Classification and differentiation adjustment methods for profile control well groups based on effective features

Aiming at the phenomena which may occur after profile control, such as decrease in water injectivity index, decrease in water content and increase in oil production, the profile control effective evaluation indicator system which can be quantized is established. On this basis, the multi-indicator evaluation classification method for profile control well groups is established by using the fuzzy clustering theory. In light of the result of classification, the differentiation adjustment measures are brought forth for different types of profile control well groups: this type of profile control agent is continuously used for the well groups with good comprehensive assessment of profile control effect; for the well groups with poor comprehensive assessment, based on the main indicators affecting the assessment result, by further analyzing the distributive location, physical property parameter and profile-control injection parameter characteristic of this block, this reason of poor adaptability of this type of profile control agent is found and the profile control plan is adjusted. Such method has been used to classify 16 profile control well groups in a block of Fuyu Oilfield, the profile control program for well groups with poor effect has been adjusted, and thereafter, the oil production per well has increased by 472 t in average, with the effect rate of profile control reaching 81%. The established classification and differentiation adjustment strategy for profile control well group may be used to evaluate the profile control effect of fractured reservoir, and can provide the guidance for subsequent formulation of adjustment measures.