北海维京地堑侏罗纪构造沉积演化

TECTONIC-SEDIMENTARY EVOLUTION OF JURASSIC IN VIKING GRABEN,THE NORTH SEA

维京地堑侏罗系是主要的生油岩,浅海相砂岩及深水海底扇砂岩是主要的储层,因此,研究其构造沉积演化具有重要意义。从北海维京地堑侏罗纪时期的构造演化入手,研究了构造对于沉积的控制。研究发现,研究区侏罗纪经历了2期构造演化阶段,分别为早—中侏罗世时期的热沉降阶段和晚侏罗世的地壳伸展阶段。热沉降阶段早期发育海相沉积至中侏罗世时期,海相沉积环境逐渐演变为陆相三角洲相沉积体系。地壳伸展阶段发育深水海底扇沉积。根据以上认识,最终建立了2种北海维京地堑侏罗纪构造沉积模型。

The Jurassic contains the major source rock in the Viking Graben,with shallow-marine sandstones and deep-water submarine-fan sandstones as main reservoirs.Careful study of tectonic-sedimentary evolution is the key to oil and gas exploration.The Jurassic in the Viking Graben could be divided to two phases： Early-Middle Jurassic thermal subsidence and Late Jurassic active stretching phases.In the early stage of the thermal subsidence phase,marine depositional environments prevailed.But in the Middle Jurassic stage it is dominated by a non-marine delta depositional system.In the phase of active stretching,there formed a deep-water submarine-fan system.Based on the facts mentioned above,two tectonic-sedimentary models were established for the Jurassic in Viking Graben of the North Sea.