基于反射波的碳酸盐岩储集层测井评价技术

为了有效地对碳酸盐岩储层进行测井评价，针对其非均质性强、各向异性大、裂缝发育、测井解释难度大的特点，中国石油渤海钻探工程公司测井公司研发了基于远探测声波反射波的成像测井技术。该技术借鉴了物探的采集技术，用测井的方法实现了对反射波的测量。在简述远探测声波反射波成像测井基本原理、仪器特点及采集基本信息的基础上，用参数估计法对所采集的基本信息进行分析，能有效地分离反射波和模式波，压制噪音，并进一步把反射波分离为上、下行反射波；还设计了典型的地质体的模拟实验，确定了不同地质体的上、下行反射波的响应特征，从而达到以实验响应特征为依据对实际测井资料进行解释的目的，可发现常规测井探测不到的储集层。在塔里木盆地碳酸盐岩储层的实际应用效果表明，该技术弥补了以往测井探测深度不足的缺陷，探测深度由原来的3 m提升到10 m，可以为试油决策提供科学依据，从而避免因常规测井探测深度不足而漏失油气层。

Logging evaluation of carbonate reservoirs based on reflected waves

The logging evaluation of carbonate reservoirs is challenging due to their strong heterogeneity, significant anisotropy and well developed fractures. A remote acoustic reflection imaging logging technique is developed by the Logging Company of CNPC Bohai Drilling Engineering Company Limited. It draws on the experiences of acquisition technologies of geophysical prospecting and realizes the measurement of reflected wave via the logging method. This paper briefly introduces the basic principles of remote acoustic reflection imaging logging, the features of the apparatus, and the basic information acquired. The analysis of the basic information by using the parameter estimation method reveals that the reflected wave and mode wave can be effectively separated, the noises can be eliminated, and the reflected waves can be further divided into downgoing and upgoing reflected waves. A simulation experiment is also designed for the typical geologic body and is used to determine the responses of the upgoing and downgoing reflected waves, so as to interpret the real logging data based on the experimental response characteristics and identify reservoir intervals invisible on conventional logs. The application in the carbonate reservoirs in the Tarim Basin indicates that the measuring depth is increased from 3 m to 10 m, thus to prevent oil/gas layers bypassing due to the limited measuring depth of conventional logging techniques.