Residual curvature migration velocity analysis for angle domain common imaging gathers

Pre-stack depth migration velocity analysis is one of the keys to influencing the imaging quality of pre-stack migration.In this paper we cover a residual curvature velocity analysis method on angle-domain common image gathers（ADCIGs） which can depict the relationship between incident angle and migration depth at imaging points and update the migration velocity.Differing from offset-domain common image gathers（ODCIGs）,ADCIGs are not disturbed by the multi-path problem which contributes to imaging artifacts,thus influencing the velocity analysis.On the basis of horizontal layers,we derive the residual depth equation and also propose a velocity analysis workflow for velocity scanning.The tests to synthetic and field data prove the velocity analysis methods adopted in this paper are robust and valid.

PLC在锅炉掺烧天然气点火系统中的应用

基于S7-200PLC设计了锅炉掺烧天然气点火程控自控系统,实现点火系统的就地单步、就地(或远方)自动控制和故障联锁报警,给出了气动阀门与二次风挡板的顺序控制和具体的操作方法。

某井偏梯形螺纹接头脱扣原因分析

某直井发生接箍工厂端偏梯形特殊螺纹套管滑脱,下部套管柱落井未能打捞出。针对此起脱扣事故,采用理论与试验相结合的方法,对脱扣接箍的化学成分和力学性能进行了分析和测试,对同批次两组套管试样螺纹参数进行了测量和实物试验,另外对脱扣接箍工厂端和现场端以及同批次新接箍工厂端内螺纹承载面和导向面处显微组织进行了比较。结果表明,接箍工厂端上扣扭矩过小是导致套管脱扣失效的主要原因,同时文章也说明螺纹接触处的显微组织比较分析法是解决此类问题的一个重要手段。