Abstract:
The development of fracture-vug carbonate reservoirs shows great randomness. According to this characteristic, through detailed analysis of Ha 601 well block in Halahatang oilfield, dynamic and static multi-type reservoir prediction was carried out based on a thorough understanding of paleo-geomorphology and tectonism background in different geological periods. On this basis, under the guidance of the understanding of paleo-karst outcrops in northern Tarim Basin, reservoir bodies were divided into five genetic types, i.e., underground-river tubulose hall caves, fault and river-controlled caves, fault-controlled caves, early fracture-vug and micro fracture-vug. According to morphological scale and development rule of reservoir bodies, the most important geological control factors for karst development in the study area were clarified, including paleo-geomorphology water system and formation lithology of Lianglitag Formation as well as the faults formed in the middle Caledonian and late Caledonian-early Hercynian. The fracture-vug system experienced three major processes, i.e., fault development in middle Caledonian, river incision in Lianglitag Formation, and fault development in late Caledonian-early Hercynian. Current fracture-vug morphologies were formed through a certain degree of reformation in the late period. Meanwhile, the control of various fracture-vug systems on oil well capacity in buried hill karst area was clarified, thus providing a geological basis for well location arrangement and development in similar blocks.