滨里海盆地东南缘的D-I、II区块石炭系盐下KT-II及KT-I油层组碳酸盐岩储层为勘探重点,开展该储层段沉积相及沉积模式研究,可以指导该新区的下一步勘探.利用薄片、测井及地震等资料,对KT-II及KT-I油层组进行了沉积相划分及沉积相演化研究,取得如下成果:①通过岩石相、测井相及地震相特征研究,划分出局限台地、开阔台地、台地边缘及台地前缘斜坡4种沉积相.②KT-II及KT-I油层组沉积相带平面上均为北东—南西向展布,向东南方向、西北方向发生相变,由开阔台地(或局限台地)相变为台地边缘—台地前缘斜坡,东西两边分别发育台地边缘及台地前缘斜坡.③建立了KT-II及KT-I油层组碳酸盐台地—台地前缘斜坡沉积模式.KT-I油层组发育开阔台地,局部发育局限台地,其中分别发育开阔台地台内滩和局限台地台内滩,KT-II油层组发育开阔台地,其中主要发育开阔台地台内滩.④研究区石炭系经历了辫状河三角洲—浅海陆棚、碳酸盐孤立台地—台地前缘斜坡、浅海陆棚、碳酸盐孤立台地—台地前缘斜坡的沉积演化过程.通过沉积特征研究,厘清了研究区KT-II及KT-I油层组的沉积模式、沉积相展布特征,为下一步勘探部署提供了依据.

The Carboniferous subsalt KT-II and KT-I carbonate reservoirs are the focus of exploration. The study of sedimentary facies and sedimentary model of these reservoir formations can guide the next exploration in this new area. In this paper, the sedimentary facies division and sedimentary facies evolution of KT-II and KT-I members are studied by using rock slices, logging and seismic data. The results are as follows: (1) Through the study of the characteristics of lithofacies, logging facies and seismic facies, four types of sedimentary facies are identified in the study area: restricted platform, open platform, platform margin and platform margin slope. (2) The sedimentary facies belts of KT-II and KT-I members are distributed in the NE-SW direction on the plane. Sedimentary facies change from open platform (or limited platform) to platform margin-platform margin slope towards the southeast and northwest directions, with platform margin and platform margin slope developed on the east and west sides respectively. (3) The sedimentary model of carbonate platform -platform margin slope of KT-II and KT-I members is established. Open platform is developed in KT-I member, and limited platform is developed locally, in which open platform inner shoal and limited platform inner shoal are developed respectively, open platform is developed in KT-II member, in which open platform inner shoal is mainly developed. (4) The Carboniferous in study area has experienced the sedimentary evolution process of braided river delta shallow sea shelf, isolated carbonate platform-platform margin slope, shallow sea shelf, isolated carbonate platform-platform margin slope. This article clarifies the sedimentary environment, sedimentary model and sedimentary facies distribution of the study area, and provides a basis for the next exploration deployment.