摘要
【目的】开江—梁平海槽广泛发育长兴组礁滩储层,油气资源丰富。海槽东侧的取心及地震资料有限,传统地质定性方法无法准确进行层序地层划分与对比,为优质储层预测带来一定困难。深入开展长兴组高频层序地层研究有助于细化层序格架内沉积相展布规律,厘清海槽东侧沉积演化历程,提高有利储层预测准确率,以期为深化礁滩储层勘探开发提供依据。【方法】基于野外剖面、岩心、测井地震等资料并融入INPEFA测井旋回技术,对川东地区长兴组高频层序地层及沉积体系特征开展研究。【结果】长兴组自下而上划分为2个三级层序和5个四级层序;长兴组早期发育碳酸盐缓坡沉积,中—晚期发育碳酸盐台地沉积,可细分为开阔台地相、台地边缘相及斜坡—盆地相,长兴组有利储集相带主要为台缘礁滩相;长兴组发育晶粒白云岩、(残余)颗粒白云岩、生物礁云岩储层,储层非均质性较强,整体呈“低孔—中、低渗”特征。【结论】有利储集区带呈“Y”形展布,主要集中在普光5井—老君1井—七里北2井—七里北101井—黄龙5井—黄龙8井—黄龙4井区域,沿台地边缘带呈断续条带状或点状分布,七里北地区后排台缘带为次有利区,在区内呈条带状分布。川东北地区长兴组沉积相时空演化规律、有利储层分布预测成果可为下步礁滩储层勘探开发提供地质依据。
[Objective]Reef-shoal reservoirs of the Changxing Formation are widely developed in the Kaijiang-Liangping trough,and contain abundant oil and gas resources.Core and seismic data on the eastern side of the trough are limited,and traditional geological qualitative methods have difficulty in accurately dividing and comparing the sequence stratigraphy,and consequently in predicting the locations of high-quality reservoirs.This in-depth study of the high-frequency sequence stratigraphy of the Changxing Formation helps to refine understanding of the distribution of sedimentary facies in the sequence framework and clarify the sedimentary evolution process on the eastern side of the trough.This improves the accuracy of favorable reservoir prediction and also provides a stronger basis for the exploration and development of reef-beach reservoirs.[Methods]This study was based on field profiles and core,logging and seismic data,together with Integrated Prediction Error Filter Analysis(INPEFA)logging cycle technology,to determine the characteristics of the high-frequency sequence stratigraphy and sedimentary system in the Changxing Formation in eastern Sichuan Basin.[Results]The Changxing Formation was found to be divided into two third-order sequences and five fourth-order sequences from bottom to top.Carbonate ramp sedimentation was developed in the early stage of the Changxing Formation,and carbonate platform sedimentation in the middle-to-late stage,subdivided into open-platform facies,platform-margin facies and slope-basin facies.The favorable reservoir belt of the Changxing Formation mainly consists of platform-margin reef facies.The Changxing Formation contains crystalline dolomite reservoirs,(residual)granular dolomite reservoirs and reef dolomite reservoirs.These are strongly heterogeneous,and their overall rating is low-porosity,producing medium and low permeability.[Conclusions]The favorable reservoir zones are distributed in a‘Y’-shape,mainly concentrated in the areas of Puguang 5-Laojun 1-Qilibei 2-Qilibei 101-Huanglong 5-Huanglong 8-Huanglong 4 distributed in discontinuous strips or dots along the platform margin.The platform margin beach in the back row of Qilibei is a sub-favorable zone occurring in a strip within the study area.The spatial and temporal evolution of the sedimentary facies belt,and the predictability of the locations of favorable reservoirs in the Changxing Formation,provides a geological basis for further exploration and development of reef-shoal reservoirs.
作者
姚鑫阳
胡忠贵
武赛军
谢武仁
杨帅奇
姚敏
毕宇航
YAO XinYang;HU ZhongGui;WU SaiJun;XIE WuRen;YANG ShuaiQi;YAO Min;BI YuHang(School of Geosciences,Yangtze University,Wuhan 430100,China;Sedimentary Basin Research Center,Yangtze University,Wuhan 430100,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)
出处
《沉积学报》
CAS
CSCD
北大核心
2024年第6期2102-2118,共17页
Acta Sedimentologica Sinica
基金
国家科技重大专项(2016ZX05007002)。
关键词
川东北地区
开江—梁平海槽东侧
长兴组
沉积特征
有利区预测
northeastern Sichuan
eastern side of Kaijiang-Liangping trough
Changxing Formation
sedimentary characteristics
favorable area prediction
