PETROLEUM RESERVES CALCULATION IN CARBONATE FORMATIONS METHOD USING RESERVOIR CONTROLLED UNIT COEFFICIENTS

Unit coefficient refers to hydrocarbon bearing volume in unit reservoir.In reserves calculation,it is in direct ratio to oil saturation which has a close relationship with hydrocarbon accumulation degree.On this basis,a method used in reserves calculation in carbonate formation with unit coefficient is put forward in this paper.For a certain reservoir,unit coefficient can be defined through comparing petroleum geological surroundings to conditions of the other known reservoirs.Reservoir thickness can be defined according to well condition and regional karst distribution.This method is more advantageous in carbonate formations due to the following points: taking full consideration of hydrocarbon transportation and accumulation;finding the key points controlling oil-and-gas reservoir formation;comparing petroleum geological surroundings with conditions of the known area.In parameters definition,more geological factors can be taken into consideration,and difficulties in reserves calculation with volume method can be avoided,therefore the result of reserves calculation with unit coefficient is more reasonable.