摘要
四川盆地川东高陡构造带油气勘探对象主要以背斜圈闭为主,因大多数地面背斜出露石灰岩,保存条件差,天然气勘探价值不高,而潜伏背斜保存条件良好,成为天然气聚集的有利场所。川东地区石炭系气藏是构造圈闭型,落实圈闭形态十分重要,直接关系钻探获气成功率。目前,石炭系潜伏背斜天然气勘探开发已进行到深入挖潜阶段,但仍有一些潜伏背斜地震成果不落实,井—震深度误差大,值得人们深入研究。依据地震剖面、地面地质、钻测井资料,建立精细潜伏背斜模式,划分为4大类、7亚类及30个小型,并对4大类潜伏背斜勘探开发效果进行总体评价。基于新建潜伏背斜模式,在3方面得到应用:①基于潜伏背斜模式,进行模型正演和反演,有利于分析复杂波长、时间域构造畸变现象及高点偏移规律;②有利于建立合理的时深转换及叠前深偏速度模型,提高深度域构造形态的可靠性;③基于潜伏背斜模式的水平叠加时间剖面(简称叠加剖面)基本反射特征,从而判定陡潜背斜的基本类型和形态,避免深度域里造成“假潜伏背斜”。川东地区新的潜伏背斜精细建模,将在石炭系气藏深入挖潜中进一步发挥积极作用。
Exploration domains on high-steep structures of eastern Sichuan Basin are dominated by anticlinal traps.Limestone exposure to anticlines with poor preservation can result in a little value in the exploration.In contrast,boasting better preservation,burial anticlines grow into favorable belts to accumulate natural gas.The Carboniferous gas reservoirs in eastern basin belong to structural-trapped ones.How to ascertain their trap morphology is very important because of the effect on drilling success.So far,the natural gas in the Carboniferous burial anticlines have entered the stage of potential tapping.But there still exist such anticlines with unconfirmed seismic data or large depth error in logging-seismic interpretation,which need to be further studied.So,based on seismic profiles,surface geology,drilling and logging data,some fine modeling on the burial anticlines was proposed.And such anticlines were divided into 4 categories,including 7 subcategories and 30 classes.Both exploration and development endings were evaluated with regards to the 4 categories.Results show that(i)model forward and inversion can be conducted,which are beneficial for analyzing complex wavelength,time-domain structural distortion,and high-point migration patterns;(ii)to create a reasonable time-depth conversion and pre-stack depth migration velocity model can improve the reliability of depth-domain structural morphology;and(iii)for steeply burial anticlines,determining their basic types and morphology based on reflection characteristics of horizontally-stacked time profiles may avoid any pseudo-burial anticlines representing in the depth domain.The proposed fine modeling on this kind of anticlines in eastern Sichuan Basin will play a positive role in the further exploration of the Carboniferous gas reservoirs.
作者
梁顺军
徐敏
郭海洋
陆林超
王征
李金枝
赵振伟
朱中华
游李伟
王兰英
LIANG Shunjun;XU Min;GUO Haiyang;LU Linchao;WANG Zheng;LI Jinzhi;ZHAO Zhenwei;ZHU Zhonghua;YOU Liwei;WANG Lanying(Southwest Geophysical Exploration Branch,CNPC BGP Inc.,Chengdu,Sichuan 610213,China;Southwest Geophysical Research Institute,CNPC BGP Inc.,Chengdu,Sichuan 610213,China;Development Division,Pet-roChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China)
出处
《天然气勘探与开发》
2024年第3期32-45,共14页
Natural Gas Exploration and Development
关键词
石炭纪
潜伏背斜
精细建模
地震成果
精度分析
Carboniferous
Burial anticline
Fine modeling
Seismic result
accuracy analysis
