钻井岩心古水流方向确定方法和原理

为了实现钻井岩心信息最大化的应用.首先利用古地磁技术对钻井岩心进行原始方位恢复,然后通过测定岩心上具有古水流指向性的沉积构造的参数,或者通过测定岩心磁性组构判定古流向,最后经过岩心校正得出研究区的古水流方向.文中以钻井岩心上的斜层理为例,推导出其在岩心坐标系中的倾向和倾角的表达式,经过公式校正得到真倾向和真倾角的表达式,确定古流向.最终将井位、岩心恢复及古水流计算结果综合反映,获得每个井位的古水流方向,进而通过连片处理分析,可获得某区块的局部及整体的古水流趋势方向,预测砂体的展布方位.本文为钻井岩心古水流方向的确定提供了研究方法,实现了岩心信息最大化利用,可以指导油田的进一步勘探开发.

Methods and principles to direction identify of the drilling core's paleocurrent

In order to maximize the application of core datum,make use of the paleomagnetic technique to separate primary remanent,this remanence can recover original position of the drilling cores.On the base of core observation of the sedimentary structures,such as oblique bedding,wavy bedding,boulder orientation,shells position and the arrangement of cephalopod fossils which reflect the paleocurrent direction.Take oblique bedding for example,its real inclination and declination is calculated,latter by strata correction and core correction getting the paleocurrent direction.If there are no sedimentary structure or not obvious,the principles of magnetic fabric can be used to obtain the paleocurrent direction.Lastly comprehensive analysis wells location,original position of drilling cores and calculation results of paleocurrent,obtain the direction of paleocurrent of each well.Through joint processing,predict the unknown region’s direction of paleocurrent in the partial and overall trend,reveal the orientation distribution of sand body.This idea provides a method for the research of paleocurrent direction,to guide the further exploration and development of oil fields.