录井水淹层评价技术用于朝阳沟油田低渗透油层的射孔选层

Use water-flooded zone evaluation of mud logging technology to choose perforated intervals of low-permeability oil layers in Chaoyanggou Oilfield

朝阳沟油田属大庆外围低渗透油藏,经过几十年注水开发,含水逐渐升高,油水关系复杂,储集层剩余油挖潜难度日趋增大。在应用岩石热解、热解气相色谱、荧光显微图像解释评价水淹程度的基础上,通过归纳近两年来朝阳沟油田所钻的两口密闭取心井资料以及其他投产井资料,总结低渗透油层剩余油的录井资料特征,可以较准确地认定低渗透储集层剩余油富集部位,较好地判断储集层剩余油分布情况及潜力,进而建立朝阳沟油田剩余油射孔选层依据为:1剩余油饱和度应该大于37%的油层;2热解气相色谱主峰碳响应值大于1.2mV,且解释为中水淹以下的油层;3厚度一般大于1.5m的油层。实践证明,该方法在朝阳沟油田低渗透油藏开发应用中取得了较好的效果。

Chaoyanggou Oilfield belongs to peripheral low-permeability oil reservoirs in Daqing,after decades of waterflooding,water cut is gradually increasing,the relationship of oil and water is complex and it is increasingly difficult to tap the potentialities of the remaining oil of the reservoirs.On the basis of using the methods of rock pyrolysis,pyrolysis gas chromatography and fluorescence micro-image to interpret and evaluate the flooded degree,and generalizing the data from 2sealed coring wells and the other brought in wells of the past two years in Chaoyanggou Oilfield,the features of mud logging data for remaining oil of low-permeability oil layers were summed up,which can correctly determine the remaining oil enriched site of the low-permeability reservoirs,better judge the remaining oil distribution and potential,the criteria for choosing the perforated intervals of the remaining oil in Chaoyanggou Oilfield were set up,that is,the remaining oil saturation of oil layers should be over 37%;the peak carbon response of oil layers is over 1.2mVfor pyrolysis gas chromatography and the water-flooded grade is below medium water-flooded grade,and the thickness of oil layers is over 1.5m.The methods have got good results in developing low-permeability oil reservoirs of Chaoyangdou Oilfield.