准中1区块古构造恢复及其演化对油气成藏的作用

准噶尔盆地中部1区块油气的成藏受车莫古隆起演化的影响较大,晚白垩世及古近纪时期是主要成藏期及调整期。文中通过目的层选取、计算地层残余厚度、去压实校正、建立压实参数平面分布模型等步骤,求得油气成藏调整期车莫古隆起的真实地层沉积厚度,以此来反映古构造特征及演化,据此分析目的层古油藏的规模及油气运聚规律,指出下一步有利勘探方向。研究表明:区内晚白垩世存在2个古背斜,是油气有利运聚方向,并通过含油包裹体、测录井、试油资料综合确定了古油水界面及古油藏的规模。工区古近纪初北部开始隆升,古背斜逐渐消失,到现今古背斜调整成为低幅构造梁。古构造破坏后,部分圈闭仍存在,能保留大量原生油气,为原生保留型油藏,部分油气经微幅构造梁调整后,在现今有利构造位置处的圈闭聚集,形成调整再聚集型油藏。建议围绕古背斜及与古背斜形成优势运移路径进行勘探。

Recovery and evolution of paleostructure of Block 1 in central Junggar Basin on hydrocarbon accumulation

Hydrocarbon accumulation of Block 1 in central Junggar Basin was strongly influened by the Che-Mo paleo-uplift.Late Crataceous and Paleogene periods were the main stages for petroleum accumulating and adjusting.By selecting the target layer,calculating the thickness of the residual stratum,correcting the compaction parameters,building the compactions parameter model,the real depositional thickness of paleo-uplift to reflect the characteristics of the paleostructure was finally reconstructed during the main stages of petroleum accumulating and adjusting.Thus the scale of paleo-reservoir and hydrocarbon accumulation rule in target layer was analyzed,as well as the favorable exploration area was pointed out for further exploration.This research shows that there are two paleo-uplifts in the late Cretaceous period,which are the favorable areas for oil and gas accumulation.By analyzing the information of GOI,logging and testing,the paleohydrocarbon-water interface and the paleo-reservoir scale are ascertained.During early Paleogene,the north section of research area began uplifting,paleo-uplift tends to disappear,and nowadays the paleo-uplift has become a low-relief ridge.After the destruction of the paleo-structure,traps partially survived,which still preserves a lot of original hydrocarbon.Parts of the hydrocarbon migrating along the low-relief ridge became the re-accumulate hydrocarbon which trapped in the favorable structural position.It is suggested that the exploration should be focus on paleo-anticline as well as the advantageous migration pathways formed by them.