玛湖446井区克拉玛依组储层特征及有利区预测  

Reservoir Characteristics and Favorable Areas of the Karamay Formation in the Mahu 446 Well District

作　　者：罗旭东 韩东威 张方贵 张斌 冯雪 陈清清 LUO Xudong;HAN Dongwei;ZHANG Fanggui;ZHANG Bin;FENG Xue;CHEN Qingqing(Second Oil Production Plant,Xinjiang Oilfield,Karamay 834000,Xinjiang,China;Beijing Geo-Tech Petroleum Technology Development Company,Beijing 100083,China)

机构地区：[1]中国石油新疆油田采油二厂,新疆克拉玛依834000 [2]北京吉奥泰科石油科技发展有限公司,北京100083

出　　处：《西北地质》2024年第5期166-180,共15页Northwestern Geology

基　　金：中石油新疆油田公司科研项目“玛湖凹陷侏罗系、三叠系油藏评价关键技术及储量升级研究”(XJYT-2022-JS-5317)资助。

摘　　要：玛湖斜坡446井区克拉玛依组是克拉玛依油田重要的产油层,三叠系克上组(克拉玛依组上段)有利砂体的准确刻画一直是制约该区增储上产的关键问题。笔者基于对克上组沉积储层特征的重新认识和有利砂体地球物理相应特征的再梳理,结合沉积相展布特征和地震反演方法,对446井区克上组T_(2)k_(2)^(2)段有利砂体进行了刻画,为进一步勘探开发提供了重要指导。研究发现,玛湖446井区属于辫状河三角洲前缘亚相沉积,包括水下分流河道、水下分流河道间湾、河口砂坝、席状砂4种沉积微相,其中水下分流河道为有利储层。T_(2)k_(2)^(2)段水下分流河道最发育,物源整体来自WN方向,中部河道最发育,沉积背景最为有利。拟声阻抗地震反演方法对识别T_(2)k_(2)^(2)砂体具有显著效果,砂体阻抗界限在8900 g/cm^(3)·m/s,可在本区识别出两套有利的河道砂体,具有强振幅和高拟声波阻抗的特征。综合考虑沉积相展布、地震反演和构造特征,预测了T_(2)k_(2)^(2)段控制含油面积以外的一个岩性圈闭及范围,该圈闭呈U型展布,发育约为6 m油层,由高往低油层减薄,面积为8.4 km2,闭合度约为300 m。The Karamay Formation in the Mahu 446 well district is an important oil-producing layer in the Karamay oilfield.However,the unclear characterization of favorable sandstone bodies in the Upper Karamay Formation has constrained further exploration and development in this area.This paper provides sedimentary facies distribution characteristics and seismic inversion methods to characterize the favorable sandbodies in the T_(2)k_(2)^(2) section of the Upper Karamay Formation in the 446 well area,based on a re-understanding of the sedimentary reservoir and geophysical response characteristics of favorable sandstone bodies in the Upper Karamay Formation.The research suggests that this area belongs to a braided river delta front subfacies sedimentation,which can be mainly divided into four sedimentary microfacies:underwater distributary channels,inter-distributary bays,mouth bars,and sheet sands.The T_(2)k_(2)^(2) section of underwater distributary channels is the most developed and is the primary favorable reservoir development section in this area.The overall provenance of the T_(2)k_(2)^(2) section comes from the northwest,with the central channels being the most developed and having the most favorable sedimentary background.The pseudo-acoustic impedance seismic inversion method has a good effect on identifying T_(2)k_(2)^(2) sandbodies,with the impedance boundary at 8900 g/cm^(3)·m/s,which can identify two sets of favorable channel sandbodies with strong amplitude and high pseudo-acoustic impedance characteristics.Combining sedimentary facies distribution,seismic inversion,and structural features,this study predicts one lithological trap and its range beyond the oil-containing area controlled by the T_(2)k_(2)^(2) section.The trap exhibits a U-shaped distribution,develops approximately 6 m of oil layer,which thins from high to low,covers an area of 8.4 km2,and has a closure of approximately 300 m.

关 键 词：有利砂体预测 玛湖斜坡 拟声波阻抗 岩性圈闭 克上组 

分 类 号：P618.13[天文地球—矿床学] TE122[天文地球—地质学]