Title

Fine characterization of complicated channels in western Sichuan and identification of sedimentary facies

单位

1.中国石油化工股份有限公司西南油气分公司勘探开发研究院,四川成都610041;2.西南大学地理科学学院,重庆400715;3.中国石油化工股份有限公司西南油气分公司,四川成都610041

Organization

1.Exploration and Development Research Institute of Southwest Petroleum Branch Company of SINOPEC,Chengdu 610041,China;2.School of Geography Sciences,Southwest University,Chongqing 400715,China;3.Southwest Petroleum Branch Company of SINOPEC,Chengdu 610041,China

摘要

精细刻画河流沉积相带是陆相油气藏勘探开发的重要研究内容,其中,针对性的地球物理预测技术及准确的沉积相解释是关键。川西侏罗系砂岩储层致密,主要发育于多期薄窄河道中,地球物理特征隐蔽,识别及刻画难度大,制约了以单河道为单元的开发建产。优选并确立河道刻画关键技术,并开展刻画结果与现今地表典型地貌对比研究,可准确识别沉积相带,提高储层预测精度。创立了地震波形分类技术、体分频像素成像技术、多河道分期剥离及三维空间刻画等关键技术,形成了三维单河道或河道组系解释方法,提升了川西侏罗系纵横交织复杂窄河道识别和表征能力。采用将今论古的研究思路,通过现今相似地貌的类比明确了地下河道沉积古地貌背景,准确识别和划分了沉积相带的类型,成果应用表明有利沉积相带的预测精度明显提升。

Abstract

Fine characterization of fluvial facies is an important research topic in the exploration and development of continental hydrocarbon resources,for which accurate geophysical predictions and interpretation of sedimentary facies are critical.The Jurassic sandstone reservoirs in western Sichuan are tight and mainly developed in thin and narrow channels belonging to several periods.Incomplete geophysical characterization makes the identification and characterization of these reservoirs difficult,thereby hindering the development and productivity of single-channel units.Defining and optimizing key technologies for channel characterization,in combination with a systematic comparison of the results of such characterizations with current typical landforms can help recognize the existing sedimentary facies and perform more accurate reservoir predictions.In this study,key technologies such as the optimized seismic waveform classification,common frequency volume pixel-imaging,multi-channel stage stripping,and three-dimensional space characterization are described.Furthermore,3D interpretation methods for single channels and channel formations are developed.The results demonstrate a significantly improved ability in recognizing and characterizing the complex narrow channels of the Jurassic in western Sichuan.Following the leading concept that “the present is the key to the past”,current landforms are compared in this work to clearly define the paleogeographic background of the underground channel deposits.Furthermore,the types of sedimentary facies are accurately identified and classified.The results of this work provide a significantly improved accuracy in the identification of favorable sedimentary facies.

关键词：

河流沉积; 精细刻画技术; 相似地貌; 沉积相; 川西;

Keywords:

fluvial deposit;; fine characterization technique;; similar landforms;; sedimentary facies;; western Sichuan;

基金项目

DOI

10.3969/j.issn.1000-1441.2019.05.014

川西侏罗系复杂河道精细刻画及沉积相带识别