Study on characterization of interlayer heterogeneity in commingling production reservoirs

Abstract

Accurate characterization of interlayer heterogeneity is the key to solving the problem of severe interlayer disturbances caused by large well sections in commingling production reservoir. The numerical applicability of the Lorenz method in development field is investigated by experiments and reservoir engineering theories because it is the most commonly employed method for describing interlayer heterogeneity， but its applicability remains uncertain. The study reveals that the Lorenz method’s characterization of the heterogeneity has a weak correlation with development effects， exerting significant influence on development effects only within a localized sensitive range. Additionally， curve shape also affects development effects when Lorenz coefficients are equal， but traditional methods are ineffective in capturing this phenomenon. Consequently， a modification to the Lorenz method is introduced， followed by physical simulation experiments and validation with oilfield data. Experimental results demonstrate that the modification significantly broadens the sensitive ranges of Lorenz coefficients， leading to a substantial enhancement in the correlation between waterflooding development effects and Lorenz coefficients. Example applications show that the correlation coefficient between the Lorenz coefficients after the modification and recovery factors increases from 0.48 to 0.87 in the KL-A area and from 0.74 to 0.87 in the KL-B area. This highlights a significant enhancement in the correlation between interlayer heterogeneity and development indicators.

Keywords

• commingling production
• interlayer heterogeneity
• lorentz method
• bohai kl oilfield
• development indicator