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泥页岩一般具有低孔、低渗的特性,北美页岩气勘探开发经验表明此类页岩储层需经过大规模的压裂改造才能够获得商业产能,因此页岩可压性是评价页岩是否能作为“甜点”的关键指标之一.本文以焦石坝地区志留系龙马溪组-奥陶系五峰组页岩为例,从岩石脆性、地应力特征以及裂缝发育程度三方面评价焦石坝地区的可压性.其中,利用Rickman公式结合叠前地震反演预测证实焦石坝页岩脆性指数较高,构造主体部位脆性指数大于50%,反映页岩易于破裂;页岩岩心实验室测试数据则表明焦石坝地区页岩水平应力差较小(小于0.14),反映页岩在进行工程压裂时易于形成裂缝网络;同时焦石坝地区页岩岩心可见的大量微裂缝,裂缝预测结果也表明构造主体部位网状裂缝发育,更加有利于页岩储层的压裂改造.综合三方面条件来看,焦石坝地区页岩较好的可压性是本区页岩获得商业开发的关键.
Shale generally has the characteristics of low porosity and low permeability. The experience of shale gas exploration and development in North America shows that such shale reservoirs need large-scale fracturing to be able to obtain commercial productivity. Therefore, shale compressibility is the evaluation page Rock as one of the key indicators of “sweetness.” In this paper, the Silurian Longmaxi Formation-Ordovician Wufeng Formation shale in the Jieshiba area is taken as an example to study the characteristics of rock fragility, stress characteristics and degree of fracture development The authors use the Rickman formula and the prestack seismic inversion prediction to confirm that the shale rock has a high brittleness index and the brittleness index of the main body part is more than 50% The rock core laboratory test data show that the horizontal stress difference of shale in Jiao Shi Dam is small (less than 0.14), which indicates that the shale is prone to form a fracture network during engineering fracturing. At the same time, a large number of micro-cracks The prediction of cracks and cracks also shows that the development of the net fractures in the main part of the structure is more conducive to the fracturing of shale reservoirs.According to the three conditions, the better compressibility of shale in Jiaoshiba area is Rock get business The key development.