连续油管喷砂射孔套管分段压裂新技术的现场应用

Field application of Abrasive Jet Multi-Stage Fracturing with coiled tubing annular frac BHA

随着我国逐步对致密气藏、页岩气藏等非常规油气藏实施勘探开发,压裂增产技术也逐步呈现大规模、多段分段压裂的趋势。连续油管带封隔器套管分级压裂技术是目前国外较新研发的一种既能实现大规模改造,又能达到分层压裂、精细压裂的一种新型分级压裂技术。这一技术通过连续油管结合带封隔器的喷射工具,利用封隔器的多次上提下放坐封解封达到不限次数多级压裂的目的;通过连续油管喷砂射孔、套管进行主压裂,可实现较大规模改造;通过连续油管的精确定位,可对储层纵向上的多个薄互层进行灵活分层,进而达到精细压裂的目的。为此,详细阐述了连续油管带封隔器环空分级压裂的工艺技术特点以及这一技术在国内四川盆地HC井区首次现场应用情况,并对HC-A井施工过程进行了计算和分析。事实证明,连续油管带封隔器环空分级压裂、作业周期短、分层灵活精细、封隔可靠且施工后井筒清洁,可直接多层测试投产的新型压裂技术。为我国致密气藏、页岩气藏的多级分段改造提供了新的且行之有效的解决手段。

With the further development of unconventional gas reservoirs such as tight gas and shale gas,stimulation fracturing treatment shows a developing trend of large scale and multi-stage fracturing.Coiled Tubing Annular Frac BHA with external packer is a new multi-stage fracturing technology that can realize the large scale reformation as well as the zonal fracturing and fine fracturing.This completion method utilizes a coiled tubing deployed bottom hole assembly(BHA) that includes abrasive jet perforating nozzles and a method of isolating all downhole fracture treatments,thus,multi-stage fracturing can be achieved by setting and unsetting of the packer.Furthermore,through main fracturing work by use of coiled tubing abrasive perforating and casing,the large scale reformation can be achieved.Finally,through the exact positioning of coiled tubing,multiple overlying thin inter-layers can be easily delaminated,which leads to the fine fracturing.Therefore,the technical characteristics of coiled tubing annular frac BHA are illustrated in detail.Moreover,the application of this technique in the HC wellblock of the Sichuan Basin is also illustrated and analyzed.The application shows that this new multi-stage fracturing will result in a short working cycle,flexible delamination,reliable isolation,and clean wellbore after construction,and even lead to a direct multi-layer test production.This provides a new and feasible solution to the multi-stage fracturing treatment for tight gas and shale gas reservoirs in China.