摘要
塔里木盆地下古生界在地质历史中相当长的时间处于深埋藏环境,明确深埋藏阶段白云岩形成/改造过程及其对储层的影响,对深层白云岩油气勘探有重要意义。以塔里木盆地台地相区寒武系和下奥陶统蓬莱坝组白云岩为研究对象,以岩石学和地球化学为主要手段,取得2点认识:一是下古生界绝大多数白云岩在浅埋藏阶段及以前就已经形成,进入深埋藏阶段,受残余蒸发卤水和热液2类流体的影响局部发生白云岩化,形成中—粗晶它形白云岩;二是深埋藏白云岩化作用通常表现为早期形成白云石的重结晶,晶体变大,加之较高的地层温度会造成白云石的过度生长,所以会堵塞原有的孔隙,是一种破坏性的成岩作用。
Lower Paleozoic strata of Tarim Basin were buried deeply in most of the late history.Understanding the formation and transformation of dolomite and the impacts on reservoir areimportant to deep petroleum exploration.Based on the study of Cambrian and Lower Ordovician Penglaiba Formation dolomite,we can get two conclusions.First,most of the Lower Paleozoic dolomite in Tarim Basin formed before deep burial stage.In deep burial stage,magnesium-rich residual evaporation brine and hydrothermal fluid cause burial dolomitization.Second,burial dolomitization generally results in recrystallizationof dolomite which will make crystal larger.Besides,higher strata temperatureleads to overgrowth of dolomite which will occupyoriginal porosity.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2016年第5期772-779,共8页
Natural Gas Geoscience
基金
国家油气重大专项(编号:2011ZX05004-001)
中国石油科技专项(编号:2014E-3201)联合资助
