MCI技术及其在塔中47油藏油源对比中的应用

MCI Analysis and Its Application in Oil-Source Correlation of TZ-47 Reservoir in Tarim Basin

流体包裹体成分分析技术(MCI)是应用分子有机地球化学参数研究烃类包裹体成分的一种方法。它与常规技术相比具有三个显著优点:可以分析包裹体内烃类组成,达到分子级水平;使用化学试剂氧化处理包裹体表面污染物,避免高温操作影响流体包裹体烃类组成;空白实验贯穿全过程以确保包裹体的清洁性。该技术能够成功解决源岩、成熟度、油气充注期次及油气二次蚀变等问题。选取塔中47井石炭系和志留系的两块样品进行了MCI分析,取得正构烷烃、萜烷、甾烷等分布参数。结果显示,塔中47油藏中石炭系与志留系原油属同源;与油砂抽提物相比,包裹体烃类的成熟度较低;志留系油砂与包裹体烃类有不同的母源;志留系中至少存在两期油气充注,其晚期充注的油气有轻微水洗或生物降解作用。

Concept, testing method, advantages and application case for analysis technique of Molecular Compositions of Inclusion （MCI） are introduced. Compared with conventional techniques, MCI analysis has the following advantages： （1） Compositions of inclusion hydrocarbons can be analyzed and molecular researching level is available; （2）Chemical oxidant is used to eliminate contaminants on inclusion surface and influence of high temperature can be avoided; （3）Blank test in the process can guarantee the cleanness of the inclusions. This technique can successfully solve the problems of source rock, source maturity, oil and gas infilling periods and secondary alteration. Two typical samples, Carboniferous and Silurian rocks respectively, of TZ47 reservoirs are chosen for MCI analysis. Analysis result of normal alkane,terpane and sterane shows that the oil from Carboniferous rock derives from the same source with that from Silurian rock.Compared with extractions of oil sand, hydrocarbon in the inclusions has lawer maturity. The kerogen in hydrocarbon from Silurian oil sand is differcnt from that from Silurian inclusion, which indicates that at least two phases of hydrocarban emplacement had existed in Silurian rock and slight water washing or biodegradation occurred during the later emplacement.