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Oil Initially In Place (OIIP) is the total hydrocarbon resource in an oil and gas field. It is the total amount of petroleum that is estimated to exist in the reservoir before production. OIIP can also be referred to as Total Petroleum Initially In Place (TPIIP).
Before oil and gas companies can begin exploring and producing resources, they must first estimate how much total petroleum is contained in a particular reservoir. This is known as ‘Oil & Gas Reserved Estimation’ using geological data and seismic data in order to estimate the volume of oil and gas contained in a reservoir. A common method used to estimate OIIP is known as the volumetric method which is when the Underground Study Team (USM) calculates the deposit size by examining the geology of the region and assesses the total amount of hydrocarbons assuming that the reservoir is 100% saturated with oil.
Taking into account the characteristics of the rock, such as porosity and permeability, the USM can calculate the pore volume of the rock and from that extrapolate to calculate the volume of oil contained in the rock. However, it is important to emphasise that the calculation of OIIP is an estimate and there is no guarantee that this estimated volume of oil can be extracted from the reservoir due to several environmental, economic, and technical constraints.
Estimating OIIP is a difficult but integral part of the oil and gas production planning process. Calculating OIIP enables oil and gas companies to determine a fair price for leases, aiding the planning of exploration wells, and helping them to assess their field development plans. It also plays a vital role in the economic evaluation of a project, as well as helping to manage the risk involved in determining production strategy and well placements.
In conclusion, OIIP is the total amount of petroleum expected to exist in an oil and gas reservoir before production is commenced. It is an estimate created through the use of various methods such as seismic studies and the volumetric method. OIIP plays a key role in the production planning process, as well as in economic evaluation, and risk management.
Before oil and gas companies can begin exploring and producing resources, they must first estimate how much total petroleum is contained in a particular reservoir. This is known as ‘Oil & Gas Reserved Estimation’ using geological data and seismic data in order to estimate the volume of oil and gas contained in a reservoir. A common method used to estimate OIIP is known as the volumetric method which is when the Underground Study Team (USM) calculates the deposit size by examining the geology of the region and assesses the total amount of hydrocarbons assuming that the reservoir is 100% saturated with oil.
Taking into account the characteristics of the rock, such as porosity and permeability, the USM can calculate the pore volume of the rock and from that extrapolate to calculate the volume of oil contained in the rock. However, it is important to emphasise that the calculation of OIIP is an estimate and there is no guarantee that this estimated volume of oil can be extracted from the reservoir due to several environmental, economic, and technical constraints.
Estimating OIIP is a difficult but integral part of the oil and gas production planning process. Calculating OIIP enables oil and gas companies to determine a fair price for leases, aiding the planning of exploration wells, and helping them to assess their field development plans. It also plays a vital role in the economic evaluation of a project, as well as helping to manage the risk involved in determining production strategy and well placements.
In conclusion, OIIP is the total amount of petroleum expected to exist in an oil and gas reservoir before production is commenced. It is an estimate created through the use of various methods such as seismic studies and the volumetric method. OIIP plays a key role in the production planning process, as well as in economic evaluation, and risk management.