【摘要】 1989年,在鄂尔多斯盆地钻探的陕参1、榆3井获高产工业气流,发现了当时我国最大的海相碳酸盐岩气田———靖边气田,证实了该盆地下古生界海相碳酸盐岩沉积层系具有巨大的天然气勘探潜力。为了推进"西部大庆"的早日建成并为该气田下一步勘探工作提供技术支持,对该盆地海相碳酸盐岩天然气成藏主控因素及勘探技术思路进行了总结。通过对鄂尔多斯盆地下古生界奥陶系沉积特征、烃源岩条件、储层类型及天然气成藏组合的综合分析,认为该区奥陶系海相碳酸盐岩发育盆地中东部奥陶系风化壳、古隆起东侧白云岩、盆地西部岩溶缝洞体等3大勘探领域;近年开展的地质研究和勘探技术攻关,明确了上述3大勘探领域的成藏主控因素,形成了岩溶古地貌精细刻画与风化壳储层预测、白云岩储层地震预测及含气性检测、岩溶缝洞体识别及储层预测等先进的勘探配套技术,天然气勘探取得了新的进展:①靖边气田含气面积不断扩大,天然气储量规模增长近2倍,是中国石油长庆油田公司天然气增储上产的现实目标;②古隆起东侧白云岩发现多个含气富集区,天然气储量规模接近1 000×108 m3,是现实接替领域;③在鄂尔多斯盆地西部岩溶缝洞体发现新苗头,是下一步天然气勘探的新领域。更多还原

【Abstract】 Industrial gas flow was obtained in Shancan-1 and Yu-3 wells in the Ordos Basin in 1989 and the Jingbian Gas Field was discovered by then as the largest marine carbonate gas field in China,which confirms the huge potential of gas exploration in the lower Paleozoic marine carbonate reservoirs in this basin.In order to promote the early buildup of another Daqing in West China and provide robust technical support for further exploration in the Jingbian field,a summary was made of the main controlling factors of gas pooling in this study area as well as the involved technical approaches to gas exploration.Through the integrated analysis of depositional characteristics,source rock conditions,reservoir types and reservoir forming assemblages,three exploration domains in this Ordovician marine carbonate-developed basin were determined including the middle and eastern Ordovician weathering crust,dolomites in eastern Central paleouplifts,karst fractures and caverns in the west.After recent years’ efforts in geological research and technological breakthrough,the main controlling factors of gas pooling in the above exploration domains have been well understood and a complete set of techniques have been formed such as a fine description of paleokarst landforms,forecast of weathering crust reservoirs,seismic prediction of dolomite reservoirs and detection of their gas-bearing property,recognization of fractures and caverns and reservoir prediction,and so on.Thus,new progress has been made in gas exploration in this study area.The discovered gas-bearing area in the Jingbian field has been increasing and gas reserves there nearly doubled,which is a realistic goal for the PetroChina Changqing Company to enhance its reserves and production.Multiple gas enrichment zones have been discovered in the dolomite reservoirs in the eastern Central paleouplift with natural gas in place of close to 100 billion m3,which is a realistic alternative domain.New signs of gas pooling have been found in the fractures and caverns in the western basin,which is a new area of further gas exploration.更多还原