焦石坝背斜上部气层开发特征及影响因素

为研究上部气层（⑥~⑨小层）与下部气层（①~⑤小层）气井开发效果存在明显差异的原因，结合压裂数据、现场生产动态、可采储量预测和地质分析等手段，评价上部气层和下部气层在页岩岩性、地化特征和储层物性等方面存在的差异.结合气井生产特征分析，认为上部气层可能存在烃源岩内的一次运移，导致上部气层构造高部位天然气富集程度高，这是造成上部气层评价井开发效果差异以及上部气层、下部气层页岩气井差异的主要原因.焦石坝背斜高部位为上部气层开发有利区，但受技术工艺水平和气价控制，其有效开发范围需要根据页岩气井的可采储量、经济性来圈定，结合上部气层页岩气井稳产能力及可采储量评价，认为上部气层开发应从构造高部位开始，逐步向低部位扩展. 

Development Characteristics and Influencing Factors of Upper Gas Reservoir in Jiaoshiba Anticline

In order to find out the reasons why there are obvious differences in the development effect of gas wells between upper gas reservoir (⑥-⑨ sublayers) and lower gas reservoirs (①-⑤ sublayers),in this paper it analyzes differences between upper and lower gas reservoirs in shale lithology,geochemical characteristics,pore type and reservoir physical properties based on fracturing data,field production performance,recoverable reserves prediction and geological analysis. Combined with the analysis of production characteristics of gas wells,it is believed that there may be a primary migration in the upper gas reservoir in the source rock,resulting in a high degree of natural gas enrichment in the upper part of the upper gas layer structure. This is the main reason for the difference of development effect between upper and lower gas reservoir gas wells. The high part of Jiaoshiba anticline is the favorable area for the development of upper gas reservoir,but its effective development scope needs to be delineated according to the recoverable reserves and economy of shale gas wells due to the limitations of technological level and gas price. Combining with the evaluation of stable production capacity and recoverable reserves of shale gas wells in upper gas reservoirs,it is considered that the development of upper gas reservoirs should start from the high part of the structure and gradually expand to the low part.