关键技术进步促进页岩气产业快速发展——以长宁—威远国家级页岩气示范区为例

四川盆地南部地区下志留统龙马溪组页岩气资源量巨大,但较之于北美地区的页岩气田,前者的地质条件复杂、地面条件较差,因而对川南地区页岩气勘探开发技术的要求就更高。为了实现页岩气工业化大规模开采,必须形成适应于川南地区的页岩气勘探开发关键技术。为此,在长宁—威远国家级页岩气示范区建设过程中,通过不懈探索和持续攻关,从无到有,创新建立了适合我国南方多期构造演化海相页岩气勘探开发的6项关键技术——综合地质评价技术、开发优化技术、水平井优快钻井技术、水平井体积压裂技术、丛式井工厂化作业技术以及高效清洁开采技术。该系列技术在上述页岩气示范区产能建设过程中,历经三轮优化调整,产能建设效果一轮比一轮好,平均单井评估最终可采页岩气储量(EUR)逐步提高,第三轮井均EUR比第一轮提升了128%。生产实践表明,上述页岩气示范区建设过程中持续优化完善了6项关键技术,使其技术适应性和可复制性不断增强,为川南页岩气快速上产提供了有力的技术支撑。

Rapid shale gas development accelerated by the progress in key technologies: A case study of the Changning–Weiyuan national shale gas demonstration zone

Shale gas resources in the Lower Silurian Longmaxi ,southern Sichuan Basin are huge, where, the geological setting, unlike that in North America, is quite complicated and ground surface infrastructure is poor. Therefore, adaptable key technologies will be essential to achieve commercial exploitation of shale gas there. In the case study of the Changning–Weiyuan national shale gas demonstration zone, six series of key techniques were summarized in comprehensive geological evaluation, development optimization, fast and superior drilling of horizontal wells, horizontal-well volumetric fracturing, cluster-well and factory-like operation in well blocks, and highly-efficient and clean exploitation. The above techniques were applied in this field after three rounds of adjustment and optimization, the resulted production rates of shale gas wells were getting higher and higher and the single-well estimated ultimate recovery (EUR) was also rising. Compared with that in the first round, the average EUR of wells in the third round was increased by 128%. In conclusion, the application practices prove that the above series of key techniques with adaptation and flexibility provide a robust technical support for the rapid output of shale gas production in South Sichuan Basin.