关键词: 水平井, 控制井, 声波时差校正, 各向异性, 相同深度

Abstract: The stratigraphic anisotropy is one of the factors that cause the complex logging response of horizontal well. Given the same target layer, the measured acoustic time in horizontal well is usually lower than that in the adjacent vertical well, resulting in a large error of porosity calculated by the measured acoustic time. By comparing the acoustic time of the same section in horizontal wells and adjacent vertical control wells, the acoustic time anisotropy can be better identified. That is, the measured acoustic time of each point of horizontal section is compared with that of the closest control well at the same depth. The results show that the acoustic time of horizontal section is generally lower than that of the adjacent vertical well, and the difference between them is closely related to GR value of the horizontal well, that is, with the increase of GR value in horizontal well, the difference of acoustic time and anisotropy gradually increase. As a result, a new method is proposed to correct the acoustic time anisotropy of Chang 6X layer in Longdong area in Ordos Basin, which shows a good practical application and supports to improve the accuracy of reservoir parameters calculation by logging data in horizontal wells.