深度域波形指示反演在薄储层预测中的应用:以苏里格气田陕18区块为例

由于地震分辨率的限制,传统的时间域反演方法很难精确预测薄储层的三维空间分布,极大制约了该类储层发育区高效水平井组的部署.要实现这类薄储层的精确预测,关键在于如何井震结合、拓宽频带,获得合理的高频成分.通过对比分析当前主流的反演方法,笔者提出深度域地震波形指示反演方法,该方法能够精确识别陆相薄层砂岩储层.以苏东南地区陕1...

Application of depth-domain waveform indication inversion in thin reservoir prediction:a case study of Shan-18 block in Sulige gas field

Due to the limitation of seismic resolution,traditional time-domain inversion methods are difficult to accurately predict 3-D spatial distribution of thin reservoirs,which greatly restricts the deployment of high-efficiency horizontal well groups in this type of reservoir.To achieve accurate prediction of such thin reservoirs,the key lies in how to combine wells and seismics,broaden the frequency band,and obtain reasonable high-frequency components.By comparing and analyzing the current mainstream inversion methods,it is proposed that the depth-domain seismic waveform indication inversion method can accurately identify the terrestrial thin sandstone reservoirs.This paper takes the thin interbedded sandstone developed in braided river delta facies of Shan-18 block in the southeastern part of Sulige as an example.On the basis of ensuring the matching of drilling geological stratification with depth-domain seismic interpretation horizons,the number of effective samples and the maximum optimal cut-off frequency were determined,and the error analysis were further conducted.On this basis,the depth-domain seismic waveform indication inversion technology is used to carry out reservoir prediction research on the thin interbedded sandstone gas reservoirs in the study area.The research results show that①though effectively avoiding the loss and error accumulation of high-frequency information during the conversion of logging curves from the depth domain to the time domain,the identification accuracy of thin reservoirs is effectively improved;②the thickness of the thin layer predicted by the seismic waveform indication inversion with a error of 5~6 m,the prediction effect is good,the quantitative characterization of thin sandstone reservoirs has been realized,and a reliable data foundation has been laid for the deployment of horizontal well groups.This method can make full use of the lateral change information of the depth-domain seismic waveform,and the high-frequency structure is controlled by the waveform change,which better reflects the constraints of the depositional environment.While improving the vertical resolution,its lateral predictability is also effectively guaranteed.