摘要
常用衰减梯度法流体检测主要利用地震波穿过含油气储层时存在明显吸收衰减的原理,采用振幅能量截止值法求取高频端能量衰减梯度值,以此为依据来判断储层含油气性.该方法在不少油田中取得了较好的应用效果,但笔者在实际油田应用中发现该方法存在一定的缺陷,存在一定的油层误判现象.本文通过理论推导、正演论证,证实储层含油气后,存在低频能量增强、高频能量衰减的现象,并结合实际地震资料频谱曲线特征,提出一种多参数算法放大油气异常现象,提高油气预测准确率.该方法在渤海A油田的油层预测中吻合率达到90%以上,相较于常用方法有效降低误判率.在对B砂体的含应用中,成功预测高丰度油气区并部署水平井,投产初期达到日产油250方,证明该方法具有很好的效果.
Absorption and attenuation of seismic wave passing through oil-gas reservoir is mainly used in fluid detection by attenuation gradient method.The gradient value of energy attenuation at high frequency is obtained by amplitude energy cut-off method,which is used to judge the oil-gas property of reservoir.This method has achieved good application results in many oilfields,but the author found that there are some defects in the application of this method,and there is a certain phenomenon of reservoir misjudgment.In this paper,through theoretical derivation and forward demonstration,it is confirmed that there is the phenomenon of low-frequency energy enhancement and high-frequency energy attenuation in oil-gasr eservoir.Combined with the characteristics of the spectrum curve of the actual seismic data,a multi parameter algorithm is proposed to amplify the oil and gas anomalies and improve the accuracy of oil and gas prediction.The coincidence rate of this method is more than 90%in the reservoir prediction of Bohai A oilfield,which can effectively reduce the misjudgment rate compared with the common methods.In the application of sand body B,the high abundance oil and gas area has been successfully predicted and horizontal wells have been deployed.The daily oil production has reached 250 cubic meters at the initial stage of production,which proves that this method has a good effect.
作者
马佳国
夏同星
周卿
郭帅
MA Jia-guo;XIA Tong-xing;ZHOU Qing;GUO Shuai(Tianjin Branch of CNOOC Limited,Tianjin 300459,China)
出处
《地球物理学进展》
CSCD
北大核心
2020年第5期1832-1836,共5页
Progress in Geophysics
基金
中海石油(中国)有限公司综合科研项目“渤海双高油田挖潜关键技术研究”(YXKY-2018-TJ-04)资助.
关键词
衰减梯度
烃类检测
频谱曲线
渤海油田
Attenuation gradient
Hydrocarbon detection
Spectrum curve
Bohai Oilfield
