Abstract
The dimensionless productivity index is an important indicator for measuring the oil production capacity of oilfields. The traditional calculation method of the dimensionless productivity index is not suitable for the continuous multiple development phases of oilfields. In this study, based on Darcy’s Law and the theory of non-piston leading edge propulsion, we considered the influence of capillary pressure and derived a differential equation for leading edge propulsion distance. We established a calculation model of the dimensionless productivity index that is suitable for the multiple development phases of oilfields, including water flooding, polymer flooding, and binary compound flooding. The model was applied to the W block of the JZ9-3 oilfield, and the calculation results of the model were compared with the actual statistical results. The results show that the calculation error rates of the dimensionless productivity index in three phases of oilfield development are 4.67%, 17.65%, and 18.50%, respectively, and the average error rate is 10.38% in the overall development phase. The dimensionless productivity index curve shows a trend of first rising, then falling, and finally stabilizing when the pore volume number is included. This calculation model expands the field application scope of the theoretical dimensionless productivity index, which is convenient for application in oilfields, and improves the efficiency of the comprehensive evaluation of oilfields during multiple development phases.
Highlights
The dimensionless productivity index is the ratio of liquid production to oil production during the initial anhydrous production period of an oilfield
Based on the traditional calculation model of the dimensionless productivity index, we considered the influence of capillary pressure, and derived the formula for calculating the dimensionless productivity index in the water flooding-polymer flooding-binary compound flooding stages
The dimensionless productivity index model established in this paper was used to calculate the liquid productivity index in this W Block, and the calculation model established was compared with the dimensionless productivity index calculated from the actual statistical data of the mine
Summary
The dimensionless productivity index is the ratio of liquid production to oil production during the initial anhydrous production period of an oilfield. Using the relative permeability curve, Jiang et al [12] deduced the formula of dimensionless productivity index under different water conditions without considering the change in fluid properties with pressure. This formula can be used to predict the liquid supply capacity of a certain small layer. Li [16] deduced the formula for calculating the dimensionless productivity index of low permeability reservoirs considering capillary pressure. The research methods of the change rule of the dimensionless productivity index based on the theory of seepage mechanics are mostly based on the water flooding development stages of single-layer and single wells. The JZ9-3 oilfield can be used to verify the feasibility of the calculation model and for comparison with the actual data provided by the field data to verify accuracy of the calculation method, providing guidance for later oilfield development
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
