关键词: 准噶尔盆地, 莫索湾, 深层, 压力预测, 地震层速度, VSP测井

Abstract: The wells in Mosuowan Uplift area indicate the wellhole overpressure characteristics of Jurassic. But it is not clear about the pressure characteristics of the formations below the well bottom. Moshen-1 well is a key scientific study well targeted at exploration of the large-scale deep Carboniferous-Triassic anticline trap on Mosuowan Uplift. The pre-drilling pressure prediction is of great significance to reasonable drilling engineering design of Moshen-1 well. Adoption of the seismic horizon velocity method for prediction of formation pressure is comparatively accurate for the normal pressure section. However, as for the overpressure section, the systematic errors between the seismic horizon velocity and the real formation velocity are considerable. The predicted pressure is obviously lower than the actual pressure. VSP logging velocity is more sensitive to the overpressure section as compared to seismic horizon velocity. Use of VSP velocity for correction of the seismic velocity can substantially reduce the systematic errors. Use of the corrected seismic horizon velocity for prediction of formation pressure can greatly raise the accuracy of prediction