塔里木盆地巴什托油气田石炭系碳酸盐岩沉积相特征

Sedimentary facies of Carboniferous carbonate rock in Bashitop Oil Field, Tarim Basin

严继新 赵习森 何云峰 钟学彬 魏少华 周刚

Yan Jixin Zhao Xisen He Yunfeng Zhao Xuebin Wei Shaohua Zhou Gang

中国石油化工股份有限公司 华东分公司 非常规指挥部, 南京 210019

Headquarter for Unconventional Petroleum Exploration, East China Branch Company, SINOPEC, Nanjing, Jiangsu 210019, China

塔里木盆地巴什托区块石炭系包括3个组,自下而上为巴楚组、卡拉沙依组和小海子组.沉积相为碳酸盐岩台地,包括蒸发台地、局限台地、开阔台地3种亚相.岩石类型主要为碳酸盐岩,夹薄层碎屑岩和膏岩.巴楚组沉积晚期,本区陆源碎屑物质注入急剧减少,形成了一套富含生物碎屑的碳酸盐岩地层,发育局限台地亚相沉积.卡拉沙依早中期为蒸发台地夹局限台地亚相沉积,晚期为局限台地环境.小海子期海侵范围扩大,大部分地区为开阔台地沉积.由于海平面升降变化的周期性,使各种微相类型在垂向序列上呈规律性重复叠置,从而在空间上构成有规律的储盖组合,石炭系共发育3套良好储盖组合,其中小海子组发育2套,巴楚组发育1套.小海子组油气层主要分布在BK4H-麦4-麦6井一带的构造高部位.巴楚组油气层分布于麦10-BK4H-麦6井一带的构造高部位.

In Bashitop area of the Tarim Basin,from bottom to top,Carboniferous can be divided into 3 formations:Bachu,Kalashayi and Xiaohaizi.Sedimentary facies of the study area are carbonate platform,which may be further divided into 3 subfacies including evaporated,restricted and open ones.Carbonate rocks are very common,interbedded with clastic and gypsum rocks.During the late Bachu period,terrigenous detrital supplies decreased and a set of carbonate rock rich in biodetritus was formed,and the restricted platform subfacies was deposited.During the early and middle Kalashayi period,the study area was dominated by evaporated and restricted platform subfacies while in the late Kalashayi period,it turned to restricted platform.In the Xiaohaizi period,open platform spread in most of the study area.Due to the cyclicity of sea level change,all microfacies lie in rule and form reservoir-seal assemblages.3 above-mentioned assemblages have been found in Carboniferous,2 in the Xiaohaizi Formation and 1 in the Bachu Formation.Petroleum in the Xiaohaizi Formation mainly locates around well BK4H,M4 and M6.Petroleum in the Bachu Formation mainly locates around well M10,BK4H and M6.

https://doi.org/10.11781/sysydz201104353