胶莱坳陷页岩气资源潜力评价

Potential Evaluation of Shale Gas Resource in Jiaolai Depression

摘要:

胶莱坳陷位于山东省东部，是山东省中生代白垩系沉积、保存最好的地区。据胶莱坳陷中生代地层及沉积特征显示，莱阳群水南组为胶莱坳陷暗色泥页岩沉积最好的层段，也是常规油气显示层位。通过对莱阳群水南组暗色泥页岩有机地化、储集物性等进行分析研究，莱阳群水南组暗色泥页岩有机碳含量介于0.17%～2.92%之间，平均为1.04%，干酪根类型以Ⅱ型为主，镜质体反射0.54%~2.04%；认为水南组暗色泥页岩具有页岩气形成的物质基础和较好的生烃能力，有机质演化程度已进入大量生烃阶段，部分进入大量生气阶段。水南组暗色泥页岩孔隙度一般为4.0%~8.0%，脆性矿物含量大于50%，说明水南组暗色泥页岩有利于页岩气的赋存和后期压裂改造。优选了莱阳凹陷、桃村凹陷、夏格庄凹陷和诸城凹陷4个远景区，估算了页岩气原地潜在资源量为537.8×108m3，为进一步工作指明了方向。

Abstract:

Jiaolai depression is located in the eastern part of Shandong province. It is the best deposit and preservation area of Mesozoic Cretaceous. According to the strata and sedimentary characteristics of Jiaolai depression in Mesozoic period, Shuinan formation of Laiyang group is the best layer of dark shale deposit in Jiaolai depression. It is also the conventional oil and gas display horizon. Through analysis of organic geochemical and reservoir properties of the dark mud shale in Laiyang group, the organic carbon content of the dark mud shale of Shuinan formation is 0.17%~2.92%, and the average value is 1.04%. The type of kerogen is mainly typeⅡ, and the vitrinite reflection is 0.54%~2.04%. It is believed that the dark shale of Shuinan formation has the material basis of shale gas formation and good hydrocarbon generation ability, the degree of organic matter has entered a large number of hydrocarbon generation stages, and some of them have entered a large number of gas generating stages. The porosity of dark shale in Shuinan formation is generally 4.0%~8.0% ,and the content of brittle minerals is more than 50%. This indicates that dark shale in Shuinan formation is favorable for shale gas occurrence and later fracturing. Four prospective areas, such as Laiyang sag, Taocun sag, Xiagezhuang sag and Zhucheng sag have been selected., and the potential resources of shale gas have been estimated to be 537.8×108m3, which indicates the direction for further work.