延长油田长6油层组沉积特征与油气分布

Sed im entary characteristics and d istribu tion of oil and gas in Chang6in the Y anchang O ilfield

目的认识储层沉积特征、油藏分布特征与控制因素,指导油田勘探。方法依据测井曲线突变面(岩性突变界面)和主要沉积不连续面(冲刷面、煤线、煤层、底界沉积间断面等),结合岩相分析延长油田长6油层组古环境变化面、沉积韵律等。结果将其沉积微相划分为分流河道、决口扇、分流间湾、河漫沼泽等;砂体为北北东向展布,发育三级层序2个,层序I为湖相层序,由湖泛期湖进体系域(TST)和高位体系域(HST)构成,层序II为湖水退出本区后形成的以平原曲流河环境为主的沉积,是冲积层序,由低位体系域、水进体系域(TST)和高位体系域(HST)构成。结论冲积层序的低位体系域中三角洲平原分流河道砂体、湖相层序高位体系域中三角洲前缘水下分流河道砂体是油田的主要储集层段。

Aim To understand the sedimentary characteristics of reservoir, oil-gas distribution and control factors in order to guide the exploration for oil field; Methods Synthetic studies on the sequence development and its relationship with the oil-gas distribution using sedimentary facies and division of the sequence stratigraphy. Results Dividing the micro-sedimentary facies of oil field and understanding the distribution characteristics of sand bodies; Dividing bedding sequence and revealing the development of sequences and its relationship with the oil-gas distribution; Conclusion The main reservoir of oil field is the distributary channel sand bodies developed on the delta plain of the low stand system tract formed by the alluvial sequences. The distributary channel sand bodies under the water developed at the delta front in the high stand tract of lake facies sequences also is the important reservoir.