油气敏感频率段极值能量和因子及其在渤海油田油气检测中的应用

Peak energy sum in hydrocarbon sensitive frequency range and its application to the Bohai Oilfield

由于地层原油和地层水的物理性质差异小,砂泥岩物性变化影响地震反射,地震资料存在噪声等多种因素的影响,利用地震资料识别含油砂体困难大,多解性强,成功应用案例少。虽然单个含油砂体产生的地震差异小,但是油气通常在地下某一空间范围内富集,多个油气层产生的地震响应的差异总和可以被明显观测到。笔者提出了油气敏感频率段极值能量和因子进行油气检测,首先利用可变因子广义S变换进行地震资料分频处理,然后分析能够突出油水性质差异的地震频率范围并确定能量阈值,计算油气敏感频率段极值能量。对于高丰度含油气区,纵向上发育多套油气层,通过纵向上极值能量进行累加可以进一步突出油气信息,因此,极值能量和油气检测因子可有效预测高丰度油气分布区。模型数据测试证明了本文方法是有效的,将本文方法应用于渤海多个油田,油气检测的结果与钻井获得的油气分布范围吻合良好。该方法指导了多口井的成功钻探,获得了良好的应用效果。

Since the difference of physical properties between formation oil and formation water is small,the physical properties change of sand and mudstone affects seismic reflection,and there exists noise of seismic data,it is very difficult to identify oil-bearing sand bodies using seismic data in that it has strong multiple solutions,and hence the successful application cases are very few.Although it is difficult for single hydrocarbon-bearing sands to generate observable difference,hydrocarbon is accumulated in underground space,and seismic data response from multi-hydrocarbon zone could be identified easily.In this paper,the authors propose peak energy sum hydrocarbon detection method.The method first utilizes the variable factor generalized S transform to achieve frequency division,and then analyzes seismic frequency range which highlights the difference between oil and water and determines energy threshold; on such a basis,the peak energy of the hydrocarbon sensitive frequency section is calculated.For high abundance oil-bearing areas,many sets of hydrocarbon reservoirs are developed longitudinally,and hydrocarbon information can be further highlighted by accumulation of peak energy in the longitudinal direction.Therefore,the peak energy sum hydrocarbon detection factor can effectively predict the high abundance of hydrocarbon distribution.The model data test proves that this method is effective.This method was applied in several oilfields in Bohai,and the results of hydrocarbon detection are in good agreement with the hydrocarbon distribution areas obtained by drilling.This method has guided many successful drilling wells and obtained good effects.