普光气田大湾区块高含硫水平井完井管柱优化设计

An optimal design of pipe strings for horizontal sour gas wells at the Dawan Block,Puguang Gas Field

为实现高含硫气藏"少井高产、安全高效"的开发目的,对四川盆地普光气田大湾区块碳酸盐岩储层采用了以水平井为主的开发模式。根据大湾区块气藏及流体特点,综合考虑国内外高含硫水平井完井工艺技术现状,选择一次管柱多级卡封,逐级投球打开各层滑套改造储层作为本区块水平井完井工艺,进而开展了管柱参数和结构设计,优化设计出高含硫水平井完井管柱:套管完井分段酸压管柱、裸眼完井分段酸压管柱、套管监测水平井分段完井管柱。该管柱通过8口井现场应用,首次实现了国内高含硫水平井分段储层改造,增产效果明显,为气田的安全高效开发提供了有力的技术支撑,也为类似气田的开发提供了借鉴。

For the purpose of developing sour gas reservoirs with few but high-production wells in a cost-effective and safe way,horizontal well drilling is mainly adopted for the carbonate gas pay zone at the Dawan Block,Puguang Gas Field,Sichuan Basin.By referring to the features of reservoirs and fluids in this study area and the state-of-the-art of the existing foreign and domestic production technologies for high sour gas wells,the technology of horizontal drilling and completion is thus chosen especially for this study area,which is involved in the stimulation methods of one trip running of strings,multi-level sealing and the ball dropping for each sleeve.On this basis,an optimal design is made for the parameters and structures of pipe strings,thus the completion string is particularly optimized for sour gas wells: staged-acid fracturing string for casing completion,staged-acid fracturing string for open-hole completion,and staged-completion string for the horizontal section with casing.When these optimally designed strings were successfully applied in 8 different wells in this study area,staged-fracturing for reservoir stimulation has been achieved by horizontal sour wells for the first time in China with an obviously good simulation results.This study provides robust technical support for safe and cost-effective development of this and other similar sour gas fields.