岩性目标油气检测技术在琼东南盆地的应用  

Application of oil and gas detection technology for lithological targets in Qiongdongnan Basin

作　　者：黄饶 王建花 叶云飞 牛聪 凌云 HUANG Rao;WANG Jianhua;YE Yunfei;NIU Cong;LING Yun(CNOOC Research Institute Co.Ltd,Beijing 100028,China;National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]海洋油气勘探国家工程研究中心,北京100028

出　　处：《石油地球物理勘探》2024年第2期320-330,共11页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“莺琼盆地超高温压跨频段地震岩石物理响应机理研究”(U20B2015);中海油“十四五”重大科技项目“高精度地震勘探技术”(KJGG2022⁃0304)联合资助。

摘　　要：琼东南盆地超深水区Y目标储层为受多级断阶控制的高位域三角洲水下分流河道砂体,钻井资料揭示的气层和水层在地震资料上均表现为“亮点”,并具有远道增强的第Ⅲ类AVO特征,常规基于振幅信息的油气检测结果存在多解性。为此,提出一种充分利用地震数据的振幅、频率和相位信息的地震全信息烃类检测技术。首先,从地震正演出发综合分析砂岩储层叠后、叠前地震响应特征及其影响因素,指出孔隙度和气层厚度是影响利用振幅信息识别流体的主要原因,明确了基于振幅信息可以识别厚层含气砂岩;其次,通过地震反射频谱分析指出造成气层主频降低、频带变窄的主要原因是含烃引起的地震波衰减;最后,通过数值模拟表明厚层气砂和水层背景下的薄层气砂均表现为明显的吸收和相位异常,可以利用与地震波衰减相关的频率、相位信息开展含油气检测。研究区实际应用表明所提方法能够有效区分气层和水层,检测结果与实钻结果相吻合,为钻井实施提供了可靠依据,有效降低了勘探风险。The Y target in the ultra deep water area of Qiongdongnan Basin is a high⁃level delta underwater distributary channel sedimentary reservoir controlled by multi⁃level fault steps.The gas and water layers revealed by drilling data are both shown as“bright spots”in seismic data and have ClassⅢAVO features with amplitude enhancement along offset.Conventional oil and gas detection results based on amplitude information have multiple solutions.Therefore,a seismic full information hydrocarbon detection technology that fully utilizes the amplitude,frequency,and phase information of seismic data is proposed.Firstly,this paper comprehensively analyzes the post⁃stack and pre⁃stack seismic response characteristics of sandstone reservoirs and influencing factors via seismic forward modeling.It is pointed out that poro⁃sity and gas layer thickness are the main reasons affecting fluid identification by using amplitude information and proves that thick gas⁃bearing sandstones can be identified based on amplitude information.Secondly,the seismic reflection spectrum analysis shows that the attenuation of seismic waves caused by hydrocarbon layers is the main reason for the decrease in the main frequency and bandwidth of gas reservoirs.Finally,numerical simulation shows that both thick gas sand and thin gas sand under the background of water layers exhibit obvious absorption and phase anomalies,so the fre⁃quency and phase information related to seismic wave attenuation can be used for oil and gas detection.The application in the research area shows the proposed method can effectively distinguish between gas and water layers.The detection results are consistent with the actual drilling results,and provide a reliable basis for drilling implementation as well as effectively reduce exploration risks.

关 键 词：琼东南盆地三角洲 岩性目标 AVO 地层吸收 子波相位 油气检测 

分 类 号：P631[天文地球—地质矿产勘探]