关键词: 二连油田, 阿南油藏, 中高含水, 重复压裂, 高砂比, 强制闭合, 稳油控水

Abstract: A set of refracturing technology systems has been proposed to counter the problems of poor effect of intermediate and high water cut periods(51% to 72%) reservoir,especially upon repeated refracturing in the same pay zone at A'nan Oilfield.The problem lies in the fact that the fracturing treatment pressure is high,the sand liquid ratio is low.The refracturing technology system includes:selection of exact destination and time,optimization of refracturing design,formulation of techniques concerning high sand concentration and forced open and close technology,strict quality control,as well as the balance of production and injection before and after refracturing.The well interval is rightly chosen by utilizing high sand ratio and forced open and close technology,aided by combination methodologies of reservoir geology,reservoir engineering,fracturing engineering, auxiliary technologies of injection, production, and fracturing.This technology has been implemented in six wells at A'nan Oilfield,raising the daily oil output to 8.1 ton from the original 2.7 ton,with the comprehensive water cut decreased to 40% from the original 60%,and the refracturing cost recovered within 14 days on the average. According to the statistics of 608-day accumulated production from the six wells after being refractured,3252 tons of oil has been added to the output, with an accumulated profit of 2.36 million yuan gained so far.And the six wells will continue to benefit from the technology.Oil stabilizing and water control has been realized to meet the demands of overall management, thus enhancing the entire refracturing levels,achieving considerable economic benefits.

Key words: Erlian Oilfield, A’nan reservoir, intermediate and high water cut, refracturing, high sand ratio, forced open and close, oil stabilizing and water control