OT26009 - Capital Allowances: Research and Development Allowances: 1967 Memorandum - Successive Stages of Work - Stages 1 & 2
The successive stages of the work involved in Oil Exploration and Development as referred to in Paragraph 2 of the Joint Statement are as follows.
Stage 1
- Study of all available literature on the geology of the region in question.
- Concession acquisition (in the case of marine areas this step is often delayed until after (3) below.
- Reconnaissance geological and/or geophysical surveys over the region in order to select the most attractive areas. Geophysical surveys may be aeromagnetic, gravity or seismic surveys.
- Detailed geological and/or geophysical surveys over the most attractive (concession) areas in order to select the best locations for drilling. Geophysical surveys may be gravity and/or seismic, most usually the latter.
- In certain marine areas sea-bed sampling might be undertaken to increase geological knowledge. On land in some cases shallow holes may be drilled for the same purpose.
Stage 2
- Drilling of exploration wells. In certain cases in marine operations sea-bed bearing capacity investigations may be required prior to commencement of drilling. During the drilling of an exploration well the obtaining of maximum information of the geological section penetrated by:
- Taking samples of cuttings at regular intervals.
- Cutting solid cores at selected depths (either full hole or side wall).
- Running electrical and other surveys in the hole.
- Testing prospective intervals.
- Either:
- If no oil shows are found or shows do not imply commercial quantities, abandonment of the exploration hole, or
- If the oil shows are sufficiently promising, the exploration well might be either:
Abandoned immediately or after prolonging testing - if production from such an isolated well is considered inadvisable, or
Completed as a test well and/or potential producing well.