歧口凹陷板桥斜坡储层流体性质判别方法研究

Genesis of High Resistivity Water Layer and Identification of Fluid Property:Case Study of Banqiao Slope, Qikou Sag

歧口凹陷板桥斜坡A37井区油层纵横向变化较大,测井响应特征不一。已有的流体识别图版显示电阻率在20Ω·m以上的储层即为油层,但钻井证实低部位井储层电阻率高达30Ω·m却试油出水。显然常规流体识别图版不适用于这种高电阻水层的判别。为此,本文在高阻水层地质成因的研究基础上,通过引入泥质含量校正,建立了流体性质判别图版,并反推出计算电阻率的公式,利用曲线重叠法快速区分油水层。结论认为:该类高阻水层主要是由于沉积环境不同造成的储层岩性差异所形成,图版的建立能够识别高阻水层,并为储层流体性质的识别提供了依据。

There are great spatial variations and different logging response characteristics in the oil layers in A37 well area of Banqiao Slope,Qikou Sag.Based on the existing fluid property identification chart,the reservoirs are interpreted as oil layers with resistivity higher than 20Ω.m,but reservoirs are tested to be water layers even the resistivity up to 30Ω.m in the lower parts.Obviously,this chart is not suitable for high resistivity water layer identification.Through the geological genesis study of the high resistivity water layers,we established the oil saturation fluid property identification chart by introducing clay content correction,then,effective oil and water layers distinction was carried out in the drilling wells.The results are as follows:the high resistivity water layers are mainly formed by lithologic differences under different sedimentary environments.This new chart provides scientific basis for subsequent fluid property identification,it can be well applied in high resistivity water layers discrimination.