库车坳陷大北—克深砾石区地震攻关与天然气勘探突破  

Seismic Research and Natural Gas Exploration Breakthrough in DB-KS Gravel Zone in Kuqa Depression

作　　者：梁顺军 雷开强 王静[1] 刘汉雄 曾健 张明柱 王中海 董同武 

机构地区：[1]中国石油川庆钻探工程有限公司地球物理勘探公司

出　　处：《中国石油勘探》2014年第5期49-58,共10页China Petroleum Exploration

摘　　要：库车坳陷大北—克深砾石区广泛发育第四系、新近系洪积扇,表层砾石层和深层砾岩层主要分布于扇根与扇中。表层砾石层岩性复杂,低(降)速层的厚度和速度变化大,导致地震资料信噪比低,应用"宽线+大组合"及"静校正+多域去噪"采集处理技术联合地震攻关,有效提高了资料信噪比;而深层砾岩层致密,速度异常增高,速度陷阱大,严重影响构造圈闭落实。根据地面露头、钻井和测井资料,解释深层洪积扇地震相和沉积相,识别砾岩层与围岩的接触边界,查明砾岩层厚度及其速度变化规律,有效地克服高速砾岩层对下伏构造圈闭的影响。通过地震采集处理解释一体化攻关,落实和发现一大批优质盐下白垩系构造圈闭,多个圈闭及多口探井、评价井相继获得高产油气流,气田个数稳健增长,油气勘探获得了重大发现和突破。The Quaternary and the Neogene alluvial fan developed extensively in Dabei-Keshen gravel zone of Kuqa depression. The surface gravel layer and deep conglomerate layer are distributed at the root of the fan and in the middle of the fan separately. The lithologic characters of the gravel layer are complicated with the thickness and velocity varying significantly, leading to a low signal-noise ratio of seismic data. The methods of ＂wide line and large assemblage＂ and ＂static correction and multi-domain filtering＂ are used in acquisition and processing to effectively improve the signal-noise ratio of data. However, compactness of the deep conglomerate layer caused the velocity to rise abnormally, seriously affecting identification of structural trap. The surface outcrop and drilling and logging data are used to interpret the seismic facies and sedimentary facies of the alluvial fan, identify the boundary between the conglomerate layer and enclosing rock, clarify the thickness of the conglomerate layer and the law for its velocity variation, and effectively eliminate the impact of the high-velocity conglomerate layer on the underlying structural traps. Based on the efforts for the research on integration of seismic acquisition, processing and interpretation, a large number of high-quality subsalt structural traps of Cretaceous were confirmed and discovered. The high-yield oil and gas flow was found from a number of traps with exploration wells and appraisal wells. The quantity of gas fields is on the rise with important discoveries and breakthroughs made in oil and gas exploration.

关 键 词：砾石区 地震攻关 信噪比 砾岩层特征 盐下圈闭 白垩系 油气大发现 

分 类 号：P631.4[天文地球—地质矿产勘探]