广西天峨-南丹地区中泥盆统罗富组页岩气地质条件研究

Study on Middle Devonian Luofu Formation Shale Gas Geological Condition in Tian'e-Nandan Area,Guangxi

通过野外地质调查、样品有机地化分析、储层物性特征分析及钻井现场含气量解析等工作,研究了广西天峨-南丹地区中泥盆统罗富组页岩气地质条件。该组泥页岩发育于台间盆地相,厚度达72.45~397m;有机质类型以II2型为主;有机碳含量平均为2.69%;热演化程度达到过成熟阶段,具有较好页岩气生烃物质条件;储集特征有利于后期开发。而该组泥页岩现场解析气含量较低,且气体成分主要为氮气,主要由于区内复杂构造条件与岩浆活动影响导致保存条件较差。含气量未达到有利区段的下限标准,认为在现阶段技术条件下,存在工业化页岩气流的可能性较低。

Through field geological investigation,sample organic geochemical,reservoir physical property characteristic,and drilling site gas content analyses have studied middle Devonian Luofu Formation shale gas geological conditions.Argillutite in the formation has developed in an interplatform basin facies with thickness 72.45~397 m;organic matter mainly belongs to II2 type;organic carbon content average 2.69%;thermal evolution degree runs up to overmature stage;and better shale gas hydrocarbon generation material condition;reservoiring features are propitious to later exploitation.However,argillutite in the formation has lower site desorbed gas content,nitrogen is main gas component;owing to complex structural condition and magmatic activities caused poorer preservation condition,thus gas content has not reached the lower limit of beneficial area.Thus considered that under current technical conditions,possibility to achieve industrial shale gas flow is rather low.