页岩气资源开采现状、问题与前景

过去的5年间,页岩气开采工作取得了长足的进步,已成为世界天然气产量增长的主要推动力。凭借着页岩油气的开采,美国正迈向能源独立之路,而且在油价低位徘徊、钻井数量减少的情况下,依靠不断提高钻井效率和单井产量,仍然实现了页岩油气产量的持续增长。通过在四川盆地下古生界五峰组—龙马溪组页岩气开采所取得的突破,国内页岩气的储量和产量也获得了迅猛增长,并已成为未来天然气工业增储上产的一个重要领域;与此同时,在最初曾被寄予厚望的陆相和海陆过渡相页岩气两大领域,以及页岩气勘探投入最大的广大南方复杂构造区则未能取得实质性进展。对国内页岩气的发展基本形势与存在问题的分析结果表明,非海相领域和强改造、过成熟的南方复杂构造区海相领域尽管广泛分布富有机质页岩,但在页岩气资源禀赋以及水平井压裂技术等方面存在的诸多问题制约了其勘探开发前景。进而分析了未来中国页岩气发展值得关注的若干问题,结论认为:要现实"十三五"页岩气储量、产量的持续稳定增长,需要有新层系、新区块的发现与接替,而四川盆地内3 500 m以深超高压深层海相页岩气开采技术的突破则是页岩气增储上产的关键和希望之所在。

Shale gas exploitation: Status,issues and prospects

Over the past five years, great progress has been made in shale gas exploitation, which has become the most driving force for global gas output growth. Hydrocarbon extraction from shale helps drive the USA on the road to energy independence. Besides, shale oil & gas production has been kept in a sustained growth by continuous improvement in drilling efficiency and well productivity in the case of tumbling oil prices and rig counts. Shale gas reserves and production have been in a rapid growth in China owing to the Lower Palaeozoic Wufeng and Longmaxi shale gas exploitation in the Sichuan Basin, which has become an important sector for the future increment of gas reserves and output in China. However, substantial progress has been made neither in non-marine shale gas exploitation as previously expected nor in the broad complicated tectonic areas in South China in for which a considerable investment was made. Analysis of the basic situation and issues in domestic shale gas development shows that shale gas exploitation prospects are constrained by many problems in terms of resources endowment, horizontal fracking technology, etc. especially in non-marine shale deposits and complicated tectonic areas in South China where hot shales are widely distributed but geological structures are found severely deformed and over matured. Discussion on the prospects shows that the sustained and steady growth in shale gas reserves and production capacity in the coming years lies in the discovery and supersession of new shale plays in addition to Wufeng and Longmaxi shale plays, and that a technological breakthrough in ultra high-pressure deep (over 3500 m in the Sichuan Basin) marine shale gas exploitation is the key and hope.