电成像测井资料校正方法研究

Study on correction of electrical imaging logging data

电成像测井资料蕴含丰富的井壁地层信息.通过电成像图像和地层倾角可直观定性地识别各种地层界面、裂缝以及构造形态,但是要获得可靠的电成像图像和地层产状,必须要求井斜角、井斜方位角等测斜数据准确可靠.由于受电缆张力、仪器运动状态,以及地质因素的影响,所测得的测斜数据可能会产生较大偏差,直接影响到后续解释成果的可靠性.因此,为了获得可靠的电成像图像和地层产状,以及与其他测井资料对比分析,在电成像测井资料处理与解释之前须进行深度和测斜校正.针对电成像测井资料与常规测井资料存在的较大深度偏差,提出一种基于双尺度相关对比的自动深度校正方法,较好地解决了当前深度校正方法的局限性,实现了常规测井资料与电成像测井资料之间的精确匹配.针对测斜数据校正方法存在不够严谨的问题,提出利用重力加速度分量与磁场加速度分量进行圆心偏移处理,计算出井斜角与井斜方位角,重构井斜角与井斜方位角曲线.实测资料处理表明:深度与测斜校正方法较好地解决了实测电成像测井资料的校正问题,在多个油田中实际应用,取得良好效果.

Electrical imaging logging data can be rich in much information around the wellbore. The variety of formation interfaces,fractures and structure features can visually be identified by the electrical image. But the data of well dip and well azimuth must be quantitative if the electrical image and the formation dip are reliably obtained. Because of the affection of the cable tension,instrument motion state and formation factor,the survey data may produce great errors which affect the reliability of the subsequent interpretation results. So as to obtain the reliable the electrical image and formation occurrence and analyse geological problems with the other log data,the depth and the survey data must be corrected before the processing of electrical data and interpretation. Aim at the depth error between the electrical imaging logging data and the conventional logging data,the method of automatic depth correction based the double scale correlation is proposed,which solves the limitation of the current depth correction methods and comes true the exact depth matching of the conventional logging data and the electrical imaging logging data. Aim at the question which the correction method of the survey data is not rigorous,it is proposed to compute the well dip and the well azimuth and restructure the well dip curve and the well azimuth curve. The measured data processing results show that the correction method of depth and dip survey improve greatly accuracy which is used in many oilfields and the results are very well.