Petroleum prospect is made up of a combination of a combination of some features necessary to have a petroleum accumulation. Once these features are combined, the only missing to make of the “five fingers of the palm” that holds the black gold, is the petroleum itself. These four features are:
1. The Source
2. The Seal
3. The Trap
4. The Reservoir
First stage prospect evaluation
At the initial stage of the prospect evaluation, we ask and try to resolves certain questions:
- Is the source rock mature?
- What is the evidence that generated oil has migrated to the reservoir?
- How good is the reservoir?
- Is the trap structure fractured?
- Was the trap available before the charging?
- Or has the oil be migrated away before the formation of the structre
- Any recent tectonics that might have destroyed the prospect<
- What is the seal efficiency and integrity?
- Has the oil or gas leaked?
- What are the main risks and uncertainties?
And many more such questions…
At the second stage of the process, we are risking the prospect and estimating the uncertainties. At the end, we provide a prognosis for drilling the well, prediction of the depth, thickness and information on the units that will be found when a well is drilled through a prospect. This is known as well prognosis, and it is the ultimate document that gives important geological and reservoir information that will include factors such as:
- Lithology of formations
- Reservoir tops and markers
- Fluid types and contacts
- Fluid (gas-water-oil) properties
- Pore Pressure predictions
The first thing is seal evaluation is to determine type and distribution. A shale seal for example, if thick enough, has a high tendency to seal. But this is not always the case as the presence of fractures could compromise the seal. No seal is completely sealing or completely leaking. It is the degree of competency that is tested in seal evaluation. The seal efficiency test the leakage through capillary entry into pore throats in the seal, while integrity tests the resistance of the seal to microfracturing under a given pressure.
Our seal evaluation uses seismic, log data, fluid sampling, core data and pressure or temperature values to infer seal behavious with respect to underlying reservoirs. Seal and reservoir conditions, reservoir types and source of hydrocarbon are taken into consideration in the analyses. We provide reports to predict both Seal Efficiency (Capillary Entry) and Seal Integrity (Top Seal Hydrofracture).