东方1-1构造底辟模糊区OBN资料关键处理技术及应用

Critical processing techniques for ocean bottom node data of the diapir fuzzy zone of the Dongfang 1-1 structure and their application

东方1-1构造位于南海北部大陆架莺歌海盆地中央泥底辟构造带的北部。该区发现的东方1-1气田是莺歌海盆地发现的第一个整装浅层大气田。该区油气储量资源丰富,然而底辟模糊区成像一直是制约该区油气勘探的主要因素。原有的拖缆地震资料经过多轮次、多公司的重处理,依旧无法有效解决底辟模糊区成像问题。因此在该区进行二次三维OBN地震资料采集,针对该区地质条件以及OBN资料特点,本文提出OBN预处理、多分量联合横波噪声压制、小波域双检合并以及全波形反演(full waveform inversion, FWI)、高精度速度反演等多项关键处理技术,对改善浅层断裂结构及中深层底辟模糊区成像卓有成效,为后续目标评价工作提供可靠的基础资料。

The Dongfang 1-1 structure is situated in the northern part of the central mud diapir tectonic belt of the Yinggehai Basin on the northern continental shelf of the South China Sea.The Dongfang 1-1 gas field is the first uncompartmentalized shallow gas field dis-covered in the Yinggehai Basin.Despite abundant oil and gas reserves in this region,the imaging of the diapir fuzzy zone has been a critical factor restricting oil and gas exploration in this region.The original streamer-based seismic data,through multiple rounds of multi-company reprocessing,still failed to effectively image the diapir fuzzy zone.Therefore,the second acquisition of three-dimensional ocean bottom node(OBN)seismic data was conducted in this region.According to the geological conditions and the characteristics of OBN data in this region,this study proposed several critical processing techniques,including OBN preprocessing,multi-component joint shear-wave noise suppression,wavelet-domain dual-sensor summation,and full-waveform-inversion(FWI)high-precision velocity model-ing.These techniques effectively improved the imaging of shallow fault structures and middle and deep diapir fuzzy zones,thus providing reliable fundamental data for the subsequent target evaluation.