in the area, which has been documented as early as 1767, and its tectonic, geological, and sedimentary basin evolution. Maps and charts illustrate the geology of the Congo, Kwanza, and Namibe basins.
Seismic data is used to determine reservoir geometry in the search for new prospects in frontier areas. Today, with improved log quality and the availability of three-component seismic measurements, a more scientific approach can be made to the problem of sonic log calibration in complex environments. Geophysical, geological, and petrophysical interpretations can be combined to characterize a reservoir and to provide a good static reservoir descriptions from which the volumes of fluids in place can be assessed.
Formation evaluation is used to determine the ability of a borehole to produce hydrocarbons. Reservoir characterization models incorporate all the characteristics of the reservoir that are pertinent to its ability to store and produce hydrocarbons. They are used to simulate the behavior of the fluids within the reservoir under different sets of circumstances and to find the optimal production techniques that will maximize the production.
Many steps are involved in drilling a well to help ensure its future performance. Each step in the process is important, from the design and execution of a primary cement job to the perforating techniques used to testing and completions, onsite fluid analysis, logging, and monitoring. In this chapter, the authors provide examples with graphs and illustrations.
Research and new technologies are being used to enhance the safety, economics, and environmental impact of drilling in Angola basins, with new capabilities constantly in development.