摘要
针对川西南地区页岩气勘探面临的激发条件变化较大、地表障碍物较多和外界干扰较大等影响三维地震勘探资料采集质量的问题,研究团队经过多年研究与试验,设计了经济适用的细分面元复合模板观测系统,从3个方面针对性制定了质量提升措施。(1)分析影响激发的主要因素,开展全工区系统试验,优化工区不同位置激发参数,确定适宜的炮井井深和炸药用量等措施优化激发参数;(2)确定煤矿、河流、水库、城镇等地表障碍物分布区域,细化观测系统方案,减少丢炮、丟道面积;(3)做实检波器埋置,控制人文和自然环境噪音,提升接收质量。一系列措施落实后,地震资料的采集质量显著提升,所采集的JY三维工区的原始单炮记录一级品率大于90%,PSTM(Pre stack time migration,叠前时间偏移)处理成果剖面具有较高的信噪比、分辨率和较强的层次感,对页岩气勘探开发具有重要支撑作用。
Directing at the problems faced in the exploration of shale gas in the southwest of Sichuan,like the larger change of excitation condition,the numerous surficial barriers,and the heavy interference of outside,which influence the acquisition quality of threedimensions seismic data,researchers have studied and test them for many years,and thus designed one economical and applicable observation system of subdivided patch composite form,and established methods of quality improvement from three aspects.Firstly,they analyzed main factors affecting excitation,carried out systematic experiments of entire work area,optimized excitation parameters of different positions in work area,and determined optimizing excitation parameter of methods like the applicable well depth of shot hole and the usage quantity of explosive.Secondly,they confirmed the distribution area of surficial barriers like coal mine,river,reservoir,and town,refine observation systematic program,and reduced the area of losing explosion and losing gallery.Thirdly,they conducted the embedment of demodulators,controlled noises of humanistic and natural environment,and improve receiving quality.After an implementation of a series of methods,collecting quality of seismic data has been improved obviously,original single shot records collected in JY three-dimension work area are larger than 90%in the percent of grade-1,and the section of dealing results of PSTM possesses higher signal noise ratio,resolution ratio,and clearer layering feeling.All this takes the supportive role in the exploration and development of shale gas.
作者
段文燊
吴朝容
涂远艮
DUAN Wenshen;WU Zhaorong;TU Yuangen(Southwest Oil-gas Branch Company,Sinopec,Chengdu,Sichuan 610041,China;School of Geophysics,Chengdu University of Technology,Chengdu,Sichuan 610051,China)
出处
《石油工业技术监督》
2023年第2期1-6,共6页
Technology Supervision in Petroleum Industry
关键词
四川盆地
页岩气
三维地震勘探
资料采集
质量提升
Sichuan basin
shale gas
three-dimension seismic exploration
data collection/acquisition
quality improvement
