层序地层三维体解释技术在歧口凹陷中的应用

Application of 3-D Cube Technology of Sequence Stratigraphy in Qikou Depression

歧口凹陷是渤海湾盆地内的一个富油凹陷,近年来开始利用层序地层学理论及其工作方法寻找各类油气藏,特别是岩性油气藏,但多局限于单井和二维层序地层分析,不仅不能充分发挥地震、测井、岩心资料的作用,而且由于该凹陷具有多物源、近物源、相变快的特点,容易造成层序地层分析的多解性。2007年对凹陷主体3150km2三维地震资料进行连片时间偏移处理,地震资料品质明显提高。研究以歧口凹陷勘探实践为例,充分利用三维大连片数据体,提出了层序地层三维体解释技术的概念,系统阐述了该方法的技术要点,克服了从二维角度认识地质体的片面性和不完整性,有效降低了岩性圈闭多解性,提高了岩性圈闭预测成功率,实现了岩性地层油藏的工业化勘探。

Qikou Depression was a depression with oil resources in Bohai Bay Basin. Many methods and theories were used to find out oil and gas reservoirs, especially lithologic reservoirs, however most of these methods and theories were based on 2-D seismic analysis and could not make full use of seismic, well logging and core data, as a result, they may cause multi-interpreting of analysis on sequence stratigraphy because of the complex geologic situation. In 2007, the 3150km2 3-D seismic data of Qikou Depression was disposed and the seismic quality was obviously improved, thus many geologic information from 3150km2 3-D seismic data help us make further geologic analysis. By taking the exploration practice in Qikou Depression for an example, the concept of 3-D cube technology is proposed based on sequence stratigraphy and this technology is systematically denoted. Making good use of this technology not only helps us to find more exploration targets, but also reduces the multi-interpretation of geologic phenomenon and increase success rate of lithologic trap prediction, as the result, the purpose of industrialized exploration is implemented.