塔里木盆地塔河油田奥陶系断控型大气水岩溶储层结构研究

摘要

Palaeo-karstification can form the potential oil and gas reservoirs.Guiding by the outcrops in north Tarim Basin,the reservoirs framework elements and its identification methods are analyzed,including underground river cave,longitudinal cave,cave hall and cave-controlling faults,and taking the S48 unit of 4th block in Tahe Oilfields as example,development characteristics including geometry dimension and assembly of elements are described.Research shows that,the underground river caves have the largest scale,and difference between longitudinal cave and isolated cave hall is the height diameter ratio.Different caves have a variety of combination way,and cave-controlling faults are important connection ways.Matching number of 3 kinds of cave and fault reached to 2.5,1.9,1.7,and cave dcvelopment and faults distribution have good coupling relationship.In addition,the paleogeography controls karst development to a certain extent too.%古岩溶作用能够形成极具潜力的油气储层.以断控型大气水岩溶储层结构为切入点,在塔里木盆地北缘奥陶系相似露头区调查的基础上,从形态及成因角度明确了4种结构单元,并以塔河油田四区S48单元为例,开展了地下研究.研究表明,主要形成于饱水带的地下河型洞穴规模最大,纵向发育型洞穴与孤立洞厅的差别在于高度直径比是否大于l；三者有多种组合方式,控洞断裂是重要的连接途径,3类洞穴与断裂的匹配数分别达到了2.5、1.9和1.7,洞穴发育与断裂分布有良好的耦合关系；此外,古地貌也在一定程度上控制着岩溶的发育.