低渗透油藏开发效果综合评价方法及应用

Comprehensive Evaluation Method for Development Effect in Low Permeability Oil Reservoirs and Its Application

大庆油田低渗透油藏开发水平差异较大,尤其是老区块存在着可采储量不足、剩余油分布零散、含水高等制约油田发展的症结。为此,在分析低渗透油藏开发特征的基础上,开展低渗透油藏开发效果综合评价方法及应用,优选反映低渗透油藏开发水平特点的5类14项参数。以朝阳沟油田扶余油层为目标储层,复核储集层实际开发水平,落实开发潜力,解决开采中出现的问题。通过校正区块井数和有效厚度,沿用套改其他参数,选用容积法复算区块的地质储量;应用模糊综合评判方法,建立不同类型区块开发效果评价标准,分析影响评价指标的主控因素,依据井网形式、开发现状,找差距、找问题、找潜力,制定一类区块水驱调整对策。结果显示,一类区块水驱效率提高,年均含水下降0.36个百分点,两年时间老井综合递减率下降0.6个百分点。目前已在朝阳沟油田扶余油层31个区块应用开发效果综合评价方法,实践表明,其适应性和可操作性较好,取得了良好的增效成果,具有推广应用前景。

The development level of low permeability oil reservoirs in Daqing Oilfield is quite different,especially in the old block,insufficient recoverable reserves,scattered distribution of remaining oil and high water cut and other problems restrict the development of the oilfield.Therefore,comprehensive evaluation method for development effect in the low permeability oil reservoirs is proposed and applied based on the analysis of development characteristics in the low permeability oil reservoirs.Fourteen parameters in five types reflecting the development levels in the low permeability oil reservoirs are optimized.Taking Fuyu reservoir in Chaoyanggou Oilfield as the target one,the actual development level of the reservoirs is reviewed,development potential is analyzed and the problems in the exploitation are solved.Through correcting well number and ef-fective thickness and using other parameters,the geological reserves of each block are recalculated by volume method.Fuzzy comprehensive evaluation method is applied to establishing evaluation standards for the develop-ment effect of each type of reservoirs.Main controlling factors of evaluation indexes are analyzed.According to well pattern and present situation of the development,adjustment countermeasures of waterflooding in type Ⅰblock are taken through finding out the difference,problems and potential.The results show that displacement efficiency of the waterflooding in the type Ⅰ block is improved,annual average water cut decreased by 0.36 percent,and composite decline rate of old wells in two years dropped by 0.6 percent.Now the comprehensive evaluation method for development effect is applied to 31 blocks in Fuyu reservoir of Chaoyanggou Oilfield.Good results of efficiency increment present that it is suitable and applicable and has the prospect of application for popularization.