阿姆河盆地卡洛夫-牛津阶碳酸盐岩储层沉积学特征

土库曼斯坦东北部的阿姆河盆地，是中亚地区最重要的含油气盆地之一。根据钻井岩心、测井、地震和分析化验资料，识别出3个三级层序，均由海侵和高位两个体系域构成。总体表现为水体向上变浅序列。通过应用层序地层学和地震沉积学研究方法，对阿姆河盆地卡洛夫-牛津阶碳酸盐台地储层沉积学特征进行了研究，划分出蒸发台地、局限台地、开阔台地、台地边缘礁滩、前缘缓斜坡和盆地6个相带。确定台地边缘生物礁、滩及前缘缓斜坡的坡内礁、滩相沉积最有利储层发育。储层岩性主要为厚壳蛤礁灰岩和各类颗粒灰岩，以发育保存良好的原生孔隙型与裂缝-孔隙型储层为主，认为台地边缘和斜坡内的储层分布明显受沉积期的有利礁、滩相带和埋藏期成岩作用等复合因素控制，这一特点可作为油气勘探潜力分析的依据。

A sedimentology study of carbonate reservoirs in Callovian-Oxfordian Stage,Amu Darya Basin,Turkmenistan

The Amu Darya basin,located in northeastern Turkmenistan,is one of the most important petroliferous basins in central Asia.Three third-order shallowing-upward stratigraphic sequences,each of which is composed of two system tracts (transgressive system tract and highstand system tract),were recognized in the basin based on analyses of core observation,logging and seismic data.A sedimentology study of the Calov-Oxfordian carbonate platform reservoirs in the area reveals that there are six facies:evaporate platform,restricted platform,open platform,platform margin reef,gentle slope and basin.Among them,the platform margin reef and gentle slope reef flat are considered potential reservoirs for play fairways.The reservoirs are mostly rudist bivalve reef limestone and all sorts of grain limestones.Primary pores are well preserved and fracture-pore networks are common in the reservoirs.It is suggested that the distribution of reservoirs in the platform margin and the slope is obviously affected by controlling factors such as reef presence,distribution of shoal facies belts favorable for oil and gas accumulations,burial diagenesis.An understanding of these factors could be useful for oil and gas exploration activities in the future.