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自从五十年代中期应用水泥胶结测井(CBL)以来,在测井资料解释影响因素的研究方面已做了大量工作。根据以往的经验,测井资料总是不能反映出水泥与套管胶结的实际情况。实际上,测井或固井技术上的失误往往导致水泥胶结解释的错误,从而造成盲目挤水泥或在有窜槽的情况下完井。可以采用各种方法,以获得有用的水泥胶结资料。对操作员来说,利用固井技术使套管与凝固的水泥之间的微间隙减至最小,这是至关重要的。这样的间隙妨碍套管与水泥之间的声耦合,从而使记录的套管信号不代表整个水泥固结的实际情况。唯有水泥胶结测井记录能显示出微间隙;当发现微间隙时,必须改变测井环境,以便获得更真实的资料。发射器—接收器的结构及间距,对于确定水泥胶结质量和弄清测量的有效性也是很重要的。例如,在胶结的套管中,套管信号幅度的分辨率是由源距决定的:源距短,分辨率就比较好。此外,单接收器测得的传播时间资料也可以供质量控制之用,它可以指示记录的声幅信号是否真实代表套管—水泥的胶结情况。因此,仪器设计是至关重要的。通过对这些因素的控制,并利用解释技术(考虑到水泥和套管的变化),操作员可以检查和改进初次固井和挤水泥作业。
Since the application of cement cementation logging (CBL) in the mid-1950s, a great deal of work has been done on the study of the influential factors in the interpretation of log data. Based on past experience, well logging data can not always reflect the actual situation of cementation of cement and casing. In fact, faults in logging or cementing techniques often lead to errors in cement cementation, resulting in blind crowding of cement or completion in the event of channeling. Various methods can be used to obtain useful cementing information. It is crucial for the operator to use cementing techniques to minimize the micro-clearance between the casing and the solidified cement. Such a gap impedes the acoustic coupling between the casing and the cement so that the recorded casing signal does not represent the actual situation of the entire cement consolidation. Only cement cementation logs can show micro-gaps; when micro-gaps are found, the logging environment must be changed in order to obtain more realistic information. The structure and spacing of the emitter-receiver are also important for determining the quality of the cement and for clarifying the validity of the measurements. For example, in cemented sleeves, the resolution of the cannula signal amplitude is determined by the source spacing: the source spacing is short and the resolution is better. In addition, the time-of-flight data measured by a single receiver can be used for quality control, which indicates whether the recorded amplitude signal truly represents the casing-cement bond. Therefore, instrument design is crucial. By controlling these factors and using interpretation techniques that take into account changes in cement and casing, operators can inspect and improve primary cementing and cementing operations.