房大志,程泽虎,李佳欣. 渝东南地区超深层煤层气高效压裂技术及精细排采制度研究与实践−以NY1井为例[J]. 煤田地质与勘探,2022,50(5):50−56. DOI: 10.12363/issn.1001-1986.21.08.0437
引用本文: 房大志,程泽虎,李佳欣. 渝东南地区超深层煤层气高效压裂技术及精细排采制度研究与实践−以NY1井为例[J]. 煤田地质与勘探,2022,50(5):50−56. DOI: 10.12363/issn.1001-1986.21.08.0437
FANG Dazhi,CHENG Zehu,LI Jiaxin. Eefficient fracturing technology and fine drainage system of ultra-deep coalbed methane in southeast Chongqing:A case study of NY1 well[J]. Coal Geology & Exploration,2022,50(5):50−56. DOI: 10.12363/issn.1001-1986.21.08.0437
Citation: FANG Dazhi,CHENG Zehu,LI Jiaxin. Eefficient fracturing technology and fine drainage system of ultra-deep coalbed methane in southeast Chongqing:A case study of NY1 well[J]. Coal Geology & Exploration,2022,50(5):50−56. DOI: 10.12363/issn.1001-1986.21.08.0437

渝东南地区超深层煤层气高效压裂技术及精细排采制度研究与实践以NY1井为例

Eefficient fracturing technology and fine drainage system of ultra-deep coalbed methane in southeast Chongqing:A case study of NY1 well

  • 摘要: 我国煤层气开发主要集中在中浅煤层,深部−超深部煤储层地质条件更加复杂,储层压裂改造技术及排采管控技术是影响深部煤层气井能否成功开发的两大关键。渝东南地区龙潭组煤层埋深可达2 000 m,且该区没有超深煤层气井开发经验可供借鉴。基于此,以渝东南地区NY1井为例,通过优化压裂工艺,以减阻水压裂液体系为基础,按照大排量、低砂比、段塞式、不同粒径复合加砂的技术思路完成该井的压裂施工;在排采过程中,采用分段控制、逐步降速、适时调整、无套压生产的方式,尽可能增加煤层气井见气前返排率,扩大供气半径,并且避免液面大幅波动形成速敏效应影响煤储层渗流通道。结果表明:NY1井压裂过程中施工压力平稳,未见砂堵现象,排采过程中保持了日产气量2 800~3 000 m3。根据生产实际,NY1井实现了高产和稳产,该井的压裂工艺和排采制度的成功实施,对超深煤层气井的理论研究和实际开发具有一定的指导意义。

     

    Abstract: According to the results of China’s new round of coalbed methane (CBM) resource evaluation, the CBM development mainly focuses on medium and shallow coal seams, and the geological conditions of deep-ultra deep coal reservoirs are more complicated. Thus, the reservoir fracturing technology and drainage management technology are two major factors in the development of CBM wells for deep coal reservoirs. In the area of southeast Chongqing, the coal seam of Longtan Formation is as deep as nearly 2 000 m, and there is no experience in ultra-deep CBM well development in this area. The NYI well is taken as an example, and its fracturing operation is completed according to the technical idea of large displacement, low sand ratio, pulsed and composite sand addition of different particle sizes by optimizing the fracturing process based on fracturing fluid system of drag reducing water. In the drainage, the method of segmented control, gradual speed reduction, timely adjustment, and low-pressure production is adopted to increase the flowback rate of CBM wells before gas breakthrough, extend the air supply radius as much as possible, and avoid the formation of velocity sensitive effect caused by large fluctuation of the liquid level and affecting the seepage channels of coal reservoirs. The results show that during the fracturing process of the NY1 well, the construction pressure is stable without sand plug occurring, and the daily gas production maintains at 2 800-3 000 m3 in the drainage. In the practice, the NY1 well has achieved high and stable production. The successful application of the fracturing technology and drainage system provide certain guidance for the theoretical research and development of ultra-deep CBM wells.

     

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