北美裂缝性页岩气勘探开发的启示

北美实践证明，非常规油气资源——页岩气是现实的接替能源，勘探风险在于能否从低渗透的页岩储集层中获取经济可采储量，勘探目标是有机质和硅质含量高、裂缝发育的脆性优质烃源岩。页岩气生产机制复杂。涉及吸附气与游离气、天然裂缝与诱导裂缝系统之间的相互关系。在地质、地化、测井和地震综合评价基础上，通过水力压裂等增产措施提高储集层渗透能力是页岩气开采的关键。中国广泛分布海相和湖相细粒碎屑岩，有效烃源岩多富含炭质、灰质或硅质，已陆续发现裂缝性油气藏，有条件寻找丰富的页岩气资源，特别是液态烃在高成熟或过成熟阶段裂解产生的甲烷气滞留在烃源岩内形成的连续分布武非常规页岩气资源。图3表5参34

Suggestions from the development of fractured shale gas in North America

The history of exploration and production in North America shows that shale gas is a realistic alternative energy.As an unconventional resource, its critical risk is whether the low permeability shale produces gas economically, Source rocks could be good reservoirs for gas if they had rich organic material and abundant silica which makes the shale more brittle. The complex production mechanism involves the relationships between absorbed and free gases and between natural and induced fractures. To enhance the permeability by artificial hydraulic fracturing is a key step for shale reservoirs on the basis of the evaluation of geology, geochemistry, wire line and seismic data. Many fractured reservoirs in China have been discovered in extensive fine-elastic source rocks from marine and lacustrine environments, with carbonaceous/calcareous mudstone or siliceous shale. The undiscovered resources within effective shale reservoirs would be significant, especially the resources due to the secondary thermogenic cracking of oil to gas at high maturity.