| Popis: |
Forecast and extraction of subsurface fractures play an extremely prominent role in unconventional petroleum exploration and development nowadays. Yingxiongling mountain of Qaidam basin was inverted from an early Himalayan depression during the late stage of late Himalayan orogeny by massive uplifting and stronger faulting which led to the extensive development of fractures. A series of fractural accumulations have been found within this area. Researches on fractural formations, distributions, accumulations controlling and permeability impact during production were received attention in academia and industry. Most of the previous studies just focused on very limited sections or areas such as outcrops observations over anticlines or downhole data analysis, and ignored characteristics of fracture distributions on the large surface so that the results had limited guiding effect for further exploration. Based on the special geology conditions of Yingxiongling, the authors forecast the distributions of fracture by integrating remote sensing interpretation, surface observation and subsurface data. Maps of 1:50,000 scale generated from high-resolution images were used to extract fractures, and fracture directions and density were analysed. Combining with fracture character of outcrops, downhole cores and well logging data, remote sensing interpreted fractures were considered to reflect approximately fracture density of subsurface. This method could be applied to predict subsurface fractural reservoirs effectively in basins and areas with deformation of low intensity and inheritance such as Yingxiongling, western Qaidam basin. |
