鄂尔多斯盆地HH油田长8储层特征及流体快速识别研究

针对鄂尔多斯盆地HH油田长8储层油层识别率低的难题,开展了储层特征、储层与测井响应机制研究,分析了研究区流体识别难题的实质,认为高束缚水饱和度和地层水矿化度多变以及局部钙质充填是造成部分井油层低阻、水层高阻的原因.借助常规测井曲线,选择尽量能反映储层流体信息的测井参数,构建了利用计算自然电位-实测自然电位、声波时差-深感应电阻率重叠法进行油层快速识别的方法,其中计算自然电位-实测自然电位重叠法回避了孔隙结构、泥浆和地层水电阻率带来的影响,减少了误差来源,无论是否低阻储层,都能有效识别.声波时差-深感应电阻率重叠法对储层流体反应灵敏,能较好地区分高阻水层与油层.以上两种流体识别技术对于类似储层流体识别具有一定的借鉴意义.

Research in the characteristics and the fast identification methods of fluid property of Chang 8 reservoirs in HH Oilfield,Ordos Basin

The accurate identification of the fluid property of Chang 8 reservoirs in HH Oilfield is difficult.For resolving the problem,the features and the logging response mechanism of the reservoirs are studied.It is held that,high irreducible water saturation and high salinity of formation lead to the low resistivity of oil layers,while the existence of calcareous cement leads to the high-resistivity of water layers,which are why the fluid property of the Chang 8 reservoirs can not be accurately identified.The fast identification methods of fluid property of Chang 8 reservoirs are presented,and they are realized by overlapping of calculated spontaneous potential curve with practically measured spontaneous potential curve and acoustic time resistivity curve with deep induction resistivity curve.The overlapping of calculated spontaneous potential curve with practically measured spontaneous potential curve can avoid the effect of pore structure,mud and water on the resistivity of reservoirs,the overlapping of acoustic time resistivity curve with deep induction resistivity curve is sensitive to the reservoir fluids and can well distinguish high-resisitivy water layers from oil layers.The cases show that all the two methods could effectively identify the fluid property of Chang 8 reservoirs,which provides the reference for the fluid identification of analogous reservoirs.