中文摘要：

大牛地气田下二叠统叠合气藏由山1、山2、盒1、盒2和盒3等气藏构成，这些气藏纵向上交错叠置，平面上连片分布。气藏类型为低渗透致密砂岩定容弹性驱动岩性气藏。山1和山2气藏储层主要为三角洲平原亚相分流河道砂体沉积，盒1、盒2和盒3气藏储层主要为辫状河流相河道砂体沉积。盒2和盒3气藏所产天然气为干气，其余均为湿气。下二叠统叠合气藏为低丰度、中深层、中-低产大型气藏。采用衰竭式开发方式，结果表明，盒3和山1气藏单井产量相对较高，稳产性好，盒2气藏次之，盒1和山2气藏单井产量相对较低。多层合采可以提高单井产量，间歇生产有利于气藏的稳产和提高气藏采收率。对下二叠统叠合气藏开发地质特征的认识是编制气田开发方案，科学、合理、高效开发气藏的基础。

英文摘要：

The Lower Permian overlapping gas reservoirs in Daniudi Gas Field consist of P1s^1, P1s^2, P1x^1 , P1x^2 and P1x^3. The gas reservoirs are overlapped each other vertically and intersected horizontally. The gas reservoir type is low permeable and dense sandstone lithologic gas reservoir, which has the constant volume and elastic drive. P1 s^1 and P1s^2 gas reservoirs are mainly delta plain subfacies distributary channel sand body deposition and P1x^1 , P1x^2 and P1x^3 gas reservoirs are mainly fluvial braided channel sand body deposition. The natural gas from P1x^2 and P1x^3 gas reservoirs are dry gas and the rest are wet. The Lower Permian overlapping gas reservoirs are large gas reservoirs with lower abundance, middeep and medium--low yielding. Adoptting natural depletion development mode, it showed that singlewell production of P1x^3 and P1s^1 gas reservoirs is relatively high with fairly stable production, P1x^2 gas reservoir takes second place and the single-well production of P1x^1 and P1x^2 gas reservoirs is relatively low. Multi-layer producing may increase production of single-well and intermission production is favorable for stable yielding and enhancing recovery of gas reservoir. Recognition to the geological characteristics of Lower Permian overlapping gas reservoirs is the basis of making gas field producing programs and developping gas reservoir scientifically, reasionablly and efficiently.