塔中地区礁滩储集体形成条件及分布规律

奥陶纪时期，塔中地区发育生物礁、丘和滩等不同类型的碳酸盐岩建隆生物礁丘发育层位主要集中在上奥陶统．塔中地区的礁滩相包括灰泥丘、中物礁、粒屑滩和地质异常体等4种类型，沉积古地理、构造作用、陆源碎屑物注入和海平面变化是控制生物礁发育的主要因素．塔中地区生物礁的分布环境主要有2个相带：一是台地内，尤其是半局限台地与开阔台地的转折处或台内缓坡上，如塘参1井、塔中23井上奥陶统的生物礁：另一个是台地边缘，如塔中45井-塔中44井-塔中24井-带为台缘外带，以发育中高能粒屑滩和骨架礁组合为特色，而大致在塔中35井-塔中12井-塔中15井-塔中161井-带为台缘内带，发育中低能粒屑滩、灰泥丘及障积礁组合．

THE DEVELOPMENTAL CONDITIONS AND DISTRIBUTIONAL RULES OF THE REEF-SHOAL RESERVOIRS IN CENTRAL TARIM BASIN

Reefs,mounds and shoals are widely developed in the Ordovician in central Tarim basin.Reefs and mounds are mainly developed in upper Ordovician.Reef-bank facies in central Tarim basin generally includes four types:(1) mudstone mound,(2) reef,(3)granule shoal,and(4) abnormal geological body.The development of reefs is mainly affected by paleogeography,paleostructure,the input of clasts and the rises and falls of the sea level.Reefs in central Tarim basin mostly developed in two zones.One is inner-platform facies,especially the area between restricted platform and open platform and the ramp of inner-platform,as reefs in the upper Ordovician in well Tangcan 1 or well Tz23.The other one is platform margin facies,as high-energy granule shoals and framework reefs are developed in the outer-belt of platform margin facies along well Tz45-Tz44-Tz24,and low-energy granule shoals,mudstone mounds and barrier-accumulated reefs are developed in the inner-belt of margin slope facies along well Tz35-Tz12-Tz15-Tz161.