南方海相碳酸盐岩油气区地震采集面临的问题和对策

The problem and countermeasure in seiamic survey in southern marine carbonate area of China

中国石油化工集团公司油田企业经营管理部,北京 100029

Oilfield Management Ministry, SINOPEC, Beijing 100029, China

我国南方海相碳酸盐岩油气区总面积200×10⁴多km³,中、古生界海相地层油气勘探区的面积达90×10⁴多km²,但由于该区地震地质条件复杂多变,干扰波发育,导致地震资料信噪比低,因此,提高资料的信噪比是该区油气勘探的重中之重。为此,针对南方海相碳酸盐岩油气区的地震地质特点,系统地分析和总结了地震采集所面临的问题和造成资料信噪比低的原因:①地表条件复杂多变,有平原水网区、碳酸盐岩出露区、砂泥岩出露区等;②地层时代老,地震反射信号弱;③地下构造复杂等。针对地震采集难点,从表层地质结构调查、激发接收因素、干扰波、观测系统设计等方面进行了深入的讨论,结合勘探实践,提出了相应的对策和技术。

The marine carbonate petroliferous area is wide in south China.Complicated geologic condition and interference wave lead to low S/N ratio, so improving S/N ratio is very important. The paper is analyzed the problem and cause facing to seismic survey aimed to seismic geologic character, such as complicated surface including water system in plain,outcrop in carbonate area and outcrop in sand-shale area; the old stratum age, the reflection signal poorly; as well as complicated subsurface structures. Structure survey in surface geology, shot receiving factor, interference wave and observation system design are discussed. Finally, corresponding countermeasure and technology are proposed according to exploration practice.