鄂尔多斯盆地石油勘探地质理论与实践

鄂尔多斯盆地中生界延长组主要发育“低渗、低压、低丰度”的“三低”油藏，油藏受优质烃源岩和大型储集砂体控制。勘探实践中，突破了传统的理论认识和勘探思路，不断创新和完善了低渗透油藏勘探理论体系，构建了曲流河三角洲成藏模式、辫状河三角洲成藏模式、多层系复合成藏模式、坳陷湖盆中部成藏模式和致密油成藏模式等，不断开创了石油勘探的新局面。包括:以曲流河三角洲成藏理论为指导，在陕北地区找到了储量超10×108t的大型含油区带;构建盆地西南辫状河三角洲成藏模式，在陇东地区发现了储量规模达10亿吨级的整装大油田;创建多层系复合成藏模式，在姬塬地区落实了超15亿吨级的规模储量;创立内陆坳陷湖盆中部成藏理论，在华庆地区勘探中取得重大突破;大力推进致密油地质研究与技术攻关，在鄂尔多斯盆地形成了新的规模储量接替区。通过创新地质理论、突破关键技术、推行勘探开发一体化和转变发展方式，提高了“三低”油田的综合勘探效益，夯实了低渗透油田快速发展的资源基础，取得了巨大的经济和社会效益。

Geological Theory and Practice of Petroleum Exploration in the Ordos Basin

The Mesozoic Yanchang Formation mainly develops “low permeability,low pressure,low abundance” reservoirs,which is controlled by high quality source rocks and large sand body.In exploration practices,the traditional theoretical knowledge and exploration ideas made breakthrough,and the exploration theory in low permeability reservoirs also had constant innovation and improvement.The accumulation models,including meandering river delta,braided river delta,multi-layer and composite,the middle part of depression lake basin and tight oil,initiate a new situation of oil exploration.Guided by the meandering river delta accumulation theory,large oil-bearing region with geological reserves more than 1 billion tons have been found in the north Shanxi area.Based on the accumulation model of braided river deltas in southwest,monoblock oilfield has been discovered in eastern Gansu province,which has geological reserves more than 1 billion ton.According to the multiple layer compound accumulation model,more than 1.5 billion tons geological reserves had been found in Jiyuan area.With the central lake accumulation model of inland depression basin,the exploration obtained a significant breakthrough in Huaqing area.With the advancement of tight oil geological research and technological breakthrough,new scaled reserve replacement area has been formed in the Ordos Basin.Based on the geological theory innovation,key technology breakthrough,systematic exploration and development implementation,and development mode change,it enhanced the integrated exploration benefit of “three low” oil and gas fields,solid the resource foundation of the rapid development of low permeability oil and gas fields,and achieved huge economic and social benefits.