咸化湖相高分辨率层序地层特征与致密油储层分布规律：以吉木萨尔凹陷A区芦草沟组为例
Characteristics of the Highresolution Sequence Stratigraphy and the Distribution of Tight Oil Reservoirs in the Salt Lake: A Case from the A Region of Lucaogou Formation, Jimsar Sag

摘要： 依据岩心、录井和测井等资料，以高分辨率层序地层学理论为指导，对吉木萨尔凹陷A区芦草沟组各级次基准面旋回演化规律及高分辨层序地层模式进行研究。研究表明，芦草沟组发育1个长期基准面旋回、6个中期基准面旋回、44个短期基准面旋回。探讨了咸化湖相各短期旋回的层序结构、叠加样式及空间变化；建立了A区芦草沟组高分辨层序地层对比格架。通过对基准面旋回期间体积分配和相分异的分析，得出了短期基准面旋回形成优质致密油储层的沉积相类型及控制因素；认为致密油储层段恰好位于2个升降旋回的转换面处，为半深湖-浅湖亚相的碳酸盐岩、席状粉砂岩等细粒沉积，因此2个旋回的基准面下降半旋回控制着上下致密储层的发育；微相类型控制着致密储层的位置与质量。该认知对于指导A区甚至咸化湖相高精度地层对比具有重要意义。
Abstract: Based on cores，log and welllog data, under the guidance of the theory of the highresolution sequence stratigraphy, evolution of all levels baselevel cycles and highresolution sequence stratigraphic model were analyzed in the A region of Lucaogou Formation of Jimsar Sag. The results show that 1 longterm, 6 middleterm and 44 shortterm baselevel cycles were classified. According to the structural feature, stacking pattern and spatial variation of shortterm baselevel cycle, the authors established A region of Lucaogou Formation highresolution sequence stratigraphic framework. By analyzing the sequence structure, stack style and space variation, suggested that sedimentary facies types and controlling factors of the high quality of tight oil reservoir is obtained by shortterm baselevel cycles; Concluded that the high quality of tight oil reservoir is located at the conversion surface of 2 eustatic cycles and formed a depositional system of carbonate and siltstone sheet from shallow to semideep lake, therefore, the 2 cycles of falling semicycle control the tight reservoir development and the types of microfacies control the position and quality of dense reservoir. This has important significant to guide the high precision stratigraphic subdivision in A region and even the salt lake facies