WY区块深层页岩气井压后返排规律及制度研究
Flowback patterns and regimes for deep shale gas wells after fracturing in WY block
刘殷韬 1康正 1夏彪 1张国东 1蒋勇 1彭翰林2
作者信息
- 1. 中石化西南油气分公司石油工程技术研究院 四川德阳 618000
- 2. 中石化西南石油工程有限公司 四川德阳 618000
- 折叠
摘要
合理的深层页岩气井压后返排制度有利于改善单井产量、延长稳产周期.基于WY区块页岩气91 口井的现场数据,采用重点井筛选、示踪剂分析、井例论证等方法,明确了返排规律,建立了WY区块页岩气压后返排制度.结果表明,压-焖-关(压裂+焖井+返排期间关井)和压-焖时间主要在 500～1 500 h之间,大部分井能在 48 h内见气,见气返排率在 1%以内;测试产量和稳产后半年单位压降产量随压-焖-关时间的增加先增加后减少,见稳产时间和见气时间随压-焖时间的增加而降低;产层为龙马溪组 2 小层的井,推荐压-焖-关时间为 1 000～1 200 h;存在最优测试返排率,油嘴调整应该以"最优测试返排率、控砂、控压"为原则.研究结果为深层页岩气井压后排采制度的建立提供了新思路.
Abstract
A rational flowback regime for deep shale gas wells after fracturing can significantly enhance well production and extend the stable production period.By utilizing field data from 91 shale gas wells in the WY block,through the methods such as key well selection,tracer analysis,and case studies,the flowback patterns of shale gas wells after fracturing in the WY block were delineated,and a flowback regime was established.The results show that the fracturing-soaking-shut-in and fracturing-soaking periods typically range from 500 to 1 500 hours.Most wells began to show gas breakthrough within 48 hours,with a flowback rate of less than 1% .Test production and unit pressure drop production after six months of stable production initially increased and then decreased with longer fracturing-soaking-shut-in periods.The period to achieve stable production and the period to show gas breakthrough decreased as soaking time increased.For wells targeting the second layer of the Longmaxi formation,a fracturing-soaking-shut-in period of 1 000～1 200 hours is recommended.There exists an optimal test flowback rate,and choke adjustments should follow the principles of"optimal test flowback rate,sand control,and pressure control".The research results provide a new idea for establishing flowback regimes for deep shale gas wells after fracturing.
关键词
深层页岩气/压后返排/返排制度/WY区块/返排规律/焖井时间/油嘴Key words
deep shale gas/flowback/flowback regime/WY block/flowback pattern/soaking period/choke引用本文复制引用
基金项目
中国石化油田部项目(YTBXD-QTKF-2022-002-003)
出版年
2024
NETL
NSTL
万方数据