不同干燥岩石体积模量计算方法在S油田的对比分析研究

Comparative analysis of bulk modulus calculation methods of different dry rocks in S Oilfield

时移地震随着OBN等海上先进采集技术的发展而得到越来越多的重视,相对传统采集技术,以OBN为代表的先进采集技术提升了时移地震资料质量,为更好地认识油气藏提供了宝贵的资料,但现阶段S油田尚未形成相适应的时移地震解释技术,目前还面临着定量化程度不够、双因素油藏参数变化引起时移地震差异规律认识不清等问题,究其原因是S油田所用的时移地震岩石物理手段研究尚不够成熟,优选出适用的干燥岩石体积模量计算方法对形成可靠的时移地震岩石物理手段非常重要,基于S油田岩石物理测试数据和油藏数据,从预测体积模量与实测体积模量对比、预测体积模量在纵波速度预测方面的应用两个角度开展分析,指出在有效压力大于等于S油田目前最低有效压力时,Macbeth法是四种方法中最优的方法,在提供两个样本的体积模量预测中,最大预测误差绝对值也仅有5.28%,且预测的纵波速度预测误差平均绝对值也只有3.16m/s。实际应用表明Macbeth法针对一定孔隙储层在已知三个压力测量参数情况下具有较好的计算精度。

With the development of advanced offshore acquisition technologies such as OBN,time-shifted seismic data has received more and more attention.Compared with traditional acquisition technologies,advanced acquisition technologies represented by OBN have improved the quality of time-shifted data and provided valuable data for a better understanding of oil and gas reservoirs.However,the S Oilfield still needs to form a suitable time-shifted seismic interpretation technology,which still faces problems such as insufficient quantization and unclear understanding of time-shifted seismic differences caused by the change of dual factor reservoir parameters.The reason is that the research on the time-shifted seismic rock physical means used in the S Oilfield needs to be more mature.It is essential to select a suitable method for calculating the bulk modulus of dry rock to form a reliable time-shifted seismic petrophysical methods.This paper compares the predicted bulk modulus with the measured bulk modulus.It applied the predicted bulk modulus in the longitudinal velocity prediction based on the petrophysical test data and reservoir data of the S Oilfield.It is pointed out that when the effective pressure is greater than or equal to the current minimum effective pressure of the S Oilfield,the Macbeth method is the optimal method among of the four methods.In the bulk modulus prediction with two samples,the maximum absolute value of prediction error is only 5.28%,and the average absolute value of prediction error of longitudinal wave velocity is only 3.16m/s.The practical application shows that the Macbeth method has good calculation accuracy for a specific pore reservoir with three known pressure measurement parameters.