塔里木盆地下古生界碳酸盐岩热液岩溶的特征及地质模型

随着塔中地区下古生界碳酸盐岩油气勘探地持续深入，分别在野外露头，塔中地区相关探井奥陶系储层中发现有萤石、闪锌矿、天青石、重晶石、硬石膏、焦沥青及热液石英等一系列热液矿物及其组合，越来越多的地质资料表明热液岩溶储层可能是塔里木盆地下古生界碳酸盐岩油气勘探中被忽视的一个重要储层类型。〖JP2〗通过总结近6年大量的针对野外露头热液岩溶现象地实地观察测量，以及通过对塔中82井区—24井区奥陶系储层发育段大量的岩石薄片观察、矿物能谱测定、地层水锶同位素测试，断裂性质的分析，深入研究热液溶蚀流体的活动特点以及对形成优质储层的控制作用，最终建立了热液岩溶储层的地质模型。研究表明，热液矿物主要沿断裂伴生的构造溶蚀缝和溶蚀孔洞发育，断裂是热液运移的主要通道，是形成优质储层的重要控制因素。塔中地区沿海西期走滑断裂附近的奥陶系灰岩将广泛发育热液溶蚀改造形成的储层，为塔中西部上奥陶统沿走滑断裂向内带拓展油气勘探打下了基础。

The Geological Model of Hydrothermal Activity in Outcrop and the Characteristics of Carbonate Hydrothermal Karst of Lower Paleozoic in Tarim Basin

Along with the continuously proceeding of petroleum exploration in the Lower Palaeozoic carbonate in Tazhong area, a series of hydrothermal minerals such as fluorite, sphalerite, schatzite, baritite, anhydrite, pyrobitumen, and hydrothermal quartz and their associations are found in the Ordovician reservoir in outcrops and the relative exploration wells of Tazhong area repectively, More and more geological data show that the hydrothermal karst reservoir may be an important type neglected in the Lower Palaeozoic carbonate petroleum exploration in Tarim Basin.By the observation and measurements of outcrop hydrothermal karst phenomena in the recent six years, large amount of thin sections observation, mineral energy spectrum detecting, formation water strontium isotopes analysis, and study about faults nature of the Ordovician reservoir in well field of Tazhong 82 and 24,The active characteristics of the hydrothermal corrosion fluid and its controlling factor on the formation of quality reservoir are in deep study, The hydrothermal karst reservoir geological model is established finally. The results show that the hydrothermal minerals are mainly developed in the associating structural dissolution fractures along faults, corrosional vugs and the faults,they are the main pathway for hydrothermal fluid migration and the important factors controlling the formation of quality reservoir. The hydrothermal corrosion altering reservoir are widely developed in the Ordovican reservoir in the proximity of the strike faults formed in Hercynian in Tazhong area, which can be the petroleum exploration targets of the Upper Ordovician strata along the strike faults in the western part of Tazhong.