深层页岩气井高频柱塞举升工艺

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Abstract：IntheWeironggas field，asthe horizontal wellexploitationofdeep shale gas enters tothe mid-late stage with high water productionand huge liquid loading in deviated sections，conventional plunger lift processes cannotsatisfytherequirements ofhigh-eficiencydrainageduetotheirlow lifting frequencyandlimited lifting rate in singlecycle.Considering thewellcompletion characteristics in the Weirong gas field，thispaper innovatively proposesa high-frequencyplunger liftprocess，and developsahigh-frequencydrainageassembly incorporating downhole sleeve，downhole striker，and split plunger.By introducing the Gidaspow drag correction fordense system，a mechanical equilibrium model of split plunger continuous lift and separated lowering was established. The proposed process was validated by pilot test at Well WY29-1HF.The results show that the high-frequency plungerlift processrealizesamaximum frequencyof3lifts，rather than1lift inconventional process，ina single well open-closecycle，significantly improving thesingle-cycle drainageeficiency，with theaveragedaily lifting rate increased by 45% infield tests.Considering that the downhole striker is prone to failure due to the frequent impactoftheplunger，aclamp-typedownholestrikerwasdesigned，with itslocatingdetentstructure more impactresistantthanthe slip-type structure，and itcan effctivelyavoid tool breakage provided thatit is maintained properlyandperiodically.The minimum critical gas flowrate required for split plunger continuous lift was clarified， and the corresponding prediction model reflected a coincidence of up to 95.8% with the actual measurements.The proposed process can becombined with continuous gas liftto form anew modeof“plunger-aided gas lift”，which enablesacontinuous and high-frequency drainage withoutshut-in，with adaily liftfrequencyupto1O，indicating asignificantly improveddrainage continuity.Theproposed high-frequency plunger lift processand associated theory/approach providereliablesolutions toeficient drainagegasrecovery inthemid-late stageof horizontal well developmentof deep shale gas，and also valuable reference for stable/enhanced recovery in similar gas fields.

Keywords：Weirong gas field；deepshale gas；horizontal well；plunger；split；striker；critical gas flow rate

0 引言

威荣气田是国内首个探明储量超千亿立方米的深层页岩气田，埋深超过 3500m[1] ，主体采用水平井泵送桥塞体积压裂改造工艺，平均单井入地液量3.8万 m3 [2-3]。（剩余12346字）