论文部分内容阅读
丽水—椒江凹陷月桂峰组属古新世早期沉积,为凹陷主力烃源岩层。依据地震反射波的振幅、连续性、内部结构和外部形态等特征,在月桂峰组识别出6种主要的地震相类型:中高频弱振幅连续平行—亚平行席状相、低频强振幅较连续亚平行席状相、变振幅连续—较连续前积相、中振幅较连续—断续楔状相、中强振幅杂乱相和中弱振幅较连续充填相。然后再结合研究区钻井资料及区域构造背景,进行地震相—沉积相分析。结果表明:研究区月桂峰组是断陷型湖泊沉积环境,主要发育扇三角洲、水下扇、三角洲、湖泊等多种沉积相类型。进而结合钻井岩样分析,得出月桂峰组湖相泥岩属中—好烃源岩,主要发育于丽东次凹、丽西次凹中北部和椒江凹陷的中央洼陷带,有效烃源岩厚度可达1 000余米,面积总共为4 974.8km2。优选了处于源岩中心或邻近源岩中心的凹中隆及斜坡构造带作为下一步勘探工作的重点目标区域,为今后的勘探工作提出了有益的建议。
Lishui - Jiaojiang sag belongs to the early Paleocene sediments, which are the main source rocks in the depression. Based on the characteristics of seismic reflection wave amplitude, continuity, internal structure and external morphology, six major seismic facies types are identified in the laurel group: the high-mid-frequency and weak-amplitude continuous parallel-sub-paralleling facies, Sub-paralleled facies, with variable amplitude - continuous phase than before, in the amplitude of more continuous - intermittent wedge-shaped phase, medium amplitude of the amplitude of the clutter and the weak phase than the continuous filling phase. Combined with drilling data and regional tectonic setting in the study area, seismic facies-sedimentary facies analysis is carried out. The results show that the Gui-Feng group in the study area is a faulted lake sedimentary environment and mainly develops various sedimentary facies types such as fan delta, underwater fan, delta, lake and so on. Combining with the analysis of drilling rock samples, it is concluded that the lacustrine mudstone in the laurel group is a moderate-good source rock mainly developed in the central sub-depression zone of Litong sub-sag, the central part of West Xili Sag and the Jiaojiang sag, and the effective source rock Thickness of up to 1 000 meters, a total area of 4 974.8km2. It is suggested that the Neogene and slope structural belts located in the center of the source rock or adjacent to the source rock should be the key target areas for the next exploration and put forward some useful suggestions for future exploration.