塔里木盆地塔中隆起南坡油气勘探领域

Oil and gas exploration domains on the southern slope of Central Tarim Uplift, Tarim Basin

通过分析塔里木盆地塔中南坡中下寒武统地震相特点,结合台盆区主要钻井中下寒武统沉积相与TOC的关系,认为塔中南坡中下寒武统沉积相与塔里木盆地中央隆起相同,主要发育蒸发台地膏盐(泥)坪—局限台地云坪相沉积,生烃潜力比满加尔斜坡盆地相深水欠补偿沉积的深灰—黑色泥(页)岩差。解剖塔中隆起主要油气藏成藏富集特点,分析南坡潜山领域近20口钻井未获油气突破的原因,提出隆起上断裂带具有控储控藏控富特点。NW与NE向断裂的交会区、塔中Ⅰ号“Y”形断裂带内、靠近NE走滑断裂(<1km)和通源断裂断距大(T18)及NE走滑断裂的断堑—张扭破碎带为塔中隆起奥陶系油气富集场所;塔中南坡潜山勘探领域应由潜山圈闭高部位向靠近主断层的白云岩潜山圈闭高部位转变;近油源、通源断裂发育、储盖组合好的大型背斜构造圈闭的高部位是寒武系盐下油气成藏富集有利区。

Based on the analysis of seismic facies characteristics,combined with the relationship between sedimentary facies and TOC content of the main wells,we suggested that the sedimentary facies of the Middle-Lower Cambrian on the southern slope of Central Tarim Uplift is the same as those of the Central Tarim Uplift.The main deposits there are the evaporative platform in salt(mud)and the restricted dolomite platform facies.The hydrocarbon generation potential in the study area is worse than that of the dark grey and black mudstone(shale)developed in a deep water and under-compensated environment on the Manjiaer Slope.Also,we analyzed the accumulation characteristics of the main oil and gas reservoirs,and the reasons why nearly 20 wells in the buried hill area on the southern slope failed to produce commercial oil or gas.It was pointed out that faults controlled storage,reservoir and enrichment.The Ordovician oil and gas enrichment areas in the Central Tarim Uplift are mainly the intersection of the NW and NE fractures,the Central Tarim no.I“Y”type fault zone,the vicinity of NE strike-slip faults(<1 km),the oil source communicating faults with a big fault throw(T 1 8),and the graben-tensional fracture zone of NE strike-slips.It was pointed out that exploration of buried hills on the southern slope of Central Tarim should change from the high trap position of buried hills to the high trap position of dolomite buried hills near the main fault.The high positions of large anticlinal structural traps close to oil source with source communicating fractures and favorable reservoir and cap assemblage are the pre-salt hydrocarbon enrichment areas in Cambrian.