利用中子伽马测井资料确定孔隙度方法研究

Method for Determining Porosity by Using Neutron Gamma Logging Data

孔隙度是储集层评价的重要参数,在研究的部分老井中,只有自然电位、电极系电阻率及中子伽马测井,没有估算孔隙度的测井曲线,给储集层评价及油水识别带来了不便。为了解决该问题,利用中子伽马测井曲线,结合岩心分析资料,分别利用中子伽马的条件单位方法和归一化方法建立了孔隙度的模型,并对实际测井资料进行处理。结果表明,估算的孔隙度合理可靠,与岩心孔隙度对比,误差很小,可在没有孔隙度测井系列的井中推广使用。

Porosity was one of the important parameters for reservoir evaluation,in the study of part of the old wells,well logging curves were mainly self-potential logging and electrode array resistivity logging and neutron gamma logging,there was no logging curve for estimating porosity,inconvenience was induced in the reservoir evaluation and identification of oil and water.In order to solve the problem,in this paper,by using neutron gamma logging curve and combined with core analysis data,aporosity model is established by using the 'condition unit'of neutron gamma ray and the method of'normalization'according to the principle of neutron gamma logging and the actual logging data are processed.The results show that the estimated porosity is reasonable and reliable,compared with core porosity,error is very small,it can be popularized in the wells without porosity logging series.