Production Variation Law Of The Waterflood Oilfield In Liaohe Province At Different Development Stages

Oilfield waterflood development is a widely used recovery method. Now, the reserves recovered by waterflood development account for 50.4% of the whole province in Liaohe Oilfield. Most of the oilfields are already at the medium-high water cut period. In this paper, the waterflood development blocks in Liaohe Oilfield are classified into medium-high permeable waterflooding sandstone reservoir, low permeable waterflooding sandstone reservoir, complex fault-block oil reservoir and burial hill oil reservoir. Further more, this paper shows the development stages classification based on the main problems existing in each reservoir and indicates production variation law at different stages and analyzes the main factors affected the waterflood. Include in this paper are also comprehensive waterflood development effect evaluation, and tap potential countermeasure adjustment and further production variation tendency forecast of waterflood oilfield, which provide scientific foundation for oilfield development.Development stages classification relies mainly on production variation while making water cut variation subsidiary, therefore, the waterflood oilfields in Liaohe Province can be classified into three types. Fuzzy comprehensive evaluation and uncertain value estimating model of different types of reservoirs at different stages are established to conduct comprehensive evaluation and sequencing for the current development effect of the waterflood development reservoirs in the whole province.According to the fact that most oilfields are in high water cut and production declining stage, some techniques, such as actively adopting and perfecting secondary recovery technique, spreading tertiary recovery with lower cost, taking further steps to perfect flood pattern, extending waterflood swept volume, enhancing utilization factor of the injected water, improving producing degree of the non-major layer, are put forward based on the fine reservoir description and remaining oil distribution to realize the accurate tap potential for the highly complex distributed remaining oil, continuously increase recoverable reserves, make efforts to slow down the decline and improve the development effect.Production forecast model suitable for different development stages in Liaohe Oilfield is selected to predicate the further production tendency.