鄂尔多斯盆地富县区块中生界页岩气成藏条件与勘探方向

鄂尔多斯盆地富县区块靠近盆地中心，发育大套黑色页岩，是页岩气成藏的有利区，分析其成藏条件对于明确该区页岩气下一步勘探方向具有重要意义。为此，根据页岩气成藏类型及成藏要素，对该区页岩分布、页岩埋藏深度、有机质丰度及类型、有机质热演化程度、孔隙度和渗透率、微裂缝、等温吸附特征与含气性等成藏条件进行了分析。结论认为：该区中生界延长组“张家滩页岩”具备页岩气富集成藏的条件；页岩厚度、有机碳含量、干酪根类型、成熟度、埋深和裂缝发育程度是该区页岩气勘探选区评价的关键地质参数。结合勘探过程中钻井气测异常的分布情况，指出该区块西南部和中部为下一步应关注的2个有利勘探目标。

Shale gas pooling conditions and exploration targets in the Mesozoic of Fuxian Block,Ordos Basin

Fuxian Block is close to the center of the Ordos Basin, where two sets of thick black shale are developed and favorable conditions exist for shale gas accumulation. It is of great significance to analyze its shale gas accumulation conditions and recognize future exploration targets. According to the types of shale gas reservoirs and gas pooling elements, this paper analyzes various conditions for shale gas accumulation, such as shale distribution, burial depth, organic matter abundance and organic matter types, thermal evolution of organic matter, porosity and permeability, microfractures, adsorption isotherm, as well as gas content. The Zhangjiatan shale of the Mesozoic Yanchang Formation in the study area has the conditions for shale gas accumulation. The shale thickness, TOC, kerogen type, maturity, burial depth and fracture are the major geologic parameters for evaluation and identification of exploration targets. In combination with mud logging anomaly, the southern and central parts are recognized to be two favorable exploration targets in this block.