塔里木盆地中部生物屑灰岩段滩体特征及储集性

塔里木盆地中部生物屑灰岩段中发育多种不同的滩体。其中生物屑滩、砂屑滩沉积体及其组合的岩石微相以生物屑灰岩、生物屑砂屑灰岩为主,在多期胶结和压实的作用下,原生孔隙基本消失,后期成岩作用对其改造不强,孔隙度和渗透率低,多为非储层,局部地区,该滩体经过后期构造作用改造并在埋藏溶蚀作用配合下,可形成具一定储集能力的储层,如罗南 1井-和 2井一带。核形石滩、鲕粒滩及其相关组合的岩石微相以核形石灰岩、鲕粒灰岩及白云岩为主,在白云石化和多期溶解作用的改造下,晶间孔、晶间溶孔等较发育,孔渗性大为提高,是区内最有利的储层。纵向上,核形石滩、鲕粒滩主要分布在生物屑灰岩段的中部,与海平面升降密切相关,随海侵的进行滩体向东、北和北东方向抬高。平面上,主要分布在塔中 22-井塔中 14井和塔中 4井-塔中 103井井区一带,即台内近陆一侧。

CHARACTERISTICS AND RESERVOIR PROPERTY OF BIOCLASTIC LIMESTONE BANKS IN CENTRAL TARIM BASIN

Various kinds of banks developed in bioclastic limestone in Central Tarin Basin.Among them,the micro lithofacies of bioclastic and calcarenite bank bodies and their combination are mainly bioclastic limestone and bioclastic calcarenitic limestone with low porosity and low permeability.After tectonic reformation and burial dissolution,some reserviors with certain accumulative potential could form in local places such as Luonan 1 and luonan 2 Wells;the micro lithofacies of oncolite and oolitic banks and the related associations are mainly oncolite limestone,oolitic limestone and dolomite with well developed intercrystal pores and intercrystal solution pores.They are the most favourable reservoirs in the study area.These reservoirs are primarily distributed along Tazhong 22-Tazhong 14-Tazhong 4 and Tazhong 103 Wells.