塔北哈拉哈塘油田奥陶系岩溶储层发育模式

针对碳酸盐岩缝洞型储层发育随机性强的特点,通过对哈拉哈塘油田哈601井区进行详细解剖,在充分认识不同时期古地貌及构造运动背景的基础上,通过动、静态多类型储层预测,以塔北奥陶系古岩溶露头认知为指导,将储集体细分为暗河管道厅堂洞、断裂明河双控洞穴、断控洞穴、早期裂缝-孔洞和微裂缝-孔洞共5种成因类型;并依据储集体形态规模及发育规律,明确了研究区最重要的岩溶发育地质控制因素为良里塔格组古地貌古水系、地层岩性、加里东中期和加里东晚期—海西早期断裂。各缝洞系统先后经历了加里东中期断裂发育、良里塔格组水系下切、晚加里东期—早海西期断裂发育3个主要过程,经过后期一定程度改造形成了现今缝洞体形态。同时明确了岩溶内幕区不同缝洞系统对于油井产能的控制,为类似区块的井位部署及开发提供了地质依据。

Evolutionary model of the Ordovician karst reservoir in Halahatang oilfield,northern Tarim Basin

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.