黔北地区下寒武统牛蹄塘组页岩储层发育特征:以岑巩区块为例

发布时间：2018-04-25 18:25

  本文选题：页岩气 + 储层特征　； 参考：《地学前缘》2017年06期

【摘要】：依据矿物学、有机地球化学、孔隙结构、甲烷吸附性、岩石力学性质、裂缝发育特征和保存条件等方面的资料,对研究区下寒武统牛蹄塘组页岩储层发育特征进行了系统研究。结果表明,牛蹄塘组页岩具有较高的有机质丰度、脆性矿物含量、热演化程度和甲烷吸附能力。与北美主要产气页岩及龙马溪组页岩相比,牛蹄塘组页岩以Ⅰ型有机质为主,有机孔发育规模较小,孔径多小于5nm,甲烷吸附/脱附能力强。矿物粒间与粒内孔缝是牛蹄塘组页岩储集空间与渗流通道的主要来源,高TOC含量伴随的高石英(刚性矿物)含量有利于微观孔缝的发育、保存及游离气的富集。牛蹄塘组宏观裂缝以构造缝为主,其次为层间缝,微观上主要为层间、粒间和粒内缝;方解石与石英等裂缝充填物内部发育开启的次级微裂缝、解理和溶蚀孔隙,滑脱缝与压扭/张扭性裂缝面糜棱化矿物粒间孔缝发育,增加了充填裂缝的有效性。在良好保存条件下,裂缝的发育对牛蹄塘组页岩含气性与渗透性均具有贡献,而对渗透性的改善是其最主要贡献。当TOC含量低于6.5%,TOC含量与孔隙度、总孔体积、脆性、兰氏压力、裂缝密度和游离气含量等储层参数具有正相关关系;当TOC含量大于6.5%时,正相关关系逐渐变为负相关。有机质类型、含量、成熟度及成岩作用对页岩储层宏观(脆性、裂缝发育程度)与微观(孔隙类型、孔隙结构、甲烷吸附性)性质均有重要影响。
[Abstract]:Based on the data of mineralogy, organic geochemistry, pore structure, methane adsorption, rock mechanical properties, fracture development characteristics and preservation conditions, the development characteristics of the shale reservoir in the lower Cambrian of the lower Cambrian group are systematically studied. The results show that the shale has high organic abundance and brittle mineral content in the shales of the lower Cambrian formation. Compared with the main gas shale and the long Ma Creek shales in North America, the shale of the cattle hoof pond group is mainly composed of type I organic matter, the organic pore is smaller, the pore size is less than 5nm, and the methane adsorption / desorption ability is strong. The intergranular and intragranular pore seams are the main source of the shale reservoir space and the seepage channel in the cattle hoof pond. Source, the content of Gao Shiying (rigid mineral) accompanied by high TOC content is beneficial to the development, preservation and accumulation of free gas in micropores. The macro cracks in the cattle hoof pond group are mainly structural seams, followed by interlayer seams, and the microcosmic mainly interlayer, intergranular and intragranular seams, and secondary microcracks and cleavage opened in the internal development of calcite and quartz fissures. In good preservation conditions, the development of the fracture has contributed to the gas and permeability of the shales of the cattle hoof and pond, and the improvement of permeability is the main contribution to the permeability. When the content of TOC is below 6.5% and TOC content, It has a positive correlation with porosity, total pore volume, brittleness, Langerhans pressure, fracture density and free gas content. When the TOC content is more than 6.5%, the positive correlation gradually becomes negative correlation. The types, content, maturity and diagenesis of the organic matter are the macro (brittle, fracture development) and microcosmic (pore type, pore) of shale. The properties of gap structure and methane adsorption have important influence.

【作者单位】： 中国石油化工股份有限公司石油勘探开发研究院;页岩油气富集机理与有效开发国家重点实验室;中国石油大学(北京)地球科学学院;中国国储能源化工集团股份公司;中国地质大学(北京)能源学院;重庆科技学院复杂油气田勘探开发重庆市重点实验室;
【基金】：国家自然科学基金项目(41202103) 国家青年科学基金项目(41402118) 国家科技重大专项(2017ZX05036002-001)
【分类号】：P534.41;P618.13
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本文编号：1802450