用PP波识别井旁裂缝技术在碳酸盐岩地层中的应用

Application of Identifying Fractures Near Borehole with PP Wave in Carbonate Reservoir.

前人在模拟碳酸盐岩地层的模型井中进行声波全波测井 ,结果在接收到的全波列上观测到了滑行纵波和滑行横波之间有一来自模型外的强反射波 ,用符号 PP表示 ,称为反射 PP波。这个反射 PP波可用于探测井旁裂缝。与之对比 ,在碳酸盐岩地层 ,XMAC(交叉多极阵列声波 )测井的全波波列上也出现了与实验的反射 PP波十分相似的波形 ,根据 XMAC测井仪的源距推算出 XMAC全波列中的反射 PP波可探测到距井壁 2 .2～ 3.2 m范围内的裂缝。这一技术在大港油田千米桥潜山碳酸盐岩储层评价中应用 。

In carbonate mock up experiments, theres a reflected wave between the refracted P wave arrivals and S wave arrivals in the full acoustic wavetrains. The experimented result has been demonstrated by Master Zhou. This reflected wave can be used to detect fractures near borehole. Using this result, the reflected wave has been found in the XMAC full waveform logging data. The reflected wave, represented as PP wave, is similar to the reflected wave received in experiments. According to the distance between transmitter and receivers in the XMAC logging tool, the fractures which are about 2 2～3 2 meters away from the borehole can be detected by PP wave, which shows a good result in Qian Mi Qiao carbonate reservoir identification of Dagang Oilfield.