准噶尔盆地结构的石油物探综合解析

THE COMPREHENSIVE INTERPRETATION OF EOPHYSICAL DATA ON JUNGER BASIN BASE

准噶尔盆地经过50年石油物探工作,取得了丰富资料,对盆地地质结构的认识有了突破性进展.资料显示,二叠系与上下地层之间,存在一个比较明显的密度分界面,对认识和分析盆地重力场特征和异常极有帮助.各时代地层的磁性差异显示,二叠纪及中新生代沉积岩属弱(非)磁性(18×10-6~85×10-6 CGSM),内部磁性差异只能引起小幅度的微弱异常.石炭纪及其以前时代的变质岩、火成岩的磁化率都很大,平均在数百个单位以上,特别是火成岩的磁化率可达数几千至数万单位.这些具有磁性的火成岩,在准噶尔盆地均产生明显局部异常,20世纪70年代以前,石油工作者认为是盆地的磁性基底.与此同时,盆地周围大规模的区域地质调查证实,周边广泛分布的主要是上古生界地槽型沉积建造,而且多是火山碎屑岩沉积,下古生界很少,未发现可靠的前寒武纪露头.地震解释技术从二维到三维、从区块三维到区带三维,不仅从宏观上认识了盆地基底结构、沉积盖层等盆地地质结构,而且能从微观上认识圈闭、储层,在含油气有利构造的发现及石油勘探方面发挥了巨大的作用.

The rich geophysical data have been obtained over 50 exploration for Junger basin ,the knowledge on basin structures have achieved breakthrough , there is significant density surface between upper and lower strata of Triassic period ,which provide helpful greatly for analyzing and interpretation gravity features. The magnetic differences of different period show that Permian,Mesozoic and Cenozoic deposits belong to wreaker magnetism(18-8510-6CGSM), inner magnetic differences can caused light magnitudes anomaly, but Carboniferous and former metamorphic rock and volcanic rock have vary greatly magnetization ,averaged above hundreds thousands units ,these magnetic volcanic rock giving rise to the clear magnetic anomaly, which caused apparent local anomalies of basin base that was thought magnetic base of Junger basin in 70's 20 century by former petroleum workers, meanwhile, the regional geology data in the surrounding of basin confirming , what the periphery extensively distributed chiefly is the upper Paleozoic geosynclines deposit and t mostly be the volcanic rock deposit , next Paleozoic strata is seldom, preceding Cambrian Period is not discovered in the surface. The explain technology of 3D or 2D seismic data that play a important role not only in knowing the basin geology structures , deposit rock etc, but also in knowing traps , reservoir, and local structure as well as next exploration domain.