摘要
波阻抗反演是寻找隐蔽油气藏常采用的技术,但由于一些地区的钻井存在扩径现象,导致声波时差和密度曲线不能反映地层的真实情况,难于区分储层和围岩。为此,在进行反演之前必须对测井曲线进行环境校正,消除扩径对测井曲线带来的影响。以平湖油气田古近系渐新统花港组为例,在分析了该区扩径对测井曲线影响情况的基础上,提出了一套有效校正密度和声波时差曲线的方法:对测井资料进行标准化;应用未扩径处的标准化测井资料,建立自然伽马与密度的相关关系,并应用该关系结合压实校正对扩径处的密度曲线进行校正;应用Gardner公式,通过密度求取声波时差;在钙质发育处对上述校正的密度和声波时差进行钙质校正。应用效果表明,该方法是有效的。这给测井曲线环境校正提出了一个新的思路。
Acoustic impedance inversion is commonly used in the exploration of subtle hydrocarbon reservoirs.However,when hole enlargement occurs during drilling,interval transit time and density curves cannot truly reflect the strata,making it difficult to distinguish between reservoirs and adjacent formations.Therefore,environment correction of logs should be performed before inversion to eliminate the influences of hole enlargement on the logs.The Oligocene Huagang Formation of the Paleogene in the Pinghu oil and gas field is taken as an example.Based on the analysis of the impacts of hole enlargement on logs in this field,several methods are proposed for correction of density and interval transit time curves.First,the logs are standardized.Then,the standard logs of intervals without hole enlargement are used to establish the relationship between the Gamma Ray and the density,which,in combination with compaction correction,is used to correct the density curves of intervals with hole enlargement.Finally,the Gardner formula is used to convert the density into transit time interval.Moreover,when the calcic is well-developed,the corrected density and transit time interval curves should be re-corrected for the calcic.This field application shows that this method is effective.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2010年第1期39-41,共3页
Natural Gas Industry
关键词
平湖油气田
测井
测井曲线校正
环境
井径
方法
Pinghu oil and gas field,logging,log correction,environment,hole diameter,methodology
