松辽盆地泉头组河流相沉积特征及古河流再造

SEDIMENTARY CHARACTERISTICS OF THE FLUVIAL FACIES AND PALAEOCHANNEL RECONSTRUCTION OF THE QUANTOU FORMATION IN THE SONGLIAO BASIN

泉头组是松辽盆地中白垩世早期地层,为主要含油层位之一,由一套含轮藻、瓣鳃类、介形虫、叶肢介及陆生植物化石为主的红色陆屑组成,自下而上可分为四段,最大厚度可达2000m。在泉头期,河流相沉积占有相当的比重。对河流相沉积特征研究及古河流的再造,无疑对确定河流砂体规模、几何形态、空间分布及油气勘探具指导意义。一。

The sandstones from the Quantou Formation consist of the most important oil-bearing horizons, and the channel sandbodies represent the main hydrocarbon reservoirs in the Songliao Basin. Therefore, the morphology and distribution of these sandbodies should be examined so as to facilitate oil and gas exploration. This paper deals in detail with sedimentary characteristics of the fluvial facies in the Quantou Formation on the basis of petrographic compositions, facies sequences, Well logs, seismic reflection, elementary geochemistry and spatial distribution of the channel sandbodies, and discusses the theoretical basis of palaeochannel reconstruction, the parameters involved and their calculations. The palaeochannel reconstruction has been made by the authors according to the measured sites of the fluvial sediments from the Quantouzhen section in Changtu and Weizigou section in Jiutai. The calculations obtained indicate that the former is thought to be characterized by the braided rivers, while the latter by the meandering rivers.